bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Exposure Time and Pupil Size on a Shack-Hartmann Metric of Forward Scatter
Authors: Donnelly William J , Applegate Raymond A
Published: December 2019

ABSTRACT

PURPOSE: To determine the influence of exposure time and pupil size on a Shack-Hartmann (S/H) derived metric of forward scatter (MAX_SD) using a physical model of nuclear cataract.

METHODS: A physical model eye was developed and mounted to a S/H wavefront sensor. The eye model consisted of a lens, variable pupil, simulated cataract, and retina. Located behind the pupil, a cuvette contained one of five polystyrene microsphere solutions simulating five levels of nuclear cataract severity. Cataract severity was described using a S/H derived metric of forward scatter (MAX_SD), which measures aspects of forward scatter contained in the S/H lenslet point spread functions (PSF). To determine the impact of exposure time and pupil size, measurements of MAXSD were regressed against cataract severity for three different exposure times and three different pupil sizes.

RESULTS: MAX_SD was well correlated to cataract severity. Exposure time had the largest influence, and pupil size had the smallest influence on the forward scatter metric. When pupil size and exposure time were allowed to vary and image saturation was allowed to occur, MAX_SD explained 83% of the variance in cataract severity. Excluding images where saturation occurred, holding optimal exposure time constant, and varying pupil size, MAX_SD explained 97% of the variance in cataract severity.

CONCLUSIONS: The ability of the forward scatter metric derived from S/H measurements to predict cataract severity for a longitudinal study is optimized by selecting a patient-specific exposure at the initial cataract assessment to avoid saturation and maximize the dynamic range of the system. This patient-specific exposure should be used in all future visits. [J Refract Surg. 2005;21:S547-S551.]
Errors in Zernike Transformations and Non-modal Reconstruction Methods
Authors: Neal Daniel R , Baer C David , Topa Daniel M
Published: December 2019

ABSTRACT

PURPOSE: Wavefront aberrometers often represent the wavefront in terms of Zernike polynomials. The fit coefficients for these polynomials are pupil-size dependent; hence it is desirable to be able to calculate polynomial coefficients at a different pupil size from the initial measurement.

METHODS: We developed a method for scaling the Zernike fit coefficients for different sized pupils and compared them to the coefficients calculated by reanalyzing the original data. We evaluated cases where the initial set of Zernike coefficients was an accurate representation of the data as well as cases where the Zernike polynomials fit the data poorly.

RESULTS: The rescaling methods work well in all cases with a good original fit (as measured by the gradient root-mean-square [RMS] fit error). Rescaling and reanalyzing also agree well over a small scaling range. However, if the original fit was poor, large errors result if the rescaling is more than ~25%.

CONCLUSIONS: Rescaling works well and is useful as long as the RMS fit error can be evaluated. The RMS difference between the zonal reconstruction and the Zernike fit is useful for determining this fit error. [J Refract Surg. 2005;21:S558-S562.]
Combined Flap Undersurface and Bed LASIK for High Myopia
Authors: Li Li Wei , Mei Wang Qin , Jun Fang Xue
Published: December 2019

ABSTRACT

PURPOSE: To discuss the predictability, stability, and safety of LASIK for high myopia using laser treatment on both the flap undersurface and bed (both-sided LASIK).

METHODS: One hundred twenty-one eyes of 63 patients underwent flap undersurface and bed LASIK for high myopia. Postoperative uncorrected visual acuity (UCVA), refraction, and topography were evaluated up to 12 months. The safety and injury indices in both-sided LASIK were compared with that of conventional LASIK.

RESULTS: In both-sided LASIK, the largest diopter correction on the undersurface of the corneal flap was -6.00 diopters (D), correlating to an ablation of 44.62 µm. The mean thickness of residual corneal stroma bed was 283.87 ± 19.83 µm after the laser treatment. Postoperative UCVA was close to the preoperative best spectacle-corrected visual acuity (BSCVA). The mean BSCVA was significantly better (P<.05) than preoperatively at each time point (1 week, 1, 3, and 6 months, and 1 year) after surgery. Postoperative corneal topography was normal in all cases. The safety and injury indices for conventional LASIK in both-sided LASIK eyes were calculated by programming the excimer laser as though conventional treatments would be performed to calculate the theoretical bed ablation. The safety factor of both-sided LASIK was higher than that calculated for conventional LASIK (P<.05); the injury index was lower than that calculated for conventional LASIK (P<.05).

CONCLUSIONS: Surgery on high myopia by bothsided LASIK is safe and effective. [J Refract Surg. 2005;21(Suppl):S606-S609.]
LASIK Enhancement Using Excimer Laser Ablation on the Back of the Flap
Authors: Grim Millicent , Sheard Janine , Martin Lynn
Published: December 2019

ABSTRACT

PURPOSE: To report our surgical technique for LASIK enhancement by ablating the underside of the flap.

METHODS: Surgical case report of clinical outcomes in three eyes of two patients who had an initial laser ablation in the bed with subsequent enhancements on the underside of the flap.

RESULTS: Following LASIK enhancement on the back of the flap, two eyes gained one line of best spectacle-corrected visual acuity (BSCVA) after treatment compared to preoperatively, going from 20/15 to 20/12, and one eye maintained BSCVA at 20/20.

