bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrology of the Sirba River: Updating and Analysis of Discharge Time Series
Authors: Tamagnone Paolo , Massazza Giovanni , Pezzoli Alessandro , Rosso Maurizio
Published: January 2019

The Sahelian regions are affected by an increasing number of catastrophic floods in recent years as a consequence of climate and land use/land cover changes. River flow data is key to understanding river behavior and develop flood mitigation and prevention strategies. The present study provides a revision and an update of the existing discharge dataset of the Sirba River with the aim of enhancing the reliability of these data. The revision also includes the recalibration of the Garbey Kourou rating curves. The analysis of the revised discharge time series strengthens the previous findings, evidencing a positive trend in flood frequency and intensity over the entire analyzed period of 1956–2018. This positive trend is more pronounced for the last 40 years due to a significant underestimation of the rating curves used. A relevant finding is a new changepoint in the time series, detected for 2008, which represents the beginning of the period in which the highest flood magnitudes were registered. The effect of land use/land cover changes and climate changes on the water resource is depicted using flow duration curves. This research produces a revised and more reliable discharge time series that will be a new starting point for future hydrological analyses.
Improving the Performance of Vegetable Leaf Wetness Duration Models in Greenhouses Using Decision Tree Learning
Authors: Wang Hui , Sanchez-Molina Jorge Antonio , Li Ming , Rodríguez Díaz Francisco
Published: January 2019

Leaf wetness duration (LWD) is a key driving variable for peat and disease control in greenhouse management, and depends upon irrigation, rainfall, and dewfall. However, LWD measurement is often replaced by its estimation from other meteorological variables, with associated uncertainty due to the modelling approach used and its calibration. This study uses the decision learning tree method (DLT) for calibrating four LWD models—RH threshold model (RHM), the dew parameterization model (DPM), the classification and regression tree model (CART) and the neural network model (NNM)—whose performances in reproducing measured data are assessed using a large dataset. The relative importance of input variables in contributing to LWD estimation is also computed for the models tested. The LWD models were evaluated at two different greenhouse locations: in a Chinese (CN) greenhouse over three planting seasons (April 2014–October 2015) and in a Spanish (ES) greenhouse over four planting seasons (April 2016–February 2018). Based on multi-evaluation indicators, the models were given a ranking for their assessment capabilities during calibration (in the Spanish greenhouse from April 2016 to December 2016 and in the Chinese greenhouse from April 2014 to November 2014). The models were then evaluated on an independent set of data, and the obtained areas under the receiver operating characteristic curve (AUC) of the LWD models were over 0.73. Therein, the best LWD model in this case was the NNM, with positive predict values (PPVs) of 0.82 (SP) and 0.90 (CN), and mean absolute errors (MAEs) of 1.85 h (SP) and 1.30 h (CN). Consequently, the DLT can decrease LWD estimation error by calibrating the model threshold and choosing black box model input variables.
Improved Curve Number Estimation in SWAT by Reflecting the Effect of Rainfall Intensity on Runoff Generation
Authors: Zhang Dejian , Lin Qiaoyin , Chen Xingwei , Chai Tian
Published: January 2019

Determining the amount of rainfall that will eventually become runoff and its pathway is a crucial process in hydrological modelling. We proposed a method to better estimate curve number by adding an additional component (AC) to better account for the effects of daily rainfall intensity on rainfall-runoff generation. This AC is determined by a regression equation developed from the relationship between the AC series derived from fine-tuned calibration processes and observed rainfall series. When incorporated into the Soil and Water Assessment Tool and tested in the Anxi Watershed, it is found, overall, the modified SWAT (SWAT-ICN) outperformed the original SWAT (SWAT-CN) in terms of stream flow, base flow, and annual extreme flow simulation. These models were further evaluated with the data sets of two adjacent watersheds. Similar results were achieved, indicating the ability of the proposed method to better estimate curve number.
Implementation Schemes for Electric Bus Fleets at Depots with Optimized Energy Procurements in Virtual Power Plant Operations
Authors: Raab Andreas F. , Lauth Enrico , Strunz Kai , Göhlich Dietmar
Published: January 2019

For the purpose of utilizing electric bus fleets in metropolitan areas and with regard to providing active energy management at depots, a profound understanding of the transactions between the market entities involved in the charging process is given. The paper examines sophisticated charging strategies with energy procurements in joint market operation. Here, operation procedures and characteristics of a depot including the physical layout and utilization of appropriate charging infrastructure are investigated. A comprehensive model framework for a virtual power plant (VPP) is formulated and developed to integrate electric bus fleets in the power plant portfolio, enabling the provision of power system services. The proposed methodology is verified in numerical analysis by providing optimized dispatch schedules in day-ahead and intraday market operations.
MATHEMATICAL MODELS FOR OPTIMAL SHAKEDOWN TRUSSES DESIGN PROBLEMS IN CASE OF MOVING LOAD
Authors: Atkočiūnas Juozas , Merkevičiūte Dalia , Venskus Artūras , Nagevičius Juozas
Published: January 2019

