Surgical Outcomes of Additional Ahmed Glaucoma Valve Implantation in Refractory Glaucoma.

PubMed

Ko, Sung Ju; Hwang, Young Hoon; Ahn, Sang Il; Kim, Hwang Ki

2016-06-01

To evaluate the surgical outcomes of the implantation of an additional Ahmed glaucoma valve (AGV) into the eyes of patients with refractory glaucoma following previous AGV implantation. This study is a retrospective review of the clinical histories of 23 patients who had undergone a second AGV implantation after a failed initial implantation. Age, sex, prior surgery, glaucoma type, number of medications, intraocular pressure (IOP), visual acuity, and surgical complications were analyzed. Surgical success was defined as IOP maintained below 21 mm Hg, with at least a 20% overall reduction in IOP, regardless of the use of IOP-lowering medications. Following the implantation of a second AGV, the mean IOP decreased from 39.3 to 18.5 mm Hg (52.9% reduction, P<0.001). The mean number of postoperative IOP-lowering medications administered decreased from 2.8 to 1.7 after the second AGV implantation (P<0.001). The cumulative probability of success for the procedure was 87% after 1 year and 52% after 3 years. Three patients (13.0%) experienced bullous keratopathy after the second AGV implantation. None of the patients showed any evidence of diplopia or ocular movement limitation as a result of the presence of 2 AGVs in the same eye. Prior trabeculectomy was found to be a significant risk factor for failure (P=0.027). A second AGV implantation can be a good choice of surgical treatment when the first AGV has failed to control IOP.

Surgically Induced Scleral Necrosis in a Patient With Rheumatoid Arthritis After AGV Implantation.

PubMed

Kumar, Suresh; Ichhpujani, Parul; Thakur, Sahil

2018-03-01

Surgically induced scleral necrosis (SINS) is a rare entity that has till date not been reported in a patient of glaucoma undergoing Ahmed glaucoma valve (AGV) implantation. We present a case of primary open-angle glaucoma who underwent AGV implantation followed by development of scleral necrosis, involving both the scleral patch graft and host sclera. After failure of surgical and medical management, AGV had to be explanted. The patient was diagnosed with rheumatoid arthritis and had to be treated with steroids and azathioprine for the same. SINS is a potentially disastrous complication of ocular surgery that can occur in patients with systemic diseases like rheumatoid arthritis and requires aggressive management to salvage the eye. SINS can occur with AGV implantation. Treatment may require aggressive medical and surgical intervention. It is imperative to evaluate patients for systemic illness before planning an AGV implant.

Five-year Treatment Outcomes in the Ahmed Baerveldt Comparison Study

PubMed Central

Budenz, Donald L.; Barton, Keith; Gedde, Steven J.; Feuer, William J.; Schiffman, Joyce; Costa, Vital P.; Godfrey, David G.; Buys, Yvonne M.

2014-01-01

Purpose To compare the five year outcomes of the Ahmed FP7 Glaucoma Valve (AGV) and the Baerveldt 101-350 Glaucoma Implant (BGI) for the treatment of refractory glaucoma. Design Multicenter randomized controlled clinical trial. Participants 276 patients, including 143 in the AGV group and 133 in the BGI group. Methods Patients 18 to 85 years of age with previous intraocular surgery or refractory glaucoma and intraocular pressure (IOP) of ≥ 18 mmHg in whom glaucoma drainage implant surgery was planned were randomized to implantation of either an AGV or BGI. Main Outcome Measures IOP, visual acuity, use of glaucoma medications, complications, and failure (IOP > 21 mmHg or not reduced by 20% from baseline, IOP ≤ 5 mmHg, reoperation for glaucoma, removal of implant, or loss of light perception). Results At 5 years, IOP (mean ± SD) was 14.7 ± 4.4 mmHg in the AGV group and 12.7 ± 4.5 mmHg in the BGI group (p = 0.012). The number of glaucoma medications in use at 5 years (mean ± SD) was 2.2 ± 1.4 in the AGV group and 1.8 ± 1.5 in the BGI group (p = 0.28). The cumulative probability of failure during 5 years of follow-up was 44.7% in the AGV group and 39.4% in the BGI group (p = 0.65). The number of subjects failing due to inadequately controlled IOP or reoperation for glaucoma was 46 in the AGV group (80% of AGV failures) and 25 in the BGI group (53% of BGI failures, p=0.003). Eleven AGV eyes (20% of AGV failures) experienced persistent hypotony, explantation of implant, or loss of light perception compared to 22 (47% of failures) in the BGI group. The 5-year cumulative reoperation rate for glaucoma was 20.8% in the AGV group compared to 8.6% in the BGI group (p=0.010). Change in logMAR Snellen visual acuity (mean ± SD) at 5 years was 0.42 ± 0.99 in the AGV group and 0.43 ± 0.84 in the BGI group (p=0.97). Conclusions Similar rates of surgical success were observed with both implants at 5 years. BGI implantation produced greater IOP reduction and a lower rate of glaucoma reoperation than AGV implantation but BGI implantation was associated with twice as many failures due to safety issues such as persistent hypotony, loss of light perception, or explantation. PMID:25439606

Pars Plana-Modified versus Conventional Ahmed Glaucoma Valve in Patients Undergoing Penetrating Keratoplasty: A Prospective Comparative Randomized Study.

PubMed

Parihar, Jitendra Kumar Singh; Jain, Vaibhav Kumar; Kaushik, Jaya; Mishra, Avinash

2017-03-01

To compare the outcome of pars-plana-modified Ahmed glaucoma valve (AGV) versus limbal-based conventional AGV into the anterior chamber, in patients undergoing penetrating keratoplasty (PK) for glaucoma with coexisting corneal diseases. In this prospective randomized clinical trial, 58 eyes of 58 patients with glaucoma and coexisting corneal disease were divided into two groups. Group 1 (29 eyes of 29 patients) included patients undergoing limbal-based conventional AGV into the anterior chamber (AC) along-with PK and group 2 (29 eyes of 29 patients) included those undergoing pars-plana-modified AGV along-with PK. Outcome measures included corneal graft clarity, intraocular pressure (IOP), number of antiglaucoma medications, and postoperative complications. Patients were followed up for a minimum period of 2 years. Out of 58 eyes (58 patients), 50 eyes (50 patients: 25 eyes of 25 patients each in group 1 and group 2) completed the study and were analyzed. Complete success rate for AGV (group 1: 76%; group 2: 72%; p = 0.842) and corneal graft clarity (group 1: 68%; group 2: 76%; p = 0.081) were comparable between the two groups at 2 years. Graft failure was more in conventional AGV (32%) as compared to pars plana-modified AGV (24%) but not statistically significant (p = 0.078) at 2 years. Though both procedures were comparable in various outcome measures, pars-plana-modified AGV is a viable option for patients undergoing PK, as it provides a relatively better corneal graft survival rate and lesser complications that were associated with conventional AGV.

True navigation in migrating gulls requires intact olfactory nerves

PubMed Central

Wikelski, Martin; Arriero, Elena; Gagliardo, Anna; Holland, Richard A.; Huttunen, Markku J.; Juvaste, Risto; Mueller, Inge; Tertitski, Grigori; Thorup, Kasper; Wild, Martin; Alanko, Markku; Bairlein, Franz; Cherenkov, Alexander; Cameron, Alison; Flatz, Reinhard; Hannila, Juhani; Hüppop, Ommo; Kangasniemi, Markku; Kranstauber, Bart; Penttinen, Maija-Liisa; Safi, Kamran; Semashko, Vladimir; Schmid, Heidi; Wistbacka, Ralf

2015-01-01

During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to < 5°N) to sensory manipulation, to determine the sensory systems required for navigation. We translocated birds westward (1080 km) or eastward (885 km) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances. PMID:26597351

True navigation in migrating gulls requires intact olfactory nerves.

PubMed

Wikelski, Martin; Arriero, Elena; Gagliardo, Anna; Holland, Richard A; Huttunen, Markku J; Juvaste, Risto; Mueller, Inge; Tertitski, Grigori; Thorup, Kasper; Wild, Martin; Alanko, Markku; Bairlein, Franz; Cherenkov, Alexander; Cameron, Alison; Flatz, Reinhard; Hannila, Juhani; Hüppop, Ommo; Kangasniemi, Markku; Kranstauber, Bart; Penttinen, Maija-Liisa; Safi, Kamran; Semashko, Vladimir; Schmid, Heidi; Wistbacka, Ralf

2015-11-24

During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to < 5°N) to sensory manipulation, to determine the sensory systems required for navigation. We translocated birds westward (1080 km) or eastward (885 km) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances.

Flight test and evaluation of Omega navigation in a general aviation aircraft. Volume 1: Technical

NASA Technical Reports Server (NTRS)

Howell, J. D.; Hoffman, W. C.; Hwoschinsky, P. V.; Wischmeyer, C. E.

1975-01-01

A low cost flight research program was conducted to evaluate the performance of differential Omega navigation in a general aviation aircraft. The flight program consisted of two distinct parts corresponding to the two major objectives of the study. The Wallops Flight Program was conducted to obtain Omega signal and phase data in the Wallops Flight Center vicinity to provide preliminary technical information and experience in preparation for a comprehensive NASA/FAA flight test program of an experimental differential Omega system. The Northeast Corridor Flight Program was conducted to examine Omega operational suitability and performance on low altitude area navigation (RNAV) routes for city-center to city-center VTOL commercial operations in the Boston-New York-Washington corridor. The development, execution and conclusions of the flight research program are discribed. The results of the study provide both quantitative and qualitative data on the Omega Navigation System under actual operating conditions.

Autonomous assistance navigation for robotic wheelchairs in confined spaces.

PubMed

Cheein, Fernando Auat; Carelli, Ricardo; De la Cruz, Celso; Muller, Sandra; Bastos Filho, Teodiano F

2010-01-01

In this work, a visual interface for the assistance of a robotic wheelchair's navigation is presented. The visual interface is developed for the navigation in confined spaces such as narrows corridors or corridor-ends. The interface performs two navigation modus: non-autonomous and autonomous. The non-autonomous driving of the robotic wheelchair is made by means of a hand-joystick. The joystick directs the motion of the vehicle within the environment. The autonomous driving is performed when the user of the wheelchair has to turn (90, 90 or 180 degrees) within the environment. The turning strategy is performed by a maneuverability algorithm compatible with the kinematics of the wheelchair and by the SLAM (Simultaneous Localization and Mapping) algorithm. The SLAM algorithm provides the interface with the information concerning the environment disposition and the pose -position and orientation-of the wheelchair within the environment. Experimental and statistical results of the interface are also shown in this work.

A Review of the Ahmed Glaucoma Valve Implant and Comparison with Other Surgical Operations.

PubMed

Riva, Ivano; Roberti, Gloria; Katsanos, Andreas; Oddone, Francesco; Quaranta, Luciano

2017-04-01

The Ahmed glaucoma valve (AGV) is a popular glaucoma drainage implant used for the control of intraocular pressure in patients with glaucoma. While in the past AGV implantation was reserved for glaucoma patients poorly controlled after one or more filtration procedures, mounting evidence has recently encouraged its use as a primary surgery in selected cases. AGV has been demonstrated to be safe and effective in reducing intraocular pressure in patients with primary or secondary refractory glaucoma. Compared to other glaucoma surgeries, AGV implantation has shown favorable efficacy and safety. The aim of this article is to review the results of studies directly comparing AGV with other surgical procedures in patients with glaucoma.

76 FR 12643 - Proposed Establishment of Helicopter Area Navigation (RNAV) Routes; Northeast United States

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-08

... (RNAV) Routes; Northeast United States AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... northeast corridor between the Washington, DC and New York City metropolitan areas. The FAA is proposing... northeast corridor between the New York City and Washington, DC, metropolitan areas. The routes would serve...

Comparative Analysis of 2-D Versus 3-D Ultrasound Estimation of the Fetal Adrenal Gland Volume and Prediction of Preterm Birth

PubMed Central

Turan, Ozhan M.; Turan, Sifa; Buhimschi, Irina A.; Funai, Edmund F.; Campbell, Katherine H.; Bahtiyar, Ozan M.; Harman, Chris R.; Copel, Joshua A.; Baschat, Ahmet A; Buhimschi, Catalin S.

2013-01-01

Objective We aim to test the hypothesis that 2D fetal AGV measurements offer similar volume estimates as volume calculations based on 3D technique Methods Fetal AGV was estimated by 3D ultrasound (VOCAL) in 93 women with signs/symptoms of preterm labor and 73 controls. Fetal AGV was calculated using an ellipsoid formula derived from 2D measurements of the same blocks (0.523× length × width × depth). Comparisons were performed by intra-class correlation coefficient (ICC), coefficient of repeatability, and Bland-Altman method. The cAGV (AGV/fetal weight) was calculated for both methods and compared for prediction of PTB within 7 days. Results Among 168 volumes, there was a significant correlation between 3D and 2D methods (ICC=0.979[95%CI: 0.971-0.984]). The coefficient of repeatability for the 3D was superior to the 2D method (Intra-observer 3D: 30.8, 2D:57.6; inter-observer 3D: 12.2, 2D: 15.6). Based on 2D calculations, a cAGV≥433mm3/kg, was best for prediction of PTB (sensitivity: 75%(95%CI=59-87); specificity: 89%(95%CI=82-94). Sensitivity and specificity for the 3D cAGV (cut-off ≥420mm3/kg) was 85%(95%CI=70-94) and 95%(95%CI=90-98), respectively. In receiver-operating-curve curve analysis, 3D cAGV was superior to 2D cAGV for prediction of PTB (z=1.99, p=0.047). Conclusion 2D volume estimation of fetal adrenal gland using ellipsoid formula cannot replace 3D AGV calculations for prediction of PTB. PMID:22644825

A biomimetic vision-based hovercraft accounts for bees' complex behaviour in various corridors.

PubMed

Roubieu, Frédéric L; Serres, Julien R; Colonnier, Fabien; Franceschini, Nicolas; Viollet, Stéphane; Ruffier, Franck

2014-09-01

Here we present the first systematic comparison between the visual guidance behaviour of a biomimetic robot and those of honeybees flying in similar environments. We built a miniature hovercraft which can travel safely along corridors with various configurations. For the first time, we implemented on a real physical robot the 'lateral optic flow regulation autopilot', which we previously studied computer simulations. This autopilot inspired by the results of experiments on various species of hymenoptera consists of two intertwined feedback loops, the speed and lateral control loops, each of which has its own optic flow (OF) set-point. A heading-lock system makes the robot move straight ahead as fast as 69 cm s(-1) with a clearance from one wall as small as 31 cm, giving an unusually high translational OF value (125° s(-1)). Our biomimetic robot was found to navigate safely along straight, tapered and bent corridors, and to react appropriately to perturbations such as the lack of texture on one wall, the presence of a tapering or non-stationary section of the corridor and even a sloping terrain equivalent to a wind disturbance. The front end of the visual system consists of only two local motion sensors (LMS), one on each side. This minimalistic visual system measuring the lateral OF suffices to control both the robot's forward speed and its clearance from the walls without ever measuring any speeds or distances. We added two additional LMSs oriented at +/-45° to improve the robot's performances in stiffly tapered corridors. The simple control system accounts for worker bees' ability to navigate safely in six challenging environments: straight corridors, single walls, tapered corridors, straight corridors with part of one wall moving or missing, as well as in the presence of wind.

Three-year Treatment Outcomes in the Ahmed Baerveldt Comparison Study

PubMed Central

Barton, Keith; Feuer, William J; Budenz, Donald L; Schiffman, Joyce; Costa, Vital P.; Godfrey, David G.; Buys, Yvonne M.

2014-01-01

Purpose To compare three year outcomes and complications of the Ahmed FP7 Glaucoma Valve (AGV) and Baerveldt 101–350 Glaucoma Implant (BGI) for the treatment of refractory glaucoma. Design Multicenter randomized controlled clinical trial. Participants 276 patients; 143 in the AGV group and 133 in the BGI group. Methods Patients aged 18–85 years with refractory glaucoma and intraocular pressures (IOPs) ≥18 mmHg in whom an aqueous shunt was planned were randomized to either an AGV or a BGI. Main Outcome Measures IOP, visual acuity, supplemental medical therapy, complications, and failure (IOP > 21 mmHg or not reduced by 20% from baseline, IOP ≤ 5 mmHg, reoperation for glaucoma or removal of implant, or loss of light perception vision). Results At 3 years, IOP (mean ± standard deviation) (SD) was 14.3 ± 4.7 mmHg (AGV group) and 13.1 ± 4.5 mmHg (BGI group) (p = 0.086) on 2.0 ± 1.4 and 1.5 ± 1.4 glaucoma medications respectively (p = 0.020). The cumulative probabilities of failure were 31.3% (standard error = 4.0%) (SE) (AGV) and 32.3% (4.2%) (BGI) (p = 0.99). Postoperative complications associated with reoperation or vision loss of ≥ 2 Snellen lines occurred in 24 patients (22%) (AGV) and 38 patients (36%) (BGI) (p = 0.035). The mean change in the Logarithm of the Minimum Angle of Resolution visual acuity (logMAR VA) at 3 years was similar (AGV: 0.21 ± 0.88, BGI: 0.26 ± 0.74) in the two treatment groups at 3 years (p=0.66). The cumulative proportion of patients (SE) undergoing reoperation for glaucoma prior to the three year postoperative time point was 14.5% (3.0%) in the AGV group compared to 7.6% (2.4%) in the BGI group (p=0.053, log-rank). The relative risk of reoperation for glaucoma in the AGV group was 2.1 times that of the BGI group (95% Confidence Interval:1.0–4.8, p=0.045; Cox proportional hazards regression). Conclusions AGV implantation was associated with the need for significantly greater adjunctive medication to achieve equal success relative to BGI implantation and resulted in a greater relative risk of reoperation for glaucoma. More subjects experienced serious postoperative complications in the BGI group than in the AGV group. PMID:24768240

Treatment Outcomes in the Ahmed Baerveldt Comparison Study after One Year of Follow-up

PubMed Central

Budenz, Donald L; Barton, Keith; Feuer, William J; Schiffman, Joyce; Costa, Vital P.; Godfrey, David G.; Buys, Yvonne

2010-01-01

Purpose To determine the relative efficacy and complications of the Ahmed FP7 Glaucoma Valve (AGV) and the Baerveldt 101–350 Glaucoma Implant (BGI) in refractory glaucoma. Design Multicenter randomized controlled clinical trial. Participants 276 patients, including 143 in the AGV group and 133 in the BGI group. Methods Patients aged 18–85 years with refractory glaucoma with intraocular pressure (IOP) greater than or equal to 18 mm Hg in whom an aqueous shunt was planned were randomized to undergo implantation of either an AGV or a BGI. Main Outcome Measures Primary outcome was failure, defined as IOP > 21 mm Hg or not reduced by 20%, IOP ≤ 5 mm Hg, reoperation for glaucoma or removal of implant, or loss of light perception vision. Secondary outcomes included mean IOP, visual acuity, use of supplemental medical therapy, and complications. Results Preoperative IOP (mean ± standard deviation, SD) was 31.2 ± 11.2 in the AGV group and 31.8 ± 12.5 in the BGI group (p = 0.71). At 1 year, IOP was 15.4 ± 5.5 mm Hg in the AGV group and 13.2 ± 6.8 mm Hg in the BGI group (p = 0.007). The number of glaucoma medications (mean ± SD) was 1.8 ± 1.3 in the AGV group and 1.5 ± 1.4 in the BGI group (p = 0.071). The cumulative probability of failure was 16.4% (standard error, SE = 3.1%) in the AGV group and 14.0% (SE = 3.1%) in the BGI group at 1 year (p = 0.52). More patients experienced early postoperative complications in the BGI group (n = 77, 58%) compared to the AGV group (n = 61, 43%, p = 0.016). Serious postoperative complications associated with reoperation and/or vision loss of ≥ 2 Snellen lines occurred in 29 patients (20%) in the AGV group and 45 patients (34%) in the BGI group (p = 0.014). Conclusions Although the average IOP after one year was slightly higher in patients who received an AGV, there were fewer early and serious postoperative complications associated with the use of the AGV than the BGI. PMID:20932583

Intelligent Transportation Systems: Automated Guided Vehicle Systems in Changing Logistics Environments

NASA Astrophysics Data System (ADS)

Schulze, L.; Behling, S.; Buhrs, S.

2008-06-01

The usage of Automated Guided Vehicle Systems (AGVS) is growing. This has not always been the case in the past. A new record of the sells numbers is the result of inventive developments, new applications and modern thinking. One market that AGVS were not able to thoroughly conquer yet were rapidly changing logistics environments. The advantages in recurrent transportation with AGVS used to be hindered by the needs of flexibility. When nowadays managers talk about Flexible Manufacturing Systems (FMS) there is no reason not to consider AGVS. Fixed guidelines, permanent transfer stations and static routes are no necessity for most AGVS producers. Flexible Manufacturing Systems can raise profitability with AGVS. When robots start saving billions in production costs, the next step at same plants are automated materials handling systems. Today, there are hundreds of instances of computer-controlled systems designed to handle and transport materials, many of which have replaced conventional human-driven platform trucks. Reduced costs due to damages and failures, tracking and tracing as well as improved production scheduling on top of fewer personnel needs are only some of the advantages.

Dynamic Task Assignment of Autonomous Distributed AGV in an Intelligent FMS Environment

NASA Astrophysics Data System (ADS)

Fauadi, Muhammad Hafidz Fazli Bin Md; Lin, Hao Wen; Murata, Tomohiro

The need of implementing distributed system is growing significantly as it is proven to be effective for organization to be flexible against a highly demanding market. Nevertheless, there are still large technical gaps need to be addressed to gain significant achievement. We propose a distributed architecture to control Automated Guided Vehicle (AGV) operation based on multi-agent architecture. System architectures and agents' functions have been designed to support distributed control of AGV. Furthermore, enhanced agent communication protocol has been configured to accommodate dynamic attributes of AGV task assignment procedure. Result proved that the technique successfully provides a better solution.

Trabeculectomy with Ex-PRESS implant versus Ahmed glaucoma valve implantation-a comparative study

PubMed Central

Waisbourd, Michael; Fischer, Naomi; Shalev, Hadas; Spierer, Oriel; Ben Artsi, Elad; Rachmiel, Rony; Shemesh, Gabi; Kurtz, Shimon

2016-01-01

AIM To compare the surgical outcomes of trabeculectomy with Ex-PRESS implant and Ahmed glaucoma valve (AGV) implantation. METHODS Patients who underwent trabeculectomy with Ex-PRESS implants or AGV implantation separately were included in this retrospective chart review. Main outcome measures were surgical failure and complications. Failure was defined as intraocular pressure (IOP) >21 mm Hg or <5 mm Hg on two consecutive visits after 3mo, reoperation for glaucoma, or loss of light perception. Eyes that had not failed were considered as complete success if they did not required supplemental medical therapy. RESULTS A total of 64 eyes from 57 patients were included: 31 eyes in the Ex-PRESS group and 33 eyes in the AGV group. The mean follow-up time was 2.6±1.1y and 3.3±1.6y, respectively. Patients in the AGV group had significantly higher baseline mean IOP (P=0.005), lower baseline mean visual acuity (VA) (P=0.02), and higher proportion of patients with history of previous trabeculectomy (P<0.0001). Crude failure rates were 16.1%, n=5/31 in the Ex-PRESS group and 24.2%, n=8/33 in the AGV group. The cumulative proportion of failure was similar between the groups, P=0.696. The proportion of eyes that experienced postoperative complications was 32.3% in the Ex-PRESS group and 60.1% in the AGV group (P=0.0229). CONCLUSION Trabeculectomy with Ex-PRESS implant and AGV implantation had comparable failure rates. The AGV group had more post-operative complications, but also included more complex cases with higher baseline mean IOP, worse baseline mean VA, and more previous glaucoma surgeries. Therefore, the results are limited to the cohort included in this study. PMID:27803857

Ahmed glaucoma valve in uveitic patients with fluocinolone acetonide implant-induced glaucoma: 3-year follow-up.

PubMed

Kubaisi, Buraa; Maleki, Arash; Ahmed, Aseef; Lamba, Neel; Sahawneh, Haitham; Stephenson, Andrew; Montieth, Alyssa; Topgi, Shobha; Foster, C Stephen

2018-01-01

To evaluate the efficacy and safety of Ahmed glaucoma valve (AGV) in eyes with noninfectious uveitis that had fluocinolone acetonide intravitreal implant (Retisert™)-induced glaucoma. This retrospective study reviewed the safety and efficacy of AGV implantation in patients with persistently elevated intraocular pressure (IOP) after implantation of a fluocinolone acetonide intravitreal implant at the Massachusetts Eye Research and Surgery Institution between August 2006 and November 2015. Nine patients with 10 uveitic eyes were included in this study, none of which had preexisting glaucoma in the study eye. Mean patient age was 42 years; 6 patients were female and 3 were male. Baseline mean IOP was 30.6 mmHg prior to AGV placement while mean IOP-lowering medications were 2.9. In the treatment groups, there was a statistically significant reduction in post-AGV IOP. IOP was lowest at 1-week after AGV implantation (9.0 mmHg). Nine out of 10 eyes achieved an IOP below target value of 22 mmHg and/or a 20% reduction in IOP from baseline 1 month and 1 year following AGV placement. All other postoperative time points showed all 10 eyes reaching this goal. A statistically significant decrease in IOP-lowering medication was seen at the 1-week, 1-month, and 3-year time points compared to baseline, while a statistically significant increase was seen at the 3-month, 6-month, and 2-year post-AGV time points. No significant change in retinal nerve thickness or visual field analysis was found. AGV is an effective and safe method of treatment in fluocinolone acetonide intravitreal implant-induced glaucoma. High survival rate is expected for at least 3 years.

Flow Test to Predict Early Hypotony and Hypertensive Phase After Ahmed Glaucoma Valve (AGV) Surgical Implantation.

PubMed

Cheng, Jason; Beltran-Agullo, Laura; Buys, Yvonne M; Moss, Edward B; Gonzalez, Johanna; Trope, Graham E

2016-06-01

To assess the validity of a preimplantation flow test to predict early hypotony [intraocular pressure (IOP)≤5 mm Hg on 2 consecutive visits and hypertensive phase (HP) (IOP>21 mm Hg) after Ahmed Glaucoma Valve (AGV) implantation. Prospective interventional study on patients receiving an AGV. A preimplantation flow test using a gravity-driven reservoir and an open manometer was performed on all AGVs. Opening pressure (OP) and closing pressure (CP) were defined as the pressure at which fluid was seen to flow or stop flowing through the AGV, respectively. OP and CP were measured twice per AGV. Patients were followed for 12 weeks. In total, 20 eyes from 19 patients were enrolled. At 12 weeks the mean IOP decreased from 29.2±9.1 to 16.8±5.2 mm Hg (P<0.01). The mean AGV OP was 17.5±5.4 mm Hg and the mean CP was 6.7±2.3 mm Hg. Early (within 2 wk postoperative) HP occurred in 37% and hypotony in 16% of cases. An 18 mm Hg cutoff for the OP gave a sensitivity of 0.71, specificity of 0.83, positive predictive value of 0.71, and negative predictive value of 0.83 for predicting an early HP. A 7 mm Hg cutoff for the CP yielded a sensitivity of 1.0, specificity of 0.38, positive predictive value of 0.23, and negative predictive value of 1.0 for predicting hypotony. Preoperative OP and CP may predict early hypotony or HP and may be used as a guide as to which AGV valves to discard before implantation surgery.

Ahmed glaucoma valve in uveitic patients with fluocinolone acetonide implant-induced glaucoma: 3-year follow-up

PubMed Central

Kubaisi, Buraa; Maleki, Arash; Ahmed, Aseef; Lamba, Neel; Sahawneh, Haitham; Stephenson, Andrew; Montieth, Alyssa; Topgi, Shobha; Foster, C Stephen

2018-01-01

Purpose To evaluate the efficacy and safety of Ahmed glaucoma valve (AGV) in eyes with noninfectious uveitis that had fluocinolone acetonide intravitreal implant (Retisert™)-induced glaucoma. Methods This retrospective study reviewed the safety and efficacy of AGV implantation in patients with persistently elevated intraocular pressure (IOP) after implantation of a fluocinolone acetonide intravitreal implant at the Massachusetts Eye Research and Surgery Institution between August 2006 and November 2015. Results Nine patients with 10 uveitic eyes were included in this study, none of which had preexisting glaucoma in the study eye. Mean patient age was 42 years; 6 patients were female and 3 were male. Baseline mean IOP was 30.6 mmHg prior to AGV placement while mean IOP-lowering medications were 2.9. In the treatment groups, there was a statistically significant reduction in post-AGV IOP. IOP was lowest at 1-week after AGV implantation (9.0 mmHg). Nine out of 10 eyes achieved an IOP below target value of 22 mmHg and/or a 20% reduction in IOP from baseline 1 month and 1 year following AGV placement. All other postoperative time points showed all 10 eyes reaching this goal. A statistically significant decrease in IOP-lowering medication was seen at the 1-week, 1-month, and 3-year time points compared to baseline, while a statistically significant increase was seen at the 3-month, 6-month, and 2-year post-AGV time points. No significant change in retinal nerve thickness or visual field analysis was found. Conclusion AGV is an effective and safe method of treatment in fluocinolone acetonide intravitreal implant-induced glaucoma. High survival rate is expected for at least 3 years. PMID:29750012

Dynamic tube movement after reimplantation of Ahmed glaucoma valve in a child with glaucoma in aphakia

PubMed Central

Senthil, Sirisha; Badakare, Akshay

2014-01-01

A 10-year-old girl underwent an Ahmed glaucoma valve (AGV) implantation as a primary procedure for glaucoma in aphakia due to congenital cataract surgery. Following an unintended accidental excision of AGV tube during bleb revision for hypertensive phase, AGV was explanted and a second AGV was implanted in the same quadrant after 2 weeks. This resulted in a rare complication of dynamic tube movement in the anterior chamber with tube corneal touch and localised corneal oedema. Excision of the offending unstable tube and placement of a paediatric AGV in a different quadrant led to resolution of this complication, stable vision and well-controlled intraocular pressure. This case highlights the possible causes of dynamic tube, related complications and its management. This case also highlights the importance of understanding the various physiological phases after glaucoma drainage device implantation and their appropriate management. PMID:24695662

On exploration of geometrically constrained space by medicinal leeches Hirudo verbana.

PubMed

Adamatzky, Andrew

2015-04-01

Leeches are fascinating creatures: they have simple modular nervous circuitry yet exhibit a rich spectrum of behavioural modes. Leeches could be ideal blue-prints for designing flexible soft robots which are modular, multi-functional, fault-tolerant, easy to control, capable for navigating using optical, mechanical and chemical sensorial inputs, have autonomous inter-segmental coordination and adaptive decision-making. With future designs of leech-robots in mind we study how leeches behave in geometrically constrained spaces. Core results of the paper deal with leeches exploring a row of rooms arranged along a narrow corridor. In laboratory experiments we find that rooms closer to ends of the corridor are explored by leeches more often than rooms in the middle of the corridor. Also, in series of scoping experiments, we evaluate leeches capabilities to navigating in mazes towards sources of vibration and chemo-attraction. We believe our results lay foundation for future developments of robots mimicking behaviour of leeches. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Accurate method for preoperative estimation of the right graft volume in adult-to-adult living donor liver transplantation.

PubMed

Khalaf, H; Shoukri, M; Al-Kadhi, Y; Neimatallah, M; Al-Sebayel, M

2007-06-01

Accurate estimation of graft volume is crucial to avoid small-for-size syndrome following adult-to-adult living donor liver transplantation AALDLT). Herein, we combined radiological and mathematical approaches for preoperative assessment of right graft volume. The right graft volume was preoperatively estimated in 31 live donors using two methods: first, the radiological graft volume (RGV) by computed tomography (CT) volumetry and second, a calculated graft volume (CGV) obtained by multiplying the standard liver volume by the percentage of the right graft volume (given by CT). Both methods were compared to the actual graft volume (AGV) measured during surgery. The graft recipient weight ratio (GRWR) was also calculated using all three volumes (RGV, CGV, and AGV). Lin's concordance correlation coefficient (CCC) was used to assess the agreement between AGV and both RGV and CGV. This was repeated using the GRWR measurements. The mean percentage of right graft volume was 62.4% (range, 55%-68%; SD +/- 3.27%). The CCC between AGV and RGV versus CGV was 0.38 and 0.66, respectively. The CCC between GRWR using AGV and RGV versus CGV was 0.63 and 0.88, respectively (P < .05). According to the Landis and Kock benchmark, the CGV correlated better with AGV when compared to RGV. The better correlation became even more apparent when applied to GRWR. In our experience, CGV showed a better correlation with AGV compared with the RGV. Using CGV in conjunction with RGV may be of value for a more accurate estimation of right graft volume for AALDLT.

Early Ahmed Glaucoma Valve Implantation after Penetrating Keratoplasty Leads to Better Outcomes in an Asian Population with Preexisting Glaucoma

PubMed Central

Tai, Ming-Cheng; Chen, Yi-Hao; Cheng, Jen-Hao; Liang, Chang-Min; Chen, Jiann-Torng; Chen, Ching-Long; Lu, Da-Wen

2012-01-01

Background To evaluate the efficacy of Ahmed Glaucoma Valve (AGV) surgery and the optimal interval between penetrating keratoplasty (PKP) and AGV implantation in a population of Asian patients with preexisting glaucoma who underwent PKP. Methodology/Principal Findings In total, 45 eyes of 45 patients were included in this retrospective chart review. The final intraocular pressures (IOPs), graft survival rate, and changes in visual acuity were assessed to evaluate the outcomes of AGV implantations in eyes in which AGV implantation occurred within 1 month of post-PKP IOP elevation (Group 1) and in eyes in which AGV implantation took place more than 1 month after the post-PKP IOP evaluation (Group 2). Factors that were associated with graft failure were analyzed, and the overall patterns of complications were reviewed. By their final follow-up visits, 58% of the patients had been successfully treated for glaucoma. After the operation, there were no statistically significant differences between the groups with respect to graft survival (p = 0.98), but significant differences for IOP control (p = 0.049) and the maintenance of visual acuity (VA) (p<0.05) were observed. One year after surgery, the success rates of IOP control in Group 1 and Group 2 were 80% and 46.7%, respectively, and these rates fell to 70% and 37.3%, respectively, by 2 years. Factors that were associated with a high risk of AGV failure were a diagnosis of preexisting angle-closure glaucoma, a history of previous PKP, and a preoperative IOP that was >21 mm Hg. The most common surgical complication, aside from graft failure, was hyphema. Conclusions/Significance Early AGV implantation results in a higher probability of AGV survival and a better VA outcome without increasing the risk of corneal graft failure as a result of post-PKP glaucoma drainage tube implantation. PMID:22629464

Changes in Corneal Endothelial Cell after Ahmed Glaucoma Valve Implantation and Trabeculectomy: 1-Year Follow-up.

PubMed

Kim, Min Su; Kim, Kyoung Nam; Kim, Chang-Sik

2016-12-01

To compare changes in corneal endothelial cell density (CECD) after Ahmed glaucoma valve (AGV) implantation and trabeculectomy. Changes in corneal endothelium in patients that underwent AGV implantation or trabeculectomy were prospectively evaluated. Corneal specular microscopy was performed at the central cornea using a non-contact specular microscope before surgery and 6 months and 12 months after surgery. The CECD, hexagonality of the endothelial cells, and the coefficient of variation of the cell areas were compared between the two groups. Forty eyes of 40 patients with AGV implantation and 28 eyes of 28 patients with trabeculectomy were studied. Intraocular pressure in the AGV implantation group was significantly higher than that in the trabeculectomy group ( p < 0.001), but there was no significant difference in other clinical variables between the two groups. In the AGV implantation group, the mean CECD significantly decreased by 9.4% at 6 months and 12.3% at 12 months compared with baseline values (both, p < 0.001), while it decreased by 1.9% at 6 months and 3.2% at 12 months in the trabeculectomy group ( p = 0.027 and p = 0.015, respectively). The changes at 6 months and 12 months in the AGV implantation group were significantly higher than those in the trabeculectomy group ( p = 0.030 and p = 0.027, respectively). In the AGV implantation group, there was a significant decrease in the CECD between baseline and 6 months and between 6 months and 12 months ( p < 0.001 and p = 0.005, respectively). However, in the trabeculectomy group, a significant decrease was observed only between baseline and 6 months ( p = 0.027). Both the AGV implantation group and the trabeculectomy group showed statistically significant decreases in the CECD 1 year after surgery. The decrease in CECD in the AVG implantation group was greater and persisted longer than that in the trabeculectomy group.

Comparison of Ahmed glaucoma valve implantation and trabeculectomy for glaucoma: a systematic review and meta-analysis.

PubMed

HaiBo, Tan; Xin, Kang; ShiHeng, Lu; Lin, Liu

2015-01-01

To compare the efficacy and safety of Ahmed glaucoma valve implantation (AGV) with trabeculectomy in the management of glaucoma patients. A comprehensive literature search (PubMed, Embase, Google, and the Cochrane library) was performed, including a systematic review with meta-analysis of controlled clinical trials comparing AGV versus trabeculectomy. Efficacy estimates were the weighted mean differences (WMDs) for the percentage intraocular pressure reduction (IOPR %) from baseline to end-point, the reduction in glaucoma medications, and the odds ratios (ORs) for complete and qualified success rates. Safety estimates were the relative risks (RRs) for adverse events. All outcomes were reported with a 95% confidence interval (CI). Statistical analysis was performed using the RevMan 5.0 software. Six controlled clinical trials were included in this meta-analysis. There was no significant difference between the AGV and trabeculectomy in the IOPR% (WMD = -3.04, 95% CI: -8.36- 2.26; P = 0.26). The pooled ORs comparing AGV with trabeculectomy were 0.46 (0.22, 0.99) for the complete success rate (P = 0.05) and 0.97 (0.78-1.20) for the quantified success rate (P = 0.76). No significant difference in the reduction in glaucoma medicines was observed (WMD = 0.24; 95% CI: -0.27-0.76; P = 0.35). AGV was found to be associated with a significantly lower frequency of all adverse events (RR = 0.71; 95%CI: 1.14-0.97; p = 0.001) than trabeculectomy, while the most common complications did not differ significantly (all p> 0.05). AGV was equivalent to trabeculectomy in reducing the IOP, the number of glaucoma medications, success rates, and rates of the most common complications. However, AGV was associated with a significantly lower frequency of overall adverse events.

Ahmed Versus Baerveldt Glaucoma Drainage Implantation in Patients With Markedly Elevated Intraocular Pressure (≥30 mm Hg).

PubMed

Resende, Arthur F; Moster, Marlene R; Patel, Neal S; Lee, Daniel; Dhami, Hermandeep; Pro, Michael J; Waisbourd, Michael

2016-09-01

Glaucoma patients with markedly elevated intraocular pressure (IOP) are at risk for developing severe hypotony-related complications. The goal of this study was to compare the surgical outcomes of the Ahmed Glaucoma Valve (AGV) and the Baerveldt Glaucoma Implant (BGI) in this patient population. Patients with preoperative IOP≥30 mm Hg were included. Outcome measures were: (1) surgical failure (IOP>21 mm Hg or <30% reduction from baseline or IOP≤5 mm Hg on 2 consecutive follow-up visits after 3 mo, or additional glaucoma surgery, or loss of light perception) and (2) surgical complications. A total of 75 patients were included: 37 in the AGV group and 38 in the BGI group. The mean±SD follow-up was 2.3±1.6 years for the AGV group and 2.4±1.7 years for the BGI group (P=0.643). Mean preoperative IOP was 38.7±6.5 mm Hg for the AGV group and 40.8±7.6 mm Hg for the BGI group. At the last follow-up, 10 (27.0%) patients failed in the AGV group compared with 6 (15.8%) patients in the BGI group (P=0.379). The BGI group had higher rate of flat or shallow anterior chamber (n=4, 10%) compared with the AGV group (n=0, 0%) (P=0.043). Failure rates of AGV and BGI in patients with IOP≥30 mm Hg were comparable. There were more early hypotony-related complications in the BGI group; however, none were vision threatening. Both glaucoma drainage implants were effective in treating patients with uncontrolled glaucoma in an emergency setting.

