bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dependence of Biological Activity on the Surface Water Fraction of Planets
Authors: Lingam Manasvi , Loeb Abraham 
Published: January 2019

Abstract
One of the unique features associated with the Earth is that the fraction of its surface covered by land is comparable to that spanned by its oceans and other water bodies. Here, we investigate how extraterrestrial biospheres depend on the ratio of the surficial land and water fractions. We find that worlds that are overwhelmingly dominated by landmasses or oceans are likely to have sparse biospheres. Our analysis suggests that major evolutionary events such as the build-up of O2 in the atmosphere and the emergence of technological intelligence might be relatively feasible only on a small subset of worlds with surface water fractions ranging approximately between 30% and 90%. We also discuss how our predictions can be evaluated by future observations and the implications for the prevalence of microbial and technological species in the universe.
BAT AGN Spectroscopic Survey. XI. The Covering Factor of Dust and Gas in Swift/BAT Active Galactic Nuclei
Authors: Ichikawa Kohei , Ricci Claudio , Ueda Yoshihiro , Bauer Franz E. , Kawamuro Taiki , Koss Michael J. , Oh Kyuseok , Rosario David J. , Shimizu T. Taro , Stalevski Marko , Fuller Lindsay , Packham Christopher , Trakhtenbrot Benny 
Published: January 2019

Abstract
We quantify the luminosity contribution of active galactic nuclei (AGNs) to the 12 μm, mid-infrared (MIR; 5–38 μm), and total IR (5–1000 μm) emission in the local AGNs detected in the all-sky 70 month Swift/Burst Alert Telescope (BAT) ultrahard X-ray survey. We decompose the IR spectral energy distributions (SEDs) of 587 objects into the AGN and starburst components using templates for an AGN torus and a star-forming galaxy. This enables us to recover the emission from the AGN torus including the low-luminosity end, down to

, which typically has significant host galaxy contamination. The sample demonstrates that the luminosity contribution of the AGN to the 12 μm, the MIR, and the total IR bands is an increasing function of the 14–150 keV luminosity. We also find that for the most extreme cases, the IR pure-AGN emission from the torus can extend up to 90 μm. The total IR AGN luminosity obtained through the IR SED decomposition enables us to estimate the fraction of the sky obscured by dust, i.e., the dust covering factor. We demonstrate that the median dust covering factor is always smaller than the median X-ray obscuration fraction above an AGN bolometric luminosity of

. Considering that the X-ray obscuration fraction is equivalent to the covering factor coming from both the dust and gas, this indicates that an additional neutral gas component, along with the dusty torus, is responsible for the absorption of X-ray emission.
Source Imaging of a Moving Type IV Solar Radio Burst and Its Role in Tracking Coronal Mass Ejection from the Inner to the Outer Corona
Authors: Vasanth V. , Chen Yao , Lv Maoshui , Ning Hao , Li Chuangyang , Feng Shiwei , Wu Zhao , Du Guohui 
Published: January 2019

Abstract
Source imaging of solar radio bursts can be used to track energetic electrons and associated magnetic structures. Here we present a combined analysis of data at different wavelengths for an eruption associated with a moving type IV (t-IVm) radio burst. In the inner corona, the sources are correlated with a hot and twisted eruptive EUV structure, while in the outer corona, the sources are associated with the top front of the bright core of a white-light coronal mass ejection (CME). This reveals the potential of using t-IVm imaging data to continuously track the CME by lighting up the specific component containing radio-emitting electrons. It is found that the t-IVm burst presents a clear spatial dispersion with observing frequencies. The burst manifests broken power law–like spectra in brightness temperature, which is as high as 107–109 K, while the polarization level is generally weak. In addition, the t-IVm burst starts during the declining phase of the flare with a duration as long as 2.5 hr. From the differential emission measure analysis of AIA data, the density of the T-IVm source is found to be at the level of 108 cm−3 at the start of the burst, and the temperature may reach up to several MK. These observations do not favor gyrosynchrotron to be the radiation mechanism but are in line with a coherent plasma emission excited by energetic electrons trapped within the source. Further studies are demanded to elucidate the emission mechanism and explore the full diagnostic potential of t-IVm bursts.
Faculty Preparation: Is Clinical Specialization a Benefit or a Deterrent to Quality Nursing Education?
Authors: Zungolo Eileen 
Published: January 2019