Prisitaikomumo teorija, nagrinejanti tampriai plastiškas konstrukcijas, veikiama kintamosios kartotines apkrovos, leidžia judamaja apkrova traktuoti kaip atskira kartotinai kintančiu jegu atveji. Apkrovai leidžiama “judeti” bet kuria konstrukcijos dalimi: nuo tilto vidurio, grižti atgal, vel i prieki ‐ taip universaliai ivertinama apkrovimo istorija, kuri yra lemiamas faktorius, nagrinejant plastines deformacijas patiriančios konstrukcijos itempiu ir deformaciju būvi. Straipsnyje atskleista galimybe taikyti prisitaikomumo teorijos metodus, sudarant teorinius santvaru optimizavimo uždaviniu matematinius modelius ir juos sprendžiant. Nagrinejama idealiai tampriai plastine žinomos geometrijos santvara, veikiama judamosios apkrovos. Sudaryti minimalaus tūrio santvaros ar javeikiančios apkrovos maksimizavimo uždaviniu matematiniai modeliai. Modeliuose ivertinamos ne tik konstrukcijos stiprumo (prisitaikomumo) ir standumo salygos, bet ir stabilumo netekimo galimybe esant plastinei santvaros darbo stadijai. Pasiūlyti nauji sprendimo algoritmai, pateikti skaitiniai strypu lankstines santvaros, veikiamos judamosios apkrovos, optimizavimo uždaviniu pavyzdžiai. Tyrimai atlikti, darant mažu poslinkiu prielaida.
SAFETY IMPROVEMENTS BY ELIMINATING HAZARDOUS COMBINATIONS
Authors: Hadad Yossi , Laslo Zohar , Ben-Yair Avner
Published: January 2019

In this paper we suggest the hazardous combinations method to facilitate safety improvements in technical and technological systems by eliminating combinations of major risk factors. The method is capable to significantly improve the safety level in systems as compared to a common situation when only the root causes of accidents were analysed (usually with unsatisfactory results), or where the usual procedures proved to be ineffective due to organisational, technological or financial constraints. In many cases the management decides to implement costly safety measures which have eventually only a minor effect, if at all, on preventing severe accidents. By focusing on prevention of not all recognised primary risk factors but only their hazardous combinations, both human lives and significant financial resources may be saved.
TESTING AND CALCULATING THREE‐HINGE SUSPENSION STRUCTURES OF HOLLOW CONCRETE‐FILLED STEEL TUBULAR MEMBERS
Authors: Šaraškinas Viačeslavas , Valiūnas Balys
Published: January 2019

Recently in the research publications an information about a new type of suspended straight‐line 3‐hinge roof structures has appeared. In this sources it was stressed that straight‐line elements is easy to manufacture and erect, roof decking service conditions are good. In the world building practice during last 30 years very effective composite structures were introduced, even hollow concrete‐filled steel tubular members. At this time no information about the application of such members for suspended roofs was obtained. In some sources very simple straight‐line suspended roofs structures were analysed, and for these shapes an effective centrifuged hollow concrete‐filled steel tubular members may be successfully applied. These members do not require additional roof stabilisation. These composite ropes may be attributed to the elements of final flexural stiffness, and they are effective and simple to decrease deflections of a suspended roof. However, for such composite ropes methods of their calculations must be developed. Investigations made into the deformation properties and methods of deflection, definition of straight‐line circular hollow concrete‐filled steel tubular members allows to declare a possibility of useful application of such members as ones of final flexural stiffness in suspended roof structures.
INTERRELATIONSHIP AND CROSS‐FIELD RESEARCH IN FINANCIAL, HUMAN AND CAPITAL MARKETS
Authors: Grundey Dainora
Published: January 2019

„Interrelationship and cross‐field research in financial, human and capital markets" Technological and economic development of economy, 13(3), p. 177-178
THE EXPERT'S ESTIMATES APPLICATION IN THE PREPARATION OF CITY GENERAL PLAN
Authors: Bardauskienė Dalia
Published: January 2019

The future of Lithuanian cities depends on a territorial planning system that is being constantly improved by the market factors and maturing democratic society. After the restoration of independence, cities underwent significant urban transformations, that lacked a clear strategy, and urban General Plans, the preparation of which intensified only after Lithuania's accession to the European Union. A limited work of general planning revealed strengths and weaknesses of the Lithuanian territorial planning system but failed to provide a clear, measurable answer how well this system meets European urban guidelines, market expectations and society's aspirations. In the absence of indicators, we have to rely upon the opinion of citizens and experts which is often different, unverified and therefore it is unclear whose interests these opinions reflects ‐ those all of the city or individual economically strong and politically influential interest groups. It is under these circumstances the second General Plan of Vilnius City to the year 2015 was drawn up after the restoration of independence. The plan was prepared by applying new planning methods based on citizens’ and experts’ poll results and broad public participation process. The reliability of the results of polls in Vilnius General Plan was estimated by applying mathematical methods. It showed great agreement among the experts’ opinions. Therefore it can be stated that solutions of the General Plan meet interests of its citizens. The tendency of the business world to evaluate territorial planning and urban problems is differently than urban developers, economists or scientists. Differently from business, citizens are more conservative in estimating the possibilities for new development and reconstruction in existing residential areas, but this opinion is not unanimous and is dependent on social economic factors (age, income, time of living in the city). Therefore a conclusion can be made that methods applied in city general planning process have enabled the preparation of a new high quality Vilnius City General Plan until 2015. Plan reflects the interests of all, of its citizens rather than individuals. The implementation of the General Plan is going to be successful if, first of all vital urban deformations are handled properly and problems of territory planning and public involvement, which are turning into systematic ones, are solved at the national level.
APPLICATION OF THE PROGRAM AGENT, THAT USES REALTY ONTOLOGY, AS THE DATA SOURCE FOR THE DECISION SUPPORT SYSTEM
Authors: Jurkevičius Darius , Laukaitis Algirdas
Published: January 2019

