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Publication
Journal: Knee Surgery, Sports Traumatology, Arthroscopy
October/31/2016
Abstract
OBJECTIVE
The purpose of this study was to evaluate a step-by-step approach to endoscopic reconstruction of the anterior talofibular ligament (ATFL) and the calcaneofibular ligament (CFL).
METHODS
Fourteen lower extremity cadaveric specimens were used. Four standard portals were defined and used. A step-by-step approach using several anatomical landmarks was used to reconstruct the ATFL and CFL. The feasibility of visualising the anatomical landmarks and both ligaments and their footprints was assessed. Both ligaments were reconstructed using a gracilis graft fixed in bone tunnels. The lateral side of the ankle was completely exposed and dissected. The specimen was assessed for clinical stability of the reconstruction and damage to the surrounding anatomical structures. The distance between the centre of the tunnel and the anatomical insertions of the ligaments was measured. The distance between the portals and the nerves was measured.
RESULTS
The step-by-step approach allowed a good visualisation of the entire course of the ATFL and CFL. An endoscopic reconstruction of both ligaments was performed, and good stability was obtained. The measurements revealed a good positioning of the reconstructed ligament insertions with a maximal error of 2 mm in most specimens. Anatomical dissection revealed no damage to the surrounding anatomical structures that were at risk. The average distance to the superficial peroneal nerve was 11.9 ± 5.3 mm (standard deviation), and the average distance to the sural nerve was 17.4 ± 3.2 mm (standard deviation). A safe zone was defined with regard to the surrounding nerves.
CONCLUSIONS
The described technique, which involves an anatomical endoscopic reconstruction of the ATFL and CFL, using a gracilis graft, is a viable option to treat lateral ankle instability. This technique is reproducible and safe with regard to the surrounding anatomical structures.
Publication
Journal: Foot and Ankle International
April/4/2012
Abstract
BACKGROUND
This study aimed to extend knowledge on the arthroscopic evaluation of the unstable ankle joint and the outcome of ligament reconstruction on rotational instability. In contrast to previous studies, we investigated the combined repair of lateral and medial ligaments.
METHODS
Ninety-six patients underwent medial and lateral ligament reconstruction between 2006 and 2008, 81 of whom, with a mean age of 31.9 (range, 14 to 44) years, completed the 12-month followup and were therefore included in this study (Table 1). Clinical, radiographic, and concomitant arthroscopic examination was performed prior to the ligament stabilization. Postoperative followup included clinical and radiographic evaluation after 3, 6, and 12 months.
RESULTS
Arthroscopy showed a lesion of the anterior fibulotalar ligament (AFTL), calcaneofibular ligament (CFL), and tibiocalcanear ligament (TCL) (Deep part of deltoid ligament complex) in 67 patients. An avulsion of the proximal insertion point of the ATTL was additionally found in 14 cases. Clinical results 3 months after surgery showed a significant increase in the AOFAS-Hindfoot Score as well as a significant decrease of the Visual Analogue-Scale for pain (VAS) (p < 0.0001). This outcome persisted at the 12-month examination.
CONCLUSIONS
Rotational instability of the ankle joint in most cases has an injury of the lateral ligaments and a component of the deltoid, the TCL, but rarely with a combined lesion of the TCL and the anterior tibiotalar ligament (ATTL) (Superficial part of deltoid ligament complex). The combined lateral and medial ligament reconstruction with an anchor technique had a good clinical outcome with high patient satisfaction with few complications.
Publication
Journal: Photochemistry and Photobiology
November/25/2013
Abstract
Compact fluorescent light (CFL) bulbs can provide the same amount of lumens as incandescent light bulbs, using one quarter of the energy. Recently, CFL exposure was found to exacerbate existing skin conditions; however, the effects of CFL exposure on healthy skin tissue have not been thoroughly investigated. In this study, we studied the effects of exposure to CFL illumination on healthy human skin tissue cells (fibroblasts and keratinocytes). Cells exposed to CFLs exhibited a decrease in the proliferation rate, a significant increase in the production of reactive oxygen species, and a decrease in their ability to contract collagen. Measurements of UV emissions from these bulbs found significant levels of UVC and UVA (mercury [Hg] emission lines), which appeared to originate from cracks in the phosphor coatings, present in all bulbs studied. The response of the cells to the CFLs was consistent with damage from UV radiation, which was further enhanced when low dosages of TiO(2) nanoparticles (NPs), normally used for UV absorption, were added prior to exposure. No effect on cells, with or without TiO(2) NPs, was observed when they were exposed to incandescent light of the same intensity.