The vision guidance and image processing of AGV

NASA Astrophysics Data System (ADS)

Feng, Tongqing; Jiao, Bin

2017-08-01

Firstly, the principle of AGV vision guidance is introduced and the deviation and deflection angle are measured by image coordinate system. The visual guidance image processing platform is introduced. In view of the fact that the AGV guidance image contains more noise, the image has already been smoothed by a statistical sorting. By using AGV sampling way to obtain image guidance, because the image has the best and different threshold segmentation points. In view of this situation, the method of two-dimensional maximum entropy image segmentation is used to solve the problem. We extract the foreground image in the target band by calculating the contour area method and obtain the centre line with the least square fitting algorithm. With the help of image and physical coordinates, we can obtain the guidance information.

An Intelligent Robotic Hospital Bed for Safe Transportation of Critical Neurosurgery Patients Along Crowded Hospital Corridors.

PubMed

Wang, Chao; Savkin, Andrey V; Clout, Ray; Nguyen, Hung T

2015-09-01

We present a novel design of an intelligent robotic hospital bed, named Flexbed, with autonomous navigation ability. The robotic bed is developed for fast and safe transportation of critical neurosurgery patients without changing beds. Flexbed is more efficient and safe during the transportation process comparing to the conventional hospital beds. Flexbed is able to avoid en-route obstacles with an efficient easy-to-implement collision avoidance strategy when an obstacle is nearby and to move towards its destination at maximum speed when there is no threat of collision. We present extensive simulation results of navigation of Flexbed in the crowded hospital corridor environments with moving obstacles. Moreover, results of experiments with Flexbed in the real world scenarios are also presented and discussed.

Wound Dehiscence and Device Migration after Subconjunctival Bevacizumab Injection with Ahmed Glaucoma Valve Implantation.

PubMed

Miraftabi, Arezoo; Nilforushan, Naveed

2016-01-01

To report a complication pertaining to subconjunctival bevacizumab injection as an adjunct to Ahmed Glaucoma Valve (AGV) implantation. A 54-year-old woman with history of complicated cataract surgery was referred for advanced intractable glaucoma. AGV implantation with adjunctive subconjunctival bevacizumab (1.25 mg) was performed with satisfactory results during the first postoperative week. However, 10 days after surgery, she developed wound dehiscence and tube exposure. The second case was a 33-year-old man with history of congenital glaucoma and uncontrolled IOP who developed AGV exposure and wound dehiscence after surgery. In both cases, for prevention of endophthalmitis and corneal damage by the unstable tube, the shunt was removed and the conjunctiva was re-sutured. The potential adverse effect of subconjunctival bevacizumab injection on wound healing should be considered in AGV surgery.

Wound Dehiscence and Device Migration after Subconjunctival Bevacizumab Injection with Ahmed Glaucoma Valve Implantation

PubMed Central

Miraftabi, Arezoo; Nilforushan, Naveed

2016-01-01

Purpose: To report a complication pertaining to subconjunctival bevacizumab injection as an adjunct to Ahmed Glaucoma Valve (AGV) implantation. Case Report: A 54-year-old woman with history of complicated cataract surgery was referred for advanced intractable glaucoma. AGV implantation with adjunctive subconjunctival bevacizumab (1.25 mg) was performed with satisfactory results during the first postoperative week. However, 10 days after surgery, she developed wound dehiscence and tube exposure. The second case was a 33-year-old man with history of congenital glaucoma and uncontrolled IOP who developed AGV exposure and wound dehiscence after surgery. In both cases, for prevention of endophthalmitis and corneal damage by the unstable tube, the shunt was removed and the conjunctiva was re-sutured. Conclusion: The potential adverse effect of subconjunctival bevacizumab injection on wound healing should be considered in AGV surgery. PMID:27195095

49 CFR 268.11 - Project eligibility standards.

Code of Federal Regulations, 2010 CFR

2010-10-01

... to run the Corridor or the project—once built and paid for—as a completely self-sustaining entity, in... location of their critical habitat; identification of navigable waterways, wetlands and other sensitive...

Comparison of the Ahmed glaucoma valve with the Baerveldt glaucoma implant: a meta-analysis.

PubMed

Wang, Yi-Wen; Wang, Ping-Bao; Zeng, Chao; Xia, Xiao-Bo

2015-10-13

This study aims to compare the efficacy and safety of the Ahmed glaucoma valve (AGV) with the Baerveldt glaucoma implant (BGI) in glaucoma patients. Databases were searched to identify studies that met pre-stated inclusion criteria, involving randomized controlled clinical trials (RCTs) and non-randomized controlled clinical trials. Treatment effect was analyzed using a random-effect model. Ten controlled clinical trials (1048 eyes) were analyzed, involving two RCTs and eight retrospective comparative studies. Short-term results (6-18 months) and long-term results (>18 months) were analyzed separately. There was no significant difference in the success rate for short-term follow-up between the AGV and BGI groups (5 studies, 714 eyes, odds ratio [OR]: 0.97; 95 % confidence interval [CI]: 0.56, 1.66; P = 0.90). For long-term pooled results (7 studies, 835 eyes), the success rate of AGVs was lower than that of BGIs (OR: 0.73; 95 % CI: 0.54, 0.99, P = 0.04), However, subgroup and sensitivity analyses did not show a significant difference in the success rate between the two groups (P ≥0.05). The AGV group had a higher mean intraocular pressure than the BGI group in short-term (6 studies, 685 eyes, weighted mean difference [WMD]: 2.12 mmHg; 95 % CI: 0.72-3.52; P <0.05) and long-term pooled results (7 studies, 659 eyes, WMD: 1.85 mmHg; 95 % CI: 0.43, 3.28; P = 0.01). The BGI group required fewer glaucoma medications after implantation than the AGV group in two follow-up periods (all P <0.05). The AGV was found to be associated with a significantly lower frequency of total complications (8 studies, 971 eyes, OR: 0.67; 95 % CI: 0.50-0.90; P = 0.007) and severe complications (8 studies, 971 eyes, OR: 0.57; 95 % CI: 0.36-0.91; P = 0.02) than the BGI. The study showed no significant difference in success rate between the two groups. The BGI was more effective for control of intraocular pressure and required fewer medications than the AGV, but the AGV had lower incidence of total and severe complications than the BGI.

The Montreux Convention Regarding the Turkish Straits and Its Importance after the South Ossetia War

DTIC Science & Technology

2009-03-01

had inevitable consequences for Turkey. Caught between Russia, a neighbor and major economic partner, and the U.S., a superpower and traditional ally...than double the extent of the territorial sea, it is considered a corridor of the high seas. Nihan Unlu notes that such a corridor falls outside the...navigation if there exists through the strait a route through the high seas or through an exclusive economic zone of similar convenience with respect

Navigation Challenges in the MAVEN Science Phase

NASA Technical Reports Server (NTRS)

Demcak, Stuart; Young, Brian; Lam, Try; Trawny, Nikolas; Lee, Clifford; Anderson, Rodney; Broschart, Stephen; Ballard, Christopher; Folta, David C.

2012-01-01

The MAVEN spacecraft will explore Mars' upper atmosphere. The primary science phase will last one (Earth) year, during which the spacecraft will be in an elliptical 4.5 hour orbit at an inclination of 75 degrees. The 75 degree inclination results in the orbit periapsis oscillating between +/-75 degrees latitude, thus naturally covering most Mars latitudes during the primary mission. The orbit will be controlled via maneuvers so that the maximum orbit density remains in a density corridor. This results in the MAVEN science phase being in a light aerobraking type orbit of around 160 km for an extended period. In addition, the mission has significantly less tracking data than aerobraking phases of other missions, and even less than other NASA Mars orbiter primary phases. This results in significant challenges for the Navigation Team. They can be summarized as a difficulty in determining the current density profile, which maps into degraded trajectory predictions and less accurate control over the spacecraft location in the targeted density corridor via maneuvers. This paper describes these challenges and the Navigation Team's plans to meet them.

Ahmed glaucoma valve in eyes with preexisting episcleral encircling element.

PubMed

Choudhari, Nikhil Shreeram; George, Ronnie; Shantha, Balekudaru; Neog, Aditya; Tripathi, Shweta; Srinivasan, Bhaskar; Vijaya, Lingam

2014-05-01

To describe the use of Ahmed glaucoma valve (AGV) in the management of intractable glaucoma in eyes with a preexisting episcleral encircling element. This is a retrospective, consecutive, noncomparative study. The study included 12 eyes of 12 patients with a preexisting episcleral encircling element that underwent implantation of silicone AGV to treat intractable glaucoma during January 2009 to September 2010. The mean patient age was 25.6 (standard deviation 17.1) years. Five (41.6%) patients were monocular. The indications for AGV were varied. The mean duration between placement of episcleral encircling element and implantation of AGV was 30.5 (33.8) months. The mean follow-up was 37.4 (22.9) weeks. Preoperatively, the mean intraocular pressure (IOP) was 31.4 (7.9) mmHg and the mean antiglaucoma medications were 2.8. At the final postoperative follow-up, the mean IOP was 12.5 (3.5) mmHg and the mean number of antiglaucoma medications was 0.8 (P < 0.001). The complications observed over the follow-up period did include corneal graft failure in three eyes, tube erosion in two eyes and rhegmatogenous retinal detachment in one eye. AGV is an effective option in the management of intractable glaucoma in eyes with a preexisting episcleral encircling element keeping in mind the possibility of significant postoperative complications.

Fixed-Wing Micro Aerial Vehicle for Accurate Corridor Mapping

NASA Astrophysics Data System (ADS)

Rehak, M.; Skaloud, J.

2015-08-01

In this study we present a Micro Aerial Vehicle (MAV) equipped with precise position and attitude sensors that together with a pre-calibrated camera enables accurate corridor mapping. The design of the platform is based on widely available model components to which we integrate an open-source autopilot, customized mass-market camera and navigation sensors. We adapt the concepts of system calibration from larger mapping platforms to MAV and evaluate them practically for their achievable accuracy. We present case studies for accurate mapping without ground control points: first for a block configuration, later for a narrow corridor. We evaluate the mapping accuracy with respect to checkpoints and digital terrain model. We show that while it is possible to achieve pixel (3-5 cm) mapping accuracy in both cases, precise aerial position control is sufficient for block configuration, the precise position and attitude control is required for corridor mapping.

33 CFR 334.770 - Gulf of Mexico and St. Andrew Sound, south of East Bay, Fla., Tyndall Drone Launch Corridor...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Gulf of Mexico and St. Andrew... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.770 Gulf of Mexico and St....; restricted area. (a) The area. The waters of the Gulf of Mexico and St. Andrew Sound within an area described...

33 CFR 334.770 - Gulf of Mexico and St. Andrew Sound, south of East Bay, Fla., Tyndall Drone Launch Corridor...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Gulf of Mexico and St. Andrew... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.770 Gulf of Mexico and St....; restricted area. (a) The area. The waters of the Gulf of Mexico and St. Andrew Sound within an area described...

33 CFR 334.770 - Gulf of Mexico and St. Andrew Sound, south of East Bay, Fla., Tyndall Drone Launch Corridor...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Gulf of Mexico and St. Andrew... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.770 Gulf of Mexico and St....; restricted area. (a) The area. The waters of the Gulf of Mexico and St. Andrew Sound within an area described...

33 CFR 334.770 - Gulf of Mexico and St. Andrew Sound, south of East Bay, Fla., Tyndall Drone Launch Corridor...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Gulf of Mexico and St. Andrew... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.770 Gulf of Mexico and St....; restricted area. (a) The area. The waters of the Gulf of Mexico and St. Andrew Sound within an area described...

33 CFR 334.770 - Gulf of Mexico and St. Andrew Sound, south of East Bay, Fla., Tyndall Drone Launch Corridor...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Gulf of Mexico and St. Andrew... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.770 Gulf of Mexico and St....; restricted area. (a) The area. The waters of the Gulf of Mexico and St. Andrew Sound within an area described...

Two-year survival of Ahmed valve implantation in the first 2 years of life with and without intraoperative mitomycin-C.

PubMed

Al-Mobarak, Faisal; Khan, Arif O

2009-10-01

To evaluate the effect of intraoperative mitomycin-C (MMC) on polypropylene Ahmed glaucoma valve (AGV) survival 2 years after implantation during the first 2 years of life. Retrospective institutional comparative series (1995-2005). Thirty-one eyes of 27 patients (23 unilateral, 4 bilateral; 16 boys, 11 girls) undergoing AGV implantation at a mean age of 11.1 months (standard deviation [SD], 5.46), all of which had 2 years of regular postoperative follow-up. MMC was applied intraoperatively in those cases in the area of AGV implantation in 16 (52%) and was not applied in 15 (48%). In some eyes, MMC was applied intraoperatively in cases done by the surgeons who routinely used MMC for all AGV implantation in young children. Failure was defined as intraocular pressure (IOP) > 22 mmHg with or without glaucoma medications, the need for an additional procedure for IOP control, or the occurrence of significant complications (e.g., endophthalmitis, retinal detachment, persistent hypotony [IOP < 5 mmHg]). Survival was the absence of failure. Failure or significant complications as defined. Mean survival for the non-MMC eyes (22.15 months; standard error [SE], 1.93) was significantly longer than survival for the MMC eyes (16.25 months; SE, 2.17) by the log-rank test (P = 0.025). The difference in cumulative survival at 2 years was also significantly different by log-rank test (P = 0.001): 80.0% (SE 10.3) and 31.3% (SE 11.6), respectively. Rather than improved survival, intraoperative use of MMC was associated with shorter survival 2 years after AGV implantation during the first 2 years of life. We speculate that MMC-induced tissue death can stimulate a reactive fibrosis around the AGV in very young eyes.

Pericardium Plug in the Repair of the Corneoscleral Fistula After Ahmed Glaucoma Valve Explantation

PubMed Central

Yoo, Chungkwon; Kwon, Sung Wook

2008-01-01

We report four cases in which a pericardium (Tutoplast®) plug was used to repair a corneoscleral fistula after Ahmed Glaucoma Valve (AGV) explantation. In four cases in which the AGV tube had been exposed, AGV explantation was performed using a pericardium (Tutoplast®) plug to seal the defect previously occupied by the tube. After debridement of the fistula, a piece of processed pericardium (Tutoplast®), measured 1 mm in width, was plugged into the fistula and secured with two interrupted 10-0 nylon sutures. To control intraocular pressure, a new AGV was implanted elsewhere in case 1, phaco-trabeculectomy was performed concurrently in case 2, cyclophotocoagulation was performed postoperatively in case 3 and anti-glaucomatous medication was added in case 4. No complication related to the fistula developed at the latest follow-up (range: 12~26 months). The pericardium (Tutoplast®) plug seems to be an effective method in the repair of corneoscleral fistulas resulting from explantation of glaucoma drainage implants. PMID:19096247

Changes in corneal endothelial cell density and the cumulative risk of corneal decompensation after Ahmed glaucoma valve implantation.

PubMed

Kim, Kyoung Nam; Lee, Sung Bok; Lee, Yeon Hee; Lee, Jong Joo; Lim, Hyung Bin; Kim, Chang-Sik

2016-07-01

To evaluate changes in the corneal endothelial cell density (ECD) and corneal decompensation following Ahmed glaucoma valve (AGV) implantation. This study was retrospective and observational case series. Patients with refractory glaucoma who underwent AGV implantation and were followed >5 years were consecutively enrolled. We reviewed the medical records, including the results of central corneal specular microscopy. Of the 127 enrolled patients, the annual change in ECD (%) was determined using linear regression for 72 eyes evaluated at least four times using serial specular microscopic examination and compared with 31 control eyes (fellow glaucomatous eyes under medical treatment). The main outcome measures were cumulative risk of corneal decompensation and differences in the ECD loss rates between subjects and controls. The mean follow-up after AGV implantation was 43.1 months. There were no cases of postoperative tube-corneal touch. The cumulative risk of corneal decompensation was 3.3%, 5 years after AGV implantation. There was a more rapid loss of ECD in the 72 subject eyes compared with the 31 controls (-7.0% and -0.1%/year, respectively; p<0.001). However, the rate of loss decreased over time and statistical significance compared with control eyes disappeared after 2 years postoperatively: -10.7% from baseline to 1 year (p<0.01), -7.0% from 1 year to 2 years (p=0.037), -4.2% from 2 years to 3 years (p=0.230) and -2.7% from 3 years to the final follow-up (p=0.111). In case of uncomplicated AGV implantation, the cumulative risk of corneal decompensation was 3.3%, 5 years after the operation. The ECD loss was statistically greater in eyes with AGV than in control eyes without AGV, but the difference was significant only up to 2 years post surgery. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

A Model for an Angular Velocity-Tuned Motion Detector Accounting for Deviations in the Corridor-Centering Response of the Bee.

PubMed

Cope, Alex J; Sabo, Chelsea; Gurney, Kevin; Vasilaki, Eleni; Marshall, James A R

2016-05-01

We present a novel neurally based model for estimating angular velocity (AV) in the bee brain, capable of quantitatively reproducing experimental observations of visual odometry and corridor-centering in free-flying honeybees, including previously unaccounted for manipulations of behaviour. The model is fitted using electrophysiological data, and tested using behavioural data. Based on our model we suggest that the AV response can be considered as an evolutionary extension to the optomotor response. The detector is tested behaviourally in silico with the corridor-centering paradigm, where bees navigate down a corridor with gratings (square wave or sinusoidal) on the walls. When combined with an existing flight control algorithm the detector reproduces the invariance of the average flight path to the spatial frequency and contrast of the gratings, including deviations from perfect centering behaviour as found in the real bee's behaviour. In addition, the summed response of the detector to a unit distance movement along the corridor is constant for a large range of grating spatial frequencies, demonstrating that the detector can be used as a visual odometer.

A Model for an Angular Velocity-Tuned Motion Detector Accounting for Deviations in the Corridor-Centering Response of the Bee

PubMed Central

Sabo, Chelsea; Gurney, Kevin; Vasilaki, Eleni; Marshall, James A. R.

2016-01-01

We present a novel neurally based model for estimating angular velocity (AV) in the bee brain, capable of quantitatively reproducing experimental observations of visual odometry and corridor-centering in free-flying honeybees, including previously unaccounted for manipulations of behaviour. The model is fitted using electrophysiological data, and tested using behavioural data. Based on our model we suggest that the AV response can be considered as an evolutionary extension to the optomotor response. The detector is tested behaviourally in silico with the corridor-centering paradigm, where bees navigate down a corridor with gratings (square wave or sinusoidal) on the walls. When combined with an existing flight control algorithm the detector reproduces the invariance of the average flight path to the spatial frequency and contrast of the gratings, including deviations from perfect centering behaviour as found in the real bee’s behaviour. In addition, the summed response of the detector to a unit distance movement along the corridor is constant for a large range of grating spatial frequencies, demonstrating that the detector can be used as a visual odometer. PMID:27148968

Modeling and deadlock avoidance of automated manufacturing systems with multiple automated guided vehicles.

PubMed

Wu, Naiqi; Zhou, MengChu

2005-12-01

An automated manufacturing system (AMS) contains a number of versatile machines (or workstations), buffers, an automated material handling system (MHS), and is computer-controlled. An effective and flexible alternative for implementing MHS is to use automated guided vehicle (AGV) system. The deadlock issue in AMS is very important in its operation and has extensively been studied. The deadlock problems were separately treated for parts in production and transportation and many techniques were developed for each problem. However, such treatment does not take the advantage of the flexibility offered by multiple AGVs. In general, it is intractable to obtain maximally permissive control policy for either problem. Instead, this paper investigates these two problems in an integrated way. First we model an AGV system and part processing processes by resource-oriented Petri nets, respectively. Then the two models are integrated by using macro transitions. Based on the combined model, a novel control policy for deadlock avoidance is proposed. It is shown to be maximally permissive with computational complexity of O (n2) where n is the number of machines in AMS if the complexity for controlling the part transportation by AGVs is not considered. Thus, the complexity of deadlock avoidance for the whole system is bounded by the complexity in controlling the AGV system. An illustrative example shows its application and power.

Ahmed glaucoma valve in eyes with preexisting episcleral encircling element

PubMed Central

Choudhari, Nikhil Shreeram; George, Ronnie; Shantha, Balekudaru; Neog, Aditya; Tripathi, Shweta; Srinivasan, Bhaskar; Vijaya, Lingam

2014-01-01

Background: To describe the use of Ahmed glaucoma valve (AGV) in the management of intractable glaucoma in eyes with a preexisting episcleral encircling element. Materials and Methods: This is a retrospective, consecutive, noncomparative study. The study included 12 eyes of 12 patients with a preexisting episcleral encircling element that underwent implantation of silicone AGV to treat intractable glaucoma during January 2009 to September 2010. Results: The mean patient age was 25.6 (standard deviation 17.1) years. Five (41.6%) patients were monocular. The indications for AGV were varied. The mean duration between placement of episcleral encircling element and implantation of AGV was 30.5 (33.8) months. The mean follow-up was 37.4 (22.9) weeks. Preoperatively, the mean intraocular pressure (IOP) was 31.4 (7.9) mmHg and the mean antiglaucoma medications were 2.8. At the final postoperative follow-up, the mean IOP was 12.5 (3.5) mmHg and the mean number of antiglaucoma medications was 0.8 (P < 0.001). The complications observed over the follow-up period did include corneal graft failure in three eyes, tube erosion in two eyes and rhegmatogenous retinal detachment in one eye. Conclusion: AGV is an effective option in the management of intractable glaucoma in eyes with a preexisting episcleral encircling element keeping in mind the possibility of significant postoperative complications. PMID:24881603

Intracameral air injection during Ahmed glaucoma valve implantation in neovascular glaucoma for the prevention of tube obstruction with blood clot: Case Report.

PubMed

Hwang, Sung Ha; Yoo, Chungkwon; Kim, Yong Yeon; Lee, Dae Young; Nam, Dong Heun; Lee, Jong Yeon

2017-12-01

Glaucoma drainage implant surgery is a treatment option for the management of neovascular glaucoma. However, tube obstruction by blood clot after Ahmed glaucoma valve (AGV) implantation is an unpredictable clinically challenging situation. We report 4 cases using intracameral air injection for the prevention of the tube obstruction of AGV by blood clot. The first case was a 57-year-old female suffering from ocular pain because of a tube obstruction with blood clot after AGV implantation in neovascular glaucoma. Surgical blood clot removal was performed. However, intractable bleeding was noted during the removal of the blood clot, and so intracameral air injection was performed to prevent a recurrent tube obstruction. After the procedure, although blood clots formed around the tube, the tube opening where air could touch remained patent. In 3 cases of neovascular glaucoma with preoperative severe intraocular hemorrhages, intracameral air injection and AGV implantation were performed simultaneously. In all 3 cases, tube openings were patent. It appears that air impeded the blood clots formation in front of the tube opening. Intracameral air injection could be a feasible option to prevent tube obstruction of AGV implant with a blood clot in neovascular glaucoma with high risk of tube obstruction. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

C-TIC Console Operator's User Manual

DOT National Transportation Integrated Search

1996-07-01

The C-TIC Console Operator's User Manual is designed to assist the operator at : the Corridor Transportation Information Center with the navigation and use of : the application programs in the C-TIC. This document will concentrate solely on : the ext...

River-corridor habitat dynamics, Lower Missouri River

USGS Publications Warehouse

Jacobson, Robert B.

2010-01-01

Intensive management of the Missouri River for navigation, flood control, and power generation has resulted in substantial physical changes to the river corridor. Historically, the Missouri River was characterized by a shifting, multithread channel and abundant unvegetated sandbars. The shifting channel provided a wide variety of hydraulic environments and large areas of connected and unconnected off-channel water bodies.Beginning in the early 1800s and continuing to the present, the channel of the Lower Missouri River (downstream from Sioux City, Iowa) has been trained into a fast, deep, single-thread channel to stabilize banks and maintain commercial navigation. Wing dikes now concentrate the flow, and revetments and levees keep the channel in place and disconnect it from the flood plain. In addition, reservoir regulation of the Missouri River upstream of Yankton, South Dakota, has substantially changed the annual hydrograph, sediment loads, temperature regime, and nutrient budgets.While changes to the Missouri River have resulted in broad social and economic benefits, they have also been associated with loss of river-corridor habitats and diminished populations of native fish and wildlife species. Today, Missouri River stakeholders are seeking ways to restore some natural ecosystem benefits of the Lower Missouri River without compromising traditional economic uses of the river and flood plain.

Outcomes and Complications of Ahmed Tube Implantation in Asian Eyes.

PubMed

Choo, Jessica Qian Hui; Chen, Ziyou David; Koh, Victor; Liang, Shen; Aquino, Cecilia Maria; Sng, Chelvin; Chew, Paul

2018-06-18

There is a lack of long-term Asian studies on the efficacy and safety of Ahmed glaucoma valve (AGV) implantation. This study seeks to determine the outcomes and complications of AGV implantation in Asians. Retrospective review of AGV surgeries performed at a single centre in Singapore was conducted. 76 patients with primary and secondary glaucoma who underwent their first AGV surgery from 1st January 2010 to 31st December 2012 were considered for our study. Primary outcomes evaluated were: failure, intra-ocular pressure, best-corrected visual acuity (BCVA), number of IOP-lowering medications and complications. Failure was defined by: IOP >21▒mm Hg on two consecutive visits after 3 months, IOP ≤5▒mm Hg on two consecutive visits after 3 months, reoperation for glaucoma, removal of implant or loss of light perception vision. Mean follow-up duration was 33.2±6.9 months. There was significant reduction in IOP (mean reduction 25.9%, P<0.001) and number of IOP-lowering medications (mean reduction 77.8%, P<0.001) at 3 years. Absolute failure rate was 23.9% at 3 years with no difference between eyes with or without previous trabeculectomy and between eyes with primary or secondary glaucoma. Occurrence of post-operative hyphema was a significant risk factor for failure. Commonest post-operative complications were hyphema and tube exposure. At 3 years after AGV surgery in Asian eyes, less than one-quarter of the eyes fulfilled the criteria for surgical failure.

Short- to long-term results of Ahmed glaucoma valve in the management of elevated intraocular pressure in patients with pediatric uveitis.

PubMed

Eksioglu, Umit; Yakin, Mehmet; Sungur, Gulten; Satana, Banu; Demirok, Gulizar; Balta, Ozgur; Ornek, Firdevs

2017-06-01

The aim of this study was to evaluate the long-term outcome of Ahmed glaucoma valve (AGV) implant for elevated intraocular pressure (IOP) in pediatric patients with uveitis. This was a retrospective chart review. The study included 16 eyes (11 children) with uveitis. Success was defined as having IOP between 6 and 21 mm Hg with (qualified success) or without (complete success) antiglaucoma medications and without the need for further glaucoma or tube extraction surgery. Mean age of patients at the time of AGV implantation was 14.19 ± 3.25 years. AGV implantation was the first glaucoma surgical procedure in 12 eyes (75%). Average postoperative follow-up period was 64.46 ± 33.56 months. Mean preoperative IOP was 33.50 ± 7.30 mm Hg versus 12.69 ± 3.20 mm Hg at the last follow-up visit (p < 0.001). Three eyes (18.7%) were determined as cases of "failure" because of tube removal in 2 eyes and a second AGV implantation in 1 eye. The cumulative probability of complete success was 68.8% at 6 months, 56.3% at 12 months, 49.2% at 36 months, 42.2% at 48 months, and 35.2% at 84 months, and the cumulative probability of eyes without complication was 75.0% at 6 months, 66.7% at 24 months, 58.3% at 36 months, 48.6% at 48 months and 24.3% at 108 months based on Kaplan-Meier survival analysis. Although AGV implant is an effective choice in the management of elevated IOP in pediatric uveitis, antiglaucoma medications are frequently needed for control of IOP. Tube exposure is an important complication in the long term. Differential diagnosis between relapse of uveitis and endophthalmitis is important in patients who received AGV implantation. Copyright © 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

Evaluation of success after second Ahmed glaucoma valve implantation.

PubMed

Nilforushan, Naveed; Yadgari, Maryam; Jazayeri, Anis Alsadat; Karimi, Nasser

2016-03-01

To evaluate the outcome of the second Ahmed glaucoma valve (AGV) surgery in eyes with failed previous AGV surgery. Retrospective case series. Following chart review, 36 eyes of 34 patients with second AGV implantation were enrolled in this study. The primary outcome measure was surgical success defined in terms of intraocular pressure (IOP) control using two criteria: Success was defined as IOP ≤21 mmHg (criterion 1) and IOP ≤16 mmHg (criterion 2), with at least 20% reduction in IOP, either with no medication (complete success) or with no more than two medications (qualified success). Kaplan-Meier survival analysis was used to determine the probability of surgical success. The average age of the patients was 32.7 years (range 4-65), and the mean duration of follow-up was 21.4 months (range 6-96). Preoperatively, the mean IOP was 26.94 mmHg (standard deviation [SD] 7.03), and the patients were using 2.8 glaucoma medications on average (SD 0.9). The mean IOP decreased significantly to 13.28 mmHg (SD 3.59) at the last postoperative visit (P = 0.00) while the patients needed even fewer glaucoma medications on average (1.4 ± 1.1, P = 0.00). Surgical success of second glaucoma drainage devices (Kaplan-Meier analysis), according to criterion 1, at 6, 12, 18, and 42 months was 94%, 85%, 80%, and 53% respectively, and according to criterion 2, was 94%, 85%, 75%, and 45%, respectively. Repeated AGV implantation seems to be a safe modality of treatment with acceptable success rate in cases with failed previous AGV surgery.

Ahmed glaucoma valve in post-penetrating-keratoplasty glaucoma: A critically evaluated prospective clinical study

PubMed Central

Panda, Anita; Prakash, Vadivelu Jaya; Dada, Tanuj; Gupta, Anoop Kishore; Khokhar, Sudarshan; Vanathi, Murugesan

2011-01-01

Aim: The aim was to evaluate the outcome of Ahmed glaucoma valve (AGV) in post-penetrating-keratoplasty glaucoma (PKPG). Materials and Methods: In this prospective study, 20 eyes of 20 adult patients with post-PKPG with intraocular pressure (IOP) >21 mmHg, on two or more antiglaucoma medications, underwent AG (model FP7) implantation and were followed up for a minimum of 6 months. Absolute success was defined as 5

Delicate Ag/V2O5/TiO2 ternary nanostructures as a high-performance photocatalyst

NASA Astrophysics Data System (ADS)

Zhu, Xiao-Dong; Zheng, Ya-Lun; Feng, Yu-Jie; Sun, Ke-Ning

2018-02-01

Here we report, for the first time, delicate ternary nanostructures consisting of TiO2 nanoplatelets co-doped with Ag and V2O5 nanoparticles. The relationship between the composition and the morphology is systematically studied. We find a remarkable synergistic effect among the three components, and the resulting delicate Ag/V2O5/TiO2 ternary nanostructures exhibit a superior photocatalytic performance over neat TiO2 nanoplatelets as well as Ag/TiO2 and V2O5/TiO2 binary nanostructures for the degradation of methyl orange. We believe our delicate Ag/V2O5/TiO2 ternary nanostructures may lay a basis for developing next-generating, high-performance composite photocatalysts.

Predicting the continuum between corridors and barriers to animal movements using Step Selection Functions and Randomized Shortest Paths.

PubMed

Panzacchi, Manuela; Van Moorter, Bram; Strand, Olav; Saerens, Marco; Kivimäki, Ilkka; St Clair, Colleen C; Herfindal, Ivar; Boitani, Luigi

2016-01-01

The loss, fragmentation and degradation of habitat everywhere on Earth prompts increasing attention to identifying landscape features that support animal movement (corridors) or impedes it (barriers). Most algorithms used to predict corridors assume that animals move through preferred habitat either optimally (e.g. least cost path) or as random walkers (e.g. current models), but neither extreme is realistic. We propose that corridors and barriers are two sides of the same coin and that animals experience landscapes as spatiotemporally dynamic corridor-barrier continua connecting (separating) functional areas where individuals fulfil specific ecological processes. Based on this conceptual framework, we propose a novel methodological approach that uses high-resolution individual-based movement data to predict corridor-barrier continua with increased realism. Our approach consists of two innovations. First, we use step selection functions (SSF) to predict friction maps quantifying corridor-barrier continua for tactical steps between consecutive locations. Secondly, we introduce to movement ecology the randomized shortest path algorithm (RSP) which operates on friction maps to predict the corridor-barrier continuum for strategic movements between functional areas. By modulating the parameter Ѳ, which controls the trade-off between exploration and optimal exploitation of the environment, RSP bridges the gap between algorithms assuming optimal movements (when Ѳ approaches infinity, RSP is equivalent to LCP) or random walk (when Ѳ → 0, RSP → current models). Using this approach, we identify migration corridors for GPS-monitored wild reindeer (Rangifer t. tarandus) in Norway. We demonstrate that reindeer movement is best predicted by an intermediate value of Ѳ, indicative of a movement trade-off between optimization and exploration. Model calibration allows identification of a corridor-barrier continuum that closely fits empirical data and demonstrates that RSP outperforms models that assume either optimality or random walk. The proposed approach models the multiscale cognitive maps by which animals likely navigate real landscapes and generalizes the most common algorithms for identifying corridors. Because suboptimal, but non-random, movement strategies are likely widespread, our approach has the potential to predict more realistic corridor-barrier continua for a wide range of species. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Safety in passenger ships: The influence of environmental design characteristics on people's perception of safety.

PubMed

Ahola, Markus; Mugge, Ruth

2017-03-01

Although objective safety is a widely studied topic in ergonomics, subjective safety has received far less research attention. Nevertheless, most of human decision-making and behavior depends on how we perceive our environment. This study investigates the effects of various environmental design characteristics on people's safety perception in a passenger ship context. Five different environmental design characteristics were manipulated to increase the openness of the space or to create more clear navigation, resulting in 20 different cabin corridors for a passenger ship. Ninety-seven respondents were asked to rate these corridors on the perceived safety in an experiment. The results showed that people feel more safe when the corridors have a curved ceiling, when the walls do not have a split-level design, and when there is a view to the outside. Designers can use these insights when designing future environments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Autonomous Visual Navigation of an Indoor Environment Using a Parsimonious, Insect Inspired Familiarity Algorithm

PubMed Central

Brayfield, Brad P.

2016-01-01

The navigation of bees and ants from hive to food and back has captivated people for more than a century. Recently, the Navigation by Scene Familiarity Hypothesis (NSFH) has been proposed as a parsimonious approach that is congruent with the limited neural elements of these insects’ brains. In the NSFH approach, an agent completes an initial training excursion, storing images along the way. To retrace the path, the agent scans the area and compares the current scenes to those previously experienced. By turning and moving to minimize the pixel-by-pixel differences between encountered and stored scenes, the agent is guided along the path without having memorized the sequence. An important premise of the NSFH is that the visual information of the environment is adequate to guide navigation without aliasing. Here we demonstrate that an image landscape of an indoor setting possesses ample navigational information. We produced a visual landscape of our laboratory and part of the adjoining corridor consisting of 2816 panoramic snapshots arranged in a grid at 12.7-cm centers. We show that pixel-by-pixel comparisons of these images yield robust translational and rotational visual information. We also produced a simple algorithm that tracks previously experienced routes within our lab based on an insect-inspired scene familiarity approach and demonstrate that adequate visual information exists for an agent to retrace complex training routes, including those where the path’s end is not visible from its origin. We used this landscape to systematically test the interplay of sensor morphology, angles of inspection, and similarity threshold with the recapitulation performance of the agent. Finally, we compared the relative information content and chance of aliasing within our visually rich laboratory landscape to scenes acquired from indoor corridors with more repetitive scenery. PMID:27119720

76 FR 37261 - Establishment of Helicopter Area Navigation (RNAV) Routes; Northeast United States

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-27

...; Northeast United States AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY...) structure and designates two helicopter RNAV routes (TK-routes) in the northeast corridor between the... Register a notice of proposed rulemaking to establish two helicopter RNAV routes in Northeast United States...

Evaluation of success after second Ahmed glaucoma valve implantation

PubMed Central

Nilforushan, Naveed; Yadgari, Maryam; Jazayeri, Anis Alsadat; Karimi, Nasser

2016-01-01

Purpose: To evaluate the outcome of the second Ahmed glaucoma valve (AGV) surgery in eyes with failed previous AGV surgery. Design: Retrospective case series. Patients and Methods: Following chart review, 36 eyes of 34 patients with second AGV implantation were enrolled in this study. The primary outcome measure was surgical success defined in terms of intraocular pressure (IOP) control using two criteria: Success was defined as IOP ≤21 mmHg (criterion 1) and IOP ≤16 mmHg (criterion 2), with at least 20% reduction in IOP, either with no medication (complete success) or with no more than two medications (qualified success). Kaplan–Meier survival analysis was used to determine the probability of surgical success. Results: The average age of the patients was 32.7 years (range 4–65), and the mean duration of follow-up was 21.4 months (range 6–96). Preoperatively, the mean IOP was 26.94 mmHg (standard deviation [SD] 7.03), and the patients were using 2.8 glaucoma medications on average (SD 0.9). The mean IOP decreased significantly to 13.28 mmHg (SD 3.59) at the last postoperative visit (P = 0.00) while the patients needed even fewer glaucoma medications on average (1.4 ± 1.1, P = 0.00). Surgical success of second glaucoma drainage devices (Kaplan–Meier analysis), according to criterion 1, at 6, 12, 18, and 42 months was 94%, 85%, 80%, and 53% respectively, and according to criterion 2, was 94%, 85%, 75%, and 45%, respectively. Conclusion: Repeated AGV implantation seems to be a safe modality of treatment with acceptable success rate in cases with failed previous AGV surgery. PMID:27146930

Comparison of the Outcome of Silicone Ahmed Glaucoma Valve Implantation with a Surface Area between 96 and 184 mm2 in Adult Eyes

PubMed Central

Koh, Kyung Min; Hwang, Young Hoon; Jung, Jong Jin; Sohn, Yong Ho

2013-01-01

Purpose To compare the success rates, complications, and visual outcomes between silicone Ahmed glaucoma valve (AGV) implantation with 96 mm2 (FP8) or 184 mm2 (FP7) surface areas. Methods This study is a retrospective review of the records from 132 adult patients (134 eyes) that underwent silicone AGV implant surgery. Among them, the outcomes of 24 eyes from 24 patients with refractory glaucoma who underwent FP8 AGV implantation were compared with 76 eyes from 76 patients who underwent FP7 AGV implantation. Preoperative and postoperative data, including intraocular pressure (IOP), visual acuity, number of medications, and complications were compared between the 2 groups. Results There were no significant differences in baseline characteristics between the 2 groups (p > 0.05). The postoperative visual acuity of the patients in the FP8 group was better than that of the patients in the FP7 group in some early postoperative periods (p < 0.05); however, after 10 postoperative months, visual acuity was not significantly different through the 3-year follow-up period (p > 0.05). Postoperative IOP was not significantly different between the 2 groups (p > 0.05) except for IOP on postoperative day 1 (11.42 mmHg for the FP7 group and 7.42 mmHg for the FP8 group; p = 0.031). There was no statistical difference in success rates, final IOP, number of medications, or complication rates between the 2 groups (p > 0.05). Conclusions The FP7 and FP8 AGV implants showed no difference in terms of vision preservation, IOP reduction, and number of glaucoma medications required. PMID:24082774

Adjunctive triamcinolone acetonide for Ahmed glaucoma valve implantation: a randomized clinical trial.