CONCLUSIONS: Excimer laser ablation of the underside of the flap is a viable alternative to treat corneas with minimal residual tissue whether primary or enhancement procedures are needed. A surgical learning curve exists with this technique. [J Refract Surg. 2005;21(Suppl): S610-S613.]
Screening Patients With the Corneal Navigator
Authors: Klyce Stephen D , Karon Michael D , Smolek Michael K
Published: December 2019

ABSTRACT

PURPOSE: To present a corneal topography screening device for the detection of corneal ectasias and various refractive procedures based on corneal topography patterns.

METHODS: A database of corneal topography patterns were analyzed and used to "train" a neural network on nine different corneal topography patterns using nineteen corneal topography indices of corneal shape and power.

RESULTS: Sample normal and corneal topographies were recognized correctly.

CONCLUSIONS: The use of the corneal navigator to screen various corneal topographies aids clinical diagnosis. [J Refract Surg. 2005;21(Suppl):S617-S622.]
Retinal Nerve Fiber Layer Changes After LASIK Evaluated With Optical Coherence Tomography
Authors: Dementyev Dmitriy D , Kourenkov Vyacheslav V , Rodin Alexander S , Fadeykina Tatyana L , Martinez Tatyana E Diaz
Published: December 2019

ABSTRACT

PURPOSE: To determine whether the increase in intraocular pressure (IOP) during LASIK suction can induce a decrease in retinal nerve fiber layer thickness assessed by optical coherence tomography (OCT).

METHODS: Nineteen patients (38 eyes) were enrolled in the study. Intraocular pressure was normal at all preand postoperative examinations. Retinal nerve fiber layer thickness was measured using OCT-3 Stratus prior to and 1 week and 3 months after LASIK. Laser in situ keratomileusis was performed using the Bausch & Lomb Hansatome microkeratome and the NIDEK EC-5000 excimer laser. Optical coherence tomography mean retinal nerve fiber layer thickness values before and after LASIK were compared using the Student paired t test.

RESULTS: Mean patient age was 27.8 years (range: 18 to 33 years). Mean preoperative spherical equivalent refractive error was -4.9 diopters (D) (range: -2.0 to -8.5 D). Mean time of microkeratome suction was 30 seconds (range: 20 to 50 seconds). Preoperatively, the mean retinal nerve fiber layer thickness obtained by OCT was 104.2±9.0 µm; at 1 week postoperatively the mean thickness was 101.9±6.9 µm, and 106.7±6.1 µm at 3 months postoperatively. Mean retinal nerve fiber layer thicknesses obtained by OCT were not significantly different between preoperative and 1 week and 3 months after LASIK (P≥.05).

CONCLUSIONS: Laser in situ keratomileusis performed on young myopic patients does not have a significant effect on retinal nerve fiber layer thickness determined by OCT. Further studies are required to reveal the risk of possible optic nerve or retinal nerve fiber layer damage by elevated IOP during LASIK. [J Refract Surg. 2005;21(Suppl):S623-S627.]
Five Techniques for Improving Outcomes of Hyperopic LASIK
Authors: Zaldivar Roberto , Orcherow Susana , Bains Harkaran S
Published: December 2019

ABSTRACT

PURPOSE: To determine whether five changes to our hyperopic LASIK protocol produced better outcomes.

METHODS: Five changes, both technical and surgical, were instituted for the treatment of hyperopia. These five changes were nomogram refinements accounting for accommodation, use of a 7.0-mm optical zone and a 9.5-mm transition zone, a targeted mean flap diameter of 10.5 mm, sequential interruption of the laser ablation, and cleaning of the interface. The study comprised 43 eyes undergoing LASIK for hyperopia or hyperopic astigmatism with a mean preoperative spherical equivalent refraction of +2.28 diopters (D), a mean sphere of +1.93 D (range: +4.25 to +0.25 D), and mean cylinder of +1.10 D (range: +4.50 to +0.25 D). The NIDEK CXII excimer laser was used for all treatments.

RESULTS: From 1 day to 3 months postoperatively, the mean hyperopic shift was <0.50 D. Postoperatively, the number of patients achieving a distance best spectacle-corrected visual acuity (BSCVA) of 20/20 gradually increased to 93% by 3 months. The number of eyes that achieved 20/15 increased by 11.7% compared to preoperatively. Eighty-eight percent of eyes maintained or gained lines of BSCVA. Four patients lost 1 line of BSCVA. One patient lost >1 line of vision due to visually significant microstriae.

CONCLUSIONS: The outcomes support the observation that five surgical and technical modifications to the hyperopic LASIK procedure result in excellent visual quality and refractive outcomes and a low rate of regression. [J Refract Surg. 2005;21(Suppl):S628-S632.]
Wavefront-guided LASIK With the NIDEK NAVEX Platform for the Correction of Myopia and Myopic Astigmatism With 6-month Follow-up
Authors: Venter Jan
Published: December 2019

ABSTRACT

PURPOSE: To assess safety, efficacy, predictability, stability, and change in higher order aberrations after wavefront-guided LASIK for myopia and myopic astigmatism using the NIDEK NAVEX platform.

METHODS: Wavefront-guided LASIK was performed in 93 eyes in a 6-month trial with a goal of emmetropia. Treated eyes had a mean subjective manifest spherical equivalent refraction of -4.08±1.99 D diopters (D), with a range of -9.50 to -0.38 D of myopia and -4.50 to 0.00 D of astigmatism. An early nomogram with the OPDCAT software program provided by the manufacturer was used in all procedures. Safety, efficacy, predictability, stability, and change in higher order aberrations were evaluated at 6 months.