Publication
Journal: Collegium Antropologicum
August/29/2012
Abstract
We compared ultrasound (US) with magnetic resonance (MR) findings of muscle tendon and ligaments (mt&l) of 17 men and 13 women, 16-66 years old, who suffered from acute ankle injury without bone fracture visible on conventional radiographs. Joint effusion (JE), and injury of the Tibials anterior muscle tendon (TAmt), Calcaneofibular ligament (CFl), Long flexor of the great toe muscle tendon (LFGTmt), Short peroneus muscle tendon (SPmt), Long peroneus muscle tendon (LPmt), and Anterior talofibular ligament (ATFl) were assessed by the US, at seven days, and MR, at seventeenth day. Grading of ligament and muscle tendon injury as stretching (Grade 1), partially ruptured (Grade 2), and complete rupture (Grade 3); no lesion was considered to be Grade 0. Joint effusion and ATFl were the most common lesions whereas the TAmt lesion was the least frequent: JE approximately ATFl>> SPmt approximately LPmt>> LFGTmt approximately CFl approximately TAmt. Both US and MR were equally sensitive in detecting the presence (or absence) of the mt&l ankle injury, whereas US was less specific than MR in detecting G3 injury.
Publication
Journal: Journal of Sports Science and Medicine
September/3/2015
Abstract
We do not know the impact an ankle sprain has on physical activity levels across the lifespan. With the negative consequences of physical inactivity well established, understanding the effect of an ankle sprain on this outcome is critical. The objective of this study was to measure physical activity across the lifespan after a single ankle sprain in an animal model. Thirty male mice (CBA/J) were randomly placed into one of three groups: the transected calcaneofibular ligament (CFL) group, the transected anterior talofibular ligament (ATFL)/CFL group, and a SHAM group. Three days after surgery, all of the mice were individually housed in a cage containing a solid surface running wheel. Physical activity levels were recorded and averaged every week across the mouse's lifespan. The SHAM mice ran significantly more distance each day compared to the remaining two running groups (post hoc p = 0.011). Daily duration was different between the three running groups (p = 0.048). The SHAM mice ran significantly more minutes each day compared to the remaining two running groups (post hoc p=0.046) while the ATFL/CFL mice ran significantly less minutes each day (post hoc p = 0.028) compared to both the SHAM and CFL only group. The SHAM mice ran at a faster daily speed versus the remaining two groups of mice (post hoc p = 0.019) and the ATFL/CFL mice ran significantly slower each day compared to the SHAM and CFL group (post hoc p = 0.005). The results of this study indicate that a single ankle sprain significantly decreases physical activity across the lifespan in mice. This decrease in physical activity can potentially lead to the development of numerous chronic diseases. An ankle sprain thus has the potential to lead to significant long term health risks if not treated appropriately. Key pointsA single ankle significantly decreased physical activity levels in mice across the lifespan.Decreased physical activity could significantly negatively impact overall health if not modified.Initial treatment and rehabilitation of ankle sprains needs to be studied to determine ways to keep physical activity levels up after injury.
Publication
Journal: NeuroReport
December/8/1992
Abstract
Epileptic temporal cortices, removed from 3 patients with intractable partial epilepsy (IPE) during neurosurgery, were studied. Pyramidal neurons (40-50 per slice) in laminae III, V and white matter, were injected with lucifer yellow. Samples were examined in a confocal laser scanning microscope (Biorad 600) and individual cells scanned at 0.1-1 microns incremental levels. 2-D maximal linear projection was used for overview. Frames (50-60) of scanned neurons were transformed into 3-D volumes, using VoxelView software on a Silicone Graphics workstation and rotated. All samples contained neurons with duplicated apical dendrites, additional basal dendrites or were misplaced in a horizontal position in the white matter. The relation between these preliminary observations and the disease is discussed.
Publication
Journal: International Orthopaedics
September/1/2016
Abstract
OBJECTIVE
We discuss the clinical effects of anatomical reconstruction of the lateral ankle ligaments to treat chronic lateral ankle instability (CAI) by creating fibular channels with a patient-specific navigational template.