PubMed

Yazdani, Shahin; Doozandeh, Azadeh; Pakravan, Mohammad; Ownagh, Vahid; Yaseri, Mehdi

2017-06-26

To evaluate the effect of intraoperative sub-Tenon injection of triamcinolone acetonide (TA) as an adjunct to Ahmed glaucoma valve (AGV) implantation. In this triple-blind randomized clinical trial, 104 eyes with refractory glaucoma were randomly assigned to conventional AGV (non-TA group) or AGV with adjunctive triamcinolone (TA group). In the TA group, 10 mg TA was injected in the sub-Tenon space around the AGV plate intraoperatively. Patients were followed for 1 year. The main outcome measure was intraocular pressure (IOP). Other outcome measures included best-corrected visual acuity (BCVA), occurrence of hypertensive phase (HP), peak IOP, number of antiglaucoma medications, and complications. A total of 90 patients were included in the final analysis. Mean IOP was lower in the TA group at most follow-up visits; however, the difference was statistically significant only at the first month (p = 0.004). Linear mixed model showed that mean IOP was 1.5 mm Hg lower in the TA group throughout the study period (p = 0.006). Peak postoperative IOP was significantly lower in the TA group (19.3 ± 4.8 mm Hg versus 29 ± 9.2 mm Hg, p = 0.032). Rates of success (defined as 6 < IOP <21 mm Hg) were similar in both groups at 12 months. There was no difference in the occurrence of the HP between the 2 groups (p = 0.123). Loss of BCVA >2 lines was more common in the non-TA group (p = 0.032). Adjunctive intraoperative TA injection during AGV implantation can blunt peak IOP levels and reduce mean IOP up to 1 year. Visual outcomes also seem to be superior to standard surgery.

Adjunctive Mitomycin C or Amniotic Membrane Transplantation for Ahmed Glaucoma Valve Implantation: A Randomized Clinical Trial.

PubMed

Yazdani, Shahin; Mahboobipour, Hassan; Pakravan, Mohammad; Doozandeh, Azadeh; Ghahari, Elham

2016-05-01

To determine whether adjunctive mitomycin C (MMC) or amniotic membrane transplantation (AMT) improve the outcomes of Ahmed glaucoma valve (AGV) implantation. This double-blind, stratified, 3-armed randomized clinical trial includes 75 eyes of 75 patients aged 7 to 75 years with refractory glaucoma. Eligible subjects underwent stratified block randomization; eyes were first stratified to surgery in the superior or inferior quadrants based on feasibility; in each subgroup, eyes were randomly assigned to the study arms using random blocks: conventional AGV implantation (group A, 25 eyes), AGV with MMC (group B, 25 eyes), and AGV with AMT (group C, 25 eyes). The 3 study groups were comparable regarding baseline characteristics and mean follow-up (P=0.288). A total of 68 patients including 23 eyes in group A, 25 eyes in group B, and 20 eyes group C completed the follow-up period and were analyzed. Intraocular pressure was lower in the MMC group only 3 weeks postoperatively (P=0.04) but comparable at other time intervals. Overall success rate was comparable in the 3 groups at 12 months (P=0.217). The number of eyes requiring medications (P=0.30), time to initiation of medications (P=0.13), and number of medications (P=0.22) were comparable. Hypertensive phase was slightly but insignificantly more common with standard surgery (82%) as compared with MMC-augmented (60%) and AMT-augmented (70%) procedures (P=0.23). Complications were comparable over 1 year (P=0.28). Although adjunctive MMC and AMT were safe during AGV implantation, they did not influence success rates or intraocular pressure outcomes. Complications, including hypertensive phase, were also comparable.

Admission glycemic variability correlates with in-hospital outcomes in diabetic patients with non-ST segment elevation acute coronary syndrome undergoing percutaneous coronary intervention

PubMed Central

Su, Gong; Zhang, Tao; Yang, Hongxia; Dai, Wenlong; Tian, Lei; Tao, Hong; Wang, Tao; Mi, Shuhua

2018-01-01

Objective The aim of this study is to evaluate the effects of admission glycemic variability (AGV) on in-hospital outcomes in diabetic patients with non-ST segment elevation acute coronary syndrome (NSTE-ACS) undergoing percutaneous coronary intervention (PCI). Methods We studied 759 diabetic patients with NSTE-ACS undergoing PCI. AGV was accessed based on the mean amplitude of glycemic excursions (MAGEs) in the first 24 hours after admission. Primary outcome was a composite of in-hospital events, all-cause mortality, new-onset myocardial infarction, acute heart failure, and stroke. Secondary outcomes were each of these considered separately. Predictive effects of AGV on the in-hospital outcomes in patients were analyzed. Results Patients with high MAGE levels had significantly higher incidence of total outcomes (9.9% vs. 4.8%, p=0.009) and all-cause mortality (2.3% vs. 0.4%, p=0.023) than those with low MAGE levels during hospitalization. Multivariable analysis revealed that AGV was significantly associated with incidence of in-hospital outcomes (Odds ratio=2.024, 95% CI 1.105-3.704, p=0.022) but hemoglobin A1c (HbA1c) was not. In the receiver-operating characteristic curve analysis for MAGE and HbA1c in predicting in-hospital outcomes, the area under the curve for MAGE (0.608, p=0.012) was superior to that for HbA1c (0.556, p=0.193). Conclusion High AGV levels may be closely correlated with increased in-hospital poor outcomes in diabetic patients with NSTE-ACS following PCI. PMID:29848920

Dynamic Echo Information Guides Flight in the Big Brown Bat

PubMed Central

Warnecke, Michaela; Lee, Wu-Jung; Krishnan, Anand; Moss, Cynthia F.

2016-01-01

Animals rely on sensory feedback from their environment to guide locomotion. For instance, visually guided animals use patterns of optic flow to control their velocity and to estimate their distance to objects (e.g., Srinivasan et al., 1991, 1996). In this study, we investigated how acoustic information guides locomotion of animals that use hearing as a primary sensory modality to orient and navigate in the dark, where visual information is unavailable. We studied flight and echolocation behaviors of big brown bats as they flew under infrared illumination through a corridor with walls constructed from a series of individual vertical wooden poles. The spacing between poles on opposite walls of the corridor was experimentally manipulated to create dense/sparse and balanced/imbalanced spatial structure. The bats’ flight trajectories and echolocation signals were recorded with high-speed infrared motion-capture cameras and ultrasound microphones, respectively. As bats flew through the corridor, successive biosonar emissions returned cascades of echoes from the walls of the corridor. The bats flew through the center of the corridor when the pole spacing on opposite walls was balanced and closer to the side with wider pole spacing when opposite walls had an imbalanced density. Moreover, bats produced shorter duration echolocation calls when they flew through corridors with smaller spacing between poles, suggesting that clutter density influences features of the bat’s sonar signals. Flight speed and echolocation call rate did not, however, vary with dense and sparse spacing between the poles forming the corridor walls. Overall, these data demonstrate that bats adapt their flight and echolocation behavior dynamically when flying through acoustically complex environments. PMID:27199690

Initial Clinical Experience with Ahmed Valve Implantation in Refractory Pediatric Glaucoma

PubMed

Novak-Lauš, Katia; Škunca Herman, Jelena; Šimić Prskalo, Marija; Jurišić, Darija; Mandić, Zdravko

2016-12-01

The purpose is to report on the safety and efficacy of Ahmed Glaucoma Valve (AGV, New World Medical, Inc., Rancho Cucamonga, CA, USA) implantation for the management of refractory pediatric glaucoma observed during one-year follow up period. A retrospective chart review was conducted on 10 eyes, all younger than 11 years, with pediatric glaucoma that underwent AGV implantation for medicamentously uncontrolled intraocular pressure (IOP) between 2010 and 2014. Outcome measures were control of IOP below 23 mm Hg (with or without antiglaucoma medications) and changes in visual acuity. Complications were recorded. After AGV implantation, IOP values ranged from 18 mm Hg to 23 mm Hg (except for one eye with postoperative hypotonia due to suprachoroid hemorrhage, where the postoperative IOP value was 4 mm Hg). The number of antiglaucoma medications was reduced, i.e. four patients had two medications, one patient had one medication, and the others did not need antiglaucoma medication on the last follow-up visit. One eye had suprachoroid hemorrhage, one eye had long-term persistent uveitic membrane, and two eyes had tube-cornea touch. In conclusion, AGV implantation appears to be a viable option for the management of refractory pediatric glaucoma and shows success in IOP control. However, there was a relatively high complication rate limiting the overall success rate.

78 FR 76784 - Proposed Modification, Revocation, and Establishment of Area Navigation (RNAV) Routes; Charlotte, NC

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-19

... proposed to support the Charlotte Optimization of Airspace and Procedures in a Metroplex (OAPM) project.... 11-2A, Notice of Proposed Rulemaking Distribution System, which describes the application procedure... corridors serving the Charlotte area and would enhance the efficiency of the National Airspace System in the...

Polypropylene vs silicone Ahmed valve with adjunctive mitomycin C in paediatric age group: a prospective controlled study

PubMed Central

El Sayed, Y; Awadein, A

2013-01-01

Purpose To compare the results of silicone and polypropylene Ahmed glaucoma valves (AGV) implanted during the first 10 years of life. Methods A prospective study was performed on 50 eyes of 33 patients with paediatric glaucoma. Eyes were matched to either polypropylene or silicone AGV. In eyes with bilateral glaucoma, one eye was implanted with polypropylene and the other eye was implanted with silicone AGV. Results Fifty eyes of 33 children were reviewed. Twenty five eyes received a polypropylene valve, and 25 eyes received a silicone valve. Eyes implanted with silicone valves achieved a significantly lower intraocular pressure (IOP) compared with the polypropylene group at 6 months, 1 year, and 2 years postoperatively. The average survival time was significantly longer (P=0.001 by the log-rank test) for the silicone group than for the polypropylene group and the cumulative probability of survival by the log-rank test at the end of the second year was 80% (SE: 8.0, 95% confidence interval (CI): 64–96%) in the silicone group and 56% (SE: 9.8, 95% CI: 40–90%) in the polypropylene group. The difference in the number of postoperative interventions and complications between both groups was statistically insignificant. Conclusion Silicone AGVs can achieve better IOP control, and longer survival with less antiglaucoma drops compared with polypropylene valves in children younger than 10 years. PMID:23579403

Navigation.

PubMed

Wiltschko, Roswitha

2017-07-01

Experiments with migrating birds displaced during autumn migration outside their normal migration corridor reveal two different navigational strategies: adult migrants compensate for the displacement, and head towards their traditional wintering areas, whereas young first-time migrants continue in their migratory direction. Young birds are guided to their still unknown goal by a genetically coded migration program that indicates duration and direction(s) of the migratory flight by controlling the amount of migratory restlessness and the compass course(s) with respect to the geomagnetic field and celestial rotation. Adult migrants that have already wintered and are familiar with the goal area approach the goal by true navigation, specifically heading towards it and changing their course correspondingly after displacement. During their first journey, young birds experience the distribution of potential navigational factors en route and in their winter home, which allows them to truly navigate on their next migrations. The navigational factors used appear to include magnetic intensity as a component in their multi-modal navigational 'map'; olfactory input is also involved, even if it is not yet entirely clear in what way. The mechanisms of migratory birds for true navigation over long distances appear to be in principle similar to those discussed for by homing pigeons.

Cheap or Robust? The practical realization of self-driving wheelchair technology.

PubMed

Burhanpurkar, Maya; Labbe, Mathieu; Guan, Charlie; Michaud, Francois; Kelly, Jonathan

2017-07-01

To date, self-driving experimental wheelchair technologies have been either inexpensive or robust, but not both. Yet, in order to achieve real-world acceptance, both qualities are fundamentally essential. We present a unique approach to achieve inexpensive and robust autonomous and semi-autonomous assistive navigation for existing fielded wheelchairs, of which there are approximately 5 million units in Canada and United States alone. Our prototype wheelchair platform is capable of localization and mapping, as well as robust obstacle avoidance, using only a commodity RGB-D sensor and wheel odometry. As a specific example of the navigation capabilities, we focus on the single most common navigation problem: the traversal of narrow doorways in arbitrary environments. The software we have developed is generalizable to corridor following, desk docking, and other navigation tasks that are either extremely difficult or impossible for people with upper-body mobility impairments.

Hypertensive phase and early complications after Ahmed glaucoma valve implantation with intraoperative subtenon triamcinolone acetonide.

PubMed

Turalba, Angela V; Pasquale, Louis R

2014-01-01

To evaluate intraoperative subtenon triamcinolone acetonide (TA) as an adjunct to Ahmed glaucoma valve (AGV) implantation. Retrospective comparative case series. Forty-two consecutive cases of uncontrolled glaucoma undergoing AGV implantation: 19 eyes receiving intraoperative subtenon TA and 23 eyes that did not receive TA. A retrospective chart review was performed on consecutive pseudophakic adult patients with uncontrolled glaucoma undergoing AGV with and without intraoperative subtenon TA injection by a single surgeon. Clinical data were collected from 42 eyes and analyzed for the first 6 months after surgery. Primary outcomes included intraocular pressure (IOP) and number of glaucoma medications prior to and after AGV implantation. The hypertensive phase (HP) was defined as an IOP measurement of greater than 21 mmHg (with or without medications) during the 6-month postoperative period that was not a result of tube obstruction, retraction, or malfunction. Postoperative complications and visual acuity were analyzed as secondary outcome measures. Five out of 19 (26%) TA cases and 12 out of 23 (52%) non-TA cases developed the HP (P=0.027). Mean IOP (14.2±4.6 in TA cases versus [vs] 14.7±5.0 mmHg in non-TA cases; P=0.78), and number of glaucoma medications needed (1.8±1.3 in TA cases vs 1.6±1.1 in the comparison group; P=0.65) were similar between both groups at 6 months. Although rates of serious complications did not differ between the groups (13% in the TA group vs 16% in the non-TA group), early tube erosion (n=1) and bacterial endophthalmitis (n=1) were noted with TA but not in the non-TA group. Subtenon TA injection during AGV implantation may decrease the occurrence of the HP but does not alter the ultimate IOP outcome and may pose increased risk of serious complications within the first 6 months of surgery.

Hypertensive phase and early complications after Ahmed glaucoma valve implantation with intraoperative subtenon triamcinolone acetonide

PubMed Central

Turalba, Angela V; Pasquale, Louis R

2014-01-01

Objective To evaluate intraoperative subtenon triamcinolone acetonide (TA) as an adjunct to Ahmed glaucoma valve (AGV) implantation. Design Retrospective comparative case series. Participants Forty-two consecutive cases of uncontrolled glaucoma undergoing AGV implantation: 19 eyes receiving intraoperative subtenon TA and 23 eyes that did not receive TA. Methods A retrospective chart review was performed on consecutive pseudophakic adult patients with uncontrolled glaucoma undergoing AGV with and without intraoperative subtenon TA injection by a single surgeon. Clinical data were collected from 42 eyes and analyzed for the first 6 months after surgery. Main outcome measures Primary outcomes included intraocular pressure (IOP) and number of glaucoma medications prior to and after AGV implantation. The hypertensive phase (HP) was defined as an IOP measurement of greater than 21 mmHg (with or without medications) during the 6-month postoperative period that was not a result of tube obstruction, retraction, or malfunction. Postoperative complications and visual acuity were analyzed as secondary outcome measures. Results Five out of 19 (26%) TA cases and 12 out of 23 (52%) non-TA cases developed the HP (P=0.027). Mean IOP (14.2±4.6 in TA cases versus [vs] 14.7±5.0 mmHg in non-TA cases; P=0.78), and number of glaucoma medications needed (1.8±1.3 in TA cases vs 1.6±1.1 in the comparison group; P=0.65) were similar between both groups at 6 months. Although rates of serious complications did not differ between the groups (13% in the TA group vs 16% in the non-TA group), early tube erosion (n=1) and bacterial endophthalmitis (n=1) were noted with TA but not in the non-TA group. Conclusions Subtenon TA injection during AGV implantation may decrease the occurrence of the HP but does not alter the ultimate IOP outcome and may pose increased risk of serious complications within the first 6 months of surgery. PMID:25050061

Long-term results of Ahmed glaucoma valve implantation in Egyptian population

PubMed Central

Elhefney, Eman; Mokbel, Tharwat; Abou Samra, Waleed; Kishk, Hanem; Mohsen, Tarek; El-Kannishy, Amr

2018-01-01

AIM To evaluate the long-term results and complications of Ahmed glaucoma valve (AGV) implantation in a cohort of Egyptian patients. METHODS A retrospective study of 124 eyes of 99 patients with refractory glaucoma who underwent AGV implantation and had a minimum follow-up of 5y was performed. All patients underwent complete ophthalmic examination and intraocular pressure (IOP) measurement before surgery and at 1d, weekly for the 1st month, 3, 6mo, and 1y after surgery and yearly afterward for 5y. IOP was measured by Goldmann applanation tonometry and/or Tono-Pen. Complications and the number of anti-glaucoma medications needed were recorded. Success was defined as IOP less than 21 mm Hg with or without anti-glaucoma medication and without additional glaucoma surgery. RESULTS Mean age was 23.1±19.9y. All eyes had at least one prior glaucoma surgery. IOP was reduced from a mean of 37.2±6.8 to 19.2±5.2 mm Hg after 5y follow-up with a reduced number of medications from 2.64±0.59 to 1.81±0.4. Complete and qualified success rates were 31.5% and 46.0% respectively at the end of follow-up. The most common complications were encapsulated cyst formation in 51 eyes (41.1%), complicated cataract in 9 eyes (7.25%), recessed tube in 8 eyes (6.45%), tube exposure in 6 eyes (4.8%) and corneal touch in 6 eyes (4.8%). Other complications included extruded AGV, endophthalmitis and persistent hypotony. Each of them was recorded in only 2 eyes (1.6%). CONCLUSION Although refractory glaucoma is a difficult problem to manage, AGV is effective and relatively safe procedure in treating refractory glaucoma in Egyptian patients with long-term follow-up. Encapsulated cyst formation was the most common complication, which limits successful IOP control after AGV implantation. However, effective complications management can improve the rate of success. PMID:29600175

The Ahmed shunt versus the Baerveldt shunt for refractory glaucoma: a meta-analysis.

PubMed

Wang, Shiming; Gao, Xiaoming; Qian, Nana

2016-06-08

The purpose of this study was to compare the efficacy and tolerability of the Ahmed glaucoma valve (AGV) implant and the Baerveldt implant for the treatment of refractory glaucoma. We comprehensively searched four databases, including PubMed, EMBASE, Web of Science, and the Cochrane Library databases, selecting the relevant studies. The continuous variables, namely, intraocular pressure reduction (IOPR) and a reduction in glaucoma medication, were pooled by the weighted mean differences (WMDs), and the dichotomous outcomes, including success rates and tolerability estimates, were pooled by the odds ratio (ORs). A total of 929 patients from six studies were included. The WMDs of the IOPR between the AGV implant and the Baerveldt implant were 1.58 [95 % confidence interval (CI): -2.99 to 6.15] at 6 months, -1.01 (95 % CI: -3.40 to 1.98) at 12 months, -0.54 (95 % CI: -4.89 to 3.82) at 24 months, and -0.47 (95 % CI: -3.29 to 2.35) at 36 months. No significant difference was detected between the two groups at any point in time. The pooled ORs comparing the AGV implant with the Baerveldt implant were 0.51 (95 % CI: 0.33 to 0.80) for the complete success rate and 0.67 (95 % CI: 0.50 to 0.91) for qualified success rate. The Baerveldt implant was associated with a reduction in glaucoma medication at -0.51 (95 % CI: -0.90 to -0.12). There were no significant differences between the AGV implant and the Baerveldt implant on the rates of adverse events. The Baerveldt implant is more effective in both its surgical success rate and reducing glaucoma medication, but it is comparable to the AGV implant in lowering IOP. Both implants may have comparable incidences of adverse events.

Long-term results of Ahmed glaucoma valve implantation in Egyptian population.

PubMed

Elhefney, Eman; Mokbel, Tharwat; Abou Samra, Waleed; Kishk, Hanem; Mohsen, Tarek; El-Kannishy, Amr

2018-01-01

To evaluate the long-term results and complications of Ahmed glaucoma valve (AGV) implantation in a cohort of Egyptian patients. A retrospective study of 124 eyes of 99 patients with refractory glaucoma who underwent AGV implantation and had a minimum follow-up of 5y was performed. All patients underwent complete ophthalmic examination and intraocular pressure (IOP) measurement before surgery and at 1d, weekly for the 1 st month, 3, 6mo, and 1y after surgery and yearly afterward for 5y. IOP was measured by Goldmann applanation tonometry and/or Tono-Pen. Complications and the number of anti-glaucoma medications needed were recorded. Success was defined as IOP less than 21 mm Hg with or without anti-glaucoma medication and without additional glaucoma surgery. Mean age was 23.1±19.9y. All eyes had at least one prior glaucoma surgery. IOP was reduced from a mean of 37.2±6.8 to 19.2±5.2 mm Hg after 5y follow-up with a reduced number of medications from 2.64±0.59 to 1.81±0.4. Complete and qualified success rates were 31.5% and 46.0% respectively at the end of follow-up. The most common complications were encapsulated cyst formation in 51 eyes (41.1%), complicated cataract in 9 eyes (7.25%), recessed tube in 8 eyes (6.45%), tube exposure in 6 eyes (4.8%) and corneal touch in 6 eyes (4.8%). Other complications included extruded AGV, endophthalmitis and persistent hypotony. Each of them was recorded in only 2 eyes (1.6%). Although refractory glaucoma is a difficult problem to manage, AGV is effective and relatively safe procedure in treating refractory glaucoma in Egyptian patients with long-term follow-up. Encapsulated cyst formation was the most common complication, which limits successful IOP control after AGV implantation. However, effective complications management can improve the rate of success.

Dual infection by streptococcus and atypical mycobacteria following Ahmed glaucoma valve surgery.

PubMed

Rao, Aparna; Wallang, Batriti; Padhy, Tapas Ranjan; Mittal, Ruchi; Sharma, Savitri

2013-07-01

To report a case of late postoperative endophthalmitis caused by Streptococcus pneumoniae and conjunctival necrosis by Streptococcus pneumoniae and Mycobacterium fortuitum following Ahmed glaucoma valve (AGV) surgery in a young patient. Case report of a 13-year-old boy with purulent exudates and extensive conjunctival necrosis two months following amniotic membrane graft and conjunctival closure (for conjunctival retraction post AGV for secondary glaucoma). The conjunctiva showed extensive necrosis causing exposure of the tube and plate associated with frank exudates in the area adjoining the plate and anterior chamber mandating explantation of the plate along with intravitreal antibiotics. The vitreous aspirate grew Streptococcus pneumoniae while Streptococcus pneumoniae with Mycobacterium fortuitum was isolated from the explanted plate. Despite adequate control of infection following surgery, the final visual outcome was poor owing to disc pallor. Conjunctival necrosis and retraction post-AGV can cause late postoperative co-infections by fulminant and slow-growing organisms. A close follow-up is therefore essential in these cases to prevent sight-threatening complications.

A Clonal Selection Algorithm for Minimizing Distance Travel and Back Tracking of Automatic Guided Vehicles in Flexible Manufacturing System

NASA Astrophysics Data System (ADS)

Chawla, Viveak Kumar; Chanda, Arindam Kumar; Angra, Surjit

2018-03-01

The flexible manufacturing system (FMS) constitute of several programmable production work centers, material handling systems (MHSs), assembly stations and automatic storage and retrieval systems. In FMS, the automatic guided vehicles (AGVs) play a vital role in material handling operations and enhance the performance of the FMS in its overall operations. To achieve low makespan and high throughput yield in the FMS operations, it is highly imperative to integrate the production work centers schedules with the AGVs schedules. The Production schedule for work centers is generated by application of the Giffler and Thompson algorithm under four kind of priority hybrid dispatching rules. Then the clonal selection algorithm (CSA) is applied for the simultaneous scheduling to reduce backtracking as well as distance travel of AGVs within the FMS facility. The proposed procedure is computationally tested on the benchmark FMS configuration from the literature and findings from the investigations clearly indicates that the CSA yields best results in comparison of other applied methods from the literature.

Small Imaging Depth LIDAR and DCNN-Based Localization for Automated Guided Vehicle †

PubMed Central

Ito, Seigo; Hiratsuka, Shigeyoshi; Ohta, Mitsuhiko; Matsubara, Hiroyuki; Ogawa, Masaru

2018-01-01

We present our third prototype sensor and a localization method for Automated Guided Vehicles (AGVs), for which small imaging LIght Detection and Ranging (LIDAR) and fusion-based localization are fundamentally important. Our small imaging LIDAR, named the Single-Photon Avalanche Diode (SPAD) LIDAR, uses a time-of-flight method and SPAD arrays. A SPAD is a highly sensitive photodetector capable of detecting at the single-photon level, and the SPAD LIDAR has two SPAD arrays on the same chip for detection of laser light and environmental light. Therefore, the SPAD LIDAR simultaneously outputs range image data and monocular image data with the same coordinate system and does not require external calibration among outputs. As AGVs travel both indoors and outdoors with vibration, this calibration-less structure is particularly useful for AGV applications. We also introduce a fusion-based localization method, named SPAD DCNN, which uses the SPAD LIDAR and employs a Deep Convolutional Neural Network (DCNN). SPAD DCNN can fuse the outputs of the SPAD LIDAR: range image data, monocular image data and peak intensity image data. The SPAD DCNN has two outputs: the regression result of the position of the SPAD LIDAR and the classification result of the existence of a target to be approached. Our third prototype sensor and the localization method are evaluated in an indoor environment by assuming various AGV trajectories. The results show that the sensor and localization method improve the localization accuracy. PMID:29320434

Small Imaging Depth LIDAR and DCNN-Based Localization for Automated Guided Vehicle.

PubMed

Ito, Seigo; Hiratsuka, Shigeyoshi; Ohta, Mitsuhiko; Matsubara, Hiroyuki; Ogawa, Masaru

2018-01-10

We present our third prototype sensor and a localization method for Automated Guided Vehicles (AGVs), for which small imaging LIght Detection and Ranging (LIDAR) and fusion-based localization are fundamentally important. Our small imaging LIDAR, named the Single-Photon Avalanche Diode (SPAD) LIDAR, uses a time-of-flight method and SPAD arrays. A SPAD is a highly sensitive photodetector capable of detecting at the single-photon level, and the SPAD LIDAR has two SPAD arrays on the same chip for detection of laser light and environmental light. Therefore, the SPAD LIDAR simultaneously outputs range image data and monocular image data with the same coordinate system and does not require external calibration among outputs. As AGVs travel both indoors and outdoors with vibration, this calibration-less structure is particularly useful for AGV applications. We also introduce a fusion-based localization method, named SPAD DCNN, which uses the SPAD LIDAR and employs a Deep Convolutional Neural Network (DCNN). SPAD DCNN can fuse the outputs of the SPAD LIDAR: range image data, monocular image data and peak intensity image data. The SPAD DCNN has two outputs: the regression result of the position of the SPAD LIDAR and the classification result of the existence of a target to be approached. Our third prototype sensor and the localization method are evaluated in an indoor environment by assuming various AGV trajectories. The results show that the sensor and localization method improve the localization accuracy.

Outcomes of Ahmed Glaucoma Valve Revision in Pediatric Glaucoma.

PubMed

Al-Omairi, Ahmed Mansour; Al Ameri, Aliah H; Al-Shahwan, Sami; Khan, Arif O; Al-Jadaan, Ibrahim; Mousa, Ahmed; Edward, Deepak P

2017-11-01

Encapsulation of the Ahmed glaucoma valve (AGV) plate is a common cause for postoperative elevation of intraocular pressure, especially in children. Many reports have described the outcomes of AGV revision in adults. However, the outcomes of AGV revision in children are poorly documented. The aim of this study was to determine the outcomes of AGV revision in children. Retrospective cross-sectional study. A retrospective chart review of patients less than 15 years of age who underwent AGV revision with a minimum postoperative follow-up of 6 months was conducted. Outcome measures included reduction in intraocular pressure from baseline, survival analysis, and reduction in the number of antiglaucoma medications. Postoperative complications were also noted. Complete success was defined as an IOP of 21 mm Hg or less without medications, while qualified success was defined as having an IOP of 21 mm Hg or less with medications. A total of 44 eyes met the inclusion criteria. Primary congenital glaucoma was present in 39 eyes (88.6%), aphakic glaucoma in 4 eyes (9.1%), and Peters anomaly-associated glaucoma in 1 eye (2.3%). The mean number of previous surgeries was 1.4, and the mean age was 6.7 years (range, 1.9-13 years) with a median follow-up of 12 months (range, 6-24 months). The IOP was reduced from a preoperative mean of 30.4 (± 10.3) to 24.9 (± 10.6) mm Hg at 6 months postoperatively. Kaplan-Meier analysis showed that the complete success rate at 1 month was 100% followed by a rapid decline at 6 months to 38.6%, 27.7% at 1 year, and 5.5% at 2 years. Qualified success rate was 100% at 1 month followed by a 6-month and 1-year survival rate of approximately 50% and a 2-year survival rate of approximately 16%. The median survival time was 14 months. No specific risk factors for failure were identified. Visual acuity remained unchanged following revision. The most common complication was recurrence of encapsulation with elevated IOP (15.9%). Other complications included hyphema (n = 3; 6.8%), endophthalmitis (n = 1; 2.3%), wound leak (n = 1; 2.3%), and choroidal detachment (n = 2; 4.5%). Although the short-term success rate of AGV revision in children is high, with longer follow-up the success rate decreases significantly. Copyright © 2017 Elsevier Inc. All rights reserved.

WETTING AND REACTIVE AIR BRAZING OF BSCF FOR OXYGEN SEPARATION DEVICES

DOE Office of Scientific and Technical Information (OSTI.GOV)

LaDouceur, Richard M.; Meier, Alan; Joshi, Vineet V.

Reactive air brazes Ag-CuO and Ag-V2O5 were evaluated for brazing Ba0.5Sr0.5Co0.8Fe0.2O(3-δ) (BSCF). BSCF has been determined in previous work to have the highest potential mixed ionic/electronic conducting (MIEC) ceramic material based on the design and oxygen flux requirements of an oxy-fuel plant such as an integrated gasification combined cycle (IGCC) used to facilitate high-efficiency carbon capture. Apparent contact angles were observed for Ag-CuO and Ag-V2O5 mixtures at 1000 °C for isothermal hold times of 0, 10, 30, and 60 minutes. Wetting apparent contact angles (θ<90°) were obtained for 1%, 2%, and 5% Ag-CuO and Ag-V2O5 mixtures, with the apparent contactmore » angles between 74° and 78° for all compositions and furnace dwell times. Preliminary microstructural analysis indicates that two different interfacial reactions are occurring: Ag-CuO interfacial microstructures revealed the same dissolution of copper oxide into the BSCF matrix to form copper-cobalt-oxygen rich dissolution products along the BSCF grain boundaries and Ag-V2O5 interfacial microstructures revealed the infiltration and replacement of cobalt and iron with vanadium and silver filling pores in the BSCF microstructure. The Ag-V2O5 interfacial reaction product layer was measured to be significantly thinner than the Ag-CuO reaction product layer. Using a fully articulated four point flexural bend test fixture, the flexural fracture strength for BSCF was determined to be 95 ± 33 MPa. The fracture strength will be used to ascertain the success of the reactive air braze alloys. Based on these results, brazes were fabricated and mechanically tested to begin to optimize the brazing parameters for this system. Ag-2.5% CuO braze alloy with a 2.5 minute thermal cycle achieved a hermetic seal with a joint flexural strength of 34 ± 15 MPa and Ag-1% V2O5 with a 30 minute thermal cycle had a joint flexural strength of 20 ± 15 MPa.« less

Ahmed Glaucoma Valve Implantation in Vitrectomized Eyes.

PubMed

Erçalık, Nimet Yeşim; İmamoğlu, Serhat

2018-01-01

To evaluate the outcomes of Ahmed glaucoma valve (AGV) implantation in vitrectomized eyes. The medical records of 13 eyes that developed glaucoma due to emulsified silicon oil or neovascularization following pars plana vitrectomy and underwent AGV implantation were retrospectively reviewed. The main outcome measures were intraocular pressure (IOP), best-corrected visual acuity (BCVA), number of antiglaucoma medications, and postoperative complications. Surgical success was defined as last IOP ≤21 mmHg or ≥6 mmHg and without loss of light perception. The mean follow-up duration was 11.7 ± 5.5 (range, 6-23) months. The mean IOP before the AGV implantation was 37.9 ± 6.7 mmHg with an average of 3.5 ± 1.2 drugs. At the final visit, the mean IOP was 15.9 ± 4.6 mmHg ( p =0.001) and the mean number of glaucoma medications decreased to 2.3 ± 1.3 ( p =0.021). At the last visit, 11 eyes (84.4%) had stable or improved VA and one eye (7.7%) had a final VA of no light perception. Surgical success was achieved in 11 of the 13 eyes (84.4%). Postoperative complications were bleb encapsulation (69.2%), early hypotony (38.5%), hyphema (23.1%), decompression retinopathy (23.1%), choroidal detachment (15.4%), intraocular hemorrhage (7.7%), and late endophthalmitis (7.7%). One eye (7.7%) was enucleated because of late endophthalmitis. Despite complications necessitating medical and surgical interventions, vitrectomized eyes were effectively managed with AGV implantation.

Clinical outcomes of trabeculectomy vs. Ahmed glaucoma valve implantation in patients with penetrating keratoplasty : (Trabeculectomy vs. Ahmed galucoma valve in patients with penetrating keratoplasty).

PubMed

Akdemir, Mehmet Orcun; Acar, Banu Torun; Kokturk, Furuzan; Acar, Suphi

2016-08-01

The aim of this study was to compare the visual outcomes, intraocular pressure (IOP), and endothelial cell loss caused by trabeculectomy (TRAB) and Ahmed glaucoma valve (AGV) implantation in patients who had previously undergone penetrating keratoplasty (PKP). The data from all patients who underwent surgical treatment of glaucoma after PKP were reviewed at the Cornea Department of Haydarpasa Numune Education and Research Hospital. Eighteen patients who had undergone surgical treatment of glaucoma after PKP were included in this retrospective study. Time between PKP and glaucoma surgeries, visual acuity results, IOP results, endothelial cell counts (ECC) before the surgery, at 1st, 6th, and 12th month of surgery were recorded. Differences between two groups were evaluated. Mean loss of ECC was 315 cells/mm(2) in the AGV group and 197 cells/mm(2) in TRAB group at 12th month of glaucoma surgery. The difference between endothelial cell loss at 12th month of surgery was statistically significant and higher in AGV group (p < 0.001). The decrease in IOP was 64.2 % in AGV group and 46.9 % in TRAB group at 12th month of surgery. Both differences were statistically significant between 2 groups (p = 0.001, 0.001). TRAB successfully decreased both the IOP and endothelial cell loss in patients with post-PKP glaucoma. Ahmed glaucoma valve had a significantly better IOP lowering but higher endothelial cell loss effect.

Long-term clinical outcomes of Ahmed valve implantation in patients with refractory glaucoma.

PubMed

Lee, Chang Kyu; Ma, Kyoung Tak; Hong, Young Jae; Kim, Chan Yun

2017-01-01

To evaluate the long-term efficacy of intraocular pressure (IOP) reduction and complications of Ahmed Glaucoma Valve (AGV) implantation in patients with refractory glaucoma. Retrospective study. The study involved 302 refractory glaucoma patients who underwent AGV implantation and had a minimum follow-up of 6 months between March 1995 and December 2013. An operation was defined as successful when (1) the postoperative IOP remained between 5 and 21 mmHg and was reduced 30% compared to the baseline IOP with or without medication, (2) there was no loss of light perception or vision-threatening severe complications, and (3) no additional filtering or aqueous drainage surgery was required. Clinical records were reviewed. IOP, anti-glaucoma medications, and complications. The mean follow-up period was 62.25 months (range, 6 to 190 months). The cumulative probability of success was 89% at 6 months, 81% at 1 year, 66% at 3 years, 44% at 10 years, and 26% at 15 years. IOP was reduced from a mean of 32.2 ± 10.5 mmHg to 18.6 ± 9.1 mmHg at 1 month, 15.2 ± 7.0 mmHg at 6 months, and 14.2 ± 3.5 mmHg at 15 years. Surgical failures were significantly increased when preoperative IOP was high, and when severe complications occurred after AGV implantation (P < 0.05). AGV implantation was successful for IOP control in patients with refractive glaucoma in the long term. However, the success rate of surgery decreased over time. Preoperative high IOP and severe complications related to the operation were significant risk factors for failure.

Histopathologic and immunohistochemical features of capsular tissue around failed Ahmed glaucoma valves.

PubMed

Mahale, Alka; Fikri, Fatma; Al Hati, Khitam; Al Shahwan, Sami; Al Jadaan, Ibrahim; Al Katan, Hind; Khandekar, Rajiv; Maktabi, Azza; Edward, Deepak P

2017-01-01

Impervious encapsulation around Ahmed glaucoma valve (AGV) results in surgical failure raising intraocular pressure (IOP). Dysregulation of extracellular matrix (ECM) molecules and cellular factors might contribute to increased hydraulic resistance to aqueous drainage. Therefore, we examined these molecules in failed AGV capsular tissue. Immunostaining for ECM molecules (collagen I, collagen III, decorin, lumican, chondroitin sulfate, aggrecan and keratan sulfate) and cellular factors (αSMA and TGFβ) was performed on excised capsules from failed AGVs and control tenon's tissue. Staining intensity of ECM molecules was assessed using Image J. Cellular factors were assessed based on positive cell counts. Histopathologically two distinct layers were visible in capsules. The inner layer (proximal to the AGV) showed significant decrease in most ECM molecules compared to outer layer. Furthermore, collagen III (p = 0.004), decorin (p = 0.02), lumican (p = 0.01) and chondroitin sulfate (p = 0.02) was significantly less in inner layer compared to tenon's tissue. Outer layer labelling however was similar to control tenon's for most ECM molecules. Significantly increased cellular expression of αSMA (p = 0.02) and TGFβ (p = 0.008) was detected within capsular tissue compared to controls. Our results suggest profibrotic activity indicated by increased αSMA and TGFβ expression and decreased expression of proteoglycan (decorin and lumican) and glycosaminoglycans (chondroitin sulfate). Additionally, we observed decreased collagen III which might reflect increased myofibroblast contractility when coupled with increased TGFβ and αSMA expression. Together these events lead to tissue dysfunction potentially resulting in hydraulic resistance that may affect aqueous flow through the capsular wall.

Tenon advancement and duplication technique to prevent postoperative Ahmed valve tube exposure in patients with refractory glaucoma.

PubMed

Tamcelik, Nevbahar; Ozkok, Ahmet; Sarıcı, Ahmet Murat; Atalay, Eray; Yetik, Huseyin; Gungor, Kivanc

2013-07-01

To present and compare the long-term results of Dr. Tamcelik's previously described technique of Tenon advancement and duplication with the conventional Ahmed glaucoma valve (AGV) implantation technique in patients with refractory glaucoma. This study was a multicenter, retrospective case series that included 303 eyes of 276 patients with refractory glaucoma who underwent glaucoma valve implantation surgery. The patients were divided into three groups according to the surgical technique applied and the outcomes compared. In group 1, 96 eyes of 86 patients underwent AGV implant surgery without patch graft; in group 2, 78 eyes of 72 patients underwent AGV implant surgery with donor scleral patch; in group 3, 129 eyes of 118 patients underwent Ahmed valve implant surgery with "combined short scleral tunnel with Tenon advancement and duplication technique". The endpoint assessed was tube exposure through the conjunctiva. In group 1, conjunctival tube exposure was seen in 11 eyes (12.9 %) after a mean 9.2 ± 3.7 years of follow-up. In group 2, conjunctival tube exposure was seen in six eyes (2.2 %) after a mean 8.9 ± 3.3 years of follow-up. In group 3, there was no conjunctival exposure after a mean 7.8 ± 2.8 years of follow-up. The difference between the groups was statistically significant. (P = 0.0001, Chi-square test). This novel surgical technique combining a short scleral tunnel with Tenon advancement and duplication was found to be effective and safe to prevent conjunctival tube exposure after AGV implantation surgery in patients with refractory glaucoma.