RESULTS: At 6 months, 100% eyes were within ±1.0 D of emmetropia and 95% eyes were within ±0.5 D. Uncorrected visual acuity (UCVA) of ≥1.0 was achieved in 89% of eyes, and 38% of eyes achieved UVCA of ≥1.2. No eyes lost ≥2 lines of best spectacle-corrected visual acuity (BSCVA), 25% of eyes gained 1 line, 3% gained 2 lines, and 1% gained ≥2 lines of BSCVA. Higher order root-mean-square (RMS) values increased by 19% on average between pre- and postoperative measurements. Eyes treated with higher order aberrations of <0.3 RMS showed on average an increase of 40% on preoperative values, whereas eyes with significant aberrations showed a decrease in aberrations following wavefront treatment.

CONCLUSIONS: Wavefront-guided ablation using the NIDEK NAVEX platform is safe, effective, and predictable. However, patients with low amounts of aberrations showed an increase in aberrations following wavefront treatment, therefore, wavefront treatment may not be indicated or beneficial to every patient. [J Refract Surg. 2005;21(Suppl):S640-S645.]
Incidence of Complications During Flap Creation in LASIK Using the NIDEK MK-2000 Microkeratome in 26,600 Cases
Authors: Carrillo Carlos , Chayet Arturo S , Dougherty Paul J , Montes Miguel , Magallanes Roberto , Najman Jacobo , Fleitman Jacobo , Morales Alfredo
Published: December 2019

ABSTRACT

PURPOSE: To evaluate the incidence of intraoperative complications using the NIDEK MK-2000 microkeratome during flap creation in LASIK.

METHODS: The incidence of intraoperative flap complications during LASIK using the NIDEK MK-2000 microkeratome was retrospectively studied in 26,600 procedures performed in 5 outpatient excimer laser surgery centers.

RESULTS: A total of 65 (0.244%) complications were identified: 23 (0.086%) eyes had free caps, 13 (0.049%) eyes had an incomplete pass, 13 (0.049%) eyes had an epithelial defect, 11 (0.041%) eyes had buttonhole, and 5 (0.019%) eyes had irregular flap. The remaining 26,535 (99.756%) eyes had uneventful flap creation.

CONCLUSIONS: Use of the NIDEK MK-2000 microkeratome resulted in a low incidence of intraoperative complications, making it a safe and reliable device for creating flaps during LASIK. [J Refract Surg. 2005;21(Suppl): S655-S657.]
Comparison of LASIK Outcomes With the Alcon LADARVision4000 and the VISX STAR S2 Excimer Lasers Using Optimized Nomograms
Authors: Gailitis Raymond P
Published: December 2019

ABSTRACT

PURPOSE: To evaluate the difference in clinical outcomes between LASIK patients treated with the Alcon LADARVision4000 laser and the VISX STAR S2 laser using optimized nomograms.

METHODS: Data from 572 UVSIK surgeries of two groups that were sequentially performed by one surgeon were retrospectively reviewed. The first group of 286 eyes were the last cases performed with the VISX STAR S2 laser. Following these surgeries, a second group of 286 eyes were the first cases performed with the Alcon LADARVision4000 laser, after an initial 50-eye adaptation period. Treatments were guided by the Refractive Surgery Consultant software.

RESULTS: For myopic eyes 3 months postoperatively, the percentage of eyes with uncorrected visual acuity (UCVA) ^20/20, accuracy of treatment within ?0.5 D, and loss of s=2 lines of best spectacle-corrected visual acuity (BSCVA) for the LADARVision4000 and STAR S2, respectively was: 89% vs 63%, 84% vs 80%, and 0.8% vs 3.8%. For hyperopic eyes 3 months postoperatively, the percentage of eyes with UCVA ^ 20/20, accuracy of treatment within ?0.5 D, and loss of >2 lines of BSCVA for the LADARVision4000 and STAR S2, respectively was: 74% vs 33%, 69% vs 74%, and 2% vs 18.5%.

CONCLUSIONS: Although good results are evident for both platforms, superior results were observed with the Alcon l_ADARVision4000 laser. [J Refract Surg. 2005;21:683-690.]
LASIK for Myopia With the Zeiss Meditec MEL 80
Authors: Goes Frank Josef
Published: December 2019

ABSTRACT

PURPOSE: To prospectively evaluate a new high-speed, small spot-scanner laser for the correction of myopia and myopic astigmatism.

METHODS: Seventy-six consecutive eyes with myopia and myopic astigmatism between -1.00 and -8.25 diopters (D) and up to -2.75 D astigmatism underwent LASIK treatment using the MEL 80 laser (Carl Zeiss M?dit?e, Jena, Germany). Parameters evaluated were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), residual refractive error, regression of correction, and aberrometry.

RESULTS: Mean preoperative BSCVA was 20/20, which improved to 20/18 postoperatively. Postoperative UCVA was 20/20 at 1 month and 20/18 at 1 year. Uncorrected visual acuity ≥20/20 was achieved in 58 (83%) of 70 eyes at 1 month and in 60 (88%) of 68 eyes at 1 year. The average refractive error before LASIK was -4.41±1.98 D. The mean residual refractive error was 0.14±0.31 D at 1 month and 0.13±0.30 D at 1 year. At 1-month and 1-year follow-up, respectively, 66 (94%) of 70 eyes and 65 (96%) of 68 eyes were within ±0.50 D of intended refractive correction. No eye lost two lines. At 1 month 17% of eyes and at 1 year 13% of eyes gained two lines or more. Between 1- month and 1-year follow-up, 100% of eyes were stable. Mean rootmean-square high order aberration changed from 0.20 µm preoperative Iy to 0.28 µm postoperatively.