For a better operation efficiency of the knowledge society, fast and qualitative information reception is an important factor that determines the organisational success in a competitive contest. It is not enough to use the Internet search systems such as Google or Yahoo in reaching the established goals. In this article we present the architecture of the program agent and the results of his implementation studies that show how the suggested decisions allow picking and arranging realty advertisements more effectively than those people who apply only Internet information searching systems. The realty was chosen because it is one of the most dynamic spheres in Lithuania, when successful decisions are determined by a fast information. Though the suggestions are oriented to the realty section, different conceptions could be adapted to other economy segments. The main accent of the shown programme agent architecture is using the ontology picking and arranging the realty information. In this article we present not only conceptual solutions of the programme agent, but also specific realisation modules developed during this project.
THE USE OF EXPLORATORY TUNNELS AS A TOOL FOR SCHEDULING AND COST ESTIMATION
Authors: Abdallah Ahmed
Published: January 2019

Exploratory tunnels are commonly used for examining the geotechnical and structural aspects of proposed tunnel alignments. This paper explores the utilisation of exploratory tunnels as a project management tool for estimating the cost and duration of construction for the entire project. Data were collected from the Kaponig 2,75 kilometers exploratory tunnel, a part of a double‐track high‐speed railway development in Austria. This knowledge and experience was used to evaluate the risks associated with design details for the final tunnel enlargement (alignment and grade, support requirements and excavation methods). A deterministic model based on Monte Carlo simulation was developed capable of predicting potential outcomes of the total project in terms of cost, duration and their associated probabilities.
BROADBAND ACCESS TECHNOLOGIES EVALUATION TOOL (BATET)
Authors: Pereira João Paulo Ribeiro , Pires José Adriano
Published: January 2019

The goal of this paper is to identify all the essential costs of building broadband access networks, and then to comparise different technologies in various scenarios. Different market segments (Scenarios) have different geographical characteristics and will require different amounts of access bandwidth. These different market segments will be served by alternative access technologies that minimise overall costs. In order to do this, we have developed a model framework and an evaluation tool.

To measure the attractiveness of several broadband access technologies, the proposed tool compares the costs, revenues, NPV, IRR, payback periods etc for 3 scenarios. The paper presents a techno‐economic analysis of 8 broadband technologies for access networks: digital subscriber line (DSL), hybrid fibre coax (HFC), power line communications (PLC), fibre to the home (FTTH), fibre to the curb (FTTC), fibre to the cabinet (FTTCab), and wireless alternatives such as WiMAX and satellite.
CONCEPT OF ECONOMICAL‐MATHEMATICAL MODEL OF LAND MARKET
Authors: Šatkauskas Gintautas
Published: January 2019

Input parameters, ie factors defining the market price of agricultural‐purpose land, are interrelated very often by means of non‐linear ties. Strength of these ties is rather different and this limits usefulness of information in the research process of land market prices. Influence of input parameter changes to the input parameters in case when there are rather substantial changes may be determined in someone direction with a sufficient precision, whereas in other directions with comparatively small changes of input parameters this influence is difficult to be separated from the “noise” background. Taking into account the above‐listed circumstances, the concept of economical‐mathematical model of land market should be as follows: there is carried out re‐parameterisation of the process by means of introduction of new parameters in such a way that the new parameters are not interrelated, and the full process is evaluated at the minimal number of these parameters. These requirements are met by the main components of the input parameters. Then normalisation of the main components is carried out and dependencies on new parameters are determined. It is easier to interpret the dependencies obtained having reduced the number of input parameters and the higher the non‐linearity of interrelations of primary land market data, the greater effect of normalisation of input-parameter components. The results are compared with the valuations of experts.
APPLICATION POSSIBILITIES OF THERMOVISION TECHNIQUE IN DIAGNOSTICS OF AERIAL SYSTEMS OF RADIO TRANSMITTERS
Authors: Šimko Milan , Michalík Ján , Chupáč Milan
Published: January 2019

The paper deals with possibilities of use of thermovision technique in diagnostics of aerial systems of radio transmitters. Graphically presented: heating characteristic of the junction at the transmitter power of 60 % (slack and polluted junction); relationship between temperature of connection (feeder ‐ line, capacitor frame) spacing collar and power; relationship between temperature rise amount of connection and feeder line upon power; thermogram of the junction feeder line - spacing collar, capacity frame; thermogram of the junction feeder line ‐ spacing collar.
ACTIVE TWIST OF MODEL ROTOR BLADES WITH D-SPAR DESIGN
Authors: Kovalovs Andrejs , Barkanov Evgeny , Gluhihs Sergejs
Published: January 2019