Simultaneous Scheduling of Jobs, AGVs and Tools Considering Tool Transfer Times in Multi Machine FMS By SOS Algorithm

NASA Astrophysics Data System (ADS)

Sivarami Reddy, N.; Ramamurthy, D. V., Dr.; Prahlada Rao, K., Dr.

2017-08-01

This article addresses simultaneous scheduling of machines, AGVs and tools where machines are allowed to share the tools considering transfer times of jobs and tools between machines, to generate best optimal sequences that minimize makespan in a multi-machine Flexible Manufacturing System (FMS). Performance of FMS is expected to improve by effective utilization of its resources, by proper integration and synchronization of their scheduling. Symbiotic Organisms Search (SOS) algorithm is a potent tool which is a better alternative for solving optimization problems like scheduling and proven itself. The proposed SOS algorithm is tested on 22 job sets with makespan as objective for scheduling of machines and tools where machines are allowed to share tools without considering transfer times of jobs and tools and the results are compared with the results of existing methods. The results show that the SOS has outperformed. The same SOS algorithm is used for simultaneous scheduling of machines, AGVs and tools where machines are allowed to share tools considering transfer times of jobs and tools to determine the best optimal sequences that minimize makespan.

Echolocating Big Brown Bats, Eptesicus fuscus, Modulate Pulse Intervals to Overcome Range Ambiguity in Cluttered Surroundings

PubMed Central

Wheeler, Alyssa R.; Fulton, Kara A.; Gaudette, Jason E.; Simmons, Ryan A.; Matsuo, Ikuo; Simmons, James A.

2016-01-01

Big brown bats (Eptesicus fuscus) emit trains of brief, wideband frequency-modulated (FM) echolocation sounds and use echoes of these sounds to orient, find insects, and guide flight through vegetation. They are observed to emit sounds that alternate between short and long inter-pulse intervals (IPIs), forming sonar sound groups. The occurrence of these strobe groups has been linked to flight in cluttered acoustic environments, but how exactly bats use sonar sound groups to orient and navigate is still a mystery. Here, the production of sound groups during clutter navigation was examined. Controlled flight experiments were conducted where the proximity of the nearest obstacles was systematically decreased while the extended scene was kept constant. Four bats flew along a corridor of varying widths (100, 70, and 40 cm) bounded by rows of vertically hanging plastic chains while in-flight echolocation calls were recorded. Bats shortened their IPIs for more rapid spatial sampling and also grouped their sounds more tightly when flying in narrower corridors. Bats emitted echolocation calls with progressively shorter IPIs over the course of a flight, and began their flights by emitting shorter starting IPI calls when clutter was denser. The percentage of sound groups containing 3 or more calls increased with increasing clutter proximity. Moreover, IPI sequences having internal structure become more pronounced when corridor width narrows. A novel metric for analyzing the temporal organization of sound sequences was developed, and the results indicate that the time interval between echolocation calls depends heavily on the preceding time interval. The occurrence of specific IPI patterns were dependent upon clutter, which suggests that sonar sound grouping may be an adaptive strategy for coping with pulse-echo ambiguity in cluttered surroundings. PMID:27445723

Study on store-space assignment based on logistic AGV in e-commerce goods to person picking pattern

NASA Astrophysics Data System (ADS)

Xu, Lijuan; Zhu, Jie

2017-10-01

This paper studied on the store-space assignment based on logistic AGV in E-commerce goods to person picking pattern, and established the store-space assignment model based on the lowest picking cost, and design for store-space assignment algorithm after the cluster analysis based on similarity coefficient. And then through the example analysis, compared the picking cost between store-space assignment algorithm this paper design and according to item number and storage according to ABC classification allocation, and verified the effectiveness of the design of the store-space assignment algorithm.

How Displaced Migratory Birds Could Use Volatile Atmospheric Compounds to Find Their Migratory Corridor: A Test Using a Particle Dispersion Model

PubMed Central

Safi, Kamran; Gagliardo, Anna; Wikelski, Martin; Kranstauber, Bart

2016-01-01

Olfaction represents an important sensory modality for navigation of both homing pigeons and wild birds. Experimental evidence in homing pigeons showed that airborne volatile compounds carried by the winds at the home area are learned in association with wind directions. When displaced, pigeons obtain information on the direction of their displacement using local odors at the release site. Recently, the role of olfactory cues in navigation has been reported also for wild birds during migration. However, the question whether wild birds develop an olfactory navigational map similar to that described in homing pigeons or, alternatively, exploit the distribution of volatile compounds in different manner for reaching the goal is still an open question. Using an interdisciplinary approach, we evaluate the possibilities of reconstructing spatio-temporally explicit aerosol dispersion at large spatial scales using the particle dispersion model FLEXPART. By combining atmospheric information with particle dispersion models, atmospheric scientists predict the dispersion of pollutants for example, after nuclear fallouts or volcanic eruptions or wildfires, or in retrospect reconstruct the origin of emissions such as aerosols. Using simple assumptions, we reconstructed the putative origin of aerosols traveling to the location of migrating birds. We use the model to test whether the putative odor plume could have originated from an important stopover site. If the migrating birds knew this site and the associated plume from previous journeys, the odor could contribute to the reorientation towards the migratory corridor, as suggested for the model scenario in displaced Lesser black-backed gulls migrating from Northern Europe into Africa. PMID:27799899

A Behavior-Based Strategy for Single and Multi-Robot Autonomous Exploration

PubMed Central

Cepeda, Jesus S.; Chaimowicz, Luiz; Soto, Rogelio; Gordillo, José L.; Alanís-Reyes, Edén A.; Carrillo-Arce, Luis C.

2012-01-01

In this paper, we consider the problem of autonomous exploration of unknown environments with single and multiple robots. This is a challenging task, with several potential applications. We propose a simple yet effective approach that combines a behavior-based navigation with an efficient data structure to store previously visited regions. This allows robots to safely navigate, disperse and efficiently explore the environment. A series of experiments performed using a realistic robotic simulator and a real testbed scenario demonstrate that our technique effectively distributes the robots over the environment and allows them to quickly accomplish their mission in large open spaces, narrow cluttered environments, dead-end corridors, as well as rooms with minimum exits.

Indoor Subspacing to Implement Indoorgml for Indoor Navigation

NASA Astrophysics Data System (ADS)

Jung, H.; Lee, J.

2015-10-01

According to an increasing demand for indoor navigation, there are great attempts to develop applicable indoor network. Representation for a room as a node is not sufficient to apply complex and large buildings. As OGC established IndoorGML, subspacing to partition the space for constructing logical network is introduced. Concerning subspacing for indoor network, transition space like halls or corridors also have to be considered. This study presents the subspacing process for creating an indoor network in shopping mall. Furthermore, categorization of transition space is performed and subspacing of this space is considered. Hall and squares in mall is especially defined for subspacing. Finally, implementation of subspacing process for indoor network is presented.

Extreme endurance flights by landbirds crossing the Pacific Ocean: Ecological corridor rather than barrier?

USGS Publications Warehouse

Gill, Robert E.; Tibbitts, T.L.; Douglas, David C.; Handel, Colleen M.; Mulcahy, D.M.; Gottschalck, J.C.; Warnock, N.; McCaffery, B.J.; Battley, Phil F.; Piersma, Theunis

2009-01-01

Mountain ranges, deserts, ice fields and oceans generally act as barriers to the movement of land-dependent animals, often profoundly shaping migration routes. We used satellite telemetry to track the southward flights of bar-tailed godwits (Limosa lapponica baueri), shorebirds whose breeding and non-breeding areas are separated by the vast central Pacific Ocean. Seven females with surgically implanted transmitters flew non-stop 8117-11680km (10153??1043 s.d.) directly across the Pacific Ocean; two males with external transmitters flew non-stop along the same corridor for 7008-7390km. Flight duration ranged from 6.0 to 9.4 days (7.8??1.3 s.d.) for birds with implants and 5.0 to 6.6 days for birds with externally attached transmitters. These extraordinary non-stop flights establish new extremes for avian flight performance, have profound implications for understanding the physiological capabilities of vertebrates and how birds navigate, and challenge current physiological paradigms on topics such as sleep, dehydration and phenotypic flexibility. Predicted changes in climatic systems may affect survival rates if weather conditions at their departure hub or along the migration corridor should change. We propose that this transoceanic route may function as an ecological corridor rather than a barrier, providing a wind-assisted passage relatively free of pathogens and predators. ?? 2008 The Royal Society.

Extreme endurance flights by landbirds crossing the Pacific Ocean: ecological corridor rather than barrier?

PubMed Central

Gill, Robert E.; Tibbitts, T. Lee; Douglas, David C.; Handel, Colleen M.; Mulcahy, Daniel M.; Gottschalck, Jon C.; Warnock, Nils; McCaffery, Brian J.; Battley, Philip F.; Piersma, Theunis

2008-01-01

Mountain ranges, deserts, ice fields and oceans generally act as barriers to the movement of land-dependent animals, often profoundly shaping migration routes. We used satellite telemetry to track the southward flights of bar-tailed godwits (Limosa lapponica baueri), shorebirds whose breeding and non-breeding areas are separated by the vast central Pacific Ocean. Seven females with surgically implanted transmitters flew non-stop 8117–11 680 km (10 153±1043 s.d.) directly across the Pacific Ocean; two males with external transmitters flew non-stop along the same corridor for 7008–7390 km. Flight duration ranged from 6.0 to 9.4 days (7.8±1.3 s.d.) for birds with implants and 5.0 to 6.6 days for birds with externally attached transmitters. These extraordinary non-stop flights establish new extremes for avian flight performance, have profound implications for understanding the physiological capabilities of vertebrates and how birds navigate, and challenge current physiological paradigms on topics such as sleep, dehydration and phenotypic flexibility. Predicted changes in climatic systems may affect survival rates if weather conditions at their departure hub or along the migration corridor should change. We propose that this transoceanic route may function as an ecological corridor rather than a barrier, providing a wind-assisted passage relatively free of pathogens and predators. PMID:18974033

Ahmed Glaucoma Valve Implantation in Vitrectomized Eyes

PubMed Central

İmamoğlu, Serhat

2018-01-01

Purpose To evaluate the outcomes of Ahmed glaucoma valve (AGV) implantation in vitrectomized eyes. Materials and Methods The medical records of 13 eyes that developed glaucoma due to emulsified silicon oil or neovascularization following pars plana vitrectomy and underwent AGV implantation were retrospectively reviewed. The main outcome measures were intraocular pressure (IOP), best-corrected visual acuity (BCVA), number of antiglaucoma medications, and postoperative complications. Surgical success was defined as last IOP ≤21 mmHg or ≥6 mmHg and without loss of light perception. Results The mean follow-up duration was 11.7 ± 5.5 (range, 6–23) months. The mean IOP before the AGV implantation was 37.9 ± 6.7 mmHg with an average of 3.5 ± 1.2 drugs. At the final visit, the mean IOP was 15.9 ± 4.6 mmHg (p=0.001) and the mean number of glaucoma medications decreased to 2.3 ± 1.3 (p=0.021). At the last visit, 11 eyes (84.4%) had stable or improved VA and one eye (7.7%) had a final VA of no light perception. Surgical success was achieved in 11 of the 13 eyes (84.4%). Postoperative complications were bleb encapsulation (69.2%), early hypotony (38.5%), hyphema (23.1%), decompression retinopathy (23.1%), choroidal detachment (15.4%), intraocular hemorrhage (7.7%), and late endophthalmitis (7.7%). One eye (7.7%) was enucleated because of late endophthalmitis. Conclusions Despite complications necessitating medical and surgical interventions, vitrectomized eyes were effectively managed with AGV implantation. PMID:29862068

Short-term to Long-term Results of Ahmed Glaucoma Valve Implantation for Uveitic Glaucoma Secondary to Behçet Disease.

PubMed

Yakin, Mehmet; Eksioglu, Umit; Sungur, Gulten; Satana, Banu; Demirok, Gulizar; Ornek, Firdevs

2017-01-01

To evaluate short-term to long-term outcomes of Ahmed glaucoma valve (AGV) implantation in the management of uveitic glaucoma (UG) secondary to Behçet disease (BD). A retrospective chart review of 47 eyes of 35 patients with UG secondary to BD who underwent AGV implantation was conducted. Success was defined as having an intraocular pressure (IOP) between 6 and 21 mm Hg with (qualified success) or without (complete success) antiglaucomatous medications and without need for further glaucoma surgery. Mean postoperative follow-up was 57.72±26.13 months. Mean preoperative IOP was 35.40±8.33 mm Hg versus 12.28±2.90 mm Hg at the last follow-up visit (P<0.001). Mean number of preoperative topical antiglaucomatous medications was 2.96±0.29 versus 0.68±1.12 at the last follow-up visit (P<0.001). In all eyes, IOP could be maintained between 6 and 21 mm Hg with or without antiglaucomatous medications during follow-up. The cumulative probability of complete success was 46.8% at 6 months, 40.4% at 12 months, and 35.9% at 36 months, and the cumulative probability of eyes without complication was 53.2% at 6 months, 46.5% at 12 months, and 39.6% at 24 months postoperatively based on Kaplan-Meier survival analysis. No persistent or irreparable complications were observed. This study includes one of the largest series of AGV implantation in the management of UG with the longest follow-up reported. AGV implantation can be considered as a primary surgical option in the management of UG secondary to BD with 100% total success rate (with or without medications).

Combined Ahmed Glaucoma Valve Placement, Intravitreal Fluocinolone Acetonide Implantation and Cataract Extraction for Chronic Uveitis.

PubMed

Chang, Ingrid T; Gupta, Divakar; Slabaugh, Mark A; Vemulakonda, Gurunadh A; Chen, Philip P

2016-10-01

To report the outcomes of combined Ahmed glaucoma valve (AGV) placement, intravitreal fluocinolone acetonide implant, and cataract extraction procedure in the treatment of chronic noninfectious uveitis. Retrospective case series of patients with chronic noninfectious uveitis who underwent AGV placement, intravitreal fluocinolone acetonide implantation, and cataract extraction in a single surgical session performed at 1 institution from January 2009 to November 2014. Outcome measures included intraocular pressure (IOP) and glaucoma medication use. Secondary outcome measures included visual acuity, systemic anti-inflammatory medications, number of uveitis flares, and complications. Fifteen eyes of 10 patients were studied, with a mean age of 40.3±15.7 and mean follow-up duration of 26 months (range, 13 to 39 mo). Before surgery, the IOP was 18.5±7.3 mm Hg and patients were using 1.5±1.5 topical glaucoma medications. At the 12-month follow-up, IOP was 12.8±3.2 mm Hg (P=0.01) and patients were using 0.5±0.8 (P=0.03) topical glaucoma medications. At 36 months of follow-up, late, nonsustained hypotony had occurred in 3 eyes (20%), and 1 eye (6%) had received a second AGV for IOP control. Before treatment, patients had 2.7±1.5 uveitis flares in the year before surgery while on an average of 2.1±0.6 systemic anti-inflammatory medications, which decreased to an average of 0.1±0.3 (P<0.01) flares the year after surgery while on an average of 0.4±1.1 (P<0.01) systemic medications. Combined AGV, intravitreal fluocinolone acetonide implant, and cataract extraction is effective in controlling IOP and reducing the number of glaucoma medications at 12 months after treatment in patients with chronic uveitis.

Outcomes of Ahmed Valve Implant Following a Failed Initial Trabeculotomy and Trabeculectomy in Refractory Primary Congenital Glaucoma

PubMed Central

Dave, Paaraj; Senthil, Sirisha; Choudhari, Nikhil; Sekhar, Garudadri Chandra

2015-01-01

Purpose: The aim was to report the outcome of Ahmed glaucoma valve (AGV) (New World Medical, Inc., Rancho Cucamonga, CA, USA) implantation as a surgical intervention following an initial failed combined trabeculotomy + trabeculectomy (trab + trab) in refractory primary congenital glaucoma (RPCG). Materials and Methods: Retrospective chart review of 11 eyes of 8 patients who underwent implantation of AGV (model FP8) for RPCG between 2009 and 2011. Prior trab + trab had failed in all the eyes. Success was defined as an intraocular pressure (IOP) >5 and ≤ 18 mmHg during examination under anesthesia with or without medications and without serious complications or additional glaucoma surgery. Results: The mean age at AGV implantation was 15.4 ± 4.9 months. The mean preoperative IOP was 28 ± 5.7 mmHg which reduced to 13.6 ± 3.4 mmHg postoperatively at the last follow-up (P < 0.0001). The number of topical antiglaucoma medications reduced from a mean of 2.6 ± 0.5 to 1.6 ± 0.9 postoperatively (P = 0.009). The definition of qualified success was met in 10 (90%) eyes. One eye developed a shallow anterior chamber with choroidal detachment at 1-week, which resolved spontaneously with medications. None of the eyes developed a hypertensive phase. One eye had a long tube resulting in tube corneal touch that required trimming of the tube. One eye developed tube retraction, which was treated with a tube extender. The mean follow-up was 17.9 ± 9.3 (6.2-35.4) months. Conclusion: Managing RPCG remains a challenge. AGV implant was successful in a significant proportion of cases. PMID:25624676

Clinical Outcomes of FP-7/8 Ahmed Glaucoma Valves in the Management of Refractory Glaucoma in the Mainland Chinese Population

PubMed Central

Yang, Xuejiao; Deng, Shuifeng; Li, Zuohong; Li, Fei; Zhuo, Yehong

2015-01-01

Background To evaluate the efficacy and safety of the Ahmed glaucoma valve (AGV) and the risk factors associated with AGV implantation failure in a population of Chinese patients with refractory glaucoma. Method In total, 79 eyes with refractory glaucoma from 79 patients treated in our institution from November 2007 to November 2010 were enrolled in this retrospective study. The demographic data, preoperative and postoperative intraocular pressures (IOPs), best corrected visual acuity (BCVA), number of anti-glaucoma medications used, completed and qualified surgery success rates and postoperative complications were recorded to evaluate the outcomes of AGV implantation. Factors that were associated with implant failure were determined using Cox proportional hazard regression model analysis and multiple linear regression analysis. Principle Findings The average follow-up time was 12.7±5.8 months (mean±SD). We observed a significant reduction in the mean IOP from 39.9±12.6 mm Hg before surgery to 19.3±9.6 mm Hg at the final follow-up. The complete success rate was 59.5%, and the qualified success rate was 83.5%. The number of previous surgeries was negatively correlated with qualified success rate (P<0.05, OR=0.736, 95% CI 0.547-0.99). Patients with previous trabeculectomy were more likely to use multiple anti-glaucoma drugs to control IOP (P<0.01). The primary complication was determined to be a flat anterior chamber (AC). Conclusion AGV implantation was safe and effective for the management of refractory glaucoma. Patients with a greater number of previous surgeries were more likely to experience surgical failure, and patients with previous trabeculectomy were more likely to use multiple anti-glaucoma drugs to control postoperative IOP. PMID:25996991

Needle Revision With 5-fluorouracil for the Treatment of Ahmed Glaucoma Valve Filtering Blebs: 5-Fluoruracil Needling Revision can be a Useful and Safe Tool in the Management of Failing Ahmed Glaucoma Valve Filtering Blebs.

PubMed

Quaranta, Luciano; Floriani, Irene; Hollander, Lital; Poli, Davide; Katsanos, Andreas; Konstas, Anastasios G P

2016-04-01

To determine the outcome of needling with adjunctive 5-fluorouracil (5-FU) in patients with a failing Ahmed glaucoma valve (AGV) implant, and to identify predictors of long-term intraocular pressure (IOP) control. A prospective observational study was performed on consecutive patients with medically uncontrolled primary open-angle glaucoma (POAG) with AGV encapsulation or fibrosis and inadequate IOP control. Bleb needling with 5-FU injection (0.1 mL of 50 mg/mL) was performed at the slit-lamp. Patients were examined 1 week following the needling, and then at months 1, 3, and 6. Subsequent follow-up visits were scheduled at 6-month intervals for at least 2 years. Needling with 5-FU was repeated no more than twice during the first 3 months of the follow-up. Procedure outcome was determined on the basis of the recorded IOP levels. Thirty-six patients with an encapsulated or fibrotic AGV underwent 67procedures (mean 1.86 ± 0.83). Complete success, defined as IOP ≤ 18 mm Hg without medications, was obtained in 25% at 24 months of observation. The cumulative proportion of cases achieving either qualified (ie, IOP ≤ 18 mm Hg with medications) or complete success at 24 months of observation was 72.2%. In a univariate Cox proportional hazards model, age was the only variable that independently influenced the risk of failing 5-FU needling revision. Fourteen eyes (38.8%) had a documented complication. Needling over the plate of an AGV supplemented with 5-FU is an effective and safe choice in a significant proportion of POAG patients with elevated IOP due to encapsulation or fibrosis.

Long-term clinical outcomes of Ahmed valve implantation in patients with refractory glaucoma

PubMed Central

Lee, Chang Kyu; Ma, Kyoung Tak; Hong, Young Jae

2017-01-01

Purpose To evaluate the long-term efficacy of intraocular pressure (IOP) reduction and complications of Ahmed Glaucoma Valve (AGV) implantation in patients with refractory glaucoma. Design Retrospective study. Subjects The study involved 302 refractory glaucoma patients who underwent AGV implantation and had a minimum follow-up of 6 months between March 1995 and December 2013. Methods An operation was defined as successful when (1) the postoperative IOP remained between 5 and 21 mmHg and was reduced 30% compared to the baseline IOP with or without medication, (2) there was no loss of light perception or vision-threatening severe complications, and (3) no additional filtering or aqueous drainage surgery was required. Clinical records were reviewed. Main outcome measures IOP, anti-glaucoma medications, and complications Results The mean follow-up period was 62.25 months (range, 6 to 190 months). The cumulative probability of success was 89% at 6 months, 81% at 1 year, 66% at 3 years, 44% at 10 years, and 26% at 15 years. IOP was reduced from a mean of 32.2 ± 10.5 mmHg to 18.6 ± 9.1 mmHg at 1 month, 15.2 ± 7.0 mmHg at 6 months, and 14.2 ± 3.5 mmHg at 15 years. Surgical failures were significantly increased when preoperative IOP was high, and when severe complications occurred after AGV implantation (P < 0.05). Conclusion AGV implantation was successful for IOP control in patients with refractive glaucoma in the long term. However, the success rate of surgery decreased over time. Preoperative high IOP and severe complications related to the operation were significant risk factors for failure. PMID:29095931

Ahmed Glaucoma Valve Implantation for Uveitic Glaucoma Secondary to Behçet Disease.

PubMed

Satana, Banu; Yalvac, Ilgaz S; Sungur, Gulten; Eksioglu, Umit; Basarir, Berna; Altan, Cigdem; Duman, Sunay

2015-01-01

To evaluate outcomes of patients with uveitic glaucoma secondary to Behçet disease (BD) who underwent Ahmed glaucoma valve (AGV) implantation. A retrospective chart review of 14 eyes of 10 patients with uveitic glaucoma associated with BD who underwent AGV implantation at a tertiary referral center. Treatment success was defined as intraocular pressure (IOP) between 6 and 21 mm Hg with or without antiglaucoma medication, without further additional glaucoma surgery or loss of light perception. The main outcome measures were IOP, best-corrected visual acuity measured with Snellen charts, and number of glaucoma medications. Mean duration of postoperative follow-up was 18.2±6.6 months (range, 6 to 31 mo). Of the 14 eyes, 10 (71.4%) were pseudophakic and 5 (35.7%) had primary AGV implantation without a history of previous glaucoma surgery. At the most recent follow-up visit, 13 of the 14 eyes had an IOP between 6 and 21 mm Hg. Mean IOP was significantly reduced during follow-up, as compared with preoperative values (P≤0.005). The cumulative probability of surgical success rate was 90.9% at 18 months based on Kaplan-Meier survival analysis. The mean number of antiglaucoma medications required to achieve the desired IOP decreased from 3.4±0.5 preoperatively to 1.0±1.1 postoperatively (P≤0.05). Visual acuity loss of >2 lines occurred in 4 eyes (28.5%) due to optic atrophy associated with retinal vasculitis. Temporary hypotony developed during follow-up in 4 eyes (28.5%) at first postoperative week. For the management of uveitic glaucoma associated with BD, AGV implantation is a successful method for glaucoma control but requires additional surgical interventions for high early hypotony rates.

Clinical Outcomes of FP-7/8 Ahmed Glaucoma Valves in the Management of Refractory Glaucoma in the Mainland Chinese Population.

PubMed

Zhu, Yingting; Wei, Yantao; Yang, Xuejiao; Deng, Shuifeng; Li, Zuohong; Li, Fei; Zhuo, Yehong

2015-01-01

To evaluate the efficacy and safety of the Ahmed glaucoma valve (AGV) and the risk factors associated with AGV implantation failure in a population of Chinese patients with refractory glaucoma. In total, 79 eyes with refractory glaucoma from 79 patients treated in our institution from November 2007 to November 2010 were enrolled in this retrospective study. The demographic data, preoperative and postoperative intraocular pressures (IOPs), best corrected visual acuity (BCVA), number of anti-glaucoma medications used, completed and qualified surgery success rates and postoperative complications were recorded to evaluate the outcomes of AGV implantation. Factors that were associated with implant failure were determined using Cox proportional hazard regression model analysis and multiple linear regression analysis. The average follow-up time was 12.7±5.8 months (mean±SD). We observed a significant reduction in the mean IOP from 39.9±12.6 mm Hg before surgery to 19.3±9.6 mm Hg at the final follow-up. The complete success rate was 59.5%, and the qualified success rate was 83.5%. The number of previous surgeries was negatively correlated with qualified success rate (P<0.05, OR=0.736, 95% CI 0.547-0.99). Patients with previous trabeculectomy were more likely to use multiple anti-glaucoma drugs to control IOP (P<0.01). The primary complication was determined to be a flat anterior chamber (AC). AGV implantation was safe and effective for the management of refractory glaucoma. Patients with a greater number of previous surgeries were more likely to experience surgical failure, and patients with previous trabeculectomy were more likely to use multiple anti-glaucoma drugs to control postoperative IOP.

Photoelectric scanning-based method for positioning omnidirectional automatic guided vehicle

NASA Astrophysics Data System (ADS)

Huang, Zhe; Yang, Linghui; Zhang, Yunzhi; Guo, Yin; Ren, Yongjie; Lin, Jiarui; Zhu, Jigui

2016-03-01

Automatic guided vehicle (AGV) as a kind of mobile robot has been widely used in many applications. For better adapting to the complex working environment, more and more AGVs are designed to be omnidirectional by being equipped with Mecanum wheels for increasing their flexibility and maneuverability. However, as the AGV with this kind of wheels suffers from the position errors mainly because of the frequent slipping property, how to measure its position accurately in real time is an extremely important issue. Among the ways of achieving it, the photoelectric scanning methodology based on angle measurement is efficient. Hence, we propose a feasible method to ameliorate the positioning process, which mainly integrates four photoelectric receivers and one laser transmitter. To verify the practicality and accuracy, actual experiments and computer simulations have been conducted. In the simulation, the theoretical positioning error is less than 0.28 mm in a 10 m×10 m space. In the actual experiment, the performances about the stability, accuracy, and dynamic capability of this method were inspected. It demonstrates that the system works well and the performance of the position measurement is high enough to fulfill the mainstream tasks.

Superior versus inferior Ahmed glaucoma valve implantation.

PubMed

Pakravan, Mohammad; Yazdani, Shahin; Shahabi, Camelia; Yaseri, Mehdi

2009-02-01

To compare the efficacy and safety of Ahmed glaucoma valve (AGV) (New World Medical Inc., Rancho Cucamonga, CA) implantation in the superior versus inferior quadrants. Prospective parallel cohort study. A total of 106 eyes of 106 patients with refractory glaucoma. Consecutive patients with refractory glaucoma underwent AGV implantation in the superior or inferior quadrants. Main outcome measures included intraocular pressure (IOP) and rate of complications. Other outcome measures included best corrected visual acuity (BCVA), number of glaucoma medications, and success rate (defined as at least 30% IOP reduction and 50.122). After 1 year, statistically significant but comparable IOP reduction from baseline (P<0.001) was achieved in both groups (47.0%+/-27.2% and 43.0%+/-24.5% reduction for superior and inferior groups, respectively, P = 0.725). The mean number of glaucoma medications was comparable after 1 year (1.3+/-1.2 vs. 1.9+/-0.8 for superior and inferior implants, respectively, P = 0.256). Success rates were also similar at 1 year: 27 eyes (81.8%) versus 20 eyes (95.2%) for superior and inferior implants, respectively (P = 0.227). However, the overall rate of complications, such as implant exposure necessitating removal, cosmetically unappealing appearance, and endophthalmitis, was higher in the inferior group: 12 eyes (25%) versus 3 eyes (5.2%) for superior and inferior groups, respectively, (P = 0.004). Superior and inferior AGV implants have similar intermediate efficacy in terms of IOP reduction, decrease in number of glaucoma medications, and preservation of vision. However, the inferior quadrants entail significantly more complications. It may be prudent to avoid AGV implantation in the inferior quadrants if the superior quadrants have no contraindications to surgery. Proprietary or commercial disclosure may be found after the references.

Comparison of 1-year outcomes after Ahmed glaucoma valve implantation with and without Ologen adjuvant.

PubMed

Kim, Tai Jun; Kang, Sohyun; Jeoung, Jin Wook; Kim, Young Kook; Park, Ki Ho

2018-02-14

Many studies have investigated the clinical benefits of Ologen for trabeculectomy. However, its benefits for Ahmed glaucoma valve (AGV) implantation have not been investigated as extensively. The aim of this study was to compare the 1-year outcomes of AGV implantation with and without Ologen adjuvant for the treatment of refractory glaucoma. This retrospective study included a total of 20 eyes of 20 glaucoma patients, who were followed for at least 1-year after undergoing AGV implantation. In 12 eyes of 12 patients, conventional AGV (CAGV) surgery was performed, while in 8 eyes of 8 patients, Ologen-augmented AGV (OAGV) implantation was performed. The outcomes were evaluated according to intraocular pressure (IOP) and the number of IOP-lowering medications. Complete success was defined as IOP ≤ 21 mmHg without medications throughout the 1-year follow-up period, and qualified success was defined as IOP ≤ 21 mmHg with or without medications throughout the 1-year follow-up period. The rate of complete success was significantly higher in the OAGV group (50.0%) than in the CAGV group (8.3%) (p = 0.035). There were no significant differences between the two groups in terms of qualified success or incidence of the early hypertensive phase. The IOP changes were similar between the groups within 1-year postoperatively, though the number of IOP-lowering medications was significantly lower in the OAGV group during the early hypertensive phase (p = 0.031, 0.031, and 0.025 at postoperative months 1, 2, and 3, respectively). When subjects were divided into groups according to the occurrence of the early hypertensive phase, the group with early hypertensive phase was more likely to use IOP-lowering medications at postoperative 6 months and 1 year (p = 0.002 and 0.005, respectively). OAGV surgery shows encouraging results for patients with refractory glaucoma, specifically with respect to the achievement of complete success and the reduction of the number of IOP-lowering medications during the early hypertensive phase. Furthermore, our results suggest that occurrence of the early hypertensive phase is predictive of which patients will require IOP-lowering medications at postoperative 6 months and 1 year.

A traffic priority language for collision-free navigation of autonomous mobile robots in dynamic environments.

PubMed

Bourbakis, N G

1997-01-01

This paper presents a generic traffic priority language, called KYKLOFORTA, used by autonomous robots for collision-free navigation in a dynamic unknown or known navigation space. In a previous work by X. Grossmman (1988), a set of traffic control rules was developed for the navigation of the robots on the lines of a two-dimensional (2-D) grid and a control center coordinated and synchronized their movements. In this work, the robots are considered autonomous: they are moving anywhere and in any direction inside the free space, and there is no need of a central control to coordinate and synchronize them. The requirements for each robot are i) visual perception, ii) range sensors, and iii) the ability of each robot to detect other moving objects in the same free navigation space, define the other objects perceived size, their velocity and their directions. Based on these assumptions, a traffic priority language is needed for each robot, making it able to decide during the navigation and avoid possible collision with other moving objects. The traffic priority language proposed here is based on a set of primitive traffic priority alphabet and rules which compose pattern of corridors for the application of the traffic priority rules.

Volcanic hazards and aviation safety

USGS Publications Warehouse

Casadevall, Thomas J.; Thompson, Theodore B.; Ewert, John W.; ,

1996-01-01

An aeronautical chart was developed to determine the relative proximity of volcanoes or ash clouds to the airports and flight corridors that may be affected by volcanic debris. The map aims to inform and increase awareness about the close spatial relationship between volcanoes and aviation operations. It shows the locations of the active volcanoes together with selected aeronautical navigation aids and great-circle routes. The map mitigates the threat that volcanic hazards pose to aircraft and improves aviation safety.

Efficacy of long scleral tunnel technique in preventing Ahmed glaucoma valve tube exposure through conjunctiva.

PubMed

Kugu, Suleyman; Erdogan, Gurkan; Sevim, M Sahin; Ozerturk, Yusuf

2015-01-01

To evaluate the efficacy of long scleral tunnel technique used in Ahmed glaucoma valve (AGV) implantation in preventing tube exposure through conjunctiva. Patients of adult age, who were unresponsive to maximum medical treatment and underwent AGV implantation, were divided into two groups and investigated retrospectively. Group 1 consisted of 40 eyes of 38 patients that underwent surgery by long scleral tunnel technique and Group 2 consisted of 38 eyes of 35 patients that underwent implantation by processed pericardium patch graft method. The mean age was 54.8 ± 14.6 years (range 26-68 years) and the mean follow-up duration was 46.7 ± 19.4 months (range 18-76 months) for the patients in Group 1, whereas the mean age was 58.6 ± 16.7 years (range 32-74 years) and mean follow-up period was 43.6 ± 15.7 months (range 20-72 months) for the patients in Group 2 (p > 0.05). In the course of follow-up, tube exposure was detected in one (2.5%) eye in Group 1 and in three (7.9%) eyes in Group 2 (p = 0.042). Long scleral tunnel technique is beneficial in preventing conjunctival tube exposure in AGV implantation surgery.

Initial Experience With the New Ahmed Glaucoma Valve Model M4: Short-term Results.

PubMed

Cvintal, Victor; Moster, Marlene R; Shyu, Andrew P; McDermott, Katie; Ekici, Feyzahan; Pro, Michael J; Waisbourd, Michael

2016-05-01

To evaluate the clinical outcomes of the new Ahmed glaucoma valve (AGV) model M4. The device consists of a porous polyethylene shell designed for improved tissue integration and reduced encapsulation of the plate for better intraocular pressure (IOP) control. Medical records of patients with an AGV M4 implantation between December 1, 2012 and December 31, 2013 were reviewed. The main outcome measure was surgical failure, defined as either (1) IOP<5 mm Hg or >21 mm Hg and/or <20% reduction of IOP at last follow-up visit, (2) a reoperation for glaucoma, and/or (3) loss of light perception. Seventy-five eyes of 73 patients were included. Postoperative IOP at all follow-up visits significantly decreased from a baseline IOP of 31.2 mm Hg (P<0.01). However, IOP increased significantly at 3 months (20.4 mm Hg), 6 months (19.3 mm Hg), and 12 months (20.3 mm Hg) compared with 1 month (13.8 mm Hg) postoperatively (P<0.05). At 6 months and 1 year, the cumulative probability of failure was 32% and 72%, respectively. The AGV M4 effectively reduced IOP in the first postoperative month, but IOP steadily increased thereafter. Consequently, failure rates were high after 1 year of follow-up.

Maintenance Dredging of the Federal Navigation Channels in the St. Clair River, Michigan.

DTIC Science & Technology

1976-01-01

Detroit livers system today constitutes a major corridor for waterborne traffic, and therefore a central axis of settlement, it should not be surprising...0 C;U2 $4 2) ~ 4 .0 41 -4 0~ 0~ ~0 -4 144 .H ,.4ul0. ".4 -4 -4 4.42 0 0 4.44 -44 ’U r rU 0 54 4-’ 4 .14 1- 1 A N.~~- A. )0 > TABLE 14. Wildife in

Endoscopic trans-nasal approach for biopsy of orbital tumours using image-guided neuro-navigation system.

PubMed

Sieskiewicz, A; Lyson, T; Mariak, Z; Rogowski, M

2008-05-01

Histopathological diagnosis of intraorbital tumours is of crucial value for planning further therapy. The aim of the study was to explore clinical utility of image-guided endoscopy for biopsy of orbital tumours. Trans-nasal endoscopic biopsy of intraorbital mass lesions was performed in 6 patients using a neuro-navigation system (Medtronic Stealth Station Treon plus). The CT and MRI 1 mm slice images were fused by the system in order to visualise both bony and soft tissue structures. The anatomic fiducial registration protocol was used during the procedure. All lesions were precisely localised and the biopsies could be taken from the representative part of the pathological mass. None of the patients developed aggravation of ocular symptoms after the procedure. The operative corridor as well as the size of orbital wall fenestration could be limited to a minimum. The accuracy of neuro-navigation remained high and stable during the entire procedure. The image-guided neuro-navigation system facilitated endoscopic localisation and biopsy of intraorbital tumours and contributed to the reduction of surgical trauma during the procedure. The technique was particularly useful in small, medially located, retrobulbar tumours and in unclear situations when the structure of the lesion resembled surrounding intraorbital tissue.

Use of Autologous Scleral Graft in Ahmed Glaucoma Valve Surgery.

PubMed

Wolf, Alvit; Hod, Yair; Buckman, Gila; Stein, Nili; Geyer, Orna

2016-04-01

To compare the efficacy of an autoscleral free-flap graft versus an autoscleral rotational flap graft in Ahmed glaucoma valve (AGV) surgery. Medical records (2005 to 2012) of 51 consecutive patients (51 eyes) who underwent AGV surgery with the use of either an autoscleral free-flap graft or an autoscleral rotational flap graft to cover the external tube at the limbus were retrieved for review. The main outcome measure was the incidence of tube exposure associated with each surgical approach. Twenty-seven consecutive patients (27 eyes) received a free-flap graft and 24 consecutive patients (24 eyes) received a rotational flap graft. The mean follow-up time was 55.6 ± 18.3 months for the former and 24.2± 5 .0 months for the latter (P<0.0001). Two patients in the free-flap group (8.9%) developed tube exposure at 24 and 55 months postoperatively compared with none of the patients in the rotational flap group. Graft thinning without evidence of conjunctival erosion was observed in 15 patients (55%) in the free-flap group and in 7 patients (29.1%) in the rotational flap group. The use of an autoscleral rotational flap graft is an efficacious technique for primary tube patch grafting in routine AGV surgery, and yielded better results than an autoscleral free-flap graft. Its main advantages over donor graft material are availability and lower cost.

Excisional Bleb Revision for Management of Failed Ahmed Glaucoma Valve.