CONCLUSIONS: The MEL 80 is effective and safe in the treatment of myopia and myopic astigmatism. [J Refract Surg. 2005;21:691-697.]
Comparison of Ablation Centration After Bilateral Sequential Versus Simultaneous LASIK
Authors: Lin Jane-Ming , Tsai Yi-Yu
Published: December 2019

ABSTRACT

PURPOSE: To compare ablation centration after bilateral sequential and simultaneous myopic LASIK.

METHODS: A retrospective randomized case series was performed of 670 eyes of 335 consecutive patients who had undergone either bilateral sequential (group 1) or simultaneous (group 2) myopic LASIK between July 2000 and July 2001 at the China Medical University Hospital, Taichung, Taiwan. The ablation centrations of the first and second eyes in the two groups were compared 3 months postoperatively.

RESULTS: Of 670 eyes, 274 eyes (137 patients) comprised the sequential group and 396 eyes (198 patients) comprised the simultaneous group. Three months postoperatively, 220 eyes of 110 patients (80%) in the sequential group and 236 eyes of 118 patients (60%) in the simultaneous group provided topographic data for centration analysis. For the first eyes, mean decent ration was 0.39±0.26 mm in the sequential group and 0.41 ±0.19 mm in the simultaneous group (P= .30). For the second eyes, mean decentration was 0.28±0.23 mm in the sequential group and 0.30±0.21 mm in the simultaneous group (P=. 36). Decentration in the second eyes significantly improved in both groups (group 1, P =.02; group 2, P<.01). The mean distance between the first and second eyes was 0.31±0.25 mm in the sequential group and 0.32±0.18 mm in the simultaneous group (P=.33). The difference of ablation center angles between the first and second eyes was 43.2 ±48.3° in the sequential group and 45.1±50.8° in the simultaneous group (P =.42).

CONCLUSIONS: Simultaneous bilateral LASIK is comparable to sequential surgery in ablation centration. [J Refract Surg. 2005;21:705-708.]
Effect of Topical Vitamin E on Ethanol-induced Corneal Epithelial Apoptosis
Authors: Bilgihan Kamil , Konuk Onur , Hondur Ahmet , Akyürek Nalan , Özogul Candan , Hasanreisoglu Berati
Published: December 2019

ABSTRACT

PURPOSE: Ethanol is used to loosen the corneal epithelium before photoablation in laser subepithelial keratomileusis (LASEK). In this study, the apoptotic index of corneal epithelium after ethanol exposure and the effects of topical vitamin E were evaluated.

METHODS: The study was performed on 28 rabbit eyes in four groups. Group 1 comprised the controls. In group 2, 20% ethanol was applied topically for 20 seconds. In group 3, topical vitamin E was applied following 20% ethanol application. In group 4, only topical vitamin E was applied. Apoptosis was evaluated with TUNEL assay and transmission electron microscopy.

RESULTS: Epithelial apoptosis was detected in all specimens in group 2. No apoptosis was detected in other groups except for one eye in group 1. The apoptotic index in group 2 was statistically higher than other groups (P<.001).

CONCLUSIONS: Topical vitamin E can prevent ethanol-induced apoptosis in the corneal epithelium in rabbits. [J Refract Surg, 2005;21:761-763.]
Conventional vs Wavefront-guided LASIK Using the LADARVision4000 Excimer Laser
Authors: Caster Andrew I , Hoff James L , Ruiz Roman
Published: December 2019

ABSTRACT

PURPOSE: To compare outcomes after LASIK surgery using the conventional LADARVision4000 laser and the wavefront-guided LADARWave CustomCornea wavefront system.

METHODS: A prospective study was performed involving 140 myopic eyes receiving conventional or CustomCornea LASIK between May and October 2003. The preoperative manifest spherical equivalent refraction was limited to myopia =s-7.00 diopters (D). The preoperative manifest cylinder was limited to ^s -2.50 D of astigmatism. Patients were evaluated for 3 months following surgery. Results evaluated were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity, manifest refraction, dilated wavefront measurements, contrast sensitivity, and patient responses to subjective questionnaires.

RESULTS: For the CustomCornea eyes at 3 months, 80% (70/87) had UCVA 2*20/20 and 95% (83/87) had UCVA > 20/25. For the conventional eyes at 3 months, 45% (9/20) had UCVA >20/20 and 80% (16/20) had UCVA >20/25. At the 3-month postoperative visit, 85% (74/87) of the CustomCornea eyes and 55% (11/20) of the conventional eyes were within ?0.50 D of their intended correction. At 1 and 3 months, the CustomCornea treated eyes had a statistically significant lower mean increase in higher order aberrations than conventionally treated eyes (P<.05).

CONCLUSIONS: CustomCornea wavefront-guided LASIK surgery appears safe and effective and provides clinical benefits that appear to exceed those of conventional LADARVision surgery. [J Refract Surg. 2005;21:S786S791.]
Alcon LADARWave CustomCornea Retreatments
Authors: Durrie Daniel S , Stahl Jason E , Schwendeman Frank
Published: December 2019

ABSTRACT

PURPOSE: To present our experience performing wavefront-guided ablations for the treatment of residual refractive error following previous refractive surgery.

METHODS: Four different cases are presented ? 1) prima iy wavefront-guided LASIK; 2) wavefront-guided lift-flap LASIK retreatment; 3) wavefront-guided photorefractive keratectomy (PRK) retreatment; and 4) wavefront-guided PRK over radial keratotomy retreatment. All procedures were performed with the Alcon CustomCornea laser platform. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, and wavefront analysis (6.5-mm pupil) were performed preoperatively and 3 months after CustomCornea retreatment. The Alcon LADARWave device was used for wavefront measurements.