The design methodology based on the planning of experiments and response surface technique has been developed for an optimum placement of Macro Fiber Composite (MFC) actuators in the helicopter rotor blades. The baseline helicopter rotor blade consists of D‐spar made of UD GFRP, skin made of +450/‐450 GFRP, foam core, MFC actuators placement on the skin and balance weight. 3D finite element model of the rotor blade has been built by ANSYS, where the rotor blade skin and spar “moustaches” are modeled by the linear layered structural shell elements SHELL99, and the spar and foam ‐ by 3D 20‐node structural solid elements SOLID 186. The thermal analyses of 3D finite element model have been developed to investigate an active twist of the helicopter rotor blade. Strain analogy between piezoelectric strains and thermally induced strains is used to model piezoelectric effects. The optimisation results have been obtained for design solutions, connected with the application of active materials, and checked by the finite element calculations.
PROPERTY RISK UNDER SOLVENCY II: EFFECTS OF DIFFERENT UNSMOOTHING TECHNIQUES
Authors: Durán Santomil Pablo , Otero González Luís , Martorell Cunill Onofre , Gil-Lafuente Anna M.
Published: January 2019

Solvency II imposes risk-based capital requirements on EU insurance companies. This paper evaluates the property risk standard model proposed. The calibration was performed from the IPD UK monthly index total returns for the period between December 1986 and December 2009. In general, it is considered that returns derived from valuation-based indices are smoother than those derived from transaction-based indices. This paper contributes to the existing literature by applying various unsmoothing techniques to this index. The results show that the capital requirements, applying the same calculation method (historical value at risk at the 99.5% confidence level) as in the calibration of the standard model, are generally bigger than those proposed in the standard model of Solvency II.
On the Maximum Pair Multiplicity of Pulsar Cascades
Authors: Timokhin A. N. , Harding A. K.
Published: January 2019

We study electron–positron pair production in polar caps of energetic pulsars to determine the maximum multiplicity of pair plasma a pulsar can produce under the most favorable conditions. This paper complements and updates our study of pair cascades presented in Timokhin & Harding (2015) with a more accurate treatment of the effects of ultrastrong

G magnetic fields and emission processes of primary and secondary particles. We include pairs produced by curvature and synchrotron radiation photons as well as resonant Compton-scattered photons. We develop a semianalytical model of electron–positron cascades that can efficiently simulate pair cascades with an arbitrary number of microphysical processes and use it to explore cascade properties for a wide range of pulsar parameters. We argue that the maximum cascade multiplicity cannot exceed

and that the multiplicity has a rather weak dependence on pulsar period. The highest multiplicity is achieved in pulsars with magnetic field

and hot surfaces, with T ≳ 106 K. We also derive analytical expressions for several physical quantities relevant for electromagnetic cascade in pulsars, which may be useful in future works on pulsar cascades, including the upper limit on cascade multiplicity and various approximations for the parameter χ, the exponential factor in the expression for photon attenuation in strong magnetic fields.
Dust Pileup at the Dead-zone Inner Edge and Implications for the Disk Shadow
Authors: Ueda Takahiro , Flock Mario , Okuzumi Satoshi
Published: January 2019

We perform simulations of the dust and gas disk evolution to investigate the observational features of a dust pileup at the dead-zone inner edge. We show that the total mass of accumulated dust particles is sensitive to the turbulence strength in the dead zone, α
dead, because of the combined effect of turbulence-induced particle fragmentation (which suppresses particle radial drift) and turbulent diffusion. For a typical critical fragmentation velocity of silicate dust particles of 1 m s−1, the stress-to-pressure ratio α
dead needs to be lower than 3 × 10−4 for dust trapping to operate. The obtained dust distribution is postprocessed using the radiative transfer code RADMC-3D to simulate infrared scattered-light images of the inner part of protoplanetary disks with a dust pileup. We find that a dust pileup at the dead-zone inner edge, if present, casts a shadow extending out to ∼10 au. In the shadowed region the temperature significantly drops, which in some cases yields even multiple water snow lines. We also find that even without a dust pileup at the dead-zone inner edge, the disk surface can become thermally unstable, and the excited waves can naturally produce shadows and ring-like structures in observed images. This mechanism might account for the ring-like structures seen in the scattered-light images of some disks, such as the TW Hya disk.
A Model-independent Mass and Moderate Eccentricity for β Pic b
Authors: Dupuy Trent J. , Brandt Timothy D. , Kratter Kaitlin M. , Bowler Brendan P.
Published: January 2019

We use a cross-calibration of Hipparcos and Gaia second data release astrometry for β Pic to measure the mass of the giant planet β Pic b (13 ± 3

) in a comprehensive joint orbit analysis that includes published relative astrometry and radial velocities. Our mass uncertainty is somewhat higher than previous work because our astrometry from the Hipparcos–Gaia Catalog of Accelerations accounts for the error inflation and systematic terms that are required to bring the two data sets onto a common astrometric reference frame, and because we fit freely for the host-star mass (1.84 ± 0.05 M
⊙). This first model-independent mass for a directly imaged planet is inconsistent with cold-start models given the age of the β Pic moving group (22 ± 6 Myr) but consistent with hot- and warm-start models, concordant with past work. We find a higher eccentricity (0.24 ± 0.06) for β Pic b compared to previous orbital fits. If confirmed by future observations, this eccentricity may help explain inner edge, scale height, and brightness asymmetry of β Pic’s disk. It could also potentially signal that β Pic b has migrated inward to its current location, acquiring its eccentricity from interaction with the 3:1 outer Lindblad resonance in the disk.
Design and Static Load Analysis Comparing Steel, Grey Cast Iron and Titanium Alloy as Materials for Breech Hinged Lugs in Recoil Weapons
Authors: Chaturvedi E. , Dwivedi R. K.
Published: January 2019