PubMed

Eslami, Yadollah; Fakhraie, Ghasem; Moghimi, Sasan; Zarei, Reza; Mohammadi, Masoud; Nabavi, Amin; Yaseri, Mehdi; Izadi, Ali

2017-12-01

To evaluate the outcome of excisonal bleb revision in patients with failed Ahmed glaucoma valve (AGV). In total, 29 patients with uncontrolled intraocular pressure (IOP) despite of maximal tolerated medical therapy at least 6 months after AGV implantation were enrolled in this prospective interventional case series. Excision of fibrotic tissue around the reservoir with application of mitomycin C 0.02% was performed. IOP, number of glaucoma medications were evaluated at baseline and 1 week and 1, 3, 6, and 12 months postoperatively. Complete and qualified success was defined as IOP≤21 mm Hg with or without glaucoma medications, respectively. Intraoperative and postopervative complications were also recorded. Mean IOP was reduced from 30±4.2 mm Hg at baseline to 19.2±3.1 mm Hg at 12-month follow-up visit (P<0.001). Average number of glaucoma medications was decrease from 3.2±0.5 at baseline to 1.9±0.7 at 12-month follow-up (P<0.001). Qualified and complete success rates at 12-month follow-up were 65.5% and 6.9%, respectively. Younger age and higher number of previous glaucoma surgeries were significantly associated with the failure of excisonal bleb revision. Excisional bleb revision could be considered as a relatively effective alternative option for management of inadequate IOP control after AGV implantation.

Navigation and Robotics in Spinal Surgery: Where Are We Now?

PubMed

Overley, Samuel C; Cho, Samuel K; Mehta, Ankit I; Arnold, Paul M

2017-03-01

Spine surgery has experienced much technological innovation over the past several decades. The field has seen advancements in operative techniques, implants and biologics, and equipment such as computer-assisted navigation and surgical robotics. With the arrival of real-time image guidance and navigation capabilities along with the computing ability to process and reconstruct these data into an interactive three-dimensional spinal "map", so too have the applications of surgical robotic technology. While spinal robotics and navigation represent promising potential for improving modern spinal surgery, it remains paramount to demonstrate its superiority as compared to traditional techniques prior to assimilation of its use amongst surgeons.The applications for intraoperative navigation and image-guided robotics have expanded to surgical resection of spinal column and intradural tumors, revision procedures on arthrodesed spines, and deformity cases with distorted anatomy. Additionally, these platforms may mitigate much of the harmful radiation exposure in minimally invasive surgery to which the patient, surgeon, and ancillary operating room staff are subjected.Spine surgery relies upon meticulous fine motor skills to manipulate neural elements and a steady hand while doing so, often exploiting small working corridors utilizing exposures that minimize collateral damage. Additionally, the procedures may be long and arduous, predisposing the surgeon to both mental and physical fatigue. In light of these characteristics, spine surgery may actually be an ideal candidate for the integration of navigation and robotic-assisted procedures.With this paper, we aim to critically evaluate the current literature and explore the options available for intraoperative navigation and robotic-assisted spine surgery. Copyright © 2016 by the Congress of Neurological Surgeons.

Application of Vehicle Dynamic Modeling in Uavs for Precise Determination of Exterior Orientation

NASA Astrophysics Data System (ADS)

Khaghani, M.; Skaloud, J.

2016-06-01

Advances in unmanned aerial vehicles (UAV) and especially micro aerial vehicle (MAV) technology together with increasing quality and decreasing price of imaging devices have resulted in growing use of MAVs in photogrammetry. The practicality of MAV mapping is seriously enhanced with the ability to determine parameters of exterior orientation (EO) with sufficient accuracy, in both absolute and relative senses (change of attitude between successive images). While differential carrier phase GNSS satisfies cm-level positioning accuracy, precise attitude determination is essential for both direct sensor orientation (DiSO) and integrated sensor orientation (ISO) in corridor mapping or in block configuration imaging over surfaces with low texture. Limited cost, size, and weight of MAVs represent limitations on quality of onboard navigation sensors and puts emphasis on exploiting full capacity of available resources. Typically short flying times (10-30 minutes) also limit the possibility of estimating and/or correcting factors such as sensor misalignment and poor attitude initialization of inertial navigation system (INS). This research aims at increasing the accuracy of attitude determination in both absolute and relative senses with no extra sensors onboard. In comparison to classical INS/GNSS setup, novel approach is presented here to integrated state estimation, in which vehicle dynamic model (VDM) is used as the main process model. Such system benefits from available information from autopilot and physical properties of the platform in enhancing performance of determination of trajectory and parameters of exterior orientation consequently. The navigation system employs a differential carrier phase GNSS receiver and a micro electro-mechanical system (MEMS) grade inertial measurement unit (IMU), together with MAV control input from autopilot. Monte-Carlo simulation has been performed on trajectories for typical corridor mapping and block imaging. Results reveal considerable reduction in attitude errors with respect to conventional INS/GNSS system, in both absolute and relative senses. This eventually translates into higher redundancy and accuracy for photogrammetry applications.

Assessment of Filtration Bleb and Endplate Positioning Using Magnetic Resonance Imaging in Eyes Implanted with Long-Tube Glaucoma Drainage Devices.

PubMed

Sano, Ichiya; Tanito, Masaki; Uchida, Koji; Katsube, Takashi; Kitagaki, Hajime; Ohira, Akihiro

2015-01-01

To evaluate ocular fluid filtration and endplate positioning in glaucomatous eyes with long-tube glaucoma drainage devices (GDDs) using magnetic resonance imaging (MRI) and the effects of various factors on postoperative intraocular pressure (IOP). This observational case series included 27 consecutive glaucomatous eyes (18 men, 7 women; mean age ± standard error, 63.0±2.0 years) who underwent GDD implantation (n = 8 Ahmed Glaucoma Valves [AGV] and n = 19 Baerveldt Glaucoma Implants [BGI]). Tubes were inserted into the pars plana in 23 eyes and anterior chamber in 4 eyes. Six months postoperatively, high-resolution orbital images were obtained using 3-Tesla MRI with head-array coils, and the filtering bleb volume, bleb height, and distances between the anterior endplate edge and corneal center or limbus or between the endplate and orbital wall were measured. In MR images obtained by three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequences, the shunt endplate was identified as low-intensity signal, and the filtering bleb was identified as high-intensity signals above and below the endplate in all eyes. The 6-month-postoperative IOP level was correlated negatively with bleb volume (r = -0.4510, P = 0.0182) and bleb height (r = -0.3954, P = 0.0412). The postoperative IOP was significantly (P = 0.0026) lower in BGI-implanted eyes (12.2±0.7 mmHg) than AGV-implanted eyes (16.7±1.2 mmHg); bleb volume was significantly (P = 0.0093) larger in BGI-implanted eyes (478.8±84.2 mm3) than AGV-implanted eyes (161.1±52.3 mm3). Other parameters did not differ. The presence of intraorbital/periocular accumulation of ocular fluid affects postoperative IOP levels in eyes implanted with long-tube GDDs. Larger filtering blebs after BGI than AGI implantations explain lower postoperative IOP levels achieved with BGI than AGV. The findings will contribute to better understanding of IOP reducing mechanism of long-tube GDDs.

Telematic Problems of Unmanned Vehicles Positioning at Container Terminals and Warehouses

NASA Astrophysics Data System (ADS)

Kwasniowski, Stanisław; Zajac, Mateusz; Zajac, Paweł

This paper describes the issues of transshipment container terminals operations, in the light of the development of this kind of transport. An increase in handling requires an expansion of stacking yard and automation of handling and transport processes. The development in this area first and foremost depends on modern handling technologies and automatic identification systems. AGV trucks play a key role in in those systems. The role of universities is to promote innovative technologies. Paper [2] contains the status of intermodal terminals development in Poland, which was awarded the prize of the Minister of Infrastructure of Poland in the field of "organization and management." The paper contains a detailed description of the principles of positioning, control and propulsion of AGV vehicles. The content was developed to make it understandable to logisticians responsible for the implementation question in Poland.

Using sensor habituation in mobile robots to reduce oscillatory movements in narrow corridors.

PubMed

Chang, Carolina

2005-11-01

Habituation is a form of nonassociative learning observed in a variety of species of animals. Arguably, it is the simplest form of learning. Nonetheless, the ability to habituate to certain stimuli implies plastic neural systems and adaptive behaviors. This paper describes how computational models of habituation can be applied to real robots. In particular, we discuss the problem of the oscillatory movements observed when a Khepera robot navigates through narrow hallways using a biologically inspired neurocontroller. Results show that habituation to the proximity of the walls can lead to smoother navigation. Habituation to sensory stimulation to the sides of the robot does not interfere with the robot's ability to turn at dead ends and to avoid obstacles outside the hallway. This paper shows that simple biological mechanisms of learning can be adapted to achieve better performance in real mobile robots.

The Results of the Use of Ahmed Valve in Refractory Glaucoma Surgery

PubMed Central

Bikbov, Mukharram Mukhtaramovich

2015-01-01

ABSTRACT The treatment of refractory glaucoma (RG) is challenging. The commonly adopted strategy in RG treatment is a glaucoma drainage device (GDD) implantation, which despite its radical nature may not always provide the desired intraocular pressure (IOP) levels for a long term. This review is based on the scientific literature on Ahmed glaucoma valve (AGV) implantation for refractory glaucoma. The technique of AGV implantation is described and data for both the types, FP7 and FP8 performance are presented. The outcome with adjunct antimetabolite and anti-VEGF drugs are also highlighted. An insight is given about experimental and histological examinations of the filtering bleb encapsulation. The article also describes various complications and measures to prevent them. How to cite this article: Bikbov MM, Khusnitdinov II. The Results of the Use of Ahmed Valve in Refractory Glaucoma Surgery. J Curr Glaucoma Pract 2015;9(3):86-91. PMID:26997843

Airborne LIDAR point cloud tower inclination judgment

NASA Astrophysics Data System (ADS)

liang, Chen; zhengjun, Liu; jianguo, Qian

2016-11-01

Inclined transmission line towers for the safe operation of the line caused a great threat, how to effectively, quickly and accurately perform inclined judgment tower of power supply company safety and security of supply has played a key role. In recent years, with the development of unmanned aerial vehicles, unmanned aerial vehicles equipped with a laser scanner, GPS, inertial navigation is one of the high-precision 3D Remote Sensing System in the electricity sector more and more. By airborne radar scan point cloud to visually show the whole picture of the three-dimensional spatial information of the power line corridors, such as the line facilities and equipment, terrain and trees. Currently, LIDAR point cloud research in the field has not yet formed an algorithm to determine tower inclination, the paper through the existing power line corridor on the tower base extraction, through their own tower shape characteristic analysis, a vertical stratification the method of combining convex hull algorithm for point cloud tower scarce two cases using two different methods for the tower was Inclined to judge, and the results with high reliability.

Outcomes of using a sutureless bovine pericardial patch graft for Ahmed glaucoma valve implantation.

PubMed

Quaranta, Luciano; Riva, Ivano; Floriani, Irene C

2013-01-01

To evaluate the long-term outcomes of a surgical technique using a sutureless bovine pericardial patch graft for the implantation of an Ahmed glaucoma valve (AGV). 
 This was a pilot study on patients with primary open-angle glaucoma refractory to repeated surgical filtering procedures. All patients underwent AGV implant technique using a sutureless bovine pericardial patch graft. The pericardial membrane was cut using an ordinary corneal trephine with a diameter of 9.0 or 10.0 mm. The anterior part of the tube was covered with the graft and kept in place with fibrin glue. Subsequently, the cap was stitched all around the tube and the dissected conjunctiva was laid over it. Intraocular pressure (IOP) and complications were evaluated 1 week and 1, 3, 6, 12, and 24 months after surgery.
 The procedure was used to treat 20 eyes of 20 consecutive patients (12 men and 8 women: mean age [SD] 64.8 [7.8] years). Mean IOP was 28.1 mm Hg (SD 4.9) at baseline and decreased to 14.9 mm Hg (SD 1.5) 24 months after surgery (p<0.001). The overall mean number of topical medications was 3.1 (SD 0.5) at baseline and decreased to 1.4 (SD 0.8) after 24 months (p<0.001). During follow-up, there was no conjunctival erosion, thinning of pericardial patch graft over the tube, or tube exposure; no signs of endophthalmitis were recorded.
 The results suggest that the sutureless technique using a bovine pericardial graft patch is a safe and rapid procedure for AGV implantation.

Sutureless human sclera donor patch graft for Ahmed glaucoma valve.

PubMed

Zeppa, Lucio; Romano, Mario R; Capasso, Luigi; Tortori, Achille; Majorana, Mara A; Costagliola, Ciro

2010-01-01

To report the safety and effectiveness of a sutureless human sclera donor patch graft covering the subconjunctival portion of glaucoma drainage implant tube to prevent its erosion throughout the overlying conjunctiva. This was a prospective pilot study. Fifteen eyes of 15 consecutive patients not responsive to medical and to not-implant surgical glaucoma treatment underwent Ahmed glaucoma valve (AGV) implant surgery with sutureless human sclera donor patch graft. The surgical procedure included AVG implant placed 8 mm behind the corneal limbus and fixed to the sclera with two 9-0 black nylon sutures. The tube was passed through the scleral tunnel, parallel to the corneal limbus, and shortened at the desired length. The anterior part of the tube was covered with human donor scleral graft and kept in place with fibrin glue (Tissue Coll) under the conjunctiva. Examinations were scheduled at baseline and then at 1 week and 1, 3, 6, and 12 months after surgery. At 12-month follow-up, the best-corrected visual acuity did not significantly improve from baseline 0.78+/-1.2 logMAR, whereas mean intraocular pressure significantly decreased from preoperative values of 29.8 (SD 8.4) mmHg. In all cases, the scleral patch was found in place at each check during the follow-up period. No conjunctival erosion over the AGV tube nor sign of endophthalmitis was recorded at any time during the follow-up period. AVG implant surgery with sutureless human sclera donor patch graft represents an effective and relatively safe surgical procedure for complicated glaucomas, avoiding conjunctival erosions over the AGV tube.

Evaluation of Ahmed glaucoma valve implantation through a needle-generated scleral tunnel in Mexican children with glaucoma.

PubMed

Albis-Donado, Oscar; Gil-Carrasco, Félix; Romero-Quijada, Rafael; Thomas, Ravi

2010-01-01

To evaluate the results and extrusion rates of the Ahmed glaucoma valve (AGV) implantation through a needle-generated scleral tunnel, without a tube-covering patch, in children. A retrospective review of the charts of 106 Mexican children implanted with 128 AGVs operated between 1994 and 2002, with the needle track technique, at our institution, with at least six months follow up was done. Main outcome measures were intraocular pressure (IOP) control, tube extrusions or exposure and other complications. Kaplan-Meier analysis demonstrated a 96.9% survival rate at six months, 82.4% at one year, 78.7% at two years, 70% at three years and 41.6% at four years. Total success at the last follow-up (IOP between 6 and 21 mm Hg without medications) was achieved in 30 eyes (23.5%), 58 eyes (45.3%) had qualified success (only topical hypotensive drugs) and 40 eyes (31.3%) were failures. The mean pre- and post-operative IOP at the last follow up was 28.4 mmHg (SD 9.3) and 14.5 mmHg (SD 6.3), respectively. No tube extrusions or exposures were observed. Tube-related complications included five retractions, a lens touch and a transitory endothelial touch. The risk of failure increased if the eye had any complication or previous glaucoma surgeries. Medium-term IOP control in Mexican children with glaucoma can be achieved with AGV implantation using a needle-generated tunnel, without constructing a scleral flap or using a patch to cover the tube. There were no tube extrusions, nor any tube exposures with this technique.

Serial intracameral visualization of the Ahmed glaucoma valve tube by anterior segment optical coherence tomography.

PubMed

Lopilly Park, H-Y; Jung, K I; Park, C K

2012-09-01

To investigate serial changes of the Ahmed glaucoma valve (AGV) implant tube in the anterior chamber by anterior segment optical coherence tomography (AS-OCT). Patients who had received AGV implantation without complications (n=48) were included in this study. Each patient received follow-up examinations including AS-OCT at days 1 and 2, week 1, and months 1, 3, 6, and 12. Tube parameters were defined to measure its length and position. The intracameral length of the tube was from the tip of the bevel-edged tube to the sclerolimbal junction. The distance between the extremity of the tube and the anterior iris surface (T-I distance), and the angle between the tube and the posterior endothelial surface of the cornea (T-C angle) were defined. Factors that were related to tube parameters were analysed by multiple regression analysis. The mean change in tube length was -0.20 ± 0.17 mm, indicating that the tube length shortened from the initial inserted length. The mean T-I distance change was 0.11 ± 0.07 mm and the mean T-C angle change was -6.7 ± 5.6°. Uveitic glaucoma and glaucoma following penetrating keratoplasty showed the most changes in tube parameters. By multiple regression analysis, diagnosis of glaucoma including uveitic glaucoma (P=0.049) and glaucoma following penetrating keratoplasty (P=0.008) were related to the change of intracameral tube length. These results suggest that the length and position of the AGV tube changes after surgery. The change was prominent in uveitic glaucoma and glaucoma following penetrating keratoplasty.

Immunological Effect of aGV Rabies Vaccine Administered Using the Essen and Zagreb Regimens: A Double-Blind, Randomized Clinical Trial.

PubMed

Miao, Li; Shi, Liwei; Yang, Yi; Yan, Kunming; Sun, Hongliang; Mo, Zhaojun; Li, Li

2018-04-01

This study evaluated the immunological effect of an aGV rabies virus strain using the Essen and Zagreb immunization programs. A total of 1,944 subjects were enrolled and divided into three groups: the Essen test group, Essen control group, and Zagreb test group. Neutralizing antibody levels and antibody seroconversion rates were determined at 7 and 14 days after the initial inoculations and then 14 days after the final inoculation in all of the subjects. The seroconversion rates for the Essen test group, Essen control group, and Zagreb test group, which were assessed 7 days after the first dosing in a susceptible population, were 35.74%, 26.92%, and 45.49%, respectively, and at 14 days, the seroconversion rates in this population were 100%, 100%, and 99.63%, respectively. At 14 days after the final dosing, the seroconversion rates were 100% in all three of the groups. The neutralizing serum antibody levels of the Essen test group, Essen control group, and Zagreb test group at 7 days after the first dosing in the susceptible population were 0.37, 0.26, and 0.56 IU/mL, respectively, and at 14 days after the initial dosing, these levels were 16.71, 13.85, and 16.80 IU/mL. At 14 days after the final dosing, the neutralizing antibody levels were 22.9, 16.3, and 18.62 IU/mL, respectively. The results of this study suggested that the aGV rabies vaccine using the Essen program resulted in a good serum immune response, and the seroconversion rates and the neutralizing antibody levels generated with the Zagreb regimen were higher than those with the Essen regimen when measured 7 days after the first dose.

Evaluation of Ahmed glaucoma valve implantation through a needle-generated scleral tunnel in Mexican children with glaucoma

PubMed Central

Albis-Donado, Oscar; Gil-Carrasco, Félix; Romero-Quijada, Rafael; Thomas, Ravi

2010-01-01

Purpose: To evaluate the results and extrusion rates of the Ahmed glaucoma valve (AGV) implantation through a needle-generated scleral tunnel, without a tube-covering patch, in children. Materials and Methods: A retrospective review of the charts of 106 Mexican children implanted with 128 AGVs operated between 1994 and 2002, with the needle track technique, at our institution, with at least six months follow up was done. Main outcome measures were intraocular pressure (IOP) control, tube extrusions or exposure and other complications. Results: Kaplan-Meier analysis demonstrated a 96.9% survival rate at six months, 82.4% at one year, 78.7% at two years, 70% at three years and 41.6% at four years. Total success at the last follow-up (IOP between 6 and 21 mm Hg without medications) was achieved in 30 eyes (23.5%), 58 eyes (45.3%) had qualified success (only topical hypotensive drugs) and 40 eyes (31.3%) were failures. The mean pre- and post-operative IOP at the last follow up was 28.4 mmHg (SD 9.3) and 14.5 mmHg (SD 6.3), respectively. No tube extrusions or exposures were observed. Tube-related complications included five retractions, a lens touch and a transitory endothelial touch. The risk of failure increased if the eye had any complication or previous glaucoma surgeries. Conclusion: Medium-term IOP control in Mexican children with glaucoma can be achieved with AGV implantation using a needle-generated tunnel, without constructing a scleral flap or using a patch to cover the tube. There were no tube extrusions, nor any tube exposures with this technique. PMID:20689189

Assessment of conditions affecting surgical success of Ahmed glaucoma valve implants in glaucoma secondary to different uveitis etiologies in adults.

PubMed

Sungur, G; Yakin, M; Eksioglu, U; Satana, B; Ornek, F

2017-10-01

PurposeThere is little known about the long-term efficacy and safety of Ahmed glaucoma valve (AGV) implant and about the conditions affecting surgical success in uveitic glaucoma (UG).Patients and methodsThe charts of adult patients with UG who underwent AGV implantation from 2006 to 2015 were reviewed retrospectively.ResultsData of 46 eyes of 39 patients were evaluated. Mean follow-up was 51.93±23.08 months. Mean preoperative IOP was 37.05±9.62 mm Hg and mean number of preoperative topical anti-glaucomatous medications was 2.98±0.27. One eye (2%) was defined as failure because of implant extraction surgery. In the rest of the eyes, intraocular pressure (IOP) was under control with or without anti-glaucomatous medications during follow-up. The cumulative probability of complete success (IOP control without medications) was 78% at 6 months, 76% at 1 year, 71% at 2 years, 66% at 3 years, and 63% at 4 years (95% confidence interval, 61.24-87.81). The cumulative probability of eyes without complication was 64% at 6 months, 48% at 12 months, 44% at 24 months, 41% at 36 months, and 38% at 48 months (95% confidence interval, 34.64-62.85). Complete success was lower in eyes with previous ocular surgery than the eyes without (P=0.061) and it was lower in eyes with active inflammation at the time of surgery than the eyes without (P=0.011).ConclusionAGV implantation is an effective and safe alternative method in the management of UG, especially when it is performed as a primary surgical option and when no inflammation is present preoperatively.

Ahmed glaucoma valve implantation with tube insertion through the ciliary sulcus in pseudophakic/aphakic eyes.

PubMed

Eslami, Yadolla; Mohammadi, Massood; Fakhraie, Ghasem; Zarei, Reza; Moghimi, Sasan

2014-02-01

To report the efficacy and safety of Ahmed glaucoma valve (AGV) insertion into the ciliary sulcus in pseudophakic/aphakic patients. A chart review was done on patients with uncontrolled glaucoma, who underwent AGV implantation with tube inserted into the ciliary sulcus. Baseline intraocular pressure (IOP) and number of medications were compared with that of postoperative follow-up visits. Surgical success was defined as last IOP <21 mm Hg and 20% reduction in IOP, without further surgery for complications or glaucoma control, and without loss of light perception. Postoperative complications were recorded. Twenty-three eyes of 23 patients were recruited with the mean follow-up of 9 months (range, 3 to 24 mo). The mean (SD) age of patients was 49.9 (16.9) years (range, 22 to 80 years). The mean (SD) IOP (mm Hg) was reduced from 37.9 (12.4) before surgery to 16.2 (3.6) at the last follow-up visit (P<0.001). The mean (SD) number of medications was reduced from 3.3 (0.9) preoperatively to 1 (1.1) at the last follow-up (P<0.001). Success rate was 18/23 (78.6%). Complications included endophthalmitis in 1 eye, tube exposure in 1 diabetic patient, and vitreous tube occlusion in 1 eye. No case of corneal decompensation or graft failure was seen during follow-up. Ciliary sulcus placement of the tube of AGV effectively reduces IOP and medication use in short term. It has the potential to lower corneal complications of anterior chamber tube insertion and avoids the need for pars plana vitrectomy and tube insertion in patients at higher risk of corneal decompensation.

Clinical outcomes of Ahmed glaucoma valve in anterior chamber versus ciliary sulcus.

PubMed

Bayer, A; Önol, M

2017-04-01

PurposeTo evaluate the outcomes of Ahmed glaucoma valve (AGV) tube insertion through the anterior chamber angle (ACA) or through the ciliary sulcus (CS).Patients and methodsIn this case-control study, we retrospectively reviewed the charts of consecutive glaucoma patients who had undergone AGV implantation either through the ACA or the CS between March 2009 and December 2014. The main outcome measures were intraocular pressure (IOP), number of glaucoma medications prescribed, best corrected visual acuity (BCVA), glaucoma type, success rate, complications, and survival ratios. Statistical analysis was carried out using SPSS.ResultsThere were 68 eyes in the ACA group and 35 eyes in the CS group. There were no significant differences between the groups for age, sex, laterality, IOP, preoperative glaucoma medication number, BCVA or glaucoma type (P>0.05). The postoperative follow-up period was 27.2±16.5 months and 30.2±17.7 months for the ACA and the CS groups (P=0.28); IOP values were significantly reduced at the last visit to 16.4±7.2 mm Hg and 14.4±6.8 mm Hg. The difference in the last-visit IOP between the groups was not significant (P=0.06), but the IOP reduction ratio was higher in the CS group (P=0.03). There was no significant difference in the number of postoperative medications (P=0.18). Postoperative complications were similar, but the incidence of flat anterior chamber was higher in the ACA group (P=0.05).ConclusionsThe use of an AGV can control IOP in the majority of cases whether placed in the ACA or the CS. The IOP reduction ratio seemed to be higher in the CS group.

Long-term Outcomes of Ahmed Glaucoma Valve Implantation in Refractory Glaucoma at Farabi Eye Hospital, Tehran, Iran

PubMed Central

Zarei, Reza; Amini, Heidar; Daneshvar, Ramin; Nabi, Fahimeh Naderi; Moghimi, Sasan; Fakhraee, Ghasem; Eslami, Yadollah; Mohammadi, Masoud; Amini, Nima

2016-01-01

Purpose: To describe long-term outcomes and complications of Ahmed glaucoma valve (AGV) implantation in subjects with refractory glaucoma at Farabi Eye Hospital, Tehran, Iran. Materials and Methods: This retrospective cohort study evaluated patient records of all subjects with refractory glaucoma who had undergone AGV implantation up to January 2013. The main outcome measure was the surgical success rate. Complete success was defined as intraocular pressure (IOP) <22 mmHg, without anti-glaucoma medications or additional surgery. Qualified success was IOP <22 mmHg regardless of number of anti-glaucoma medications. In all cases, loss of vision (no light perception) was considered an independent indicator of failure. Data were also collected on intraoperative and postoperative complications. Results: Twenty-eight eyes were included in the study. With a mean follow-up of 48.2 ± 31.7 months (median: 40.50 months; range: 3–124 months), the IOP decreased from a mean preoperative value of 30.8 ± 5.6 mmHg to 20.0 ± 6.4 mmHg at last visit. The number of medications decreased from 3.7 ± 0.4 preoperatively to 2.5 ± 1.1 postoperatively. Cumulative qualified success was achieved in 69% of eyes. Mean time to failure according to qualified success criteria was 92.3 ± 9.4 months. Postoperative complications were recorded in 16 (57.1%) eyes. The most common complication was focal endothelial corneal decompensation at the site of tube-cornea touch. Conclusion: AGV implantation with adjunctive topical anti-glaucoma drops controlled IOP in approximately 70% of eyes with refractory glaucoma with a median of 40.5 months of follow-up. However, complication rates were higher. PMID:26957848

Clinical outcomes of Ahmed glaucoma valve in anterior chamber versus ciliary sulcus

PubMed Central

Bayer, A; Önol, M

2017-01-01

Purpose To evaluate the outcomes of Ahmed glaucoma valve (AGV) tube insertion through the anterior chamber angle (ACA) or through the ciliary sulcus (CS). Patients and methods In this case-control study, we retrospectively reviewed the charts of consecutive glaucoma patients who had undergone AGV implantation either through the ACA or the CS between March 2009 and December 2014. The main outcome measures were intraocular pressure (IOP), number of glaucoma medications prescribed, best corrected visual acuity (BCVA), glaucoma type, success rate, complications, and survival ratios. Statistical analysis was carried out using SPSS. Results There were 68 eyes in the ACA group and 35 eyes in the CS group. There were no significant differences between the groups for age, sex, laterality, IOP, preoperative glaucoma medication number, BCVA or glaucoma type (P>0.05). The postoperative follow-up period was 27.2±16.5 months and 30.2±17.7 months for the ACA and the CS groups (P=0.28); IOP values were significantly reduced at the last visit to 16.4±7.2 mm Hg and 14.4±6.8 mm Hg. The difference in the last-visit IOP between the groups was not significant (P=0.06), but the IOP reduction ratio was higher in the CS group (P=0.03). There was no significant difference in the number of postoperative medications (P=0.18). Postoperative complications were similar, but the incidence of flat anterior chamber was higher in the ACA group (P=0.05). Conclusions The use of an AGV can control IOP in the majority of cases whether placed in the ACA or the CS. The IOP reduction ratio seemed to be higher in the CS group. PMID:27983734

Short term outcome of Ahmed glaucoma valve implantation in management of refractory glaucoma in a tertiary hospital in Oman

PubMed Central

Shah, Manali R.; Khandekar, Rajiv B.; Zutshi, Rajiv; Mahrooqi, Rahima

2013-01-01

Background: We present outcomes of Ahmed Glaucoma Valve (AGV) implantation in treating refractory glaucoma in a tertiary hospital in Oman. Refractory glaucoma was defined as previously failed conventional glaucoma surgery and an uncontrolled intraocular pressure (IOP) of more than 21 mm Hg despite treatment with three topical and/or oral therapy. Materials and Methods: This historical cohort study was conducted in 2010. Details of medical and surgical treatment were recorded. Ophthalmologists examined eyes and performed glaucoma surgeries using AGV. The best corrected distant vision, IOP, and glaucoma medications were prospectively reviewed on 1st day, 1st, 6th, 12th week postoperatively, and at the last follow up. Result: Glaucoma specialists examined and treated 40 eyes with refractory glaucoma of 39 patients (20 males + 19 females). Neo-vascular glaucoma was present in 23 eyes. Vision before surgery was <3/60 in 21 eyes. At 12 weeks, one eye had vision better than 6/12, seven eyes had vision 6/18 to 6/60, and eight eyes had vision 6/60 to 3/60. Mean IOP was reduced from 42.9 (SD 16) to 14.2 (SD 8) and 19.1 (SD 7.8) mmHg at one and 12 weeks after surgery, respectively. At 12 weeks, five (12.5%) eyes had IOP controlled without medication. In 33 (77.5%) eyes, pressure was controlled by using one or two eye drops. The mean number of preoperative anti-glaucoma medications (2.38; SD 1.1) was reduced compared to the mean number of postoperative medications (1.92; SD 0.9) at 12 weeks. Conclusion: We succeeded in reducing visual disabilities and the number of anti-glaucoma medications used to treat refractory glaucoma by AGV surgery. PMID:23772122

Long-term Outcomes of Ahmed Glaucoma Valve Implantation in Refractory Glaucoma at Farabi Eye Hospital, Tehran, Iran.

PubMed

Zarei, Reza; Amini, Heidar; Daneshvar, Ramin; Nabi, Fahimeh Naderi; Moghimi, Sasan; Fakhraee, Ghasem; Eslami, Yadollah; Mohammadi, Masoud; Amini, Nima

2016-01-01

To describe long-term outcomes and complications of Ahmed glaucoma valve (AGV) implantation in subjects with refractory glaucoma at Farabi Eye Hospital, Tehran, Iran. This retrospective cohort study evaluated patient records of all subjects with refractory glaucoma who had undergone AGV implantation up to January 2013. The main outcome measure was the surgical success rate. Complete success was defined as intraocular pressure (IOP) <22 mmHg, without anti-glaucoma medications or additional surgery. Qualified success was IOP <22 mmHg regardless of number of anti-glaucoma medications. In all cases, loss of vision (no light perception) was considered an independent indicator of failure. Data were also collected on intraoperative and postoperative complications. Twenty-eight eyes were included in the study. With a mean follow-up of 48.2 ± 31.7 months (median: 40.50 months; range: 3-124 months), the IOP decreased from a mean preoperative value of 30.8 ± 5.6 mmHg to 20.0 ± 6.4 mmHg at last visit. The number of medications decreased from 3.7 ± 0.4 preoperatively to 2.5 ± 1.1 postoperatively. Cumulative qualified success was achieved in 69% of eyes. Mean time to failure according to qualified success criteria was 92.3 ± 9.4 months. Postoperative complications were recorded in 16 (57.1%) eyes. The most common complication was focal endothelial corneal decompensation at the site of tube-cornea touch. AGV implantation with adjunctive topical anti-glaucoma drops controlled IOP in approximately 70% of eyes with refractory glaucoma with a median of 40.5 months of follow-up. However, complication rates were higher.

Clinical Outcomes of Ahmed Glaucoma Valve Implantation Using Tube Ligation and Removable External Stents

PubMed Central

Lee, Jong Joo; Kim, Dong Myung; Kim, Tae Woo

2009-01-01

Purpose To investigate the immediate and long-term outcomes of Ahmed glaucoma valve (AGV) implantation with silicone tube ligation and removable external stents. Methods This retrospective non-comparative study investigated the outcomes of AGV implantation with silicone tube ligation and removable external stents in 95 eyes (90 patients) with at least 12 months of postoperative follow-up. Qualified success was defined as an intraocular pressure (IOP) of ≤21 mmHg and ≥6 mmHg regardless of anti-glaucoma medication. Those who required additional glaucoma surgery, implant removal or who had phthisis bulbi were considered failures. Hypotony was defined as an IOP of <6 mmHg. Results Mean IOP reduced from 37.1±9.7 mmHg preoperatively to 15.2±5.6 mmHg at 12 months postoperatively (p<0.001). Qualified success was achieved in 84.2% at 1 year. Hypotony with an IOP of <6 mmHg was seen in 8.4% and an IOP of <5 mmHg in 3.2% on the first postoperative day. No case of hypotony required surgical intervention. Suprachoroidal hemorrhage did not occur in this study. When stents were removed on the first postoperative day because of an insufficient IOP decrease, the mean IOP decreased significantly from 42.0 mmHg to 14.1 mmHg (p<0.001) after 1 hour. The most common complication was hyphema, which occurred in 17.9%. Conclusions Hypotony-related early complications requiring surgical intervention were reduced by ligation and external stents in the tube. In addition, early postoperative high IOPs were managed by removing external stents. The described method can prevent postoperative hypotony after AGV implantation and showed long-term success rates comparable to those reported previously. PMID:19568356

Clinical outcomes of Ahmed glaucoma valve implantation using tube ligation and removable external stents.

PubMed

Lee, Jong Joo; Park, Ki Ho; Kim, Dong Myung; Kim, Tae Woo

2009-06-01

To investigate the immediate and long-term outcomes of Ahmed glaucoma valve (AGV) implantation with silicone tube ligation and removable external stents. This retrospective non-comparative study investigated the outcomes of AGV implantation with silicone tube ligation and removable external stents in 95 eyes (90 patients) with at least 12 months of postoperative follow-up. Qualified success was defined as an intraocular pressure (IOP) of or=6 mmHg regardless of anti-glaucoma medication. Those who required additional glaucoma surgery, implant removal or who had phthisis bulbi were considered failures. Hypotony was defined as an IOP of <6 mmHg. Mean IOP reduced from 37.1+/-9.7 mmHg preoperatively to 15.2+/-5.6 mmHg at 12 months postoperatively (p<0.001). Qualified success was achieved in 84.2% at 1 year. Hypotony with an IOP of <6 mmHg was seen in 8.4% and an IOP of <5 mmHg in 3.2% on the first postoperative day. No case of hypotony required surgical intervention. Suprachoroidal hemorrhage did not occur in this study. When stents were removed on the first postoperative day because of an insufficient IOP decrease, the mean IOP decreased significantly from 42.0 mmHg to 14.1 mmHg (p<0.001) after 1 hour. The most common complication was hyphema, which occurred in 17.9%. Hypotony-related early complications requiring surgical intervention were reduced by ligation and external stents in the tube. In addition, early postoperative high IOPs were managed by removing external stents. The described method can prevent postoperative hypotony after AGV implantation and showed long-term success rates comparable to those reported previously.

Validating an artificial intelligence human proximity operations system with test cases

NASA Astrophysics Data System (ADS)

Huber, Justin; Straub, Jeremy

2013-05-01

An artificial intelligence-controlled robot (AICR) operating in close proximity to humans poses risk to these humans. Validating the performance of an AICR is an ill posed problem, due to the complexity introduced by the erratic (noncomputer) actors. In order to prove the AICR's usefulness, test cases must be generated to simulate the actions of these actors. This paper discusses AICR's performance validation in the context of a common human activity, moving through a crowded corridor, using test cases created by an AI use case producer. This test is a two-dimensional simplification relevant to autonomous UAV navigation in the national airspace.

Rabies in southeast Brazil: a change in the epidemiological pattern.

PubMed

Queiroz, Luzia Helena; Favoretto, Silvana Regina; Cunha, Elenice Maria S; Campos, Angélica Cristine A; Lopes, Marissol Cardoso; de Carvalho, Cristiano; Iamamoto, Keila; Araújo, Danielle Bastos; Venditti, Leandro Lima R; Ribeiro, Erica S; Pedro, Wagner André; Durigon, Edison Luiz

2012-01-01

This epidemiological study was conducted using antigenic and genetic characterisation of rabies virus isolates obtained from different animal species in the southeast of Brazil from 1993 to 2007. An alteration in the epidemiological profile was observed. One hundred two samples were tested using a panel of eight monoclonal antibodies, and 94 were genetically characterised by sequencing the nucleoprotein gene. From 1993 to 1997, antigenic variant 2 (AgV-2), related to a rabies virus maintained in dog populations, was responsible for rabies cases in dogs, cats, cattle and horses. Antigenic variant 3 (AgV-3), associated with Desmodus rotundus, was detected in a few cattle samples from rural areas. From 1998 to 2007, rabies virus was detected in bats and urban pets, and four distinct variants were identified. A nucleotide similarity analysis resulted in two primary groups comprising the dog and bat antigenic variants and showing the distinct endemic cycles maintained in the different animal species in this region.

Case study of rotating sonar sensor application in unmanned automated guided vehicle

NASA Astrophysics Data System (ADS)

Chandak, Pravin; Cao, Ming; Hall, Ernest L.

2001-10-01

A single rotating sonar element is used with a restricted angle of sweep to obtain readings to develop a range map for the unobstructed path of an autonomous guided vehicle (AGV). A Polaroid ultrasound transducer element is mounted on a micromotor with an encoder feedback. The motion of this motor is controlled using a Galil DMC 1000 motion control board. The encoder is interfaced with the DMC 1000 board using an intermediate IMC 1100 break-out board. By adjusting the parameters of the Polaroid element, it is possible to obtain range readings at known angles with respect to the center of the robot. The readings are mapped to obtain a range map of the unobstructed path in front of the robot. The idea can be extended to a 360 degree mapping by changing the assembly level programming on the Galil Motion control board. Such a system would be compact and reliable over a range of environments and AGV applications.

Grid cells form a global representation of connected environments.