ABSTRACT
This article presents a point of view regarding the impact of specialty preparation at the master's level on performance as a faculty member in an entry-level program. Essentially, the focus in depth on a particular branch of nursing practice restricts the perception of the individual to the role and demands of the beginning generalist nurse. Continued attention to the development of expertise in the specialty reduces the effectiveness of the faculty member to develop a comprehensive view of the knowledge required by the beginning generalist nurse. Because faculty prepared in this manner also frequently lack formal knowledge regarding teaching and curriculum, they continue to teach in the same manner as they were taught, often with an eye toward teaching the extensive content taught in the specialty program. More broadly based master's degree programs that couple advanced nursing knowledge with nursing education content and skill can foster in new nurse faculty a more comprehensive picture of the learning needs of beginning general ist nurses.
Principled Thinking: A Comparison of Nursing Students and Experienced Nurses
Authors: Ham Kathy 
Published: January 2019

ABSTRACT
Background: A descriptive study was used to compare ethical reasoning abilities in senior baccalaureate nursing students and experienced registered nurses. The effects of environmental factors and previous experience with ethical dilemmas in regard to nursing principled thinking were also examined.
Results: Findings on the Nursing Dilemma Test indicated a significant difference in the level of nursing principled thinking in the two groups, with nursing students scoring higher than experienced nurses. There was a significant negative correlation between years of experience and level of nursing principled thinking. The level of nursing education (e.g., associate degree of nursing, diploma, bachelor of science in nursing, masters degree, or doctorate) did not appear to have an effect on nursing principled thinking. In addition, subjects who were most affected by practical considerations demonstrated less use of higher level moral reasoning. The effect of previous experience with ethical dilemmas on nursing principled thinking was found to be nonsignificant.
Conclusion: Ethical dilemmas continue to create much confusion and uncertainty for practicing nurses. Suggestions are made regarding individual analysis of personal and professional values in nurses. In addition, recommendations include ongoing educational offerings and nursing administration support to assist nurses during times of moral distress.
Learning and Teaching: The Reciprocal Link
Authors: Forrest Sandy 
Published: January 2019

ABSTRACT
Background: Learning and teaching are active processes occurring simultaneously on a continual basis. Within this framework, the learner and the teacher are reliant on each other. Understanding the intricacies of this linkage enhances the teacher's effectiveness in enabling learners to achieve their full potential.
Method: A review of the literature on teaching and learning styles was completed.
Conclusion: Learning best occurs when learners are motivated and attend to the important aspects of what is to be learned. Using a wide variety of teaching approaches in the hope of covering most individuals' preferences is expedient but not necessarily effective. The process of exploring the effectiveness of one's teaching styles enhances the ability to facilitate the learning process.
Lincoln's Vertical Strabismus
Authors: Goldstein Joseph H 
Published: January 2019

ABSTRACT
Background: The vertical strabismus manifested by Abraham Lincoln has been noted. This article reviews the historical findings and provides a specific diagnosis.
Materials: Previous reports of symptoms and history relating to Lincoln's left hypertropia were reviewed. A series of photographs were reviewed. Lincoln's own description of his symptoms is provided.
Results: Previous history indicates an intermittent left hypertropia. A family history of vertical strabismus was noted with regard to Mr Lincoln's cousin. There also is a history of trauma to the left frontal area and life-mask evidence of fracture over the left eye. The findings include a history of head tilt and diplopia, presumably most readily in downgaze.
Conclusion: Given the history and findings, the diagnosis of left superior oblique paresis of either congenital or traumatic origin seems appropriate.
Vision-related Quality of Life Comparison for Emmetropes, Myopes After Refractive Surgery, and Myopes Wearing Spectacles or Contact Lenses
Authors: Chen Christine Y , Keeffe Jill E , Garoufalis Pam , Islam Fakir M A , Dirani Mohamed , Couper Terry A , Taylor Hugh R , Baird Paul N 
Published: January 2019