METHODS
From August 2010 to February 2014, 15 patients presenting with CAI were treated by creating fibular channels with a patient-specific navigational template for anatomical reconstruction of the lateral ankle ligaments.
RESULTS
All patients were followed up for nine to 24 months postoperatively (15 months on average); no recurrent CAI was found. Pre- and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) scores for patients in the calcaneofibular ligament (CFL) plus anterior talofibular ligament (ATFL) repair group were 48.3 ± 5.1 and 88.1 ± 6.7) respectively. The difference (average 39.8) showed high statistical significance (P < 0.001). Pre- and postoperative scores in the ATFL group were 50.4 ± 6.2 and 90.3 ± 7.8, respectively. The difference (average 39.9) showed high statistical significance (P < 0.001). Regarding the Good score, 14 patients were rated as "excellent and one as good (good = 100 %). No severe complications were found in the patients in this group.
CONCLUSIONS
We studied and successfully built a digital navigation template for creating fibular channels to anatomically reconstruct the lateral ankle ligament. By using the template, fibular channels could be built, and lateral ligaments could be anatomically reconstructed individually, easily and safely, which largely facilitates the treatment of CAI.
Publication
Journal: Regulatory Toxicology and Pharmacology
January/21/2013
Abstract
Human health risk to infants/toddlers and adults was evaluated based on two exposure scenarios from compact fluorescent lamp (CFL) breakage; first in a room with no ventilation and no clean-up, and second in a room with adequate ventilation and clean-up. Concentration data from multiple exposure scenarios tested in a study by Stahler et al. (2008) were compared to human toxicity benchmarks to calculate hazard quotients. For the no clean-up scenario, hazard quotients were generally less than 1, suggesting an unlikely health risk. When the room was ventilated and the broken CFL was cleaned-up, mercury concentrations were generally lower. A review of release scenarios, along with duration-adjusted toxicity benchmarks, indicated that few releases produced levels of concern, but some scenarios resulted in exceedance of risk targets and require further study. Uncertainties in this screening characterization include assumptions about room size, ventilation, age of lamp, the distribution of mercury in the room, and also the choice of the toxicity benchmarks used to develop the hazard quotients.
Publication
Journal: IEEE transactions on image processing : a publication of the IEEE Signal Processing Society
May/12/2013
Abstract
The level set method is a popular technique for tracking moving interfaces in several disciplines, including computer vision and fluid dynamics. However, despite its high flexibility, the original level set method is limited by two important numerical issues. First, the level set method does not implicitly preserve the level set function as a distance function, which is necessary to estimate accurately geometric features, s.a. the curvature or the contour normal. Second, the level set algorithm is slow because the time step is limited by the standard Courant-Friedrichs-Lewy (CFL) condition, which is also essential to the numerical stability of the iterative scheme. Recent advances with graph cut methods and continuous convex relaxation methods provide powerful alternatives to the level set method for image processing problems because they are fast, accurate, and guaranteed to find the global minimizer independently to the initialization. These recent techniques use binary functions to represent the contour rather than distance functions, which are usually considered for the level set method. However, the binary function cannot provide the distance information, which can be essential for some applications, s.a. the surface reconstruction problem from scattered points and the cortex segmentation problem in medical imaging. In this paper, we propose a fast algorithm to preserve distance functions in level set methods. Our algorithm is inspired by recent efficient l(1) optimization techniques, which will provide an efficient and easy to implement algorithm. It is interesting to note that our algorithm is not limited by the CFL condition and it naturally preserves the level set function as a distance function during the evolution, which avoids the classical re-distancing problem in level set methods. We apply the proposed algorithm to carry out image segmentation, where our methods prove to be 5-6 times faster than standard distance preserving level set techniques. We also present two applications where preserving a distance function is essential. Nonetheless, our method stays generic and can be applied to any level set methods that require the distance information.
Publication
Journal: Foot and Ankle Surgery
February/26/2012
Abstract
BACKGROUND
Many surgical technique have been described to assess the outcome of anatomical reconstruction of the lateral ligaments using Gracillis tendon. This technique aims to restore the stability of the ankle by reconstruction of the talofibular ligament (ATFL) and the calcaneofibular ligament (CFL) using the Gracillis tendon.