PubMed

Carpenter, Francis; Manson, Daniel; Jeffery, Kate; Burgess, Neil; Barry, Caswell

2015-05-04

The firing patterns of grid cells in medial entorhinal cortex (mEC) and associated brain areas form triangular arrays that tessellate the environment [1, 2] and maintain constant spatial offsets to each other between environments [3, 4]. These cells are thought to provide an efficient metric for navigation in large-scale space [5-8]. However, an accurate and universal metric requires grid cell firing patterns to uniformly cover the space to be navigated, in contrast to recent demonstrations that environmental features such as boundaries can distort [9-11] and fragment [12] grid patterns. To establish whether grid firing is determined by local environmental cues, or provides a coherent global representation, we recorded mEC grid cells in rats foraging in an environment containing two perceptually identical compartments connected via a corridor. During initial exposures to the multicompartment environment, grid firing patterns were dominated by local environmental cues, replicating between the two compartments. However, with prolonged experience, grid cell firing patterns formed a single, continuous representation that spanned both compartments. Thus, we provide the first evidence that in a complex environment, grid cell firing can form the coherent global pattern necessary for them to act as a metric capable of supporting large-scale spatial navigation. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Grid Cells Form a Global Representation of Connected Environments

PubMed Central

Carpenter, Francis; Manson, Daniel; Jeffery, Kate; Burgess, Neil; Barry, Caswell

2015-01-01

Summary The firing patterns of grid cells in medial entorhinal cortex (mEC) and associated brain areas form triangular arrays that tessellate the environment [1, 2] and maintain constant spatial offsets to each other between environments [3, 4]. These cells are thought to provide an efficient metric for navigation in large-scale space [5–8]. However, an accurate and universal metric requires grid cell firing patterns to uniformly cover the space to be navigated, in contrast to recent demonstrations that environmental features such as boundaries can distort [9–11] and fragment [12] grid patterns. To establish whether grid firing is determined by local environmental cues, or provides a coherent global representation, we recorded mEC grid cells in rats foraging in an environment containing two perceptually identical compartments connected via a corridor. During initial exposures to the multicompartment environment, grid firing patterns were dominated by local environmental cues, replicating between the two compartments. However, with prolonged experience, grid cell firing patterns formed a single, continuous representation that spanned both compartments. Thus, we provide the first evidence that in a complex environment, grid cell firing can form the coherent global pattern necessary for them to act as a metric capable of supporting large-scale spatial navigation. PMID:25913404

Orion Optical Navigation Progress Toward Exploration: Mission 1

NASA Technical Reports Server (NTRS)

Holt, Greg N.; D'Souza, Christopher N.; Saley, David

2018-01-01

Optical navigation of human spacecraft was proposed on Gemini and implemented successfully on Apollo as a means of autonomously operating the vehicle in the event of lost communication with controllers on Earth. It shares a history with the "method of lunar distances" that was used in the 18th century and gained some notoriety after its use by Captain James Cook during his 1768 Pacific voyage of the HMS Endeavor. The Orion emergency return system utilizing optical navigation has matured in design over the last several years, and is currently undergoing the final implementation and test phase in preparation for Exploration Mission 1 (EM-1) in 2019. The software development is being worked as a Government Furnished Equipment (GFE) project delivered as an application within the Core Flight Software of the Orion camera controller module. The mathematical formulation behind the initial ellipse fit in the image processing is detailed in Christian. The non-linear least squares refinement then follows the technique of Mortari as an estimation process of the planetary limb using the sigmoid function. The Orion optical navigation system uses a body fixed camera, a decision that was driven by mass and mechanism constraints. The general concept of operations involves a 2-hour pass once every 24 hours, with passes specifically placed before all maneuvers to supply accurate navigation information to guidance and targeting. The pass lengths are limited by thermal constraints on the vehicle since the OpNav attitude generally deviates from the thermally stable tail-to-sun attitude maintained during the rest of the orbit coast phase. Calibration is scheduled prior to every pass due to the unknown nature of thermal effects on the lens distortion and the mounting platform deformations between the camera and star trackers. The calibration technique is described in detail by Christian, et al. and simultaneously estimates the Brown-Conrady coefficients and the Star Tracker/Camera interlock angles. Accurate attitude information is provided by the star trackers during each pass. Figure 1 shows the various phases of lunar return navigation when the vehicle is in autonomous operation with lost ground communication. The midcourse maneuvers are placed to control the entry interface conditions to the desired corridor for safe landing. The general form of optical navigation on Orion is where still images of the Moon or Earth are processed to find the apparent angular diameter and centroid in the camera focal plane. This raw data is transformed into range and bearing angle measurements using planetary data and precise star tracker inertial attitude. The measurements are then sent to the main flight computer's Kalman filter to update the onboard state vector. The images are, of course, collected over an arc to converge the state and estimate velocity. The same basic technique was used by Apollo to satisfy loss-of-comm, but Apollo used manual crew sightings with a vehicle-integral sextant instead of autonomously processing optical imagery. The software development is past its Critical Design Review, and is progressing through test and certification for human rating. In support of this, a hardware-in-the-loop test rig was developed in the Johnson Space Center Electro-Optics Lab to exercise the OpNav system prior to integrated testing on the Orion vehicle. Figure 2 shows the rig, which the test team has dubbed OCILOT (Orion Camera In the Loop Optical Testbed). Analysis performed to date shows a delivery that satisfies an allowable entry corridor as shown in Figure 3.

Sediment Transport into the Swinomish Navigation Channel, Puget Sound—Habitat Restoration versus Navigation Maintenance Needs

DOE PAGES

Khangaonkar, Tarang; Nugraha, Adi; Hinton, Steve; ...

2017-04-21

The 11 mile (1.6 km) Swinomish Federal Navigation Channel provides a safe and short passage to fishing and recreational craft in and out of Northern Puget Sound by connecting Skagit and Padilla Bays, US State abbrev., USA. A network of dikes and jetties were constructed through the Swinomish corridor between 1893 and 1936 to improve navigation functionality. Over the years, these river training dikes and jetties designed to minimize sedimentation in the channel have deteriorated, resulting in reduced protection of the channel. The need to repair or modify dikes/jetties for channel maintenance, however, may conflict with salmon habitat restoration goalsmore » aimed at improving access, connectivity and brackish water habitat. Several restoration projects have been proposed in the Skagit delta involving breaching, lowering, or removal of dikes. To assess relative merits of the available alternatives, a hydrodynamic model of the Skagit River estuary was developed using the Finite Volume Community Ocean Model (FVCOM). Here, in this paper, we present the refinement and calibration of the model using oceanographic data collected from the years 2006 and 2009 with a focus on the sediment and brackish water transport from the river and Skagit Bay tide flats to the Swinomish Channel. The model was applied to assess the feasibility of achieving the desired dual outcome of (a) reducing sedimentation and shoaling in the Swinomish Channel and (b) providing a direct migration pathway and improved conveyance of freshwater into the Swinomish Channel. Finally, the potential reduction in shoaling through site-specific structure repairs is evaluated. Similarly, the potential to significantly improve of brackish water habitat through dike breach restoration actions using the McGlinn Causeway project example, along with its impacts on sediment deposition in the Swinomish Navigation Channel, is examined« less

Sediment Transport into the Swinomish Navigation Channel, Puget Sound—Habitat Restoration versus Navigation Maintenance Needs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khangaonkar, Tarang; Nugraha, Adi; Hinton, Steve

The 11 mile (1.6 km) Swinomish Federal Navigation Channel provides a safe and short passage to fishing and recreational craft in and out of Northern Puget Sound by connecting Skagit and Padilla Bays, US State abbrev., USA. A network of dikes and jetties were constructed through the Swinomish corridor between 1893 and 1936 to improve navigation functionality. Over the years, these river training dikes and jetties designed to minimize sedimentation in the channel have deteriorated, resulting in reduced protection of the channel. The need to repair or modify dikes/jetties for channel maintenance, however, may conflict with salmon habitat restoration goalsmore » aimed at improving access, connectivity and brackish water habitat. Several restoration projects have been proposed in the Skagit delta involving breaching, lowering, or removal of dikes. To assess relative merits of the available alternatives, a hydrodynamic model of the Skagit River estuary was developed using the Finite Volume Community Ocean Model (FVCOM). Here, in this paper, we present the refinement and calibration of the model using oceanographic data collected from the years 2006 and 2009 with a focus on the sediment and brackish water transport from the river and Skagit Bay tide flats to the Swinomish Channel. The model was applied to assess the feasibility of achieving the desired dual outcome of (a) reducing sedimentation and shoaling in the Swinomish Channel and (b) providing a direct migration pathway and improved conveyance of freshwater into the Swinomish Channel. Finally, the potential reduction in shoaling through site-specific structure repairs is evaluated. Similarly, the potential to significantly improve of brackish water habitat through dike breach restoration actions using the McGlinn Causeway project example, along with its impacts on sediment deposition in the Swinomish Navigation Channel, is examined« less

GPS-aided inertial technology and navigation-based photogrammetry for aerial mapping the San Andreas fault system

USGS Publications Warehouse

Sanchez, Richard D.; Hudnut, Kenneth W.

2004-01-01

Aerial mapping of the San Andreas Fault System can be realized more efficiently and rapidly without ground control and conventional aerotriangulation. This is achieved by the direct geopositioning of the exterior orientation of a digital imaging sensor by use of an integrated Global Positioning System (GPS) receiver and an Inertial Navigation System (INS). A crucial issue to this particular type of aerial mapping is the accuracy, scale, consistency, and speed achievable by such a system. To address these questions, an Applanix Digital Sensor System (DSS) was used to examine its potential for near real-time mapping. Large segments of vegetation along the San Andreas and Cucamonga faults near the foothills of the San Bernardino and San Gabriel Mountains were burned to the ground in the California wildfires of October-November 2003. A 175 km corridor through what once was a thickly vegetated and hidden fault surface was chosen for this study. Both faults pose a major hazard to the greater Los Angeles metropolitan area and a near real-time mapping system could provide information vital to a post-disaster response.

Rabies Virus in Bats, State of Pará, Brazil, 2005-2011.

PubMed

Pereira, Armando de Souza; Casseb, Livia Medeiros Neves; Barbosa, Taciana Fernandes Souza; Begot, Alberto Lopes; Brito, Roberto Messias Oliveira; Vasconcelos, Pedro Fernando da Costa; Travassos da Rosa, Elizabeth Salbé

2017-08-01

Rabies is an acute, progressive zoonotic viral infection that in general produces a fatal outcome. This disease is responsible for deaths in humans and animals worldwide and, because it can affect all mammals, is considered one of the most important viral infections for public health. This study aimed to determine the prevalence of rabies in bats of different species found in municipalities of the state of Pará from 2005 to 2011. The rabies virus was detected in 12 (0.39%) bats in a total of 3100 analyzed, including hematophagous, frugivorous, and insectivorous bats. Of these, eleven were characterized as AgV3, which is characteristic of the hematophagous bat Desmodus rotundus (E. Geoffroy 1810); one insectivorous animal showed a different profile compatible with the Eptesicus pattern and may therefore be a new antigenic variant. This study identified the need for greater intensification of epidemiological surveillance in municipalities lacking rabies surveillance (silent areas); studies of rabies virus in bats with different alimentary habits, studies investigating the prevalence of AgV3, and prophylactic measures in areas where humans may be infected are also needed.

A new memetic algorithm for mitigating tandem automated guided vehicle system partitioning problem

NASA Astrophysics Data System (ADS)

Pourrahimian, Parinaz

2017-11-01

Automated Guided Vehicle System (AGVS) provides the flexibility and automation demanded by Flexible Manufacturing System (FMS). However, with the growing concern on responsible management of resource use, it is crucial to manage these vehicles in an efficient way in order reduces travel time and controls conflicts and congestions. This paper presents the development process of a new Memetic Algorithm (MA) for optimizing partitioning problem of tandem AGVS. MAs employ a Genetic Algorithm (GA), as a global search, and apply a local search to bring the solutions to a local optimum point. A new Tabu Search (TS) has been developed and combined with a GA to refine the newly generated individuals by GA. The aim of the proposed algorithm is to minimize the maximum workload of the system. After all, the performance of the proposed algorithm is evaluated using Matlab. This study also compared the objective function of the proposed MA with GA. The results showed that the TS, as a local search, significantly improves the objective function of the GA for different system sizes with large and small numbers of zone by 1.26 in average.

Navigating the Return Trip from the Moon Using Earth-Based Ground Tracking and GPS

NASA Technical Reports Server (NTRS)

Berry, Kevin; Carpenter, Russell; Moreau, Michael C.; Lee, Taesul; Holt, Gregg N.

2009-01-01

NASA s Constellation Program is planning a human return to the Moon late in the next decade. From a navigation perspective, one of the most critical phases of a lunar mission is the series of burns performed to leave lunar orbit, insert onto a trans-Earth trajectory, and target a precise re-entry corridor in the Earth s atmosphere. A study was conducted to examine sensitivity of the navigation performance during this phase of the mission to the type and availability of tracking data from Earth-based ground stations, and the sensitivity to key error sources. This study also investigated whether GPS measurements could be used to augment Earth-based tracking data, and how far from the Earth GPS measurements would be useful. The ability to track and utilize weak GPS signals transmitted across the limb of the Earth is highly dependent on the configuration and sensitivity of the GPS receiver being used. For this study three GPS configurations were considered: a "standard" GPS receiver with zero dB antenna gain, a "weak signal" GPS receiver with zero dB antenna gain, and a "weak signal" GPS receiver with an Earth-pointing direction antenna (providing 10 dB additional gain). The analysis indicates that with proper selection and configuration of the GPS receiver on the Orion spacecraft, GPS can potentially improve navigation performance during the critical final phases of flight prior to Earth atmospheric entry interface, and may reduce reliance on two-way range tracking from Earth-based ground stations.

Outcomes of Ahmed glaucoma valve implantation in advanced primary congenital glaucoma with previous surgical failure.

PubMed

Huang, Jingjing; Lin, Jialiu; Wu, Ziqiang; Xu, Hongzhi; Zuo, Chengguo; Ge, Jian

2015-01-01

The purpose of this study was to evaluate the intermediate surgical results of Ahmed glaucoma valve (AGV) implantation in patients less than 7 years of age, with advanced primary congenital glaucoma who have failed previous surgeries. Consecutive patients with advanced primary congenital glaucoma that failed previous operations and had undergone subsequent AGV implantation were evaluated retrospectively. Surgical success was defined as 1) intraocular pressure (IOP) ≥6 and ≤21 mmHg; 2) IOP reduction of at least 30% relative to preoperative values; and 3) without the need for additional surgical intervention for IOP control, loss of light perception, or serious complications. Fourteen eyes of eleven patients were studied. Preoperatively, the average axial length was 27.71±1.52 (25.56-30.80) mm, corneal diameter was 14.71±1.07 (13.0-16.0) mm, cup-to-disc ratio was 0.95±0.04 (0.9-1.0), and IOP was 39.5±5.7 (30-55) mmHg. The mean follow-up time was 18.29±10.96 (5-44, median 18) months. There were significant reductions in IOPs and the number of glaucoma medications (P<0.001) postoperatively. The IOPs after operation were 11.3±3.4, 13.6±5.1, 16.3±2.7, and 16.1±2.6 mmHg at 1 month, 6 months, 12 months, and 18 months, respectively. Kaplan-Meier estimates of the cumulative probability of valve success were 85.7%, 71.4%, and 71.4% at 6, 12, and 18 months, respectively. Severe surgical complications, including erosion of tube, endophthalmitis, retinal detachment, choroidal detachment, and delayed suprachoroidal hemorrhage, occurred in 28.6% cases. AGV implantation remains a viable option for patients with advanced primary congenital glaucoma unresponsive to previous surgical intervention, despite a relatively high incidence of severe surgical complications.

Long-term outcomes of uveitic glaucoma treated with Ahmed valve implant in a series of Chinese patients.

PubMed

Bao, Ning; Jiang, Zheng-Xuan; Coh, Paul; Tao, Li-Ming

2018-01-01

To report long-term outcomes of secondary glaucoma due to uveitis treated with Ahmed glaucoma valve (AGV) implantation in a series of Chinese patients. The retrospective study included 67 eyes from 56 patients with uveitic glaucoma who underwent AGV implantation. Success of the treatment was defined as patients achieving intraocular pressure (IOP) levels between 6 and 21 mm Hg with or without additional anti-glaucoma medications and/or a minimum of 20% reduction from baseline IOP. The main outcome measurements included IOP, the number of glaucoma medications at 1, 3, 6, 12, 24, 36, 48 and 60mo after surgery, surgical complications, final best-corrected vision acuity (BCVA), visual field (VF) and retinal nerve fiber layer (RNFL). The mean follow-up was 53.3±8.5 (range 48 to 60)mo. The cumulative probability of success rate was 98.5%, 95.5%, 89.6%, 83.6%, 76.1%, 70.1%, 65.7% and 61.2% at 1, 3, 6, 12, 24, 36, 48 and 60mo, respectively. IOP was reduced from a baseline of 30.8±6.8 to 9.9±4.1, 10.1±4.2, 10.9±3.7, 12.9±4.6, 13.8±3.9, 13.2±4.6, 12.3±3.5 and 13.1±3.7 mm Hg at 1, 3, 6, 12, 24, 36, 48 and 60mo, respectively ( P <0.01). The number of postoperative glaucoma medications was significantly decreased compared with baseline at all time points during the study period ( P <0.05). There was no significant difference between preoperative and postoperative BCVA. Remarkable surgical complications were not found after surgery. The VF and RNFL of the patients were stable after the surgery. AGV implantation is safe and effect in terms of reducing IOP, decreasing the number of glaucoma medications, and preserving vision for patients with uveitic glaucoma.

Use of Mitomycin C to reduce the incidence of encapsulated cysts following ahmed glaucoma valve implantation in refractory glaucoma patients: a new technique.

PubMed

Zhou, Minwen; Wang, Wei; Huang, Wenbin; Zhang, Xiulan

2014-09-06

To evaluate the surgical outcome of Ahmed glaucoma valve (AGV) implantation with a new technique of mitomycin C (MMC) application. This is a retrospective study. All patients with refractory glaucoma underwent FP-7 AGV implantation. Two methods of MMC application were used. In the traditional technique, 6 × 4 mm cotton soaked with MMC (0.25-0.33 mg/ml) was placed in the implantation area for 2-5mins; in the new technique, the valve plate first was encompassed with a thin layer of cotton soaked with MMC, then inserted into the same area. A 200 ml balanced salt solution was applied for irrigation of MMC. The surgical success rate, intraocular pressure (IOP), number of anti-glaucoma medications used, and postoperative complications were analyzed between the groups. The surgical outcomes of two MMC applied techniques were compared. The new technique group had only one case (2.6%) of encapsulated cyst formation out of 38 eyes, while there were eight (19.5%) cases out of 41 eyes the in traditional group. The difference was statistically significant (P = 0.030). According to the definition of success rate, there was 89.5% in the new technique group and 70.7% in the traditional group at the follow-up end point. There was a significant difference between the two groups (P = 0.035). Mean IOP in the new technique group were significantly lower than those of the traditional group at 3 and 6 months (P < 0.05). By using a thin layer of cotton soaked with MMC to encompass the valve plate, the new MMC application technique could greatly decrease the incidence of encapsulated cyst and increase the success rate following AGV implantation.

Outcomes of Ahmed glaucoma valve implantation in advanced primary congenital glaucoma with previous surgical failure

PubMed Central

Huang, Jingjing; Lin, Jialiu; Wu, Ziqiang; Xu, Hongzhi; Zuo, Chengguo; Ge, Jian

2015-01-01

Purpose The purpose of this study was to evaluate the intermediate surgical results of Ahmed glaucoma valve (AGV) implantation in patients less than 7 years of age, with advanced primary congenital glaucoma who have failed previous surgeries. Patients and methods Consecutive patients with advanced primary congenital glaucoma that failed previous operations and had undergone subsequent AGV implantation were evaluated retrospectively. Surgical success was defined as 1) intraocular pressure (IOP) ≥6 and ≤21 mmHg; 2) IOP reduction of at least 30% relative to preoperative values; and 3) without the need for additional surgical intervention for IOP control, loss of light perception, or serious complications. Results Fourteen eyes of eleven patients were studied. Preoperatively, the average axial length was 27.71±1.52 (25.56–30.80) mm, corneal diameter was 14.71±1.07 (13.0–16.0) mm, cup-to-disc ratio was 0.95±0.04 (0.9–1.0), and IOP was 39.5±5.7 (30–55) mmHg. The mean follow-up time was 18.29±10.96 (5–44, median 18) months. There were significant reductions in IOPs and the number of glaucoma medications (P<0.001) postoperatively. The IOPs after operation were 11.3±3.4, 13.6±5.1, 16.3±2.7, and 16.1±2.6 mmHg at 1 month, 6 months, 12 months, and 18 months, respectively. Kaplan–Meier estimates of the cumulative probability of valve success were 85.7%, 71.4%, and 71.4% at 6, 12, and 18 months, respectively. Severe surgical complications, including erosion of tube, endophthalmitis, retinal detachment, choroidal detachment, and delayed suprachoroidal hemorrhage, occurred in 28.6% cases. Conclusion AGV implantation remains a viable option for patients with advanced primary congenital glaucoma unresponsive to previous surgical intervention, despite a relatively high incidence of severe surgical complications. PMID:26082610

Clinical efficacy analysis of Ahmed glaucoma valve implantation in neovascular glaucoma and influencing factors

PubMed Central

He, Ye; Tian, Ying; Song, Weitao; Su, Ting; Jiang, Haibo; Xia, Xiaobo

2017-01-01

Abstract This study aimed to evaluate the efficacy of Ahmed glaucoma valve (AGV) implantation in treating neovascular glaucoma (NVG) and to analyze the factors influencing the surgical success rate. This is a retrospective review of 40 eyes of 40 NVG patients who underwent AGV implantation at Xiangya Hospital of Central South University, China, between January 2014 and December 2016. Pre- and postoperative intraocular pressure (IOP), visual acuity, surgical success rate, medications, and complications were observed. Surgical success criteria were defined as IOP ≤21 and >6 mm Hg with or without additional medications. Kaplan–Meier survival curves and Multivariate cox regression analysis were used to examine success rates and risk factors for surgical outcomes. The mean follow-up period was 8.88 ± 3.12 months (range: 3–17). IOP declined at each visit postoperatively and it was statistically significant (P < .001). An average of 3.55 ± 0.86 drugs was applied preoperatively, while an average of 0.64 ± 0.90 drugs was used postoperatively, with the difference being of statistical significance (P < .05). The complete surgical success rate of 3, 6, and 12 months after the operation was 85%, 75%, and 65%, respectively. Meanwhile, the qualified success rate of 3, 6, and 12 months after the operation was 85%, 80%, and 77.5%, respectively. The multivariate cox regression analysis showed that age (hazard ratio: 3.717, 7.246; 95% confidence interval: 1.149–12.048, 1.349–38.461; P = .028, .021) was influencing factors for complete success rate and qualified success rate among all NVG patients. Gender, previous operation history, primary disease, and preoperative IOP were found to be not significant. AGV implantation is an effective and safe surgical method to treat NVG. Age is an important factor influencing the surgical success rate. PMID:29049253

Outcome of Descemet stripping automated endothelial keratoplasty in eyes with an Ahmed glaucoma valve.

PubMed

Chiam, Patrick J; Cheeseman, Robert; Ho, Vivian W; Romano, Vito; Choudhary, Anshoo; Batterbury, Mark; Kaye, Stephen B; Willoughby, Colin E

2017-05-01

The purpose was to investigate the survival of Descemet stripping automated endothelial keratoplasty (DSAEK) in eyes with an Ahmed glaucoma valve (AGV). The study had a retrospective case-series of patients with an AGV in the anterior chamber undergoing a DSAEK. Included in the analysis were graft size, number of previous operations, post-operative glaucoma medications, post-operative intraocular pressure (IOP) control, graft size and donor factors (age, endothelial cell density, and post-mortem time). A generalised linear model with binary logistic regression was used to test for an effect on graft survival at 1 year and 1.5 years. Fourteen eyes from 13 patients were included. The survival rate of the first DSAEK at 6, 12, 18, 24 and 30-months was 85%, 71%, 50%, 36% and 30%, respectively. The mean duration to graft failure was 12.9 ± 6.2 months. Five of the seven failed first grafts went on to have a repeat DSAEK. The mean follow-up in this subgroup was 30.7 ± 18.4 months. The survival rate of second DSAEK at 6, 12, 18 and 24 months was 100% (5/5), 100% (5/5), 75% (3/4) and 67% (2/3). Only one second DSAEK failed in the duration of the study and went on to receive a third DSAEK which failed at 18-months. The mean IOP within the first year was significantly lower for grafts that survived at 1 and 1.5 years (17.4 mmHg, 16.9 mmHg) than for grafts that failed (19.4 mmHg, 19.4 mmHg) (p = 0.04, p = 0.009). DSAEK is a viable alternative to PK to restore visual function in eyes with an AGV sited in the anterior chamber. IOP is an important risk factor for graft failure.

Mars Aerobraking Spacecraft State Estimation by Processing Inertial Measurement Unit Data

NASA Technical Reports Server (NTRS)

Jah, Moriba K.; Lisano, Michael E.,, II; Born, George H.; Axelrad, Penina

2006-01-01

Aerobraking is an efficient technique for orbit adjustment of planetary spacecraft, such as Magellan (Venus), Mars Global Surveyor, and Mars Odyssey. Determination of the vehicle state during the aerobraking phase has conventionally been performed using only radiometric tracking data prior to and following the atmospheric drag pass. This approach is sufficiently accurate and timely to meet current mission operational requirements; however, it is expensive in terms of ground support and leads to delayed results because ofthe need for post-drag pass data. This research presents a new approach to estimation of the vehicle state during the atmospheric pass that sequentially incorporates observations from an Inertial Measurement Unit (IMU) and models of the vehicle and environment. The approach, called Inertial Measurements for Aerobraking Navigation (IMAN), is shown to perform at a level comparable to the conventional methods in terms of navigation accuracy and superior to them in terms of availability of the results immediately after completion ofthe pass. Furthermore, the research shows that IMAN can be used to reliably predict subsequent periapsis times and locations over all aerobraking regimes. IMAN also yields accurate peak dynamic pressure and heating rates, critical for a successful corridor control strategy, comparable to navigation team reconstructed values. This research also provides the first instance of the utilization of the Unscented Kalman Filter for the purpose of estimating an actual spacecraft trajectory arc about another planet.

Mars aerobraking spacecraft state estimation by processing inertial measurement unit data

NASA Astrophysics Data System (ADS)

Jah, Moriba Kemessia

Aerobraking is an efficient technique for orbit adjustment of planetary spacecraft such as Magellan (Venus), Mars Global Surveyor, and Mars Odyssey. Determination of the vehicle state during the Aerobraking phase has conventionally been performed using only radiometric tracking data prior to and following the atmospheric drag pass. This approach is sufficiently accurate and timely to meet current mission operational requirements; however, it is expensive in terms of ground support and leads to delayed results because of the need for post drag pass data. This dissertation presents a new approach to estimation of the vehicle state during the atmospheric pass that sequentially incorporates observations from an Inertial Measurement Unit (IMU) and models of the vehicle and environment. The approach, called Inertial Measurements for Aerobraking Navigation (IMAN), is shown to perform at a level comparable to the conventional methods in terms of navigation accuracy and superior to them in terms of availability of the results immediately after completion of the pass. Furthermore, the research shows that IMAN can be used to reliably predict subsequent periapsis times and locations over all aerobraking regimes. IMAN also yields accurate peak dynamic pressure and heating rates, critical for a successful corridor control strategy, comparable to navigation team reconstructed values. This research also provides the first instance of the utilization of the Unscented Kalman Filter for the purpose of estimating an actual spacecraft trajectory arc about another planet.

mapKITE: a New Paradigm for Simultaneous Aerial and Terrestrial Geodata Acquisition and Mapping

NASA Astrophysics Data System (ADS)

Molina, P.; Blázquez, M.; Sastre, J.; Colomina, I.

2016-06-01

We introduce a new mobile, simultaneous terrestrial and aerial, geodata collection and post-processing method: mapKITE. By combining two mapping technologies such as terrestrial mobile mapping and unmanned aircraft aerial mapping, geodata are simultaneously acquired from air and ground. More in detail, a mapKITE geodata acquisition system consists on an unmanned aircraft and a terrestrial vehicle, which hosts the ground control station. By means of a real-time navigation system on the terrestrial vehicle, real-time waypoints are sent to the aircraft from the ground. By doing so, the aircraft is linked to the terrestrial vehicle through a "virtual tether," acting as a "mapping kite." In the article, we entail the concept of mapKITE as well as the various technologies and techniques involved, from aircraft guidance and navigation based on IMU and GNSS, optical cameras for mapping and tracking, sensor orientation and calibration, etc. Moreover, we report of a new measurement introduced in mapKITE, that is, point-and-scale photogrammetric measurements [of image coordinates and scale] for optical targets of known size installed on the ground vehicle roof. By means of accurate posteriori trajectory determination of the terrestrial vehicle, mapKITE benefits then from kinematic ground control points which are photogrametrically observed by point-and-scale measures. Initial results for simulated configurations show that these measurements added to the usual Integrated Sensor Orientation ones reduce or even eliminate the need of conventional ground control points -therefore, lowering mission costs- and enable selfcalibration of the unmanned aircraft interior orientation parameters in corridor configurations, in contrast to the situation of traditional corridor configurations. Finally, we report about current developments of the first mapKITE prototype, developed under the European Union Research and Innovation programme Horizon 2020. The first mapKITE mission will be held at the BCN Drone Center (Collsuspina, Moià, Spain) in mid 2016.

Extension of an iterative closest point algorithm for simultaneous localization and mapping in corridor environments

NASA Astrophysics Data System (ADS)

Yue, Haosong; Chen, Weihai; Wu, Xingming; Wang, Jianhua

2016-03-01

Three-dimensional (3-D) simultaneous localization and mapping (SLAM) is a crucial technique for intelligent robots to navigate autonomously and execute complex tasks. It can also be applied to shape measurement, reverse engineering, and many other scientific or engineering fields. A widespread SLAM algorithm, named KinectFusion, performs well in environments with complex shapes. However, it cannot handle translation uncertainties well in highly structured scenes. This paper improves the KinectFusion algorithm and makes it competent in both structured and unstructured environments. 3-D line features are first extracted according to both color and depth data captured by Kinect sensor. Then the lines in the current data frame are matched with the lines extracted from the entire constructed world model. Finally, we fuse the distance errors of these line-pairs into the standard KinectFusion framework and estimate sensor poses using an iterative closest point-based algorithm. Comparative experiments with the KinectFusion algorithm and one state-of-the-art method in a corridor scene have been done. The experimental results demonstrate that after our improvement, the KinectFusion algorithm can also be applied to structured environments and has higher accuracy. Experiments on two open access datasets further validated our improvements.

Mapping landscape corridors

Treesearch

Peter Vogt; Kurt H. Riitters; Marcin Iwanowski; Christine Estreguil; Jacek Kozak; Pierre Soille

2007-01-01

Corridors are important geographic features for biological conservation and biodiversity assessment. The identification and mapping of corridors is usually based on visual interpretations of movement patterns (functional corridors) or habitat maps (structural corridors). We present a method for automated corridor mapping with morphological image processing, and...

A meta-analytic review of corridor effectiveness.

PubMed

Gilbert-Norton, Lynne; Wilson, Ryan; Stevens, John R; Beard, Karen H

2010-06-01

Using corridors for conservation is increasing despite a lack of consensus on their efficacy. Specifically, whether corridors increase movement of plants and animals between habitat fragments has been addressed on a case-by-case basis with mixed results. Because of the growing number of well-designed experiments that have addressed this question, we conducted a meta-analysis to determine whether corridors increase movement; whether corridor effectiveness differs among taxa; how recent changes in experimental design have influenced findings; and whether corridor effectiveness differs between manipulative and natural experiments. To conduct our meta-analysis, we analyzed 78 experiments from 35 studies using a conservative hierarchical Bayesian model that accounts for hierarchical and sampling dependence. We found a highly significant result that corridors increase movement between habitat patches by approximately 50% compared to patches that are not connected with corridors. We found that corridors were more important for the movement of invertebrates, nonavian vertebrates, and plants than they were for birds. Recent methodological advances in corridor experiments, such as controlling for the area added by corridors, did not influence whether corridors increased movement, whereas controlling for the distance between source and connected or unconnected recipient patches decreased movement through corridors. After controlling for taxa differences and whether studies controlled for distance in experimental design, we found that natural corridors (those existing in landscapes prior to the study) showed more movement than manipulated corridors (those created and maintained for the study). Our results suggest that existing corridors increase species movement in fragmented landscapes and that efforts spent on maintaining and creating corridors are worthwhile.

14 CFR 93.307 - Minimum flight altitudes.

Code of Federal Regulations, 2013 CFR

2013-01-01

... feet MSL. (b) Minimum corridor altitudes—(1) Commercial air tours—(i) Zuni Point Corridors. 7,500 feet MSL. (ii) Dragon Corridor. 7,500 feet MSL. (2) Transient and general aviation operations—(i) Zuni Point Corridor. 10,500 feet MSL. (ii) Dragon Corridor. 10,500 feet MSL. (iii) Tuckup Corridor. 10,500...

14 CFR 93.307 - Minimum flight altitudes.

Code of Federal Regulations, 2014 CFR

2014-01-01

... feet MSL. (b) Minimum corridor altitudes—(1) Commercial air tours—(i) Zuni Point Corridors. 7,500 feet MSL. (ii) Dragon Corridor. 7,500 feet MSL. (2) Transient and general aviation operations—(i) Zuni Point Corridor. 10,500 feet MSL. (ii) Dragon Corridor. 10,500 feet MSL. (iii) Tuckup Corridor. 10,500...

A vision-based automated guided vehicle system with marker recognition for indoor use.

PubMed

Lee, Jeisung; Hyun, Chang-Ho; Park, Mignon

2013-08-07

We propose an intelligent vision-based Automated Guided Vehicle (AGV) system using fiduciary markers. In this paper, we explore a low-cost, efficient vehicle guiding method using a consumer grade web camera and fiduciary markers. In the proposed method, the system uses fiduciary markers with a capital letter or triangle indicating direction in it. The markers are very easy to produce, manipulate, and maintain. The marker information is used to guide a vehicle. We use hue and saturation values in the image to extract marker candidates. When the known size fiduciary marker is detected by using a bird's eye view and Hough transform, the positional relation between the marker and the vehicle can be calculated. To recognize the character in the marker, a distance transform is used. The probability of feature matching was calculated by using a distance transform, and a feature having high probability is selected as a captured marker. Four directional signals and 10 alphabet features are defined and used as markers. A 98.87% recognition rate was achieved in the testing phase. The experimental results with the fiduciary marker show that the proposed method is a solution for an indoor AGV system.

Ecology and geography of transmission of two bat-borne rabies lineages in Chile.

PubMed

Escobar, Luis E; Peterson, A Townsend; Favi, Myriam; Yung, Verónica; Pons, Daniel J; Medina-Vogel, Gonzalo

2013-01-01

Rabies was known to humans as a disease thousands of years ago. In America, insectivorous bats are natural reservoirs of rabies virus. The bat species Tadarida brasiliensis and Lasiurus cinereus, with their respective, host-specific rabies virus variants AgV4 and AgV6, are the principal rabies reservoirs in Chile. However, little is known about the roles of bat species in the ecology and geographic distribution of the virus. This contribution aims to address a series of questions regarding the ecology of rabies transmission in Chile. Analyzing records from 1985-2011 at the Instituto de Salud Pública de Chile (ISP) and using ecological niche modeling, we address these questions to help in understanding rabies-bat ecological dynamics in South America. We found ecological niche identity between both hosts and both viral variants, indicating that niches of all actors in the system are undifferentiated, although the viruses do not necessarily occupy the full geographic distributions of their hosts. Bat species and rabies viruses share similar niches, and our models had significant predictive power even across unsampled regions; results thus suggest that outbreaks may occur under consistent, stable, and predictable circumstances.

Ecology and Geography of Transmission of Two Bat-Borne Rabies Lineages in Chile

PubMed Central

Escobar, Luis E.; Peterson, A. Townsend; Favi, Myriam; Yung, Verónica; Pons, Daniel J.; Medina-Vogel, Gonzalo

2013-01-01

Rabies was known to humans as a disease thousands of years ago. In America, insectivorous bats are natural reservoirs of rabies virus. The bat species Tadarida brasiliensis and Lasiurus cinereus, with their respective, host-specific rabies virus variants AgV4 and AgV6, are the principal rabies reservoirs in Chile. However, little is known about the roles of bat species in the ecology and geographic distribution of the virus. This contribution aims to address a series of questions regarding the ecology of rabies transmission in Chile. Analyzing records from 1985–2011 at the Instituto de Salud Pública de Chile (ISP) and using ecological niche modeling, we address these questions to help in understanding rabies-bat ecological dynamics in South America. We found ecological niche identity between both hosts and both viral variants, indicating that niches of all actors in the system are undifferentiated, although the viruses do not necessarily occupy the full geographic distributions of their hosts. Bat species and rabies viruses share similar niches, and our models had significant predictive power even across unsampled regions; results thus suggest that outbreaks may occur under consistent, stable, and predictable circumstances. PMID:24349592

Evolved atmospheric entry corridor with safety factor

NASA Astrophysics Data System (ADS)

Liang, Zixuan; Ren, Zhang; Li, Qingdong

2018-02-01

Atmospheric entry corridors are established in previous research based on the equilibrium glide condition which assumes the flight-path angle to be zero. To get a better understanding of the highly constrained entry flight, an evolved entry corridor that considers the exact flight-path angle is developed in this study. Firstly, the conventional corridor in the altitude vs. velocity plane is extended into a three-dimensional one in the space of altitude, velocity, and flight-path angle. The three-dimensional corridor is generated by a series of constraint boxes. Then, based on a simple mapping method, an evolved two-dimensional entry corridor with safety factor is obtained. The safety factor is defined to describe the flexibility of the flight-path angle for a state within the corridor. Finally, the evolved entry corridor is simulated for the Space Shuttle and the Common Aero Vehicle (CAV) to demonstrate the effectiveness of the corridor generation approach. Compared with the conventional corridor, the evolved corridor is much wider and provides additional information. Therefore, the evolved corridor would benefit more to the entry trajectory design and analysis.

Habitat corridors facilitate genetic resilience irrespective of species dispersal abilities or population sizes.

PubMed

Christie, Mark R; Knowles, L Lacey

2015-06-01

Corridors are frequently proposed to connect patches of habitat that have become isolated due to human-mediated alterations to the landscape. While it is understood that corridors can facilitate dispersal between patches, it remains unknown whether corridors can mitigate the negative genetic effects for entire communities modified by habitat fragmentation. These negative genetic effects, which include reduced genetic diversity, limit the potential for populations to respond to selective agents such as disease epidemics and global climate change. We provide clear evidence from a forward-time, agent-based model (ABM) that corridors can facilitate genetic resilience in fragmented habitats across a broad range of species dispersal abilities and population sizes. Our results demonstrate that even modest increases in corridor width decreased the genetic differentiation between patches and increased the genetic diversity and effective population size within patches. Furthermore, we document a trade-off between corridor quality and corridor design whereby populations connected by high-quality habitat (i.e., low corridor mortality) are more resilient to suboptimal corridor design (e.g., long and narrow corridors). The ABM also revealed that species interactions can play a greater role than corridor design in shaping the genetic responses of populations to corridors. These results demonstrate how corridors can provide long-term conservation benefits that extend beyond targeted taxa and scale up to entire communities irrespective of species dispersal abilities or population sizes.

Habitat corridors facilitate genetic resilience irrespective of species dispersal abilities or population sizes

PubMed Central

Christie, Mark R; Knowles, L Lacey

2015-01-01

Corridors are frequently proposed to connect patches of habitat that have become isolated due to human-mediated alterations to the landscape. While it is understood that corridors can facilitate dispersal between patches, it remains unknown whether corridors can mitigate the negative genetic effects for entire communities modified by habitat fragmentation. These negative genetic effects, which include reduced genetic diversity, limit the potential for populations to respond to selective agents such as disease epidemics and global climate change. We provide clear evidence from a forward-time, agent-based model (ABM) that corridors can facilitate genetic resilience in fragmented habitats across a broad range of species dispersal abilities and population sizes. Our results demonstrate that even modest increases in corridor width decreased the genetic differentiation between patches and increased the genetic diversity and effective population size within patches. Furthermore, we document a trade-off between corridor quality and corridor design whereby populations connected by high-quality habitat (i.e., low corridor mortality) are more resilient to suboptimal corridor design (e.g., long and narrow corridors). The ABM also revealed that species interactions can play a greater role than corridor design in shaping the genetic responses of populations to corridors. These results demonstrate how corridors can provide long-term conservation benefits that extend beyond targeted taxa and scale up to entire communities irrespective of species dispersal abilities or population sizes. PMID:26029259

Low-quality habitat corridors as movement conduits for two butterfly species.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haddad, Nick, M.; Tewksbury, Joshua, J.