ABSTRACT
PURPOSE: To compare the vision-related quality of life among emmetropes, myopes who had refractive surgery, and myopes who wore spectacles and/or contact lenses.
METHODS: This cross-sectional study assessed vision-related quality of life using the Vision Quality of Life Index. Participants were age 18 years or older with a presenting visual acuity of 20/40 or better and no other ocular pathology. Responses were compared among three groups: emmetropes (spherical equivalent [SE] <0.50 to >-0.50 diopters [D]), myopes (SE ≤ -0.50 D) who wore spectacles and/or contact lenses, and myopes who had refractive surgery.
RESULTS: The study population included 64 emmetropes, 66 myopes who wore spectacles and/or contact lenses, and 65 myopes who had refractive surgery. No significant differences were found between the refractive surgery and emmetropic groups. In contrast, the spectacle and/or contact lens group had significantly increased odds of having concerns about injuring themselves (odds ratio=11.5, 95% confidence interval [CI] 2.3, 57.1), difficulties coping with demands in life (odds ratio=23.6, 95% CI 23.8, 198.1), difficulties fulfilling roles (odds ratio=5.6, 95% CI 1.4, 22.1), and less confidence joining in everyday activities (odds ratio=30.6, 95% CI 3.2, 292.3) compared to emmetropes.
CONCLUSIONS: Myopia corrected with spectacles or contact lenses had a negative impact on some areas of vision-related quality of life. However, individuals with myopia who had refractive surgery enjoyed the same vision-related quality of life as those with emmetropia. The potential improvement in vision-related quality of life should be considered when recommending treatment for myopia. [J Refract Surg, 2007;23:752-759.]
Corneal Wavefront-guided LASIK Retreatments for Correction of Highly Aberrated Corneas Following Refractive Surgery
Authors: Alió Jorge , Galal Ahmed , Montalbán Raúl , Piñero David 
Published: January 2019

ABSTRACT
PURPOSE: To investigate the safety and efficacy of customized corneal wavefront-guided retreatment in symptomatic patients with highly aberrated corneas following LASIK.
METHODS: This prospective study included 75 eyes of 59 patients with significant visual symptoms who underwent LASIK for the correction of residual refractive error. Ablation profiles were calculated using CSO corneal topography and ESIRIS/Schwind laser platform. Eyes were divided into two groups: those with significant night vision symptoms (37 eyes; night symptoms group) and those with decentration, irregular ablation profile, and flap complications (38 eyes; corneal complications group). Corneal topography and aberrations, visual acuity, point spread function (PSF), refractive outcome, and subjective symptoms were evaluated preoperatively, and 1, 3, and 6 months postoperatively.
RESULTS: Mean uncorrected visual acuity was 20/32 preoperatively and 20/25 at 6 months postoperatively in the night symptoms group and 20/40 preoperatively and 20/30 at 6 months postoperatively in the corneal complications group. Mean best spectacle-corrected visual acuity was 20/25 both preoperatively and 6 months postoperatively in both groups (t test, P=.219 and P =.149 for the night symptoms and corneal complications groups, respectively). Safety index was 1.1 in both groups, and efficacy index was 0.93 and 0.92, respectively. Statistically significant improvement of total corneal higher order aberrations, tilt, and improvement of spherical aberrations and coma were observed, with corresponding improvement of PSF.
CONCLUSIONS: Corneal wavefront-guided LASIK retreatment with CSO topography, ORK-W software, and ESIRIS/Schwind laser platform is safe and effective for treating symptomatic patients affected by corneal higher order aberrations or corneal irregularities following LASIK surgery. [J Refract Surg. 2007;23:760-773.]
Higher Order Wavefront Aberrations and Topography in Early and Suspected Keratoconus
Authors: Jafri Batool , Li Xiaohui , Yang Huiying , Rabinowitz Yaron S 
Published: January 2019