This design innovation work is related to design validation of short recoil weapons mechanism’s critical components in context of upper receivers. It explains a new mechanism for locking and unlocking of bolt with the breech and subsequent advantageous design changes in the bolt’s construction. This design intends to build a new platform for a short recoil weapon chambered in 5.56×45 NATO ammunition which promises competency with its existing counter parts of the same domain, but exhibiting exceptionally improved reliability due to elimination of interdependence of reciprocating cycles of barrel and bolt assemblies. This work involves the design of the whole functioning system using Solidworks 2015 version and a static structural analysis to compare and choose the most suitable material among commonly used ones: steel AISI 4340, grey cast iron and titanium alloy Ti-6Al-4V, for locking lugs, being critical pair of components, using ANSYS 14.5. Results showed that titanium alloy was the most suitable material for the strength purpose. It is to be noted that this system may not only be utilized for assault rifles, but also for sub-machine guns, machine gun variants and even in handguns.
Topologie d’un nombre premier
Authors: Battut Mireille
Published: January 2019

Cet article reprend, de façon plus développée, un texte prononcé lors du congrès de la cippa en mars 2018 à Dijon sous le titre « Plus d’Un ou la poétique du nombre premier ». Il porte sur la construction d’un monde intérieur, qui n’est différencié d’un extérieur que de façon précaire. Je mets au jour les élaborations logiques qui vont permettre à mon fils Louis, sujet rétif à la division, de s’extraire des premières sensations massives pour ordonner le chaos des éléments, construire une temporalité, élaborer une pensée, s’identifier comme tel dans une vidéo, réaliser qu’on a une valeur aux yeux de l’autre, reconnaître enfin l’autre comme partenaire, De mon côté, il aura fallu en passer par une chute du Savoir, dont j’ai pu me relever en acceptant d’être non pas « autre » mais « plus Un » pour l’accompagner
La personne autiste et sa machine
Authors: Tordo Frédéric
Published: January 2019

La personne autiste se sent proche des machines, parfois même plus proche que de l’autre humain. Cette parenté intime implique un « branchement » précoce sur la technologie : la personne se « couple » à la machine. C’est pourquoi l’utilisation des robots en psychothérapie semble particulièrement pertinente : d’une part, le robot réactualise le couplage à la machine de la personne autiste ; d’autre part, l’objet possède des caractéristiques du vivant, et de l’humain, qui prépare à une interaction avec un autre, donc également à la relation transférentielle avec le thérapeute.
Autisme et synchronisations sociales. De la clinique à la thérapie
Authors: Barthélémy Catherine
Published: January 2019

L’approche clinique neuro-fonctionnelle nous éclaire sur les particularités sensorimotrices et émotionnelles qui altèrent les interactions du très jeune enfant autiste avec autrui et le développement de son répertoire d’activité personnelle et de communication. Cette dyspraxie sociale est liée, nous le savons maintenant, à des troubles du développement des réseaux nerveux intracérébraux dits du « cerveau social ». Les études cellulaires, moléculaires et la génétique orientent vers certaines substances-clés qui pourraient constituer la base de futurs médicaments de la connectivité. À ce jour, il n’existe pas de traitement pharmacologique qui guérisse l’autisme. On sait que les interventions rééducatives et éducatives précoces, ciblées et coordonnées, permettent, grâce à la plasticité cérébrale, de relancer la dynamique du développement des réseaux intracérébraux et d’améliorer les fonctionnements adaptatifs et de communication tout au long de la vie.
La destructivité des enfants et des adolescents malvoyants
Authors: Oppenheim Daniel
Published: January 2019

La destructivité (tournée vers soi ou vers les autres) des enfants et des adolescents atteints de déficience visuelle sévère a été peu étudiée. L’auteur en présente les causes, en particulier les peurs et les terreurs, le sentiment d’insécurité, le trouble identitaire, le décalage, voire la rupture relationnelle avec les parents et les autres. Cette destructivité est accentuée par des situations sociales et familiales difficiles, marquées par des violences externes ou intra-familiales, des ruptures de continuité de lieux et/ou de références linguistiques, culturelles, identitaires. Pour prévenir et traiter cette destructivité en actes, il importe de tenir compte de ces éléments. Cette question sera développée dans un autre article. Un cas clinique illustre ces remarques. Néanmoins, la destructivité des enfants déficients visuels s’exprime de façon plus ou moins forte et n’est qu’un élément parmi bien d’autres de leur expérience.
Posterior Continuous Curvilinear Capsulorhexis With and Without Optic Capture of the Posterior Chamber Intraocular Lens in the Absence of Vitrectomy
Authors: Raina Usha K , Gupta Vinita , Arora Ritu , Mehta D K
Published: January 2019

ABSTRACT

Purpose: To evaluate the efficacy of posterior continuous curvilinear capsulorhexis (PCCC) with optic capture of the posterior chamber intraocular lens (PC IOL) in the absence of vitrectomy in preventing secondary opacification of the visual axis following pediatric cataract surgery.

Patients and Methods: Thirty-four eyes of 28 children with congenital or developmental cataract, aged 1.5 to 12 years (mean, 6.39 years), were included in this prospective, randomized study. Anterior continuous curvilinear capsulorhexis (ACCC) with PCCC without optic capture of the PC IOL was performed in group A (18 eyes) and ACCC with PCCC with optic capture of the PC IOL was performed in group B (16 eyes). None of the eyes underwent anterior vitrectomy. Secondary opacification of the visual axis, visual acuity, and possible complications were observed and analyzed.