2005-01-01

Haddad, Nick, M, and Joshua J. Tewksbury. Low-quality habitat corridors as movement conduits for two butterfly species. Ecol. Apps. 15(1):250-257. Abstract. Corridors are a primary conservation tool to increase connectivity, promote individual movement, and increase gene flow among populations in fragmented landscapes. The establishment of effective conservation corridors will depend on constructing or pre-serving connecting habitat that attracts dispersing individuals. Yet, it remains unclear whether corridors must necessarily be composed of high-quality habitat to be effective and promote dispersal and gene flow. We address this issue with two mobile, open-habitat butterfly species, Junonia coenia HuÈbner and Euptoieta claudia Cramer. Usingmore » experimental landscapes created explicitly to examine the effects of corridors on dispersal rates, we show that open-habitat corridors can serve as dispersal conduits even when corridors do not support resident butterfly populations. Both butterfly species were rare near forest edges and equally rare in narrow corridors, yet both species dispersed more often between patches connected by these corridors than between isolated patches. At least for species that can traverse corridors within a generation, corridor habitat may be lower in quality than larger patches and still increase dispersal and gene flow. For these species, abundance surveys may not accurately represent the conservation value of corridors.« less

Corridor Use Predicted from Behaviors at Habitat Boundaries.

PubMed

Haddad, Nick M

1999-02-01

Through empirical studies and simulation, I demonstrate how simple behaviors can be used in lieu of detailed dispersal studies to predict the effects of corridors on interpatch movements. Movement paths of three butterfly species were measured in large (1.64 ha) experimental patches of open habitat, some of which were connected by corridors. Butterflies that "reflected" off boundaries between open patches and the surrounding forest also emigrated from patches through corridors at rates higher than expected from random movement. This was observed for two open-habitat species, Eurema nicippe and Phoebis sennae; however, edges and corridors had no effect on a habitat generalist, Papilio troilus. Behaviorally based simulation models, which departed from correlated random walks only at habitat boundaries, predicted that corridors increase interpatch movement rates of both open-habitat species. Models also predicted that corridors have proportionately greater effects as corridor width increases, that movement rates increase before leveling off as corridor width increases, and that corridor effects decrease as patch size increases. This study suggests that corridors direct movements of habitat-restricted species and that local behaviors may be used to predict the conservation potential of corridors in fragmented landscapes.

Habitat corridors function as both drift fences and movement conduits for dispersing flies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fried, Joanna H.; Levey Douglas J.; Hogsette, Jerome A.

2005-03-30

Abstract Corridors connect otherwise isolated habitat patches and can direct movement of animals among such patches. In eight experimental landscapes, we tested two hypotheses of how corridors might affect dispersal behavior. The Traditional Corridor hypothesis posits that animals preferentially leave patches via corridors, following them into adjacent patches. The Drift Fence hypothesis posits that animals dispersing through matrix habitat are diverted into patches with corridors because they follow corridors when encountered. House flies (Musca domestica L.), a species that prefers the habitat of our patches and corridors, were released in a central patch (100•100 m) and recaptured in peripheral patchesmore » that were or were not connected by a corridor. Flies were captured more frequently in connected than unconnected patches, thereby supporting the Traditional Corridor hypothesis. The Drift Fence hypothesis was also supported, as flies were captured more frequently in unconnected patches with blind (dead end) corridors than in unconnected patches of equal area without blind corridors. A second experiment tested whether these results might be dependent on the type of patch-matrix boundary encountered by dispersing flies and whether edge-following behavior might be the mechanism underlying the observed corridor effect in the first experiment. We recorded dispersal patterns of flies released along forest edges with dense undergrowth in the forest (‘‘closed’’ edges) and along edges with little forest understory (‘‘open’’ edges). Flies were less likely to cross and more likely to follow closed edges than open edges, indicating that when patch and corridor edges are pronounced, edge-following behavior of flies may direct them along corridors into connected patches. Because edges in the first experiment were open, these results also suggest that corridor effects for flies in that experiment would have been even stronger if the edges around the source patches and corridors had been more closed. Taken together, our results suggest that corridors can affect dispersal of organisms in unappreciated ways (i.e., as drift fences) and that edge type can alter dispersal behavior.« less

Natural Whisker-Guided Behavior by Head-Fixed Mice in Tactile Virtual Reality

PubMed Central

Sofroniew, Nicholas J.; Cohen, Jeremy D.; Lee, Albert K.

2014-01-01

During many natural behaviors the relevant sensory stimuli and motor outputs are difficult to quantify. Furthermore, the high dimensionality of the space of possible stimuli and movements compounds the problem of experimental control. Head fixation facilitates stimulus control and movement tracking, and can be combined with techniques for recording and manipulating neural activity. However, head-fixed mouse behaviors are typically trained through extensive instrumental conditioning. Here we present a whisker-based, tactile virtual reality system for head-fixed mice running on a spherical treadmill. Head-fixed mice displayed natural movements, including running and rhythmic whisking at 16 Hz. Whisking was centered on a set point that changed in concert with running so that more protracted whisking was correlated with faster running. During turning, whiskers moved in an asymmetric manner, with more retracted whisker positions in the turn direction and protracted whisker movements on the other side. Under some conditions, whisker movements were phase-coupled to strides. We simulated a virtual reality tactile corridor, consisting of two moveable walls controlled in a closed-loop by running speed and direction. Mice used their whiskers to track the walls of the winding corridor without training. Whisker curvature changes, which cause forces in the sensory follicles at the base of the whiskers, were tightly coupled to distance from the walls. Our behavioral system allows for precise control of sensorimotor variables during natural tactile navigation. PMID:25031397

Graph Structure-Based Simultaneous Localization and Mapping Using a Hybrid Method of 2D Laser Scan and Monocular Camera Image in Environments with Laser Scan Ambiguity

PubMed Central

Oh, Taekjun; Lee, Donghwa; Kim, Hyungjin; Myung, Hyun

2015-01-01

Localization is an essential issue for robot navigation, allowing the robot to perform tasks autonomously. However, in environments with laser scan ambiguity, such as long corridors, the conventional SLAM (simultaneous localization and mapping) algorithms exploiting a laser scanner may not estimate the robot pose robustly. To resolve this problem, we propose a novel localization approach based on a hybrid method incorporating a 2D laser scanner and a monocular camera in the framework of a graph structure-based SLAM. 3D coordinates of image feature points are acquired through the hybrid method, with the assumption that the wall is normal to the ground and vertically flat. However, this assumption can be relieved, because the subsequent feature matching process rejects the outliers on an inclined or non-flat wall. Through graph optimization with constraints generated by the hybrid method, the final robot pose is estimated. To verify the effectiveness of the proposed method, real experiments were conducted in an indoor environment with a long corridor. The experimental results were compared with those of the conventional GMappingapproach. The results demonstrate that it is possible to localize the robot in environments with laser scan ambiguity in real time, and the performance of the proposed method is superior to that of the conventional approach. PMID:26151203

Analysis of Potential Energy Corridors Proposed by the Western Electricity Coordinating Council

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuiper, James A.; Cantwell, Brian J.; Hlava, Kevin J.

2014-02-24

This report, Analysis of Potential Energy Corridors Proposed by the Western Electricity Coordinating Council (WECC), was prepared by the Environmental Science Division of Argonne National Laboratory (Argonne). The intent of WECC’s work was to identify planning-level energy corridors that the Department of Energy (DOE) and its affiliates could study in greater detail. Argonne was tasked by DOE to analyze the WECC Proposed Energy Corridors in five topic areas for use in reviewing and revising existing corridors, as well as designating additional energy corridors in the 11 western states. In compliance with Section 368 of the Energy Policy Act of 2005more » (EPAct), the Secretaries of Energy, Agriculture, and the Interior (Secretaries) published a Programmatic Environmental Impact Statement in 2008 to address the proposed designation of energy transport corridors on federal lands in the 11 western states. Subsequently, Records of Decision designating the corridors were issued in 2009 by the Bureau of Land Management (BLM) and the U.S. Forest Service (USFS). The 2012 settlement of a lawsuit, brought by The Wilderness Society and others against the United States, which identified environmental concerns for many of the corridors requires, among other things, periodic reviews of the corridors to assess the need for revisions, deletions, or additions. A 2013 Presidential Memorandum requires the Secretaries to undertake a continuing effort to identify and designate energy corridors. The WECC Proposed Energy Corridors and their analyses in this report provide key information for reviewing and revising existing corridors, as well as designating additional energy corridors in the 11 western states. Load centers and generation hubs identified in the WECC analysis, particularly as they reflect renewable energy development, would be useful in reviewing and potentially updating the designated Section 368 corridor network. Argonne used Geographic Information System (GIS) technology to analyze the proposed energy corridors in the WECC report in five topic areas: Federal land jurisdiction, Existing Section 368 corridors, Existing transmission lines, Previously studied corridor locations, and Protected areas. Analysis methods are explained and tables and maps are provided to describe the results of the analyses in all five topic areas. WECC used a rational approach to connecting the hubs it identified, although there may be opportunities for adapting some of the proposed WECC routes to previously designated Section 368 corridors, for example: The WECC proposed energy corridors are in fact centerlines of proposed routes connecting hubs of various descriptions related to electric energy transmission. Although the centerlines were sited to avoid sensitive areas, infrastructure proposed within actual pathways or corridors defined by the centerlines would sometimes affect lands where such development would not normally be allowed, such as National Parks and Monuments, National Wildlife Refuges, and Wilderness Areas. Many WECC proposed energy corridors are sited along centerlines of existing roads, including Interstate Highways, where in some cases additional width to accommodate energy transmission infrastructure may not be available. Examples include the WECC Proposed Corridor along Interstate 70 through Glenwood Canyon in Colorado, and along U.S. Highway 89 across Glen Canyon Dam in Arizona. Several WECC proposed energy corridors are parallel to designated Section 368 corridors that have already cleared the preliminary steps to right-of-way approval. In many of these cases, the WECC hub connection objectives can be met more efficiently by routing on the designated Section 368 corridors.« less

The Limits of Soviet Airpower: The Bear Versus the Mujahideen in Afghanistan, 1979-1989

DTIC Science & Technology

1997-06-01

satellite imagery identified Soviet TMS-65 decontamination vehicles and AGV-3 detox chambers in the vicinity of combat areas. In addition, the...Vladislav Tamarov, Afghanistan: Soviet Vietnam, trans. Naomi Marcus, Marianne Clarke Trangen, and Vladislav Tamarov (San Francisco: Mercury House...Tamarov. San Francisco: Mercury House, 1992. Turbiville, Graham. Ambush! The Road War in Afghanistan. Fort Leavenworth, KS: Soviet Army Studies Office

Intraocular pressure control after the implantation of a second Ahmed glaucoma valve.

PubMed

Jiménez-Román, Jesús; Gil-Carrasco, Félix; Costa, Vital Paulino; Schimiti, Rui Barroso; Lerner, Fabián; Santana, Priscila Rezende; Vascocellos, Jose Paulo Cabral; Castillejos-Chévez, Armando; Turati, Mauricio; Fabre-Miranda, Karina

2016-06-01

The objective of this study is to evaluate the efficacy and safety of a second Ahmed glaucoma valve (AGV) in eyes with refractory glaucoma that had undergone prior Ahmed device implantation. This multicenter, retrospective study evaluated 58 eyes (58 patients) that underwent a second AGV (model S2-n = 50, model FP7-n = 8) due to uncontrolled IOP under maximal medical therapy. Outcome measures included IOP, visual acuity, number of glaucoma medications, and postoperative complications. Success was defined as IOP <21 mmHg (criterion 1) or 30 % reduction of IOP (criterion 2) with or without hypotensive medications. Persistent hypotony (IOP <5 mmHg after 3 months of follow-up), loss of light perception, and reintervention for IOP control were defined as failure. Mean preoperative IOP and mean IOPs at 12 and 30 months were 27.55 ± 1.16 mmHg (n = 58), 14.45 ± 0.83 mmHg (n = 42), and 14.81 ± 0.87 mmHg (n = 16), respectively. The mean numbers of glaucoma medications preoperatively at 12 and 30 months were 3.17 ± 0.16 (n = 58), 1.81 ± 0.2 (n = 42), and 1.83 ± 0.35 (n = 18), respectively. The reductions in mean IOP and number of medications were statistically significant at all time intervals (P < 0.001). According to criterion 1, Kaplan-Meier survival curves disclosed success rates of 62.9 % at 12 months and 56.6 % at 30 months. According to criterion 2, Kaplan-Meier survival curves disclosed success rates of 43.9 % at 12 months and 32.9 % at 30 months. The most frequent early complication was hypertensive phase (10.3 %) and the most frequent late complication was corneal edema (17.2 %). Second AGV implantation may effectively reduce IOP in eyes with uncontrolled glaucoma, and is associated with relatively few complications.

Supra-Tenon Capsule Implantation of the Ahmed Glaucoma Valve in Refractory Pediatric Glaucoma.

PubMed

Elhefney, Eman M; Al-Sharkawy, Hossam T; Kishk, Hanem M

2016-09-01

To evaluate the efficacy of supra-Tenon capsule implantation of an Ahmed glaucoma valve (AGV) as a measure to decrease the fibrotic potential of the Tenon capsule on bleb formation and its subsequent effect on intraocular pressure (IOP) control in children with refractory glaucoma. Mansoura Ophthalmic Centre, Faculty of Medicine, Mansoura University, Egypt. A prospective interventional study. Twenty-two eyes of 12 children with refractory glaucoma underwent supra-Tenon capsule implantation of AGV. Ophthalmic examinations under general anesthesia including measurement of the corneal diameter and the IOP with Perkin's tonometer were performed preoperatively, on the first postoperative day, the first postoperative week, weekly for the first month, 2-weekly for the following 3 months, and monthly for at least 18 months. Postoperative complications and the number of glaucoma medications used preoperatively and postoperatively were recorded. The paired Student t test was used to compare preoperative and postoperative data. There were 12 eyes (54.6%) with refractory congenital glaucoma, 7 eyes (31.8%) with refractory pseudophakic glaucoma, and 3 eyes (13.6%) with refractory aphakic glaucoma. Patients included 10 male (83.3%) and 2 female (16.7%) children with a mean age of 16.3±9.7 months. The mean follow-up duration was 24.1±4.3 months. There was a statistically significant difference between the mean preoperative IOP (30.7±2.88 mm Hg) and the mean postoperative IOP (16.1±3.60 mm Hg) (t=16.22 and P=0.000, with a mean decrease in the IOP by 47.6%). The difference between the mean number of antiglaucoma medications before surgery (1.86±0.4) and after surgery (1.0±0.9) was also statistically significant (t=4.31 and P=0.000). Total success was achieved in 18 eyes (81.9%). Postoperative complications included tube exposure and slippage (10%), hypotony (10%), and hyphema (5%). Supra-Tenon capsule implantation of the AGV was successful in controlling the IOP with few postoperative complications in the management of children with refractory glaucoma.

Advanced obstacle avoidance for a laser based wheelchair using optimised Bayesian neural networks.

PubMed

Trieu, Hoang T; Nguyen, Hung T; Willey, Keith

2008-01-01

In this paper we present an advanced method of obstacle avoidance for a laser based intelligent wheelchair using optimized Bayesian neural networks. Three neural networks are designed for three separate sub-tasks: passing through a door way, corridor and wall following and general obstacle avoidance. The accurate usable accessible space is determined by including the actual wheelchair dimensions in a real-time map used as inputs to each networks. Data acquisitions are performed separately to collect the patterns required for specified sub-tasks. Bayesian frame work is used to determine the optimal neural network structure in each case. Then these networks are trained under the supervision of Bayesian rule. Experiment results showed that compare to the VFH algorithm our neural networks navigated a smoother path following a near optimum trajectory.

Background Oriented Schlieren (BOS) of a Supersonic Aircraft in Flight

NASA Technical Reports Server (NTRS)

Heineck, James T.; Banks, Daniel W.; Schairer, Edward T.; Haering, Edward A.; Bean, Paul S.

2016-01-01

This article describes the development and use of Background Oriented Schlieren on a full-scale supersonic jet in flight. A series of flight tests was performed in October, 2014 and February 2015 using the flora of the desert floor in the Supersonic Flight Corridor on the Edwards Air Force Base as a background. Flight planning was designed based on the camera resolution, the mean size and color of the predominant plants, and the navigation and coordination of two aircraft. Software used to process the image data was improved with additional utilities. The planning proved to be effective and the vast majority of the passes of the target aircraft were successfully recorded. Results were obtained that are the most detailed schlieren imagery of an aircraft in flight to date.

Planning, guidance, and quality assurance of pelvic screw placement using deformable image registration

NASA Astrophysics Data System (ADS)

Goerres, J.; Uneri, A.; Jacobson, M.; Ramsay, B.; De Silva, T.; Ketcha, M.; Han, R.; Manbachi, A.; Vogt, S.; Kleinszig, G.; Wolinsky, J.-P.; Osgood, G.; Siewerdsen, J. H.

2017-12-01

Percutaneous pelvic screw placement is challenging due to narrow bone corridors surrounded by vulnerable structures and difficult visual interpretation of complex anatomical shapes in 2D x-ray projection images. To address these challenges, a system for planning, guidance, and quality assurance (QA) is presented, providing functionality analogous to surgical navigation, but based on robust 3D-2D image registration techniques using fluoroscopy images already acquired in routine workflow. Two novel aspects of the system are investigated: automatic planning of pelvic screw trajectories and the ability to account for deformation of surgical devices (K-wire deflection). Atlas-based registration is used to calculate a patient-specific plan of screw trajectories in preoperative CT. 3D-2D registration aligns the patient to CT within the projective geometry of intraoperative fluoroscopy. Deformable known-component registration (dKC-Reg) localizes the surgical device, and the combination of plan and device location is used to provide guidance and QA. A leave-one-out analysis evaluated the accuracy of automatic planning, and a cadaver experiment compared the accuracy of dKC-Reg to rigid approaches (e.g. optical tracking). Surgical plans conformed within the bone cortex by 3-4 mm for the narrowest corridor (superior pubic ramus) and  >5 mm for the widest corridor (tear drop). The dKC-Reg algorithm localized the K-wire tip within 1.1 mm and 1.4° and was consistently more accurate than rigid-body tracking (errors up to 9 mm). The system was shown to automatically compute reliable screw trajectories and accurately localize deformed surgical devices (K-wires). Such capability could improve guidance and QA in orthopaedic surgery, where workflow is impeded by manual planning, conventional tool trackers add complexity and cost, rigid tool assumptions are often inaccurate, and qualitative interpretation of complex anatomy from 2D projections is prone to trial-and-error with extended fluoroscopy time.

42 CFR 423.336 - Risk-sharing arrangements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... payments to a Part D sponsor subject to risk—(1) Adjusted allowable risk corridor costs. For purposes of this paragraph, the term adjusted allowable risk corridor costs means— (i) The allowable risk corridor... coverage year. (2) Establishment of risk corridors. (i) Risk corridors. For each year, CMS establishes a...

Corridors affect plants, animals, and their interactions in fragmented landscapes

PubMed Central

Tewksbury, Joshua J.; Levey, Douglas J.; Haddad, Nick M.; Sargent, Sarah; Orrock, John L.; Weldon, Aimee; Danielson, Brent J.; Brinkerhoff, Jory; Damschen, Ellen I.; Townsend, Patricia

2002-01-01

Among the most popular strategies for maintaining populations of both plants and animals in fragmented landscapes is to connect isolated patches with thin strips of habitat, called corridors. Corridors are thought to increase the exchange of individuals between habitat patches, promoting genetic exchange and reducing population fluctuations. Empirical studies addressing the effects of corridors have either been small in scale or have ignored confounding effects of increased habitat area created by the presence of a corridor. These methodological difficulties, coupled with a paucity of studies examining the effects of corridors on plants and plant–animal interactions, have sparked debate over the purported value of corridors in conservation planning. We report results of a large-scale experiment that directly address this debate. In eight large-scale experimental landscapes that control for patch area and test alternative mechanisms of corridor function, we demonstrate that corridors not only increase the exchange of animals between patches, but also facilitate two key plant–animal interactions: pollination and seed dispersal. Our results show that the beneficial effects of corridors extend beyond the area they add, and suggest that increased plant and animal movement through corridors will have positive impacts on plant populations and community interactions in fragmented landscapes. PMID:12239344

Evaluation of the effect of buccal corridor size on smile attractiveness.

PubMed

Oshagh, Morteza; Zarif, Najafi H; Bahramnia, F

2010-01-01

an attractive smile helps people feel more self-confident and look younger. One of the more controversial aspects of smile attractiveness pertains to buccal corridor size. There is no previous study by those with artistic knowledge that has assessed the asthetic considerations of buccal corridor size. The purpose of this study was to observe whether the size of buccal corridors has an impact on smile attractiveness evaluated by lay people, dental students, and art students. colored post-treatment photograph with posed smiles of two subjects (one male, one female) were selected. The maxillary posterior dentitions were digitally altered to produce different buccal corridor sizes: narrow (28% buccal corridor), medium-narrow (22% buccal corridor), medium-broad (10% buccal corridor), and broad (2% buccal corridor). The 5 images of each subject were paired into 11 possible combinations and presented to three group: art students, dental students, and lay people, who compared the two images in each pair of smile attractiveness. The statistical test used were Wilcoxon signed rank and Mann-Whitney test. minimal and excessive buccal corridors were the least attractive when judged by three groups. All groups preferred smaller buccal corridors for the male subject and larger buccal corridors for the female subject. No significant judging differences were found between male and female judges from among art and dental students. minimal or excessive buccal corridor should be included in the problem list during orthodontic diagnosis and treatment planning.

I-880 Integrated Corridor Management Concept of Operation : Final Submittal: Concept of Operations for the I-880 Corridor in Oakland, California

DOT National Transportation Integrated Search

2008-03-31

This report describes the draft Concept of Operations that has been developed for the Integrated Corridor Mobility (ICM) program by the I-880 corridor team. The I-880 corridor team has defined this Concept of Operations (ConOps) based on two primary ...

[Perception and attitude of rural community to the construction of Asian elephant conservation corridors in Xishuangbanna].

PubMed

Li, Zheng-Ling; Chen, Ming-Yong; Wu, Zhao-Lu; Wang, Qian; Dong, Yong-Hua

2009-06-01

By using contingent valuation method (CVM), an investigation was made from November 2007 to March 2008 on the perception and attitude of 196 households in 5 villages within 2 planned Asian elephant conservation corridors in Xishuangbanna to the construction of the corridors. 80.61% of the interviewees conditionally supported the corridors construction. The main factors affecting the interviewees' support willingness included their education level, per capita income, and perceptions to Asian elephant protection, human-elephant relations, and corridor utilization patterns and its beneficiaries, among which, the interviewees' awareness of Asian elephant conservation, corridor utilization patterns, and corridor beneficiaries had strong influence on the support willingness, with the correlation coefficient being 0.231, 0.236, and -0.304, respectively. The rural community holding the land tenure played a key role in the corridors construction. To effectively design and planning the construction of biological conservation corridor, it is necessary to have a deep understanding on the perceptions and attitudes of rural community to the construction of the corridor and to obtain their support and participation for this construction.

Corridor use by diverse taxa.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haddad, Nick, M.; Browne, David, R.; Cunningham, Alan

2003-01-01

Haddad, N.M., D.R. Browne, A. Cunningham, B.J. Danielson, D.J. Levey, S. Sargent, and T. Spira. 2003. Corridor use by diverse taxa. Ecology, 84(3):609-615. One of the most popular approaches for maintaining populations and conserving biodiversity in fragmented landscapes is to retain or create corridors that connect otherwise isolated habitat patches. Working in large-scale, experimental landscapes in which open-habitat patches and corridors were created by harvesting pine forest, we showed that corridors direct movements of different types of species, including butterflies, small mammals, and bird dispersed plants, causing higher movement between connected than between unconnected patches. Corridors directed the movement ofmore » all 10 species studied, with all corridor effect sizes >68%. However, this corridor effect was significant for five species, not significant for one species, and inconclusive for four species because of small sample sizes. Although we found no evidence that corridors increase emigration from a patch, our results show that movements of disparate taxa with broadly different life histories and functional roles are directed by corridors.« less

GCM work order status

DOT National Transportation Integrated Search

1996-12-31

The GCM Corridor is one of four "Priority Corridors" throughout the country. These corridors have been selected for special federal transportation funding based on very specific transportation and environmental criteria. The corridor includes the gre...

Can dispersal mode predict corridor effects on plant parasites?

PubMed

Sullivan, Lauren L; Johnson, Brenda L; Brudvig, Lars A; Haddad, Nick M

2011-08-01

Habitat corridors, a common management strategy for increasing connectivity in fragmented landscapes, have experimentally validated positive influences on species movement and diversity. However, long-standing concerns that corridors could negatively impact native species by spreading antagonists, such as disease, remain largely untested. Using a large-scale, replicated experiment, we evaluated whether corridors increase the incidence of plant parasites. We found that corridor impacts varied with parasite dispersal mode. Connectivity provided by corridors increased incidence of biotically dispersed parasites (galls on Solidago odora) but not of abiotically dispersed parasites (foliar fungi on S. odora and three Lespedeza spp.). Both biotically and abiotically dispersed parasites responded to edge effects, but the direction of responses varied across species. Although our results require additional tests for generality to other species and landscapes, they suggest that, when establishing conservation corridors, managers should focus on mitigating two potential negative effects: the indirect effects of narrow corridors in creating edges and direct effects of corridors in enhancing connectivity of biotically dispersed parasites.

Procedural Tests for Anti-G Protective Devices. Volume II. G-Sensitivity Tests

DTIC Science & Technology

1979-12-01

of these valves was used in only one type of aircraft--the ALAR AGV in ...pattern. 3) Total included, inexplicitly in the total for this column along with Failures au.d OTH/MAL’s are Type 6 HOW MALFUNCTION CODES--which...maintenance. Because Type 6 HOW MALFUNCTION CODESI. .were not considered pertinent to this investigation, they wer!. not included in the report. All figures of

Endophthalmitis associated with the Ahmed glaucoma valve implant

PubMed Central

Al-Torbak, A A; Al-Shahwan, S; Al-Jadaan, I; Al-Hommadi, A; Edward, D P

2005-01-01

Aim: To investigate the rate, risk factors, clinical course, and treatment outcomes of endophthalmitis following glaucoma drainage implant (GDI) surgery. Methods: A computerised relational database search was conducted to identify all patients who were implanted with Ahmed glaucoma valve (AGV) and developed endophthalmitis following surgery at the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia, between 1 January 1994 and 30 November 2003. Only medical records of the patients who developed endophthalmitis were retrospectively reviewed. Results: 542 eyes of 505 patients who were on active follow up were included in the study. Endophthalmitis developed in nine (1.7%) eyes; the rate was five times higher in children than in adults. Delayed endophthalmitis (developed 6 weeks after surgery) occurred in eight of nine eyes. Conjunctival erosion overlying the AGV tube was present in six of nine eyes. Common organisms isolated in the vitreous included Haemophilus influenzae and Streptococcus species. Multiple regression analysis revealed that younger age and conjunctival erosion over the tube were significant risk factors associated with endophthalmitis. Conclusion: Endophthalmitis is a rare complication of GDI surgery that appears to be more common in children. Conjunctival dehiscence over the GDI tube seems to represent a major risk factor for endophthalmitis. Prompt surgical revision of an exposed GDI tube is highly recommended. PMID:15774923

Endophthalmitis associated with the Ahmed glaucoma valve implant.

PubMed

Al-Torbak, A A; Al-Shahwan, S; Al-Jadaan, I; Al-Hommadi, A; Edward, D P

2005-04-01

To investigate the rate, risk factors, clinical course, and treatment outcomes of endophthalmitis following glaucoma drainage implant (GDI) surgery. A computerised relational database search was conducted to identify all patients who were implanted with Ahmed glaucoma valve (AGV) and developed endophthalmitis following surgery at the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia, between 1 January 1994 and 30 November 2003. Only medical records of the patients who developed endophthalmitis were retrospectively reviewed. 542 eyes of 505 patients who were on active follow up were included in the study. Endophthalmitis developed in nine (1.7%) eyes; the rate was five times higher in children than in adults. Delayed endophthalmitis (developed 6 weeks after surgery) occurred in eight of nine eyes. Conjunctival erosion overlying the AGV tube was present in six of nine eyes. Common organisms isolated in the vitreous included Haemophilus influenzae and Streptococcus species. Multiple regression analysis revealed that younger age and conjunctival erosion over the tube were significant risk factors associated with endophthalmitis. Endophthalmitis is a rare complication of GDI surgery that appears to be more common in children. Conjunctival dehiscence over the GDI tube seems to represent a major risk factor for endophthalmitis. Prompt surgical revision of an exposed GDI tube is highly recommended.

Alternative Fuels Data Center: West Virginia CNG Corridor Now Open

Science.gov Websites

West Virginia CNG Corridor Now Open to someone by E-mail Share Alternative Fuels Data Center: West Virginia CNG Corridor Now Open on Facebook Tweet about Alternative Fuels Data Center: West Virginia CNG Corridor Now Open on Twitter Bookmark Alternative Fuels Data Center: West Virginia CNG Corridor Now Open on

Response variables for evaluation of the effectiveness of conservation corridors.

PubMed

Gregory, Andrew J; Beier, Paul

2014-06-01

Many studies have evaluated effectiveness of corridors by measuring species presence in and movement through small structural corridors. However, few studies have assessed whether these response variables are adequate for assessing whether the conservation goals of the corridors have been achieved or considered the costs or lag times involved in measuring the response variables. We examined 4 response variables-presence of the focal species in the corridor, interpatch movement via the corridor, gene flow, and patch occupancy--with respect to 3 criteria--relevance to conservation goals, lag time (fewest generations at which a positive response to the corridor might be evident with a particular variable), and the cost of a study when applying a particular variable. The presence variable had the least relevance to conservation goals, no lag time advantage compared with interpatch movement, and only a moderate cost advantage over interpatch movement or gene flow. Movement of individual animals between patches was the most appropriate response variable for a corridor intended to provide seasonal migration, but it was not an appropriate response variable for corridor dwellers, and for passage species it was only moderately relevant to the goals of gene flow, demographic rescue, and recolonization. Response variables related to gene flow provided a good trade-off among cost, relevance to conservation goals, and lag time. Nonetheless, the lag time of 10-20 generations means that evaluation of conservation corridors cannot occur until a few decades after a corridor has been established. Response variables related to occupancy were most relevant to conservation goals, but the lag time and costs to detect corridor effects on occupancy were much greater than the lag time and costs to detect corridor effects on gene flow. © 2014 Society for Conservation Biology.

Complexity Analysis of Traffic in Corridors-in-the-Sky

NASA Technical Reports Server (NTRS)

Xue, Min; Zelinski, Shannon Jean

2010-01-01

The corridors-in-the-sky concept imitates the highway system in ground transportation. The benefit expected from a corridor relies on its capability of handling high density traffic with negligible controller workload, the acceptance of extra fuel or distance, and the complexity reduction in underlying sectors. This work evaluates a selected corridor from these perspectives through simulations. To examine traffic inside the corridor, a corridor traffic simulation tool that can resolve conflicts is developed using C language. Prescribed conflict resolution maneuvers mimic corridor users behaviors and conflict resolution counts measure complexity. Different lane options and operational policies are proposed to examine their impacts on complexity. Fuel consumption is calculated and compared for corridor traffic. On the other hand, to investigate the complexity of non-corridor traffic in underlying sectors, the existing Airspace Concept Evaluation System tool is utilized along with the Automated Airspace Concept tool. The number of conflict resolutions is examined and treated as the complexity measurement. The results show heavy traffic can be managed with low complexity for a historical traffic schedule simulated with appropriate operational policies and lane options. For instance, with 608 flights and peak aircraft count of 100, only 84 actions need to be taken in a 24-hour period to resolve the conflicts for an 8-lane corridor. Compared with the fuel consumptions with great circle trajectories, the simulation of corridor traffic shows that the total extra fuel for corridor flights is 26,373 gallons, or 2.76%, which is 0.38% less than flying filed flight plans. Without taking climb and descent portions of corridor traffic, the complexity of underlying sectors is reduced by 17.71%. However the climb and descent portions will eliminate the reduction and the overall complexity of sectors is actually increased by 9.14%.

Interior, underground corridor going to building 500 from the corridor ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Interior, underground corridor going to building 500 from the corridor connecting buildings 511 and 515. - Fitzsimons General Hospital, Infirmary, Northwest Corner of East Bushnell Avenue & South Page Street, Aurora, Adams County, CO

System architecture efforts in the Gary-Chicago-Milwaukee corridor

DOT National Transportation Integrated Search

1998-01-01

The Gary-Chicago-Milwaukee (GCM) Corridor is one of four Priority Corridors throughout the country. These corridors were selected for special federal transportation funding based on very specific transportation and environmental criteria. One o...

Remote sensing impact on corridor selection and placement

NASA Technical Reports Server (NTRS)

Thomson, F. J.; Sellman, A. N.

1975-01-01

Computer-aided corridor selection techniques, utilizing digitized data bases of socio-economic, census, and cadastral data, and developed for highway corridor routing are considered. Land resource data generated from various remote sensing data sources were successfully merged with the ancillary data files of a corridor selection model and prototype highway corridors were designed using the combined data set. Remote sensing derived information considered useful for highway corridor location, special considerations in geometric correction of remote sensing data to facilitate merging it with ancillary data files, and special interface requirements are briefly discussed.

Potential negative ecological effects of corridors.

PubMed

Haddad, Nick M; Brudvig, Lars A; Damschen, Ellen I; Evans, Daniel M; Johnson, Brenda L; Levey, Douglas J; Orrock, John L; Resasco, Julian; Sullivan, Lauren L; Tewksbury, Josh J; Wagner, Stephanie A; Weldon, Aimee J

2014-10-01

Despite many studies showing that landscape corridors increase dispersal and species richness for disparate taxa, concerns persist that corridors can have unintended negative effects. In particular, some of the same mechanisms that underlie positive effects of corridors on species of conservation interest may also increase the spread and impact of antagonistic species (e.g., predators and pathogens), foster negative effects of edges, increase invasion by exotic species, increase the spread of unwanted disturbances such as fire, or increase population synchrony and thus reduce persistence. We conducted a literature review and meta-analysis to evaluate the prevalence of each of these negative effects. We found no evidence that corridors increase unwanted disturbance or non-native species invasion; however, these have not been well-studied concerns (1 and 6 studies, respectively). Other effects of corridors were more often studied and yielded inconsistent results; mean effect sizes were indistinguishable from zero. The effect of edges on abundances of target species was as likely to be positive as negative. Corridors were as likely to have no effect on antagonists or population synchrony as they were to increase those negative effects. We found 3 deficiencies in the literature. First, despite studies on how corridors affect predators, there are few studies of related consequences for prey population size and persistence. Second, properly designed studies of negative corridor effects are needed in natural corridors at scales larger than those achievable in experimental systems. Third, studies are needed to test more targeted hypotheses about when corridor-mediated effects on invasive species or disturbance may be negative for species of management concern. Overall, we found no overarching support for concerns that construction and maintenance of habitat corridors may result in unintended negative consequences. Negative edge effects may be mitigated by widening corridors or softening edges between corridors and the matrix. Other negative effects are relatively small and manageable compared with the large positive effects of facilitating dispersal and increasing diversity of native species. © 2014 Society for Conservation Biology.

Corridors promote fire via connectivity and edge effects.

PubMed

Brudvig, Lars A; Wagner, Stephanie A; Damschen, Ellen I

2012-04-01

Landscape corridors, strips of habitat that connect otherwise isolated habitat patches, are commonly employed during management of fragmented landscapes. To date, most reported effects of corridors have been positive; however, there are long-standing concerns that corridors may have unintended consequences. Here, we address concerns over whether corridors promote propagation of disturbances such as fire. We collected data during prescribed fires in the world's largest and best replicated corridor experiment (Savannah River Site, South Carolina, USA), six -50-ha landscapes of open (shrubby/herbaceous) habitat within a pine plantation matrix, to test several mechanisms for how corridors might influence fire. Corridors altered patterns of fire temperature through a direct connectivity effect and an indirect edge effect. The connectivity effect was independent of fuel levels and was consistent with a hypothesized wind-driven "bellows effect." Edges, a consequence of corridor implementation, elevated leaf litter (fuel) input from matrix pine trees, which in turn increased fire temperatures. We found no evidence for corridors or edges impacting patterns of fire spread: plots across all landscape positions burned with similar probability. Impacts of edges and connectivity on fire temperature led to changes in vegetation: hotter-burning plots supported higher bunch grass cover during the field season after burning, suggesting implications for woody/herbaceous species coexistence. To our knowledge, this represents the first experimental evidence that corridors can modify landscape-scale patterns of fire intensity. Corridor impacts on fire should be carefully considered during landscape management, both in the context of how corridors connect or break distributions of fuels and the desired role of fire as a disturbance, which may range from a management tool to an agent to be suppressed. In our focal ecosystem, longleaf pine woodland, corridors might provide a previously unrecognized benefit during prescribed burning activities, by promoting fire intensity, which may assist in promoting plant biodiversity.

RISK CORRIDORS AND REINSURANCE IN HEALTH INSURANCE MARKETPLACES

PubMed Central

LAYTON, TIMOTHY J.; MCGUIRE, THOMAS G.; SINAIKO, ANNA D.

2016-01-01

Health Insurance Marketplaces established by the Affordable Care Act implement reinsurance and risk corridors. Reinsurance limits insurer costs associated with specific individuals, while risk corridors protect against aggregate losses. Both tighten the insurer’s distribution of expected costs. This paper compares the economic costs and consequences of reinsurance and risk corridors. We simulate the insurer’s cost distribution under reinsurance and risk corridors using data for a group of individuals likely to enroll in Marketplace plans from the Medical Expenditure Panel Survey. We compare reinsurance and risk corridors in terms of risk reduction and incentives for cost containment. We find that reinsurance and one-sided risk corridors achieve comparable levels of risk reduction for a given level of incentives. We also find that the policies being implemented in the Marketplaces (a mix of reinsurance and two-sided risk corridor policies) substantially limit insurer risk but perform similarly to a simpler stand-alone reinsurance policy. PMID:26973861

Deformable 3D-2D registration for guiding K-wire placement in pelvic trauma surgery

NASA Astrophysics Data System (ADS)

Goerres, J.; Jacobson, M.; Uneri, A.; de Silva, T.; Ketcha, M.; Reaungamornrat, S.; Vogt, S.; Kleinszig, G.; Wolinsky, J.-P.; Osgood, G.; Siewerdsen, J. H.