METHODS
From January 2004 to February 2008; inclusive, 16 patients; 11 male and 5 female, underwent an anatomic reconstruction of the lateral ankle ligament for chronic ankle instability. Their ages ranged from 18 to 29 giving a mean age of 25 years. Patients were then subjected to radiologic and clinical assessments for a period of at least 33.5 months. For pain scoring the Americans Orthopaedic Foot and Ankle Society (AOFAS) scores were used; whilst subjective symptom was evaluated using the Olerud and Molander ankle scoring system.
RESULTS
All patients returned for the final evaluation and subjective excellent or good results were recorded on self-assessment, pain scores, AOFAS and Karissons scores. Additionally Olerud and Molander ankle scoring was also done. During the final follow-up, the mean post-operative AOFAS score was 96 (range 80-100), the Visual analog score was 6 (range 0-4), Karissons score was 94.7 (range 80-100) and last but not least Olerud and Molander score was 87.5 (range 70-100). It was noted that the ankle range of motion was not affected by lateral ankle reconstruction. The talar tilt was reduced from a mean of 12-4° (p<0.0001) and the anterior drawer was reduced from a mean of 11-4mm (p<0.001) by the ankle ligament reconstruction.
CONCLUSIONS
Anatomical reconstruction of the lateral ligaments of chronic ankle instability using Gracillis tendon graft resulted in successful results, excellent ankle stability, significant reduction in pain and negligible loss of ankle and hind foot motion.
Publication
Journal: Journal of Theoretical Biology
May/23/2012
Abstract
Cell free layer (CFL), a plasma layer bounded by the red blood cell (RBC) core and the endothelium, plays an important physiological role. Its width affects the effective blood viscosity as well as the scavenging and production of nitric oxide (NO). Measurements of the CFL and its spatio-temporal variability are highly uncertain, exhibiting random fluctuations. Yet traditional models of blood flow and NO scavenging treat the CFL's bounding surfaces as deterministic and smooth. We investigate the effects of the endothelium roughness and uncertain (random) spatial variability on blood flow and the estimates of effective blood viscosity.
Publication
Journal: Journal of Neurophysiology
March/20/1977
Abstract
1. Single units of the plantaris pool were isolated in ventral root filaments of decerebrate cats and their critical firing levels (CFLs) were determined. Motoneurons of similar size, as judged by their CFLs and other criteria, were compared in firing rate (FR) during repetitive stimulation of the plantaris nerve. 2. Such units either differed very little or quite widely, suggesting that they were sampled randomly from two populations, one firing rapidly, the other slowly. The relationship between the two rates remained approximately constant, regardless of the intensity or rate of input the units received, as long as both of them discharged rhythmically. 3. In single experiments 10-15 of the smallest units in the pool (all with CFLs in the 0-8% range) were isolated and compared. Statistical analyses and visual inspection of these small samples again suggested the existence of two species of motoneurons. 4. Statistical analyses also indicated that the FRs of units in single experiments were not sampled from any one of a variety of parametric, single-modal distributions. This suggests that the data were sampled from a distribution having more than one mode, indicating the existence of separate populations or species of motoneurons among the small units of the pool (0-8% range of CFL). 5. Pooling of the normalized data from different experiments revealed a bimodal histogram, reinforcing the conclusion that there are two species of small alpha motoneurons in the plantaris pool.
Publication
Journal: Optometry and Vision Science
May/27/1998
Abstract
Most people with low vision need magnification to read. Page navigation is the process of moving a magnifier during reading. Modern electronic technology can provide many alternatives for navigating through text. This study compared reading speeds for four methods of displaying text. The four methods varied in their page-navigation demands. The closed-circuit television (CCTV) and MOUSE methods involved manual navigation. The DRIFT method (horizontally drifting text) involved no manual navigation, but did involve both smooth-pursuit and saccadic eye movements. The rapid serial visual presentation (RSVP) method involved no manual navigation, and relatively few eye movements. There were 7 normal subjects and 12 low-vision subjects (7 with central-field loss, CFL group, and 5 with central fields intact, CFI group). The subjects read 70-word passages at speeds that yielded good comprehension. Taking the CCTV reading speed as a benchmark, neither the normal nor low-vision subjects had significantly different speeds with the MOUSE method. As expected from the reduced navigational demands, normal subjects read faster with the DRIFT method (85% faster) and the RSVP method (169%). The CFI group read significantly faster with DRIFT (43%) and RSVP (38%). The CFL group showed no significant differences in reading speed for the four methods.