RESULTS: Total lower order and higher order aberrations were decreased following wavefront-guided retreatment, resulting in improved quality of vision. The maximum target offset (+0.75 diopters) can be used to prevent an overcorrection of defocus (myopia) when treating a significant amount of spherical aberration.

CONCLUSIONS: Wavefront-guided ablation was an effective treatment for residual lower and higher order aberrations following previous refractive surgery. Custom ablation treatment algorithms need to be developed specifically for retreatment procedures. [J Refract Surg. 2005;21:S804-S807.]
Vida y obra de un médico morisco en el exilio: Muḥammad b. Aḥmad b. Abī l-‛Āṣ (ss. XVI-XVII)
Authors: Coullaut Cordero Jaime
Published: December 2019

Uno de los autores hispanomusulmanes que hasta la fecha no había podido ser identificado es Muḥammad b. Aḥmad b. Abī l-‛Āṣ al-Andalusī, a quien se atribuyen dos breves tratados sobre medicina. Un estudio de los manuscritos conservados de ambas obras, así como la revisión de algunas fuentes y estudios recientemente publicados, nos permiten identificar a este autor con el morisco granadino Muḥammad b. Abī l-‛Āṣī (o Muhhemed Bulhaç), médico que en la primera mitad del s. XVII abandonó la Península Ibérica para residir durante algunos años en Estambul y posteriormente en El Cairo, donde se pierde su pista en el año 1637. En el presente artículo, expondremos todos los datos biográficos disponibles de este personaje, y haremos un breve análisis de sus dos tratados.
Reflexiones acerca de la formación intelectual de Abū Ya‛zà y al-Yuḥānisī: dos modelos de santidad en el Occidente Islámico medieval
Authors: El Hour Rachid
Published: December 2019

Este trabajo estudia las figuras de Abū Ya῾zà y al-Yuḥānisī desde la perspectiva de su educación y formación intelectuales. Los dos personajes analizados pueden ayudarnos, por un lado, a revisar en profundidad las características de aquellos que se consideran awliyā’ o «amigos de Dios» así como a sugerir la posibilidad de la existencia de dos modelos de santidad en el occidente islámico, uno típicamente magrebí y el otro andalusí. Los dos modelos propuestos muestran características comunes pero también claras diferencias, especialmente en lo relativo a su educación y formación intelectual. De esta forma, el estudio presta especial atención a factores como la enseñanza recibida por parte de los sujetos de estudio y sus maestros, la presencia de la lengua bereber en esta enseñanza así como el fenómeno de la rihla a las tierras orientales como parte inseparable de la propia formación intelectual.
Noticias para la Arqueología e Historia de Granada: Plano de la Mezquita Mayor de Granada de 1507 en poder de Cisneros
Authors: Espinar Moreno Manuel
Published: December 2019

El hallazgo del Plano de la Mezquita Mayor de Granada, fechado en 1507, nos permite ofrecer esta interesante noticia. La Arqueología, la Historia y el Arte de Granada cuentan con nuevos datos para estudiar la Mezquita Mayor y sus alrededores. Teníamos trabajos de reconocidos autores. Sin embargo, esta nueva aportación plantea nuevos enfoques en la investigación del conjunto monumental.
Efecto de las nanopartículas de ZrO2 y L-Cys como agentes dopantes de recubrimientos sol-gel de sílice mesoporosa para la protección anticorrosiva de la aleación de magnesio AZ61
Authors: Hernández Leonardo , Veleva Lucien , García-Galván Federico R. , Galván Juan Carlos
Published: December 2019

Sobre la superficie de la aleación de magnesio AZ61 se aplicaron recubrimientos de sol-gel basados en el precursor GPTMS-TMOS, incluyendo como agentes dopantes L-Cysteína y ZrO2 en diferentes concentraciones. Su resistencia a la corrosión se estudió en solución de 0,6M NaCl, por inmersión hasta 14 días. Los patrones de DRX revelaron que el principal producto de corrosión en las superficies recubiertas es Mg(OH)2, mientras que en la de AZ61 no tratada adicionalmente se formaron varios compuestos de Zn con cloro. El ataque de la corrosión localizada en el AZ61 no tratada se manifiesta en forma de grietas y cavernas, mientras que en las superficies recubiertas la corrosión fue principalmente a través de picaduras. Dos métodos electroquímicos no destructivos fueron empleados en este estudio, que contrastan el comportamiento electroquímico del AZ61 recubierto con el de la aleación no recubierta. La tendencia en los cambios del potencial de corrosión en circuito abierto se correlacionó positivamente con el análisis SEM-EDS y DRX. Los diagramas EIS se ajustaron satisfactoriamente al modelo de circuito equivalente y los valores obtenidos de resistencia a la corrosión Rcorr (Rs + Rct) disminuyen drásticamente con el tiempo de exposición. El efecto de ZrO2 y L-cisteína están marcadamente influenciados por los cambios del pH de la solución, el potencial Zeta de la carga superficial, los procesos de quimisorción y desorción, el estrés interno en el precursor sol-gel, así como el cambio en su estructura, después de la encapsulación de ambos dopantes.
La pensée de l’impermanence à Rome : autour du mot uanitas
Authors: Thomas Jean-François
Published: December 2019