Results: The follow-up period ranged from 8 to 28 months (mean, 17.5 months). All 16 eyes (100%) in group B had a clear visual axis at the end of followup. Eight eyes (44.4%) in group A had significant opacification of the visual axis. The difference between the two groups was statistically significant (P = .0011). No eye in group B required secondary intervention, whereas all 8 eyes in group A with significant secondary opacification required secondary intervention. There was no statistically significant difference in other complications such as anterior chamber reaction, fibrin formation, lenticular precipitates, and posterior synechiae. The final best-corrected visual acuity at the end of follow-up was comparable in the two groups (P > .05).

Conclusion: PCCC with optic capture of the PC IOL prevents secondary opacification of the visual axis even in the absence of vitrectomy.

J Pediatr Ophthalmol Strabismus 2002;39:278-287.
Early Surgery for Dysthyroid Orbitomyopathy Based on Magnetic Resonance Imaging Findings
Authors: Yolar Murat , Oguz Velittin , Pazarli Halit , Yetik Hüseyin , Özkan Sehirbay
Published: January 2019

ABSTRACT

Purpose: To investigate the value of magnetic resonance imaging (MRI) in the determination of lhe fibrotic phase in dysfbyroid orbitopathy, which may be an indication for early surgery.

Patients and Methods: Thirteen patients with dysthyroid orbitopathy who had vertical deviation in excess of 20 PD and associated diplopia in the primary position that did not respond to medical treatment were included in the study. On MRI, the absence of high-intensity foci in the T2 sequence, especially in the coronal planes, indicated that the extraocular muscles were not edematous. These muscles were evaluated as being in the fibrotic phase, and surgery was performed without waiting the recommended 6 months for the stabilization of the angle of deviation.

Results: The complaint of diplopia disappeared after a single operation in 8 patients, and after a second operation in 4. Thus, success was obtained in 1 2 of the 1 3 patients. One patient with persistent vertical diplopia refused a second operation.

Conclusion: Our results indicate that MRI is an effective and reliable method for the determination of the fibrotic phase in patients with dysthyroid orbitopathy who have diplopia in the primary position, and that MRI results have an important role in determining whether early surgery is appropriate.

J Pediatr Ophlhalmol Strabismus 2002;39:336-339.
A Comparison of Quantitative Mapping and Stereoscopic Fundus Photography Grading of Retinal Thickness in Diabetic Eyes With Macular Edema
Authors: Yang Yunsik , Vitale Susan , Ding Yulan , O'Connell Stephen R , Alexander Judith , Bressler Neil M , Schachat Andrew P , Zeimer Ran
Published: January 2019

* OBJECTIVE: To evaluate the ability of a retina specialists grading of 30° color stereoscopic fundus photographs to identify areas of significant retinal thickening as assessed by the Retinal Thickness Analyzer (RTA) and to determine whether this ability was affected by the presence of retinal pathology.

* MATERIALS AND METHODS: Thirty-two eyes in 29 patients clinically diagnosed as having diabetic macular edema underwent RTA scanning and nonsimultaneous 30° color stereoscopic fundus photography. Retinal thickness maps of the macular area were generated, and regions with significant retinal thickening (≥2 SD above normal values) were identified. A retina specialist reader, masked to the RTA measurements, identified areas with macular edema on the stereoscopic fundus photographs, which subsequently were overlaid on the retinal thickness maps. The sensitivity (percent of significant retinal thickening areas identified by the retina specialist grading the stereoscopic fiindus photographs) was calculated separately for areas with and without retinal pathology. Specificity of the stereoscopic fundus photograph grading was assessed similarly.

* RESULTS: The retina specialists stereoscopic fundus photography grading identified 78.8% of areas with significant retinal thickening (range over eyes: 20.4%1 00%) and was slightly more likely to identify significant retinal thickening when pathology was present (89.6%) than when pathology was not present (78.4%; pooled risk ratio, 1.14 [95% CI=0.54, 2.42]). Specificity of stereoscopic fundus photography grading was 58%, ie, 42% of areas without significant retinal thickening were (incorrectly) identified as edematous by the stereoscopic fundus photograph grading. This misidentification was more likely if pathology was present (76.9%) than if pathology was not present (41.1%; pooled risk ratio, 1.87 [95% CI= 1.28, 2.73]).

* CONCLUSION: This study shows the determination of macular edema by a retina specialist reading color stereoscopic fundus photographs is sensitive but not specific with reference to edema identified by the RTA, Furthermore, the presence of retinopathy tends to cause false-positive readings with reference to edema identified by the RTA. These findings indicate the need to use objective, quantitative methods in clinical studies to detect and monitor macular edema.

[Ophthalmic Surg Lasers Imaging 2003;34:7-16]
Peripapillary Nerve Fiber Layer Thickness Measurement Reproducibility Using Optical Coherence Tomography
Authors: Villain Max A , Greenfield David S
Published: January 2019

* OBJECTIVE: To assess reproducibility of quadrantic and clock hour sectors of retinal nerve fiber layer thickness in normal eyes using optical coherence tomography.