Publication
Journal: Foot and Ankle International
March/17/2004
Abstract
BACKGROUND
The aim of this study was to examine the mechanical behavior of human ankle ligaments at low forces. Predominantly, ankle ligaments have been studied under the auspices of ligament injury. While the mechanical properties of a ligament when tested to failure provide a basis for comparisons, the loads and displacement do not reflect normal physiologic loading.
METHODS
Eight fresh-frozen ankles (mean age 65) were dissected to expose the ligaments surrounding the talocrural joint. Eight ankle ligaments were studied and included: medially-anterior tibiotalar (ATTL), posterior tibiotalar (PTTL), tibiocalcaneal (TCL); laterally-anterior tibiofibular (ATiFL), posterior tibiofibular (PTiFL), anterior talofibular (ATFL), posterior talofibular (PTFL), and calcaneofibular (CFL). Stress relaxation tests were carried out at 30% and 10% strain. The peak load and area under the curve were assessed for all experiments.
RESULTS
Significant differences were found for the average peak loads of the elastic response between 30% and 10% strain for each ligament (p < .05). At 10% strain the relationship between the ligaments on the medial and lateral side revealed a Pearson R value of .991 (p = .087). No significant difference was found between the strain energies of the various ligaments (p>> .05). The anterior talofibular ligament was found to possess similar relaxation results to the medial ligaments. The calcaneofibular ligament relaxed up to 10% more compared to the anterior talofibular for the same relaxation period. The mechanical testing was performed in uniaxial tension and did not consider off-axis loading that may occur in vivo during ankle motion.
CONCLUSIONS
The stress relaxation experiments revealed all ligaments to relax even when loaded to less than 5 N, reflecting the viscoelastic nature of ligaments. The stress relaxation results show that the anterior talofibular ligament does not relax to the same extent as the other lateral ligaments. Examining the properties of human ankle ligaments at low loads has revealed some new findings.
CONCLUSIONS
This study highlights the need to understand the synergistic effects of the ligaments. This is important for reconstruction and arthroplasty procedures.
Publication
Journal: Journal of Biomechanics
July/1/2012
Abstract
Patients with subtalar joint instability may be misdiagnosed with ankle instability, which may lead to chronic instability at the subtalar joint. Therefore, it is important to understand the difference in kinematics after ligament sectioning and differentiate the changes in kinematics between ankle and subtalar instability. Three methods may be used to determine the joint kinematics; the Euler angles, the Joint Coordinate System (JCS) and the helical axis (HA). The purpose of this study was to investigate the influence of using either method to detect subtalar and ankle joints instability. 3D kinematics at the ankle and subtalar joint were analyzed on 8 cadaveric specimens while the foot was intact and after sequentially sectioning the anterior talofibular ligament (ATFL), the calcaneofibular ligament (CFL), the cervical ligament and the interosseous talocalcaneal ligament (ITCL). Comparison in kinematics calculated from sensor and anatomical landmarks was conducted as well as the influence of Euler angles and JCS rotation sequence (between ISB recommendation and previous research) on the subtalar joint. All data showed a significant increase in inversion when the ITCL was sectioned. There were differences in the data calculated using sensors coordinate systems vs. anatomic coordinate systems. Anatomic coordinate systems were recommended for these calculations. The Euler angle and JCS gave similar results. Differences in Euler angles and JCS sequence lead to the same conclusion in detecting instability at the ankle and subtalar joint. As expected, the HA detected instability in plantarflexion at the ankle joint and in inversion at the subtalar joint.
Publication
Journal: International Journal of Radiation Biology
August/4/2013
Abstract
OBJECTIVE
A previous report has indicated that over-expression of cofilin-1 (CFL-1), a member of the actin depolymerizing factor (ADF)/cofilin protein family, enhances cellular radiosensitivity. This study explores the involvement of various DNA damage responses and repair systems in the enhanced cellular radiosensitivity as well as assessing the role of CFL-1 phosphorylation in radiosensitivity.
METHODS
Human non-small lung cancer H1299 cells harboring a tet-on gene expression system were used to induce exogenous expression of wild-type CFL-1. Colony formation assays were used to determine cell survival after γ-ray exposure. DNA damage levels were determined by Comet assay. DNA repair capacity was assessed by fluorescence-based DNA repair analysis and antibody detection of various repair proteins. The effects of CFL-1 phosphorylation on radiation responses were explored using two mutant CFL-1 proteins, S3D and S3A. Finally, endogenous CFL-1 phosphorylation levels were investigated using latrunculin A (LA), cytochalasin B (CB) and Y27632.