Le mot latin uanitas montre que l’impermanence n’est pas forcément une vanité illusoire. Elle est d’abord une menace que la pensée traditionnelle surmonte par la religion ; la finitude est, pour certaines philosophies d’origine grecque, intrinsèque au monde. C’est la Bible qui la pense comme une illusion face à la vérité supérieure.
Le discours de la vanité du monde dans les Rêveries sur la nature primitive de l’homme de Senancour : du « sentiment du néant de la vie » à la jouissance de l’éphémère
Authors: Bercegol Fabienne
Published: December 2019

L’article retrace l’itinéraire intellectuel et spirituel de Senancour dans les Rêveries sur la nature primitive de l’homme, où le discours sur la vanité de la vie nourrit une méditation désabusée qui ménage pourtant des ouvertures vers un idéal postulé par le désir.
Exportations et exonérations, les deux vont-elles de pair ? – analyse empirique sur des données individuelles d’entreprises françaises
Authors: Garsaa Aziza , Levratto Nadine
Published: December 2019

Les exonérations de cotisations sociales patronales appliquées aux entreprises représentent le poste le plus important des dépenses de soutien aux entreprises et à l’emploi. Si leur influence directe sur la création d’emploi a fait l’objet de nombreuses évaluations, rares sont les recherches qui proposent d’en estimer les effets sur la compétitivité. Cet article apporte un éclairage sur le sujet en abordant la question du point de vue des exportations des entreprises. Pour ce faire, cet article propose une analyse empirique des déterminants de la probabilité d’exporter, de la fréquence des exportations et de leur intensité, en s’appuyant sur des données individuelles d’entreprises françaises pour la période 2004-2011. Nos résultats mettent en évidence un effet négatif des exonérations sur l’engagement à l’export des entreprises. Il est confirmé, quels que soient l’indicateur, la période et le secteur retenus.Classification JEL : L21, L25, L53, L6.
Competitive landscape: are tourism sectors different? Why does it matter?
Authors: Varum Celeste , Bannò Mariasole
Published: December 2019

This study advances empirical knowledge of tourism as an economic sector, from an economics and supply-side perspective. It studies the competitive landscape of tourism sectors in Portugal, based upon a rich, firm level database, of over 3,000,000 observations, over the period of nine years, from 2006 to 2014 (over 300,000 firms per year). The results show a lower level of concentration, and consequently a higher level of competition, just in some sectors of the tourism industry, hence the need to take into account sub-sector specificities when analysing a competitive landscape. The results for Portugal show that tourism as a sector may have contributed to the economic recovery from the financial crisis that began in 2008; but tourism growth should not blur the need to care for efficiency or financial soundness. Managerial and policy implications are derived from our research.
Les déterminants de l’adoption du mobile money : l’importance des facteurs spécifiques au Cameroun
Authors: Bidiasse Honoré , Mvogo Gregory Paulin
Published: December 2019

Cet article identifie, à l’aide d’un logit simple, les déterminants de l’adoption du mobile money au Cameroun. Il s’agit des avantages offerts, de l’information disponible et de la proximité des points de vente. Des facteurs socio-économiques permettent d’affiner la compréhension de ces facteurs spécifiques. Au final, les recommandations faites aux opérateurs de télécommunication sont relatives à une communication optimale sur l’usage du produit, à une augmentation de l’offre des points de vente, à une interopérabilité permettant de bénéficier des effets de réseaux et au développement de nouveaux services de paiement dans des secteurs à haute fréquentation.Classification JEL : E42, O33, O35.
Taxe, subvention et coût fixe d’entrée : oligopole de Cournot avec entrée endogène
Authors: Ba Bocar Samba
Published: December 2019

Nous considérons un oligopole de Cournot à deux périodes avec entrée endogène où plusieurs firmes identiques extraient et vendent une ressource polluante et paient une taxe sur chaque unité produite. À la deuxième période, elles font face à d’autres firmes identiques qui recyclent une partie de l’extraction de la première période. Ces firmes doivent supporter un coût fixe pour entrer sur le marché. Une fois entrées, elles perçoivent d’un régulateur bienveillant une subvention car le recyclage est perçu comme une activité verte. Nous avons établi les résultats suivants. Premièrement, la combinaison d’une taxe, d’une subvention et d’un coût fixe d’entrée supporté par les recycleurs permet de restaurer l’optimum social. Deuxièmement, l’implémentation de ces politiques peut être financièrement rentable pour le régulateur, sous certaines conditions. Troisièmement, les niveaux des taxes, de la subvention et du coût fixe dépendent du fait que les élasticités de la demande sont des nombres finis ou non.Classification JEL : L13, L72, Q56, Q58.
The Business Process Management Systems to Improve the Performance of Universities
Authors: Renna Paolo , Izzo Carmen , Romaniello Tiziana
Published: December 2019

Starting from the application of the Business Process Management to support the Higher Education Management System at University of Basilicata, this chapter focuses on the new developments of state regulation that require implementing a strategic performance system to measure, evaluate, and improve system performance in terms of efficiency, effectiveness, quality, outcome, and customer satisfaction. More specifically, the Italian legislative decree n°150/2009 imposes the implementation of a so-called “performance cycle” in all public organizations. One of the pillars of the “performance cycle” is the process management and the definition of the process map. Then, the Business Process Management developed to support the Higher Education Management Systems can be extended to the entire organization to support and manage the integrated cycle of performance of the University. This allows for developing an adequate risk mapping and assessment.
From Reflective Practice to Critical Thinking
Authors: Cendon Eva
Published: December 2019