* MATERIALS AND METHODS: Normal eyes of healthy volunteers meeting eligibility criteria, were imaged by two inexperienced operators. Six 360° circular scans with a diameter of 3.4 mm centered on the optic disc were obtained during each scanning session, and a baseline image was formed using 3 high-quality images defined by the software. Images were obtained on three different days within a 4-week period. Variance and coefficient of variation (CV) were calculated for quadrantic and retinal nerve fiber layer clock hour sectors obtained from the baseline image.

* RESULTS: Five normal eyes were scanned. Intraoperator reproducibility was high. The mean (±SD) CV for total retinal nerve fiber layer thickness was 5.3±3.82% and 4.33±3.7% for operators 1 and 2, respectively. Interoperator reproducibility was good with statistically similar variance for all quadrantic and clock hour retinal nerve fiber layer parameters (P=.42 to .99), The nasal retinal nerve fiber layer was the most variable sector for both operators (mean CV: 10.42% and 7.83% for operators 1 and 2, respectively). Differences in mean total, nasal, temporal, and superior retinal nerve fiber layer thickness were not statistically significant between operators for all eyes; however, for inferior retinal nerve fiber layer thickness, there was a significant (/^.0007) difference between operators in one eye.

* CONCLUSION: Peripapillary retinal nerve fiber layer thickness assessments using optical coherence tomography have good intraoperator and interoperator reproducibility. Inexperienced operators can generate useful measurement data with acceptable levels of variance.

[Ophthalmic Surg Lasers Imaging 2003:34:33-37]
Improvements After Sheathotomy for Branch Retinal Vein Occlusion Documented by Optical Coherence Tomography and Scanning Laser Ophthalmoscope
Authors: Fujii Gildo Y , de Juan Eugene , Humayun Mark S
Published: January 2019

Abstract. A 55-year-old man presented with decreased visual acuity of 20/400 and central foveal thickness of 450 pm as measured using optical coherence tomography due to a superior temporal branch retinal vein occlusion. Adventitial sheathotomy was performed with a 25-gauge sutureless transconjunctival vitrectomy system. At 1 day, 1 month, and 6 months postoperatively, visual acuity improved to 20/80, 20/40, and 20/30 OS, respectively; central foveal thickness decreased to 228, 195, and 161 \im, respectively; and the scanning laser ophthalmoscope microperimetry showed improved retinal sensitivity and fixation pattern with more stable and central fixation at both postoperative visits. This case indicates optical coherence tomography can detect an early positive effect of sheathotomy surgery on macular edema, and scanning laser ophthalmoscope can document associated improvement in fixation stability. [Ophthalmic Surg Lasers Imaging 2003;34:49-52]
Increased Diode Laser Uptake in Inner Retinal Layers After Indocyanine Green Staining of the Internal Limiting Membrane
Authors: Benz Matthew S , Smiddy William E
Published: January 2019

Abstract. Intraoperative use of indocyanine green to stain the internal limiting membrane assists in its visualization and removal. This article describes increased uptake of diode laser energy by the superficial layers of the retina after indocyanine green staining of the internal limiting membrane in a patient with diabetic macular edema and a taut, attached posterior hyaloid. The patient was undergoing pars plana vitrectomy, removal of the posterior hyaloid, and indocyanine green -assisted peeling of the internal limiting membrane. In addition, panretinal diode laser endophotocoagulation was performed after discovering retinal neo vascular iza tion. In areas that were more intensely stained with indocyanine green, the clinical appearance and optical coherence tomography scans demonstrated markedly increased laser energy uptake in the superficial layers of the retina. This case indicates near-infrared or infrared laser procedures performed in areas of indocyanine green-stained internal limiting membrane may necessitate adjustment of laser power and technique. [Ophthalmic Surg Lasers Imaging 2003;34:64-67]
Normative Retardation Data Corrected For the Corneal Polarization Axis With Scanning Laser Polarimetry
Authors: Greenfield David S , Knighton Robert W , Feuer William J , Shiffman Joyce C
Published: January 2019

* BACKGROUND AND OBJECTIVE: To evaluate the distribution of retinal nerve fiber layer thickness measurements in normal eyes corrected for corneal polarization axis (CPA).

* METHODS: Complete ocular examination, standard automated perimetry, peripapillary and macular scanning laser polarimetry imaging, and CPA measurements were performed in normal eyes. A noninvasive device mounted on a slit lamp that incorporated two crossed linear polarizers and an optical retarder to measure the slow axis of corneal birefringence was constructed. One eye per patient was enrolled. Exclusion criteria consisted of visual acuity of less than 20/40, a refractive error exceeding ± 5.0 diopter sphere, 2.0 diopter cylinder, or both, previous intraocular surgery, or ocular disease except cataract. According to scanning laser polarimetry, peripapillary retardation parameters within 90% normal limits were recorded as "normal," parameters outside 95% normal limits were recorded as "abnormal," and parameters between 90% and 95% limits were recorded as "borderline."

* RESULTS: Fifty-one eyes of 51 subjects (14 men, 37 women) were enrolled (mean age, 51 ± 17 years). Prediction limits (± 2 standard deviation outside of regression line) were calculated for 14 peripapillary retardation parameters. The prediction limits of the average thickness of the retinal nerve fiber layer (µm) were reduced 35% by correction of the CPA; for ellipse average (µm), the limits were reduced 33%. Sixteen of 51 normal eyes (31%) had at least one abnormal retardation parameter, and among these 16 eyes there was a bimodal distribution of CPA values (0° to 20° nasally downward, 60° to 80° nasally downward).