RESULTS
When phosphorylatable CFL-1 was expressed, radiosensitivity was enhanced after exposure to γ-rays and this was accompanied by DNA damage. Phosphorylated histone H2AX (γ-H2AX) and p53-binding protein-1 (53BP1) foci, as well as Chk1/2 phosphorylation, were apparently suppressed, although ataxia telangiectasia mutated (ATM) kinase activation was apparently unaffected. In addition, two radiation-induced double-strand break (DSB) repair systems, namely homologous recombination repair (HRR) and non-homologous end joining (NHEJ), were suppressed. Moreover, over-expression of CFL-1 S3D and CFL-1 S3A both enhanced radiosensitivity. However, enhanced radiosensitivity and reduced γ-H2AX expression were only detected in cells treated with LA which increased endogenous phospho-CFL-1, and not in cells treated with Y27632, which dephosphorylates CFL-1.
CONCLUSIONS
CFL-1 over-expression enhances radiosensitivity and this is associated with reduced DNA repair capacity. Although phosphorylated CFL-1 seems to be involved in radiosensitivity, further studies are required to address the importance of CFL-1 activity to the regulation of radiosensitivity.
Publication
Journal: Indian Pediatrics
April/29/2009
Abstract
OBJECTIVE
To evaluate the efficacy of white reflecting material (slings) hung from the sides of compact fluorescent lamp (CFL) phototherapy equipment in reducing the duration of phototherapy in healthy term neonates with non-hemolytic jaundice.
METHODS
Randomized controlled trial.
METHODS
Postnatal ward of a tertiary level neonatal unit.
METHODS
Healthy term neonates with non-hemolytic jaundice between 24 hours and 10 days of age were randomly assigned to receive single surface phototherapy with (n=42) or without slings (n=42).
METHODS
Duration of phototherapy in hours (h) and the requirement of exchange transfusion.
RESULTS
Birthweight (2790+/-352 vs. 2923+/-330 g), gestation (38+/-1.3 vs. 37+/-1.0 wk) and initial serum total bilirubin (STB) (16.6+/-2.4 vs. 16.1+/-2.2 mg/dL) were comparable between the two groups. There was no significant difference in the duration of phototherapy (mean+/-SD) between the Sling (23.3+/-12.9 h) and No sling (24.9+/-15.4 h) groups (P=0.6). The irradiance of photo-therapy equipment (microwatt/cm2, mean+/-SD) was higher in Sling group compared to No sling group (195.8+/-24.2 versus 179.7+/-27.7, P=0.01). There was a trend towards a higher rate of fall of serum total bilirubin (mg/dL, mean +/-SD) in the Sling group (0.23+/-0.49) compared to No sling group (0.03+/-0.47) (P=0.06).
CONCLUSIONS
Though hanging of white reflective sling on sides of CFL phototherapy equipment resulted in marginal increase in irradiance, it did not decrease the duration of phototherapy.
Publication
Journal: Investigative Ophthalmology and Visual Science
June/14/2017
Abstract
To describe and quantify a largely unnoticed oculomotor pattern that often occurs when patients with central field loss (CFL) read continuous text: Horizontal distribution of eye fixations dramatically varies across sentences and often reveals clusters. Also to statistically analyze the effect of this new factor on reading speed while controlling for the effect of saccadic amplitude (measured in letters per forward saccade, L/FS), an established oculomotor effect.
Quantification of nonuniformity of eye fixations (NUF factor) was based on statistical analysis of the curvature of fixation distributions. Linear mixed-effects analyses were performed to predict reading speed from oculomotor factors based on eye movements of 34 AMD and 4 Stargardt patients (better eye decimal acuity from 0.08 to 0.3). Single-line French sentences were read aloud by these patients, who all had a dense scotoma covering the fovea as assessed with MP1 microperimetry.
Nonuniformity of fixations is a strong determinant of reading speed (-0.76 log units; 95% confidence interval [CI] [-0.86, -0.66]). This effect is not confounded with the effect of L/FS. The per sentence proportion of trials with clustering is predicted by the frequency of occurrence of the lowest-frequency word in each sentence.
The NUF factor is a new oculomotor predictor of reading speed. This effect is independent of the effect of L/FS. Reading performance, as well as motivation to read, might be enhanced if new visual aids or automatic text simplification were used to reduce the occurrence of fixation clustering.