This chapter explores the role of reflection and the development of reflexivity in programs of professional studies in higher education. Serving as empirical basis is a qualitative explorative longitudinal study with students in different master's programs at a University for Professional Studies, considering the students' perspective and their changing understanding and practice of reflection both at the workplace and in their studies. The students' perspective is complemented by an analysis of interviews with teachers in professional master's programs about their teaching strategies supporting students' learning. Linking these two perspectives leads to a developmental model of reflection over the course of studies that allows new ways of interpreting the reflective practitioner in higher education.
Educational Serious Games Enhance Social Intelligence Through Collective Action
Authors: Nuninger Walter , Châtelet Jean-Marie
Published: December 2019

Pedagogical serious games sound like up-to-date pedagogical devices for learning efficiency. But the challenge of higher performance in HE lies in tailored pedagogical devices and their usage for the learning goal; a choice to consider according to the training specifications (learning outcome), the learners' needs, and the trainer's expertise (tailored approach). The guidance by the trainer is a value-added, but a risk-taking activity changing the paradigm with the trainee. Digital integration into serious games is a 4-dimension transition: 1) group characterization facilitation for social intelligence, 2) subliminal learning in a virtual environment for commitment, 3) trainer dashboard based on individual e-preparation for feedback priorization, and 4) automation of events for gameplay and increasing skills. The splitting of space and time constraints is a new opportunity that challenges the trainer's role, changing the usual balance during face-to-face training. The proposed standard for hybrid PSG design should overcome the gaps and guarantee a real benefit from digital technology.
Creating a Framework for Future Learning
Authors: Elander Kelly R.
Published: December 2019

This chapter proposes the use of a two-pronged framework to reinforce, support, and extend learning far beyond the classroom. This approach uses a community of practice (CoP) in conjunction with an online resource tool called an Electronic Performance Support System (EPSS). The CoP begins in the classroom, whether physical or online, during higher education or training and is intended to continue throughout the person's working career. The EPSS, an online data storehouse of sorts, also provides ongoing benefits, since its content can be continually updated and expanded. The EPSS can be accessible on desktop or mobile devices and could potentially allow for user-generated content.
Resource-Based Logistics (RBL) and Competitive Advantage
Authors: Karia Noorliza , Kays H.M. Emrul
Published: December 2019

Logistics service is more complex and knowledge-based in the fourth industrial revolution era. Given this significance, this chapter emphasizes the logistics industry and its specific dynamic capabilities, and measures generating the Industry 4.0 by extending the resource-based logistics (RBL) of Noorliza (2011). The chapter has three parts: Logistics in the fourth industrial revolution, RBL theory, and its impacts and Logistics 4.0 models in the fast-moving environment. This explains how logisticians or logistics firms obtain competitive advantages in the fourth industrial revolution era.
Management and Organization in Transportation and Logistics
Authors: Rüzgar Nilüfer
Published: December 2019

In today's business environment, in which organizations try to outpace their rivals, the power of management and organization come into prominence. Management, as an art and science, constitutes great importance in terms of creating sustainability in the organizations, and sustainability acts as an important agent for being successful in the competition. Especially supply chain management is evaluated to be among the most crucial organizational activities, which needs to be heavily focused on, in order to create customer satisfaction in the process of product and/or service delivery. Furthermore, as it is known, supply chain management is the key element of transportation and logistics. This chapter scrutinizes the importance of management and organization in transportation and logistics. With this purpose, a literature review presents the study both in a historical and contemporary point of view.
An Analysis for Coal Transportation and Demand in US and International Markets
Authors: Yücekaya Ahmet
Published: December 2019

Since coal resources are located around the world and often far away from where the coal is consumed, transportation is important. The industries that use coal such as power plants, industrial plants, coke plants, and commercial institutions usually prefer different transportation methods. The demand in these industries and the transportation methods they use differ over time. This chapter analyzes the international coal transportation and demand. An analysis for the US coal market and the transportation to industries along with the methods that are used between 2001-2015 are presented. A trend analysis was performed to show the long-term demand for each transportation method in each industry. Such analysis is also useful as it allows observing the coal demand from each industry. Analysis results reveal the change in coal amounts that are transported to each industry using the railroad, truck, and other methods.
The Effect of Reverse Logistics Activities on Brand Equity and Customer Satisfaction
Authors: Yanginlar Gözde
Published: December 2019

In the last few decades, the rapid development of customer awareness of environmental issues has encouraged many enterprises to adopt reverse logistics activities, which resulted in growing importance among enterprises of enhancing customer satisfaction and improving brand equity. This chapter examines the effect of reverse logistics activities in Turkish firms which are required to act responsibly towards the environment, and explains the relationship between reverse logistics processes and customer satisfaction and brand equity. The findings of this study contribute to understanding that an increasing number of them have integrated reverse logistics practices into their operations to develop a sustainable competitive advantage. The findings also indicate that reverse logistics plays an active role in Turkish enterprises improving brand equity and customer satisfaction while preserving the environment in the local and the global communities.
A Digital Transformation in International Transport and Logistics
Authors: Koldemir Birsen
Published: December 2019

Firms must deal with the factors that increase performance, which support the delivery of the produced goods at minimal cost and time. In this respect, the advantages of digitization have been studied. The path to international trade in its quest to reduce logistics and supply chain costs cross with Blockchain technology. Blockchain technology isn't only an inter-user money transfer technology, but it also includes all the trade supply chain actors. Thus, a visible “supply chain network” that's directed by blockchain, which holds the record in real time and doesn't change pursuant to the sequence occurs. All actors on the network can access and track the flow and distribution of the transaction across borders. How does blockchain technology improve yield and reduce costs? To find the answer, the application areas of digital technology in trade have been investigated. In international trade, a transaction draft was created and the advantages and disadvantages of blockchain were exposed.
A Conceptual System of Blockchain-Based Electronic Bill of Lading
Authors: Baştuğ Sedat , Akan Ercan , Battal Turgay
Published: December 2019