* CONCLUSIONS: Correction for CPA reduces the variance of normal retardation measurements. Normal eyes with a CPA of 0° to 20° nasally downward and 60° to 80° nasally downward were characterized by "abnormal" summary retardation parameters as interpreted by scanning laser polarimetry.

[Ophthalmic Surg Lasers Imaging 2003;34:165-171.]
Spontaneous Closure of a Recurrent Macular Hole Following Vitrectomy Corroborated by Optical Coherence Tomography
Authors: Shaikh Saad , Garretson Bruce
Published: January 2019

Abstract. Although previously reported with primary macular holes, spontaneous closure of a recurrent macular hole after previous vitrectomy has not been described. In a 71-year-old man, a recurrent macular hole diagnosed by clinical examination and optical coherence tomography was associated with cystoid macular edema on fluorescein angiography and decreased vision 9 months after macular hole surgery and 6 weeks after cataract extraction. Spontaneous closure of the macular hole and improved visual acuity were noted while awaiting repeat vitrectomy. Findings were corroborated by optical coherence tomography. To date, this represents the first such case in the literature. [Ophthalmic Surg Lasers Imaging 2003;34:172-174.]
Retinal Pigment Epithelial Tear Involving the Fovea With Preserved Visual Function
Authors: Yoshitani Shigeki , Katsura Mari , Minamoto Atsushi , Tsumura Kiyoshi , Tamura Hiroki , Hasebe Haruyuki , Mishima Hiromu K
Published: January 2019

Abstract. Tears of the retinal pigment epithelium are known to occur either spontaneously or after laser photocoagulation in eyes with retinal pigment epithelium detachment. A 65-year-old man with preexisting retinal pigment epithelium detachment developed a retinal pigment epithelium tear after dye laser retinal photocoagulation. The tear gradually expanded to involve the fovea, but his best-corrected visual acuity remained 0.7 in the left eye during 20 months. Optical coherence tomography showed a defect of the retinal pigment epithelium with absence of regeneration. Scanning laser ophthalmoscopy revealed his fixation approached intact retinal pigment epithelium, but was still beneath the fovea. This case may indicate that the retinal pigment epithelium directly beneath the central macula is not essential for maintenance of the overlying foveal function under some conditions. [Ophthalmic Surg Lasers Imaging 2003;34:217-220.]
Intraocular Intrusion of a Scleral Sponge Implant
Authors: Ünlü Nurten , Kocaoglan Hülya , Acar Mehmet A , Aslan Bekir S , Duman Sunay
Published: January 2019

Abstract. A patient with intrusion of a scleral sponge implant after retinal reattachment surgery is described. Retinal incarceration occurred during primary retinal reattachment surgery and the patient underwent additional cryopexy and radial sponge implant. However, the retina remained detached and pars plana vitrectomy was performed with silicone oil endotamponade to reattach the retina. The interval between placement of the scleral buckle and development of intrusion was 3 months. The buckle was sutured to the sclera with mattress sutures. During the postoperative follow-up period, the intraocular pressure was elevated and controlled with topical antiglaucomatous medication. The encircling band was cut but left in place to avoid perforation, and the retina remained attached. Intrusion of a buckle after retinal reattachment surgery is a rare complication that usually does not require surgical intervention. Cutting the silicone band without removing it may be a treatment option. [Ophthalmic Surg Lasers Imaging 2003;34:223-225.]
Temporary Use of a Customized, Glued-on Hard Contact Lens Before Penetrating Keratoplasty for Descemetocele or Corneal Perforation
Authors: Kobayashi Akira , Shirao Yutaka , Segawa Yasunori , Kawasaki Kazuo , Tanahashi Toshiro , Komata Miki , Deguchi Hiroko , Tagawa Kosaku , Tseng Scheffer C G
Published: January 2019

Abstract. Descemetocele or corneal perforation makes it difficult to perform penetrating keratoplasty (PKP). To circumvent this difficulty, a polymethylmethacrylate hard contact lens with a diameter of 4.0 mm was customized and applied to the cornea with tissue adhesive prior to PKP in three patients, one with corneal perforation and two with descemetoceles. The results showed that this modified method facilitated trephination during PKP without complications in all three patients, suggesting that it may be applicable to other similar clinical situations. [Ophthalmic Surg Lasers Imaging 2003;34:226-229.]
Surgical Management of Unilateral Elevator Deficiency Associated With Horizontal Deviation Using a Modified Knapp's Procedure
Authors: Kamlesh  , Dadeya Subhash
Published: January 2019

Abstract. Both horizontal recti are transpositioned in unilateral elevator deficiency, leaving no alternative to correct any significant ipsilateral horizontal deviation. An effective method to correct vertical and horizontal deviations simultaneously is reported. A modified Knapp's procedure was performed by transposition of the superior half of equally divided (up to 15 mm) medial and lateral recti for vertical deviation and the inferior half after suitable recession or resection for horizontal deviation. This procedure was performed in ten patients who had type II unilateral elevator deficiency with horizontal deviation ranging from 18 to 45 prism diopters (PD). We were able to correct 20 PD of horizontal deviation and 25 PD of vertical deviation with a modified Knapp's procedure without any significant adverse effects after a follow-up of 21 months. A modified Knapp's procedure is recommended for unilateral elevator deficiency associated with horizontal deviation. [Ophthalmic Surg Lasers Imaging 2003;34:230-235.]