Publication
Journal: Environmental Science & Technology
June/23/2013
Abstract
Artificial lighting systems are transitioning from incandescent to compact fluorescent lamp (CFL) and light-emitting diode (LED) bulbs in response to the U.S. Energy Independence and Security Act and the EU Ecodesign Directive, which leads to energy savings and reduced greenhouse gas emissions. Although CFLs and LEDs are more energy-efficient than incandescent bulbs, they require more metal-containing components. There is uncertainty about the potential environmental impacts of these components and whether special provisions must be made for their disposal at the end of useful life. Therefore, the objective of this study is to analyze the resource depletion and toxicity potentials from the metals in incandescent, CFL, and LED bulbs to complement the development of sustainable energy policy. We assessed the potentials by examining whether the lighting products are to be categorized as hazardous waste under existing U.S. federal and California state regulations and by applying life cycle impact-based and hazard-based assessment methods (note that "life cycle impact-based method" does not mean a general life cycle assessment (LCA) but rather the elements in LCA used to quantify toxicity potentials). We discovered that both CFL and LED bulbs are categorized as hazardous, due to excessive levels of lead (Pb) leachability (132 and 44 mg/L, respectively; regulatory limit: 5) and the high contents of copper (111,000 and 31,600 mg/kg, respectively; limit: 2500), lead (3860 mg/kg for the CFL bulb; limit: 1000), and zinc (34,500 mg/kg for the CFL bulb; limit: 5000), while the incandescent bulb is not hazardous (note that the results for CFL bulbs excluded mercury vapor not captured during sample preparation). The CFLs and LEDs have higher resource depletion and toxicity potentials than the incandescent bulb due primarily to their high aluminum, copper, gold, lead, silver, and zinc. Comparing the bulbs on an equivalent quantity basis with respect to the expected lifetimes of the bulbs, the CFLs and LEDs have 3-26 and 2-3 times higher potential impacts than the incandescent bulb, respectively. We conclude that in addition to enhancing energy efficiency, conservation and sustainability policies should focus on the development of technologies that reduce the content of hazardous and rare metals in lighting products without compromising their performance and useful lifespan.
Publication
Journal: Physical review. E, Statistical, nonlinear, and soft matter physics
April/26/2006
Abstract
The temperature dependence of intermembrane interactions in freely suspended multilamellar membranes of dimiristoylphosphatidylcholine in D2O was studied using small-angle neutron scattering (SANS) and high-resolution x-ray diffraction (HRXRD). The study reveals that the Helfrich's undulation force is the dominating repulsion force at temperatures above 48.6 degrees C and intermembrane distances larger than 20.5 A. At approximately 77 degrees C the onset of the unbinding transition in the multilamellar membranes is observed. This transition has a continuous behavior in agreement with theoretical predictions and proceeds in accordance with a two-state model. Complimentary analysis of SANS and HRXRD data permits accurate calculation of the fundamental undulation force constant cfl. The obtained value of cfl=0.111+/-0.005 is in good agreement with theoretical calculations. The results of this work demonstrate a key role of Helfrich's undulations in the balance of intermembrane interactions of lipid membranes under physiological temperatures and suggest that thermal undulations play an important part in the interactions of biological membranes. The agreement of the predictions with the experimental data confirms that lipid membranes can be considered as random fluctuating surfaces that can be described well by current theoretical models and that they can serve as a powerful tool for studying behavior of such surfaces.
Publication
Journal: Optometry and Vision Science
October/13/1999
Abstract
Central field loss (CFL) and cataract both decrease visual acuity. For patients with CFL, visual acuity is further reduced when the acuity target is more visually complex. We tested visual acuity for targets of varying complexity (letters alone, letters flanked by one or two x's on each side, and words) in subjects with normal vision and in the presence of a simulated cataract, simulated scotoma, and their combination (scotoma + cataract). Visual acuity was best with normal vision and worst with scotoma + cataract for all of the acuity targets. There was little difference in visual acuity between the letters alone and flanked letters, and visual acuity was best for words under all vision conditions. The cataract had a greater impact on visual acuity when the subject's central visual field was clear (normal vision) than when it was occluded by the simulated scotoma.