ABSTRACT
PURPOSE: To determine whether higher order wavefront aberrations or a combination of topography and wavefront variables distinguishes between early and suspected keratoconus.
METHODS: This prospective comparative study evaluated 70 eyes using videokeratography (Tomey TMS-1) and aberrometry (Alcon LADARWave). Videokeratography and clinical evaluation were used to divide the eyes into three groups: 50 normal eyes, 10 eyes with early keratoconus, and 10 eyes with suspected keratoconus. Data were analyzed to determine whether higher order aberrations could separate eyes with early and suspected keratoconus from normal eyes. The product of the Inferior-Superior (I-S) topographic value in combination with the wavefront vertical coma also was evaluated to determine whether this could distinguish normal eyes from eyes with early and suspected keratoconus.
RESULTS: Differences in vertical coma, root-meansquare coma, and secondary astigmatism for the three groups were statistically significant. Vertical coma was -0.03±0.28 for normal eyes, -0.525±0.253 for eyes with suspected keratoconus, and -1.949±1.416 for eyes with early keratoconus. Root-mean-square coma was 0.229±0.149 for normal eyes, 0.639±0.250 for eyes with suspected keratoconus, and 2.034±1.532 for eyes with early keratoconus. The product of vertical coma and the topographic I-S value separated the three groups better than aberrometry alone (P<.0001).
CONCLUSIONS: Although both vertical coma and the I-S topographic value were useful for distinguishing among the three study groups, a combination of wavefront aberrometry and videokeratography appears to be the most sensitive way for distinguishing among normal eyes, eyes with suspected keratoconus, and eyes with early keratoconus. [J Refract Surg. 2007;23:774-781.]
Determination of the Modulus of Elasticity of the Human Cornea
Authors: Elsheikh Ahmed , Wang Defu , Pye David 
Published: January 2019

ABSTRACT
PURPOSE: To determine the material behavior of the human cornea in the form of simple relationships between the modulus of elasticity and intraocular pressure (IOP) and to establish the effect of age on the material behavior.
METHODS: Human corneal specimens with age between 50 and 95 years were tested under inflation conditions to determine their behavior. The corneas were subjected to two extreme load rates to represent dynamic and static loading conditions. The pressure-deformation results were analyzed using shell theory to derive the relationship between the modulus of elasticity and IOP.
RESULTS: The corneas demonstrated a nonlinear hyperelastic behavior pattern with an initial low stiffness stage and a final high stiffness stage. Despite the non linearity of the pressure deformation results, the relationship between the modulus of elasticity and the applied pressure was almost linear. A considerable increase was noted in the values of the modulus of elasticity associated with both age and load rate. General equations were derived to calculate the values of the secant and tangent moduli of elasticity in terms of IOP for any age greater than 50 years, and these equations are presented in a simple form suitable for use in numerical simulations.
CONCLUSIONS: Adequate representation of corneal material behavior is essential for the accurate predictive modeling of corneal biomechanics. The material models developed in this work could be implemented in numerical simulations of refractive surgery procedures, corneal shape changes due to contact lens wear, and other applications. [J Refract Surg. 2007;23:808-818.]
Anterior Chamber Gas Bubble Formation During Femtosecond Laser Flap Creation for LASIK
Authors: Srinivasan Sathish , Rootman David S 
Published: January 2019

ABSTRACT
PURPOSE: To report anterior chamber gas bubble formation during corneal flap creation in a myopic patient who underwent LASIK using a femtosecond laser (IntraLase).
METHODS: A 30-year-old man underwent customized wavefront-guided LASIK for myopia. The IntraLase FS15 was used to create the corneal flap.
RESULTS: During flap creation, gas bubble formation was noted in the anterior chamber, in addition to cavitation bubbles under the flap. Flap creation was successful and myopic ablation was uneventful. One day postoperatively, the flap was well apposed, and no air bubbles were present in the anterior chamber.
CONCLUSIONS: Gas bubbles in the anterior chamber can be an infrequent occurrence during the use of femtosecond laser for corneal flap creation. Although gas bubbles do not hinder flap creation, their presence may interfere with eye-tracking mechanisms. [J Refract Surg. 2007;23:828-830.]
The Kelman Duet Phakic Intraocular Lens: 1-year Results
Authors: Alió Jorge L , Piñero David , Bernabeu Gonzalo , Galal Ahmed , Vargas José Manuel , Ismail Mahmoud M 
Published: January 2019