Blockchain-based electronic bill of lading will reshape the global logistics industry, replacing old-style paper bill of lading documents. This chapter establishes blockchain-based electronic bill of lading conceptual model, with which stakeholders may be able to state and transfer cargo ownership rights without the hassle of the handling paper, and proposes an implementation of the framework for researchers. This chapter provides a way for stakeholders to exchange these documents digitally, securely, and with no possibility of fraud in a neutral environment – extremely quickly and much more affordably than currently possible. The ecosystem of blockchain-based electronic bill of lading services will transform the global logistics industry. The study findings offer logistics managers and software programmers the ability to develop their documentation strategies and own blockchain-based electronic bill of lading platforms.
Basic Types of Project Initiators
Authors: Vidal-García Javier , Vidal Marta
Published: December 2019

Crowdfunding has helped many businesses and projects to take off easily and is replacing the traditional methods of fundraising since more platforms are being created. Evaluation of the risk for both the borrower and the donor is important before investing or borrowing to ensure that the project is a success. Crowdfunding is changing the way that projects and startups get funded. Most of crowdfunding money is raised on reward-based platforms, although equity crowdfunding is growing quickly. It can be expected that crowdfunding will become more popular, with many crowdfunding new opportunities available, which will make not easy for potential investors to choose what to support. In this chapter, we introduce the reader to the basic types of project initiators-contributor relations in online crowdfunding. We review the current literature identifying the research questions relevant for our purpose. We subsequently conduct a research method of systematic review to identify the relevant papers that address those research questions.
A Model to Reduce the Risk of Projects Guided by the Knowledge Management Process
Authors: Brahami Menaouer , Matta Nada
Published: December 2019

Knowledge plays a key role in the information revolution. Major challenges are to select the information from numerous sources and transform it into useful knowledge. In this context and in an economy strongly focused on the “Knowledge”, take the turn of knowledge management becomes a strategic issue for the survival of organizations. However, the research in knowledge management focuses mainly on the creation, capitalization, and knowledge transfer process. Researchers are centered on the establishment of the knowledge management process in companies, but little about interaction between the knowledge management process and the risk management process. In this article, the authors propose a new model to reduce the risk of projects guided by the knowledge management process represented by the GAMETH method. They apply their approach to ammonia industry presented by the FERTIAL (Algerian-Spanish company).
Social Media Strategies for Small and Medium Scale Enterprise in the Klang Valley Region of Malaysia
Authors: Chan Donovan , Kumar Sameer
Published: December 2019

Despite the current widespread adoption and use of social media as a marketing tool, very little empirical research focusing on local small and medium-sized enterprises (SMEs) is available. This study examines the usage of social media by small and medium-sized enterprises (SMEs) in Malaysia. The study assesses the impacts of age, educational attainment, and industry characteristics to the utilization, perceived benefits and barriers of SMEs. Results of the study indicate that social media is used by most SMEs for customer acquisition and its benefits are developing new business opportunities, reduced cost of advertising, 24 hours accessibility and decreased travelling time. The results however indicate that there is a lack of allocation of resources mainly in staffing and training when adopting the social media. Results also indicate that manager's age and educational attainment had significant impacts on social media strategies. The results did not reveal any evidence of different industry sectors relevance towards social media strategies. Implications for research are discussed.
Can Social Dynamics Be Channeled from Offline to Online Communities?
Authors: Alijani Sharam , Assadi Djamchid , Ashta Arvind
Published: December 2019

As alternative source of financing, microfinance and crowdfunding organizations are increasingly relying on commitment, compliance and cooperation among individuals, groups, and communities. In considering the extraordinary growth of the market for microfunding and microlending in recent years, this article aims to investigate a number of important questions. Can the conventional rule of social collateral applied to group lending be replicated in online crowdfunding? What are the institutional, social and organizational requirements in order to transpose the social collateral model of solidarity and responsibility to heterogeneous online crowdfunding and microlending platforms? What would be the implications for borrowers and lenders in terms of group compliance, collaboration and cooperation? By highlighting the differences and similarities between microfinance and crowdfunding structures, the article seeks to provide a broad comparative framework for analyzing different patterns of behavior in communities, organizations and networks that engage in crowdfunding and microlending activities.
Towards a Framework to Improve IT Security and IT Risk Management in Small and Medium Enterprises
Authors: Mühe Stephan , Drechsler Andreas
Published: December 2019

In this article, an IT risk management (ITRM) framework for small and medium enterprises (SMEs) is designed and evaluated. The framework's objective is to provide an uncomplicated and accessible ITRM approach primarily aimed at SMEs without a dedicated ITRM. The framework combines essential elements from three leading (IT) risk management frameworks: COBIT 5 for Risk, ISO/IEC 27005:2011 and M_o_R. The framework was developed by employing a design science research methodology for social artefacts and evaluated in two healthcare SMEs. The ITRM framework itself was assessed as comprehensible and potentially useful. Simultaneously, over-arching IT governance issues prevented the immediate framework implementation in the two cases. IT management researchers can draw on this article's findings to better understand the role of the social context in SMEs to achieve an effective practical impact. Practitioners in SMEs can draw on the current state of the framework for an initial ITRM implementation or to increase their current ITRM approaches' maturity.