Publication
Journal: Vision Research
December/7/1997
Abstract
Normally sighted younger and older (mean age 71 years) observers read sentences and random lists of words from a rapid serial visual presentation (RSVP) display and a scroll display using their normal vision and through two levels of cataract simulators. Unlike patients with central field loss (CFL), there was no decrease in the benefit of RSVP with reduced vision due to the cataract simulators. However, the usefulness of sentence-level context was reduced as visual acuity was reduced. In addition, older readers did not benefit as much from RSVP as younger readers, and many in the older group were unable to read using the more severe cataract simulators from either display format. From these data we conclude that the benefits of RSVP are not reduced with reduced acuity and contrast sensitivity, and that there are age-related changes in reading rates from dynamic text displays not related to acuity.
Publication
Journal: Knee Surgery, Sports Traumatology, Arthroscopy
October/29/2018
Abstract
OBJECTIVE
Ankle lateral collateral ligament complex has been the focus of multiple studies. However, there are no specific descriptions of how these ligaments are connected to each other as part of the same complex. The aim of this study was to describe in detail the components of the lateral collateral ligament complex-ATFL and CFL-and determine its anatomical relationships.
METHODS
An anatomical study was performed in 32 fresh-frozen below-the-knee ankle specimens. A plane-per-plane anatomical dissection was performed. Overdissecting the area just distal to the inferior ATFL fascicle was avoided to not alter the original morphology of the ligaments and the connecting fibers between them. The characteristics of the ATFL and CFL, as well as any connecting fibers between them were recorded. Measures were obtained in plantar and dorsal flexion, and by two different observers.
RESULTS
The ATFL was observed as a two-fascicle ligament in all the specimens. The superior ATFL fascicle was observed intra-articular in the ankle, in contrast to the inferior fascicle. The mean distance measured between superior ATFL fascicle insertions increases in plantar flexion (median 19.2 mm in plantar flexion, and 12.6 mm in dorsal flexion, p < 0.001), while the same measures observed in the inferior ATFL fascicle does not vary (median 10.6 mm in plantar flexion, and 10.6 mm in dorsal flexion, n.s.). The inferior ATFL fascicle was observed with a common fibular origin with the CFL. The CFL distance between insertions does not vary with ankle movement (median 20.1 mm in plantar flexion, and 19.9 mm in dorsal flexion, n.s.). The inferior ATFL fascicle and the CFL were connected by arciform fibers, that were observed as an intrinsic reinforcement of the subtalar joint capsule.
CONCLUSIONS
The superior fascicle of the ATFL is a distinct anatomical structure, whereas the inferior ATFL fascicle and the CFL share some features being both isometric ligaments, having a common fibular insertion, and being connected by arciform fibers, and forming a functional and anatomical entity, that has been named the lateral fibulotalocalcaneal ligament (LFTCL) complex. The clinical relevance of this study is that the superior fascicle of the ATFL is anatomical and functionally a distinct structure from the inferior ATFL fascicle. The superior ATFL fascicle is an intra-articular ligament, that will most probably not be able to heal after a rupture, and a microinstability of the ankle is developed. However, when the LFTCL complex is injured, classical ankle instability resulted. In addition, because of the presence of LFTCL complex, excellent results are observed when an isolated repair of the ATFL is performed even when an injury of both the ATFL and CFL exists.
Publication
Journal: Bioresource Technology
November/29/2009
Abstract
Schistosomiasis or bilharzia, which affects millions of people living in Africa, Asia and Latin America, is closely associated with certain species of aquatic snails. One way of attacking the disease is to eradicate the host snails. Molluscicidal activities of natural compounds are especially important in the widespread control of this tropical disease. As part of our search for natural compounds with molluscicidal properties for the vector control of schistosomiasis, we are now evaluating for the first time the toxicity of the plant lectins from Canavalia brasiliensis (ConBr), Cratylia floribunda (CFL), Dioclea guianensis (Dgui), Dioclea grandiflora (DGL) and Dioclea virgata (Dvir) to Biomphalaria glabrata Say and Artemia salina Leach. Results indicate that all the samples were toxic to A. salina Leach, some of them with values of lethal concentration that kills 90% of the population (LC(90))<10 microg mL(-1). They are also active against B. glabrata Say, killing 100% of adult snails, at a concentration of 50 microg mL(-1). The lectins CFL and Dgui possess properties lethal to mollusks, with values of LC(90)=50.3 microg mL(-1) and LC(90)=41.0 microg mL(-1), respectively.
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