ABSTRACT
PURPOSE: To evaluate the efficacy and safety of the Kelman Duet phakic intraocular lens (PIOL) for correction of moderate and high myopia.
METHODS: Kelman Duet PIOLs were implanted in 169 eyes of 110 patients with moderate or high myopia. In all cases, implantation of the lens was feasible through an incision of less than 2.5 mm without complications. Uncorrected visual acuity (UCVA), manifest refraction, best spectacle-corrected visual acuity (BSCVA), intraocular pressure, central corneal endothelial change, and complications were recorded preoperatively and during 12 months of follow-up.
RESULTS: Following PIOL implantation, 23 (13.61%) eyes required LASIK retreatment for the correction of residual astigmatic refractive error and were excluded from the refractive analysis. Best spectacle-corrected visual acuity remained the same or improved in 95.04% of eyes, 81.30% of eyes (100) were within ±1.00 diopter (D) of emmetropia, and 57.72% (71) were within ±0.50 D. Intraocular pressure increased slightly in the first 4 weeks postoperatively but stabilized to the preoperative level by 3 months. Mean endothelial cell ioss at 12 months was 5.43%. Oval pupils developed in 10.1% of eyes. Haptic exchange or reposition was performed in 7.76% of cases.
CONCLUSIONS: The Kelman Duet PIOL was safe and effective for the correction of moderate to high myopia in this study with 1-year follow-up and offered the advantage of using a 2. 5-mm or less incision width. Accurate haptic sizing remains a challenge and haptic exchange to correct haptic size mismatching is possible. [J Refract Surg. 2007;23:868-879.]
Central Corneal Thickness Measurements in Unoperated Eyes and Eyes After PRK For Myopia Using Pentacam, Orbscan II, and Ultrasonic Pachymetry
Authors: Kim Sun Woong , Byun Yeo Jue , Kim Eung Kweon , Kim Tae-im 
Published: January 2019

ABSTRACT
PURPOSE: To compare central corneal thickness measurements obtained in unoperated eyes and eyes after myopic photorefractive keratectomy (PRK) using a rotating Scheimpflug camera (Pentacam), a scanning slit corneal topography system (Orbscan II), and ultrasonic pachymetry.
METHODS: Corneal thickness was measured using Pentacam, Orbscan II, and ultrasonic pachymetry in 25 unoperated eyes (unoperated group), 24 eyes 1 to 3 months after myopic PRK (early postoperative PRK group), and 21 eyes 4 months or more after myopic PRK (late postoperative PRK group).
RESULTS: In the unoperated group, corneal thickness measurements were similar for all three methods (P =.12 5). In the early postoperative PRK group, Orbscan measurements were thinner than Pentacam and ultrasonic measurements by a mean of 69.4 µm and 63.4 µm (P<.001 and P=.002, respectively). In the late postoperative PRK group, Orbscan measurements were thinner than Pentacam measurements by a mean of 36.0 pm (P= .017). Pentacam and ultrasonic pachymetry measurements were similar for all three groups with a mean difference of approximately 10 ???.
CONCLUSIONS: Following myopic PRK, Pentacam was comparable to ultrasonic pachymetry in measuring corneal thickness, whereas Orbscan measurements were thinner. [J Refract Surg. 2007;23:888-894.]
Medennium Posterior Chamber Phakic Refractive Lens to Correct High Myopia
Authors: Verde Celeste Marina , Teus Miguel A , Arranz-Marquez Esther , Cazorla Raquel Gil 
Published: January 2019

ABSTRACT
PURPOSE: To determine the efficacy and safety of phakic refractive lens implantation to correct high myopia.
METHODS: In this prospective study, a phakic refractive lens was implanted in 90 myopic eyes in which refractive errors ranged from -6.00 to -20.00 diopters (D) and laser refractive surgery was contra indicated. Uncorrected visual acuity (UCVA) and best-spectacle corrected visual acuity (BSCVA), manifest and cycloplegic refractions, and intraocular pressure (IOP) were assessed during a 1-year follow-up period. Possible complications, including endothelial cell counts, were evaluated.
RESULTS: Spherical equivalent refraction measurements revealed a significant change from the preoperative mean value of -11.90±5.00 D to 0.04±0.20 D 1 year postoperatively (P= .001). The UCVA and BSCVA significantly improved postoperatively (P =.001 and P =.01, respectively). Seventy-two (80%) eyes and 61 (68%) eyes were within ±1.00 D and ±0.50 D of the target refraction, respectively. A significant increase in IOP was found at every postoperative visit (P=. 01). There was a trend toward decreased endothelial cell density postoperatively, although the difference did not reach significance. No major complications were found during the 1-year follow-up period.
CONCLUSIONS: The implantation of a phakic refractive lens seems to be a predictable and well -to Ie rated procedure for correcting high myopia. Complications such as development of cataract, implant dislocation, decreases in endothelial cell counts, or development of glaucoma did not occur in this study. [J Refract Surg, 2007;23:900-904.]