2017-03-01

Pelvic Kirschner wire (K-wire) insertion is a challenging surgical task requiring interpretation of complex 3D anatomical shape from 2D projections (fluoroscopy) and delivery of device trajectories within fairly narrow bone corridors in proximity to adjacent nerves and vessels. Over long trajectories ( 10-25 cm), K-wires tend to curve (deform), making conventional rigid navigation inaccurate at the tip location. A system is presented that provides accurate 3D localization and guidance of rigid or deformable surgical devices ("components" - e.g., K-wires) based on 3D-2D registration. The patient is registered to a preoperative CT image by virtually projecting digitally reconstructed radiographs (DRRs) and matching to two or more intraoperative x-ray projections. The K-wire is localized using an analogous procedure matching DRRs of a deformably parametrized model for the device component (deformable known-component registration, or dKC-Reg). A cadaver study was performed in which a K-wire trajectory was delivered in the pelvis. The system demonstrated target registration error (TRE) of 2.1 ± 0.3 mm in location of the K-wire tip (median ± interquartile range, IQR) and 0.8 ± 1.4º in orientation at the tip (median ± IQR), providing functionality analogous to surgical tracking / navigation using imaging systems already in the surgical arsenal without reliance on a surgical tracker. The method offers quantitative 3D guidance using images (e.g., inlet / outlet views) already acquired in the standard of care, potentially extending the advantages of navigation to broader utilization in trauma surgery to improve surgical precision and safety.

Estimating the Environmental Costs of Africa's Massive "Development Corridors".

PubMed

Laurance, William F; Sloan, Sean; Weng, Lingfei; Sayer, Jeffrey A

2015-12-21

In sub-Saharan Africa, dozens of major "development corridors" have been proposed or are being created to increase agricultural production [1-4], mineral exports [5-7], and economic integration. The corridors involve large-scale expansion of infrastructure such as roads, railroads, pipelines, and port facilities and will open up extensive areas of land to new environmental pressures [1, 4, 8]. We assessed the potential environmental impacts of 33 planned or existing corridors that, if completed, would total over 53,000 km in length and crisscross much of the African continent. We mapped each corridor and estimated human occupancy (using the distribution of persistent night-lights) and environmental values (endangered and endemic vertebrates, plant diversity, critical habitats, carbon storage, and climate-regulation services) inside a 50-km-wide band overlaid onto each corridor. We also assessed the potential for each corridor to facilitate increases in agricultural production. The corridors varied considerably in their environmental values, and many were only sparsely populated. Because of marginal soils or climates, some corridors appear to have only modest agricultural potential. Collectively, the corridors would bisect over 400 existing protected areas and could degrade a further ~1,800 by promoting habitat disruption near or inside the reserves. We conclude that many of the development corridors will promote serious and largely irreversible environmental changes and should proceed only if rigorous mitigation and protection measures can be employed. Some planned corridors with high environmental values and limited agricultural benefits should possibly be cancelled altogether. VIDEO ABSTRACT. Copyright © 2015 Elsevier Ltd. All rights reserved.

Study on the oasis corridor landscape in the arid regions based on RS and GIS methods--application of Jinta Oasis, China.

PubMed

Ma, Ming-guo; Wang, Xue-mei; Cheng, Guo-dong

2003-03-01

The study on the oasis corridor landsape is a new hotspot in the ecological environment research in the arid regions. In oasis, main corridor landscape types include river, ditch, shelterbelt and road. This paper introduces the basic ecological effects of the corridor landscape on the transporting mass and energy and obstructing desert landscape expansion and incursion. Using Geographic Information System (GIS), we have researched the corridor distribution and its spatial relationship with other landscape types in the Jinta Oasis. Based on the dynamically monitoring on the landscape pattern change of the Jinta Oasis during the latter 10 years by using Remote Sensing (RS) and GIS, the driving functions of the corridors on this change have been analyzed in detail. The analysis results showed that all kinds of corridors' characteristics can be quantified by the indexes such as length and width, ratio of perimeter and area, density and non-heterogeneity. The total corridor length of Jinta Oasis is 1838.5 km and its density is 2.1 km/km2. The corridor density of the irrigation land, forest and resident area is maximal, which shows that affection degree of the oasis corridors on them is the most. The improvement of the corridors quality is one of the important driving factors on the irrigation land and so on. The organic combination of the RS and GIS technologies and landscape research methods would be an effective means for the corridor landscape research on arid region oasis.

52. 2E corridor, from intersection of 2F corridor, second floor, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

52. 2E corridor, from intersection of 2F corridor, second floor, building 500, looking east - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

Corridor Planning And Feasibility Analysis Corridor, Master Plan

DOT National Transportation Integrated Search

1996-04-01

THE I-70 RURAL IVHS CORRIDOR MASTER PLAN IS THE GUIDANCE DOCUMENT FOR DEPLOYMENT OF THE INTELLIGENT TRANSPORTATION SYSTEM (ITS) FOR THE INTERSTATE-70 CORRIDOR FROM DENVER TO GLENWOOD SPRINGS, COLORADO. AS A WORKING DOCUMENT, THE PLAN RECOMMENDS STRAT...

Civil tiltrotor missions and applications. Phase 2: The commercial passenger market

NASA Technical Reports Server (NTRS)

Thompson, P.; Neir, R.; Reber, R.; Scholes, R.; Alexander, H.; Sweet, D.; Berry, D. (Editor)

1991-01-01

The commercial passenger market for the civil tiltrotor was examined in phase 2. A market responsive commercial tiltrotor was found to be technically feasible, and a significant worldwide market potential was found to exist for such an aircraft, especially for relieving congestion in urban area-to-urban area service and for providing cost effective hub airport feeder service. Potential technical obstacles of community noise, vertiport area navigation, surveillance, and control, and the pilot/aircraft interface were determined to be surmountable. Nontechnical obstacles relating to national commitment and leadership and development of ground and air infrastructure were determined to be more difficult to resolve; an innovative public/private partnership is suggested to allow coordinated development of an initial commercial tiltrotor network to relieve congestion in the crowded US Northeast corridor by the year 2000.

D Topological Indoor Building Modeling Integrated with Open Street Map

NASA Astrophysics Data System (ADS)

Jamali, A.; Rahman, A. Abdul; Boguslawski, P.

2016-09-01

Considering various fields of applications for building surveying and various demands, geometry representation of a building is the most crucial aspect of a building survey. The interiors of the buildings need to be described along with the relative locations of the rooms, corridors, doors and exits in many kinds of emergency response, such as fire, bombs, smoke, and pollution. Topological representation is a challenging task within the Geography Information Science (GIS) environment, as the data structures required to express these relationships are particularly difficult to develop. Even within the Computer Aided Design (CAD) community, the structures for expressing the relationships between adjacent building parts are complex and often incomplete. In this paper, an integration of 3D topological indoor building modeling in Dual Half Edge (DHE) data structure and outdoor navigation network from Open Street Map (OSM) is presented.

I-10 national freight corridor study : phase II report, corridor ITS architecture.

DOT National Transportation Integrated Search

2007-01-01

The Interstate 10 National Freight Corridor extends : across the eight states that form the southern boundary : of the contiguous 48 states. From west to east, the : corridor crosses parts of California, Arizona, New : Mexico, Texas, Louisiana, Missi...

77 FR 3326 - Northeast Corridor Safety Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-23

.... 3] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of Northeast Corridor Safety Committee Meeting. SUMMARY: FRA announced the first meeting of the Northeast Corridor Safety Committee, a Federal...

76 FR 34139 - Northeast Corridor Safety Committee; Meeting Postponement

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-10

.... 2] Northeast Corridor Safety Committee; Meeting Postponement AGENCY: Federal Railroad Administration... announced the first meeting of the Northeast Corridor Safety Committee, a Federal Advisory Committee... future date. DATES: The meeting of the Northeast Corridor Safety Committee scheduled to commence on...

76 FR 32391 - Northeast Corridor Safety Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-06

.... 1] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of the Northeast Corridor Safety Committee Meeting. SUMMARY: FRA announces the first meeting of the Northeast Corridor Safety Committee, a...

Integrated corridor management analysis, modeling, and simulation results for the test corridor.

DOT National Transportation Integrated Search

2008-06-01

This report documents the Integrated Corridor Management (ICM) Analysis Modeling and Simulation (AMS) tools and strategies used on a Test Corridor, presents results and lessons-learned, and documents the relative capability of AMS to support benefit-...

Corridors Increase Plant Species Richness at Large Scales

DOE Office of Scientific and Technical Information (OSTI.GOV)

Damschen, Ellen I.; Haddad, Nick M.; Orrock,John L.

2006-09-01

Habitat fragmentation is one of the largest threats to biodiversity. Landscape corridors, which are hypothesized to reduce the negative consequences of fragmentation, have become common features of ecological management plans worldwide. Despite their popularity, there is little evidence documenting the effectiveness of corridors in preserving biodiversity at large scales. Using a large-scale replicated experiment, we showed that habitat patches connected by corridors retain more native plant species than do isolated patches, that this difference increases over time, and that corridors do not promote invasion by exotic species. Our results support the use of corridors in biodiversity conservation.

Corridors increase plant species richness at large scales.

PubMed

Damschen, Ellen I; Haddad, Nick M; Orrock, John L; Tewksbury, Joshua J; Levey, Douglas J

2006-09-01

Habitat fragmentation is one of the largest threats to biodiversity. Landscape corridors, which are hypothesized to reduce the negative consequences of fragmentation, have become common features of ecological management plans worldwide. Despite their popularity, there is little evidence documenting the effectiveness of corridors in preserving biodiversity at large scales. Using a large-scale replicated experiment, we showed that habitat patches connected by corridors retain more native plant species than do isolated patches, that this difference increases over time, and that corridors do not promote invasion by exotic species. Our results support the use of corridors in biodiversity conservation.

Observations of particulates within the North Atlantic Flight Corridor: POLINAT 2, September-October 1997

NASA Astrophysics Data System (ADS)

Paladino, J. D.; Hagen, D. E.; Whitefield, P. D.; Hopkins, A. R.; Schmid, O.; Wilson, M. R.; Schlager, H.; Schulte, P.

2000-02-01

This paper discusses participate concentration and size distribution data gathered using the University of Missouri-Rolla Mobile Aerosol Sampling System (UMR-MASS), and used to investigate the southern extent of the eastern end of the North Atlantic Flight Corridor (NAFC) during project Pollution From Aircraft Emissions in the North Atlantic Flight Corridor/Subsonic Assessment (SASS) Ozone and Nitrogen Oxide Experiment (POLINAT 2/SONEX) from September 19 to October 23, 1997. The analysis presented in this paper focuses on "the corridor effect," or enhancement of pollutants by jet aircraft combustion events. To investigate the phenomena, both vertical and horizontal profiles of the corridor, and regions immediately adjacent to the corridor, were performed. The profiles showed a time-dependent enhancement of particulates within the corridor, and a nonvolatile (with respect to thermal volatilization at 300°C) aerosol enhancement at corridor altitudes by a factor of 3.6. The southern extent of the North Atlantic Flight Corridor was established from a four flight average of the particulate data and yielded a boundary near 42.5°N during the study period. A size distribution analysis of the nonvolatile particulates revealed an enhancement in the <40 nm particulates for size distributions recorded within the flight corridor.

Environmental effects of maritime traffic on the Istanbul Strait.

PubMed

Birpinar, Mehmet E; Talu, Gonca F; Gönençgil, Barbaros

2009-05-01

The Istanbul Strait, which separates the European and the Asian parts of Istanbul, is one of the narrowest straits in the world that is used for international shipping. The Strait has very special ecological conditions in terms of marine environment (atmospheric/oceanographic conditions, plant and animal diversity) and terrestrial environment. It also has roles as biological corridor and biological barrier between the Mediterranean Sea and the Black Sea and form an acclimatization zone for migrating species. Due to being the only maritime access for the neighboring Black Sea states and the Central Asian Turki Republics, the Istanbul Strait has been exposed to dense marine traffic for centuries and substantial increase has occurred in size and tonnage of the ships passing through the Strait with hazardous cargo varieties and amounts they carry. Increase in the number of vessels that navigates on the Strait and being on the transportation way of hazardous and dangerous materials pose serious environmental and safety hazards for the Istanbul Strait, Marmara Sea and the surrounding residential areas. Geographic and oceanographic features of the Istanbul Strait makes the navigation on the Strait rather difficult and consequently the Strait has faced many casualties that caused severe environmental problems due to thousands tons of oil spill occurring in recent decades.

Indoor Navigation Design Integrated with Smart Phones and Rfid Devices

NASA Astrophysics Data System (ADS)

Ortakci, Y.; Demiral, E.; Atila, U.; Karas, I. R.

2015-10-01

High rise, complex and huge buildings in the cities are almost like a small city with their tens of floors, hundreds of corridors and rooms and passages. Due to size and complexity of these buildings, people need guidance to find their way to the destination in these buildings. In this study, a mobile application is developed to visualize pedestrian's indoor position as 3D in their smartphone and RFID Technology is used to detect the position of pedestrian. While the pedestrian is walking on his/her way on the route, smartphone will guide the pedestrian by displaying the photos of indoor environment on the route. Along the tour, an RFID (Radio-Frequency Identification) device is integrated to the system. The pedestrian will carry the RFID device during his/her tour in the building. The RFID device will send the position data to the server directly in every two seconds periodically. On the other side, the pedestrian will just select the destination point in the mobile application on smartphone and sent the destination point to the server. The shortest path from the pedestrian position to the destination point is found out by the script on the server. This script also sends the environment photo of the first node on the acquired shortest path to the client as an indoor navigation module.

Oil pipeline corridor through an intact forest alters ground beetle (Coleoptera: Carabidae) assemblages in southeastern Ohio.

PubMed

Silverman, Bareena; Horn, David J; Purrington, Foster F; Gandhi, Kamal J K

2008-06-01

Litter-dwelling ground beetle (Coleoptera: Carabidae) assemblages were monitored 1 yr after the construction of a corridor for installation of an oil pipeline along a xeric ridge-top forest in southeastern Ohio. After the creation of the corridor, three distinct habitats were evident in these sites: open corridor, ecotone areas around the corridor, and undisturbed forest interior. Carabidae were collected using directional pitfall traps that were placed parallel and perpendicular to the corridor in each of the three habitats. Results indicate that more carabids were present in the ecotone than in the other two habitats. Carabid diversity as estimated by rarefaction was highest in the corridor followed by ecotone and forest interior. Generalist and forest specialists such as Synuchus impunctatus (Say), Carabus goryi Dejean, and Pterostichus trinarius (Casey) were present in greater numbers in the forest interior and ecotone assemblages. In contrast, open-habitat specialists such as Harpalus pensylvanicus (DeGeer) and Selenophorus opalinus (LeConte) were present in greater numbers in the corridor assemblages. Carabid assemblages of the corridor were distinct from those of the ecotone and forest interior, whereas the latter two habitats had very similar assemblages. The successional pathway of the corridor carabid assemblage will therefore be likely different from that of the forest interior and ecotone. Overall, results indicate that construction of the oil pipeline corridor had significant short-term effects on the carabid numbers, diversity, and species composition because of ensuing habitat changes and fragmentation of the forest.

Integrated corridor management initiative : demonstration phase evaluation – Dallas corridor performance analysis test plan.

DOT National Transportation Integrated Search

2012-08-01

This report presents the test plan for conducting the Corridor Performance Analysis for the United States Department of Transportation (U.S. DOT) evaluation of the Dallas U.S. 75 Integrated Corridor Management (ICM) Initiative Demonstration. The ICM ...

Integrated corridor management initiative : demonstration phase evaluation – San Diego corridor performance analysis test plan.

DOT National Transportation Integrated Search

2012-08-01

This report presents the test plan for conducting the Corridor Performance Analysis for the United States Department of Transportation (U.S. DOT) evaluation of the San Diego Integrated Corridor Management (ICM) Initiative Demonstration. The ICM proje...

20. Readiness Crew Building interior, upper level corridor. This corridor ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. Readiness Crew Building interior, upper level corridor. This corridor runs from northwest to southeast. Photograph taken at the northwest end looking southeast. Lyon - Whiteman Air Force Base, Bomber Alert Facility S-6, 1300 Alert Road, Knob Noster, Johnson County, MO

Research notes : are safety corridors really safe? Evaluation of the corridor safety improvement program.

DOT National Transportation Integrated Search

1998-08-26

High accident frequencies on Oregons highway corridors are of concern to the Oregon Department of Transportation (ODOT). : ODOT adopted the Corridor Safety Improvement Program as part of an overall program of safety improvements using federal and ...

Reinforcement learning in scheduling

NASA Technical Reports Server (NTRS)

Dietterich, Tom G.; Ok, Dokyeong; Zhang, Wei; Tadepalli, Prasad

1994-01-01

The goal of this research is to apply reinforcement learning methods to real-world problems like scheduling. In this preliminary paper, we show that learning to solve scheduling problems such as the Space Shuttle Payload Processing and the Automatic Guided Vehicle (AGV) scheduling can be usefully studied in the reinforcement learning framework. We discuss some of the special challenges posed by the scheduling domain to these methods and propose some possible solutions we plan to implement.

FRACOR-software toolbox for deterministic mapping of fracture corridors in oil fields on AutoCAD platform

NASA Astrophysics Data System (ADS)

Ozkaya, Sait I.

2018-03-01

Fracture corridors are interconnected large fractures in a narrow sub vertical tabular array, which usually traverse entire reservoir vertically and extended for several hundreds of meters laterally. Fracture corridors with their huge conductivities constitute an important element of many fractured reservoirs. Unlike small diffuse fractures, actual fracture corridors must be mapped deterministically for simulation or field development purposes. Fracture corridors can be identified and quantified definitely with borehole image logs and well testing. However, there are rarely sufficient image logs or well tests, and it is necessary to utilize various fracture corridor indicators with varying degrees of reliability. Integration of data from many different sources, in turn, requires a platform with powerful editing and layering capability. Available commercial reservoir characterization software packages, with layering and editing capabilities, can be cost intensive. CAD packages are far more affordable and may easily acquire the versatility and power of commercial software packages with addition of a small software toolbox. The objective of this communication is to present FRACOR, a software toolbox which enables deterministic 2D fracture corridor mapping and modeling on AutoCAD platform. The FRACOR toolbox is written in AutoLISPand contains several independent routines to import and integrate available fracture corridor data from an oil field, and export results as text files. The resulting fracture corridor maps consists mainly of fracture corridors with different confidence levels from combination of static and dynamic data and exclusion zones where no fracture corridor can exist. The exported text file of fracture corridors from FRACOR can be imported into an upscaling programs to generate fracture grid for dual porosity simulation or used for field development and well planning.

Effects of weighting schemes on the identification of wildlife corridors generated with least-cost methods.

PubMed

Parks, Sean A; McKelvey, Kevin S; Schwartz, Michael K

2013-02-01

The importance of movement corridors for maintaining connectivity within metapopulations of wild animals is a cornerstone of conservation. One common approach for determining corridor locations is least-cost corridor (LCC) modeling, which uses algorithms within a geographic information system to search for routes with the lowest cumulative resistance between target locations on a landscape. However, the presentation of multiple LCCs that connect multiple locations generally assumes all corridors contribute equally to connectivity, regardless of the likelihood that animals will use them. Thus, LCCs may overemphasize seldom-used longer routes and underemphasize more frequently used shorter routes. We hypothesize that, depending on conservation objectives and available biological information, weighting individual corridors on the basis of species-specific movement, dispersal, or gene flow data may better identify effective corridors. We tested whether locations of key connectivity areas, defined as the highest 75th and 90th percentile cumulative weighted value of approximately 155,000 corridors, shift under different weighting scenarios. In addition, we quantified the amount and location of private land that intersect key connectivity areas under each weighting scheme. Some areas that appeared well connected when analyzed with unweighted corridors exhibited much less connectivity compared with weighting schemes that discount corridors with large effective distances. Furthermore, the amount and location of key connectivity areas that intersected private land varied among weighting schemes. We believe biological assumptions and conservation objectives should be explicitly incorporated to weight corridors when assessing landscape connectivity. These results are highly relevant to conservation planning because on the basis of recent interest by government agencies and nongovernmental organizations in maintaining and enhancing wildlife corridors, connectivity will likely be an important criterion for prioritization of land purchases and swaps. ©2012 Society for Conservation Biology.

Large-Scale Habitat Corridors for Biodiversity Conservation: A Forest Corridor in Madagascar

PubMed Central

Ramiadantsoa, Tanjona; Ovaskainen, Otso; Rybicki, Joel; Hanski, Ilkka

2015-01-01

In biodiversity conservation, habitat corridors are assumed to increase landscape-level connectivity and to enhance the viability of otherwise isolated populations. While the role of corridors is supported by empirical evidence, studies have typically been conducted at small spatial scales. Here, we assess the quality and the functionality of a large 95-km long forest corridor connecting two large national parks (416 and 311 km2) in the southeastern escarpment of Madagascar. We analyze the occurrence of 300 species in 5 taxonomic groups in the parks and in the corridor, and combine high-resolution forest cover data with a simulation model to examine various scenarios of corridor destruction. At present, the corridor contains essentially the same communities as the national parks, reflecting its breadth which on average matches that of the parks. In the simulation model, we consider three types of dispersers: passive dispersers, which settle randomly around the source population; active dispersers, which settle only in favorable habitat; and gap-avoiding active dispersers, which avoid dispersing across non-habitat. Our results suggest that long-distance passive dispersers are most sensitive to ongoing degradation of the corridor, because increasing numbers of propagules are lost outside the forest habitat. For a wide range of dispersal parameters, the national parks are large enough to sustain stable populations until the corridor becomes severely broken, which will happen around 2065 if the current rate of forest loss continues. A significant decrease in gene flow along the corridor is expected after 2040, and this will exacerbate the adverse consequences of isolation. Our results demonstrate that simulation studies assessing the role of habitat corridors should pay close attention to the mode of dispersal and the effects of regional stochasticity. PMID:26200351

Evaluating Landscape Options for Corridor Restoration between Giant Panda Reserves

PubMed Central

Wang, Fang; McShea, William J.; Wang, Dajun; Li, Sheng; Zhao, Qing; Wang, Hao; Lu, Zhi

2014-01-01

The establishment of corridors can offset the negative effects of habitat fragmentation by connecting isolated habitat patches. However, the practical value of corridor planning is minimal if corridor identification is not based on reliable quantitative information about species-environment relationships. An example of this need for quantitative information is planning for giant panda conservation. Although the species has been the focus of intense conservation efforts for decades, most corridor projects remain hypothetical due to the lack of reliable quantitative researches at an appropriate spatial scale. In this paper, we evaluated a framework for giant panda forest corridor planning. We linked our field survey data with satellite imagery, and conducted species occupancy modelling to examine the habitat use of giant panda within the potential corridor area. We then conducted least-cost and circuit models to identify potential paths of dispersal across the landscape, and compared the predicted cost under current conditions and alternative conservation management options considered during corridor planning. We found that due to giant panda's association with areas of low elevation and flat terrain, human infrastructures in the same area have resulted in corridor fragmentation. We then identified areas with high potential to function as movement corridors, and our analysis of alternative conservation scenarios showed that both forest/bamboo restoration and automobile tunnel construction would significantly improve the effectiveness of corridor, while residence relocation would not significantly improve corridor effectiveness in comparison with the current condition. The framework has general value in any conservation activities that anticipate improving habitat connectivity in human modified landscapes. Specifically, our study suggested that, in this landscape, automobile tunnels are the best means to remove current barriers to giant panda movements caused by anthropogenic interferences. PMID:25133757

Trade-offs and efficiencies in optimal budget-constrained multispecies corridor networks.

PubMed

Dilkina, Bistra; Houtman, Rachel; Gomes, Carla P; Montgomery, Claire A; McKelvey, Kevin S; Kendall, Katherine; Graves, Tabitha A; Bernstein, Richard; Schwartz, Michael K

2017-02-01

Conservation biologists recognize that a system of isolated protected areas will be necessary but insufficient to meet biodiversity objectives. Current approaches to connecting core conservation areas through corridors consider optimal corridor placement based on a single optimization goal: commonly, maximizing the movement for a target species across a network of protected areas. We show that designing corridors for single species based on purely ecological criteria leads to extremely expensive linkages that are suboptimal for multispecies connectivity objectives. Similarly, acquiring the least-expensive linkages leads to ecologically poor solutions. We developed algorithms for optimizing corridors for multispecies use given a specific budget. We applied our approach in western Montana to demonstrate how the solutions may be used to evaluate trade-offs in connectivity for 2 species with different habitat requirements, different core areas, and different conservation values under different budgets. We evaluated corridors that were optimal for each species individually and for both species jointly. Incorporating a budget constraint and jointly optimizing for both species resulted in corridors that were close to the individual species movement-potential optima but with substantial cost savings. Our approach produced corridors that were within 14% and 11% of the best possible corridor connectivity for grizzly bears (Ursus arctos) and wolverines (Gulo gulo), respectively, and saved 75% of the cost. Similarly, joint optimization under a combined budget resulted in improved connectivity for both species relative to splitting the budget in 2 to optimize for each species individually. Our results demonstrate economies of scale and complementarities conservation planners can achieve by optimizing corridor designs for financial costs and for multiple species connectivity jointly. We believe that our approach will facilitate corridor conservation by reducing acquisition costs and by allowing derived corridors to more closely reflect conservation priorities. © 2016 Society for Conservation Biology.

Trade-offs and efficiencies in optimal budget-constrained multispecies corridor networks

USGS Publications Warehouse

Dilkina, Bistra; Houtman, Rachel; Gomes, Carla P.; Montgomery, Claire A.; McKelvey, Kevin; Kendall, Katherine; Graves, Tabitha A.; Bernstein, Richard; Schwartz, Michael K.

2017-01-01

Conservation biologists recognize that a system of isolated protected areas will be necessary but insufficient to meet biodiversity objectives. Current approaches to connecting core conservation areas through corridors consider optimal corridor placement based on a single optimization goal: commonly, maximizing the movement for a target species across a network of protected areas. We show that designing corridors for single species based on purely ecological criteria leads to extremely expensive linkages that are suboptimal for multispecies connectivity objectives. Similarly, acquiring the least-expensive linkages leads to ecologically poor solutions. We developed algorithms for optimizing corridors for multispecies use given a specific budget. We applied our approach in western Montana to demonstrate how the solutions may be used to evaluate trade-offs in connectivity for 2 species with different habitat requirements, different core areas, and different conservation values under different budgets. We evaluated corridors that were optimal for each species individually and for both species jointly. Incorporating a budget constraint and jointly optimizing for both species resulted in corridors that were close to the individual species movement-potential optima but with substantial cost savings. Our approach produced corridors that were within 14% and 11% of the best possible corridor connectivity for grizzly bears (Ursus arctos) and wolverines (Gulo gulo), respectively, and saved 75% of the cost. Similarly, joint optimization under a combined budget resulted in improved connectivity for both species relative to splitting the budget in 2 to optimize for each species individually. Our results demonstrate economies of scale and complementarities conservation planners can achieve by optimizing corridor designs for financial costs and for multiple species connectivity jointly. We believe that our approach will facilitate corridor conservation by reducing acquisition costs and by allowing derived corridors to more closely reflect conservation priorities.

Large-Scale Habitat Corridors for Biodiversity Conservation: A Forest Corridor in Madagascar.

PubMed

Ramiadantsoa, Tanjona; Ovaskainen, Otso; Rybicki, Joel; Hanski, Ilkka

2015-01-01

In biodiversity conservation, habitat corridors are assumed to increase landscape-level connectivity and to enhance the viability of otherwise isolated populations. While the role of corridors is supported by empirical evidence, studies have typically been conducted at small spatial scales. Here, we assess the quality and the functionality of a large 95-km long forest corridor connecting two large national parks (416 and 311 km2) in the southeastern escarpment of Madagascar. We analyze the occurrence of 300 species in 5 taxonomic groups in the parks and in the corridor, and combine high-resolution forest cover data with a simulation model to examine various scenarios of corridor destruction. At present, the corridor contains essentially the same communities as the national parks, reflecting its breadth which on average matches that of the parks. In the simulation model, we consider three types of dispersers: passive dispersers, which settle randomly around the source population; active dispersers, which settle only in favorable habitat; and gap-avoiding active dispersers, which avoid dispersing across non-habitat. Our results suggest that long-distance passive dispersers are most sensitive to ongoing degradation of the corridor, because increasing numbers of propagules are lost outside the forest habitat. For a wide range of dispersal parameters, the national parks are large enough to sustain stable populations until the corridor becomes severely broken, which will happen around 2065 if the current rate of forest loss continues. A significant decrease in gene flow along the corridor is expected after 2040, and this will exacerbate the adverse consequences of isolation. Our results demonstrate that simulation studies assessing the role of habitat corridors should pay close attention to the mode of dispersal and the effects of regional stochasticity.

Evaluating landscape options for corridor restoration between giant panda reserves.

PubMed

Wang, Fang; McShea, William J; Wang, Dajun; Li, Sheng; Zhao, Qing; Wang, Hao; Lu, Zhi

2014-01-01

The establishment of corridors can offset the negative effects of habitat fragmentation by connecting isolated habitat patches. However, the practical value of corridor planning is minimal if corridor identification is not based on reliable quantitative information about species-environment relationships. An example of this need for quantitative information is planning for giant panda conservation. Although the species has been the focus of intense conservation efforts for decades, most corridor projects remain hypothetical due to the lack of reliable quantitative researches at an appropriate spatial scale. In this paper, we evaluated a framework for giant panda forest corridor planning. We linked our field survey data with satellite imagery, and conducted species occupancy modelling to examine the habitat use of giant panda within the potential corridor area. We then conducted least-cost and circuit models to identify potential paths of dispersal across the landscape, and compared the predicted cost under current conditions and alternative conservation management options considered during corridor planning. We found that due to giant panda's association with areas of low elevation and flat terrain, human infrastructures in the same area have resulted in corridor fragmentation. We then identified areas with high potential to function as movement corridors, and our analysis of alternative conservation scenarios showed that both forest/bamboo restoration and automobile tunnel construction would significantly improve the effectiveness of corridor, while residence relocation would not significantly improve corridor effectiveness in comparison with the current condition. The framework has general value in any conservation activities that anticipate improving habitat connectivity in human modified landscapes. Specifically, our study suggested that, in this landscape, automobile tunnels are the best means to remove current barriers to giant panda movements caused by anthropogenic interferences.

Population dynamics of Microtus pennsylvanicus in corridor-linked patches

USGS Publications Warehouse

Coffman, C.J.; Nichols, J.D.; Pollock, K.H.

2001-01-01

Corridors have become a key issue in the discussion of conservation planning: however, few empirical data exist on the use of corridors and their effects on population dynamics. The objective of this replicated, population level, capture-re-capture experiment on meadow voles was to estimate and compare population characteristics of voles between (1) corridor-linked fragments, (2) isolated or non-linked fragments, and (3) unfragmented areas. We conducted two field experiments involving 22600 captures of 5700 individuals. In the first, the maintained corridor study, corridors were maintained at the time of fragmentation, and in the second, the constructed corridor study, we constructed corridors between patches that had been fragmented for some period of time. We applied multistate capture-recapture models with the robust design to estimate adult movement and survival rates, population size, temporal variation in population size, recruitment, and juvenile survival rates. Movement rates increased to a greater extent on constructed corridor-linked grids than on the unfragmented or non-linked fragmented grids between the pre- and post-treatment periods. We found significant differences in local survival on the treated (corridor-linked) grids compared to survival on the fragmented and unfragmented grids between the pre- and post-treatment periods. We found no clear pattern of treatment effects on population size or recruitment in either study. However, in both studies, we found that unfragmented grids were more stable than the fragmented grids based on lower temporal variability in population size. To our knowledge, this is the first experimental study demonstrating that corridors constructed between existing fragmented populations can indeed cause increases in movement and associated changes in demography, supporting the use of constructed corridors for this purpose in conservation biology.

76 FR 72029 - Multistate Corridor Operations and Management Program

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-21

... in the FHWA Multistate Corridor Operations and Management Program as authorized in 23 U.S.C. 511... Multistate Corridor Operations and Management Program as authorized in 23 U.S.C. 511. This notice clarifies... DEPARTMENT OF TRANSPORTATION Federal Highway Administration Multistate Corridor Operations and...

76 FR 3695 - Environmental Impact Statement: Interstate 64 Corridor, Virginia

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-20

...: Interstate 64 Corridor, Virginia AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice of Intent... Transportation for potential transportation improvements along the Interstate 64 corridor in Virginia. FOR... improvements along the Interstate 64 corridor in Virginia. The approximate limits of the study are Interstate...

45 CFR 153.530 - Risk corridors data requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 153.530 Public Welfare Department of Health and Human Services REQUIREMENTS RELATING TO HEALTH CARE ACCESS STANDARDS RELATED TO REINSURANCE, RISK CORRIDORS, AND RISK ADJUSTMENT UNDER THE AFFORDABLE CARE ACT Health Insurance Issuer Standards Related to the Risk Corridors Program § 153.530 Risk corridors...

45 CFR 153.530 - Risk corridors data requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 153.530 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS STANDARDS RELATED TO REINSURANCE, RISK CORRIDORS, AND RISK ADJUSTMENT UNDER THE AFFORDABLE CARE ACT Health Insurance Issuer Standards Related to the Risk Corridors Program § 153.530 Risk corridors...

45 CFR 153.530 - Risk corridors data requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 153.530 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS STANDARDS RELATED TO REINSURANCE, RISK CORRIDORS, AND RISK ADJUSTMENT UNDER THE AFFORDABLE CARE ACT Health Insurance Issuer Standards Related to the Risk Corridors Program § 153.530 Risk corridors...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sullivan, Lauren, L.; Johnson, Brenda, L.; Brudvig, Lars, A.

Habitat corridors, a common management strategy for increasing connectivity in fragmented landscapes, have experimentally validated positive influences on species movement and diversity. However, long-standing concerns that corridors could negatively impact native species by spreading antagonists, such as disease, remain largely untested. Using a large-scale, replicated experiment, we evaluated whether corridors increase the incidence of plant parasites. We found that corridor impacts varied with parasite dispersal mode. Connectivity provided by corridors increased incidence of biotically dispersed parasites (galls on Solidago odora) but not of abiotically dispersed parasites (foliar fungi on S. odora and three Lespedeza spp.). Both biotically and abiotically dispersedmore » parasites responded to edge effects, but the direction of responses varied across species. Although our results require additional tests for generality to other species and landscapes, they suggest that, when establishing conservation corridors, managers should focus on mitigating two potential negative effects: the indirect effects of narrow corridors in creating edges and direct effects of corridors in enhancing connectivity of biotically dispersed parasites.« less

Effectiveness of a regional corridor in connecting two Florida black bear populations.

PubMed

Dixon, Jeremy D; Oli, Madan K; Wooten, Michael C; Eason, Thomas H; McCown, J Walter; Paetkau, David

2006-02-01

Corridors may mitigate the adverse effects of habitat fragmentation by restoring or maintaining connectivity between disjunct populations. The efficacy of corridors for large carnivores, however has rarely been evaluated objectively. We used noninvasive sampling, microsatellite analysis, and population assignment tests to evaluate the effectiveness of a regional corridor in connecting two Florida black bear (Ursus americanus floridanus) populations (Osceola and Ocala). Bear movement was predominantly unidirectional, with a limited mixing of individuals from the two populations in one area of the corridor We also documented bears in Osceola that were genetically assigned to Ocala and bears in Osceola that may be offspring from an Osceola-Ocala mating. Our results indicate that the Osceola-Ocala corridor is functional and provides a conduit for gene flow between these populations. Human development, however may hinder the use of the Osceola-Ocala corridor by bears. The noninvasive sampling and genetic methods we used provide a means of evaluating corridor effectiveness that can help identify linkages necessary for maintaining metapopulation structure and population viability.

Mortality patterns among residents in Louisiana's industrial corridor, USA, 1970–99

PubMed Central

Tsai, S; Cardarelli, K; Wendt, J; Fraser, A

2004-01-01

Background: Because of the high concentration of oil refining and petrochemical facilities, the industrial area of the lower Mississippi River of South Louisiana has been termed the Industrial Corridor and has frequently been referred to as the "Cancer Corridor". Aims: To quantitatively assess the "Cancer Corridor" controversy based on mortality data available in the public domain, and to identify potential contributing factors to the observed differences in mortality. Methods: Age adjusted mortality rates were calculated for white and non-white males and females in the Industrial Corridor, Louisiana, and the United States for the time periods 1970–79, 1980–89, and 1990–99. Results: All-cause mortality and all cancer combined for white males in the Industrial Corridor were significantly lower than the corresponding Louisiana population while Louisiana had significantly higher rates than the US population for all three time periods. Cancer of the lung was consistently higher in the Industrial Corridor region relative to national rates but lower than or similar to Louisiana. Non-respiratory disease and cerebrovascular disease mortality for white males in the Industrial Corridor were consistently lower than either Louisiana or the USA. However, mortality due to diabetes and heart disease, particularly during the 1990s, was significantly higher in the Industrial Corridor and Louisiana when compared to the USA. Similar mortality patterns were observed for white females. The mortality for non-white males and females in the Industrial Corridor was generally similar to the corresponding populations in Louisiana. There were no consistent patterns for all cancer mortality combined. Stomach cancer was increased among non-whites in both the Industrial Corridor and Louisiana when compared to the corresponding US data. Mortality from diabetes and heart disease among non-whites was significantly higher in the Industrial Corridor and Louisiana than in the USA. Conclusions: Mortality rates in the Industrial Corridor area were generally similar to or lower than the State of Louisiana, which were increased compared to the United States. Contrary to prior public perceptions, mortality due to cancer in the Industrial Corridor does not exceed that for the State of Louisiana. PMID:15031386

Connecting science, policy, and implementation for landscape-scale habitat connectivity.

PubMed

Brodie, Jedediah F; Paxton, Midori; Nagulendran, Kangayatkarasu; Balamurugan, G; Clements, Gopalasamy Reuben; Reynolds, Glen; Jain, Anuj; Hon, Jason

2016-10-01

We examined the links between the science and policy of habitat corridors to better understand how corridors can be implemented effectively. As a case study, we focused on a suite of landscape-scale connectivity plans in tropical and subtropical Asia (Malaysia, Singapore, and Bhutan). The process of corridor designation may be more efficient if the scientific determination of optimal corridor locations and arrangement is synchronized in time with political buy-in and establishment of policies to create corridors. Land tenure and the intactness of existing habitat in the region are also important to consider because optimal connectivity strategies may be very different if there are few, versus many, political jurisdictions (including commercial and traditional land tenures) and intact versus degraded habitat between patches. Novel financing mechanisms for corridors include bed taxes, payments for ecosystem services, and strategic forest certifications. Gaps in knowledge of effective corridor design include an understanding of how corridors, particularly those managed by local communities, can be protected from degradation and unsustainable hunting. There is a critical need for quantitative, data-driven models that can be used to prioritize potential corridors or multicorridor networks based on their relative contributions to long-term metacommunity persistence. © 2016 Society for Conservation Biology.

Suprachiasmatic translamina terminalis corridor used in endoscopic endonasal approach for resecting third ventricular craniopharyngioma.

PubMed

Gu, Ye; Zhang, Xiaobiao; Hu, Fan; Yu, Yong; Xie, Tao; Sun, Chongjing; Li, Wensheng

2015-05-01

The translamina terminalis corridor was used in the transcranial anterior route to treat third ventricular craniopharyngioma (TVC), which presents a challenge to neurosurgeons. The endoscopic endonasal approach (EEA) has recently been used to treat craniopharyngiomas. However, there are few reports of the EEA being used to treat TVC. The authors' novel surgical approach of treating selected TVC by the endoscopic endonasal route via the suprachiasmatic translamina terminalis (STLT) corridor is described. In this single-center study, the EEA via the STLT corridor was used to resect TVC with great upper and anterior extension causing bulged lamina terminalis, and TVC with a residual upper compartment, after routine infrachiasmatic transmetastalk corridor resection. The STLT corridor was used in 3 patients. Gross-total resection was achieved in all cases. One patient achieved visual improvement, and the other 2 patients showed partial visual improvement. Leakage of CSF occurred in 1 patient. Postoperative hormone replacement therapy was required in all patients. The STLT corridor is a complementary minimally invasive corridor used in the EEA for treating selected TVC. The STLT alone or combined with infrachiasmatic transmetastalk corridors should be selected depending on the size of suprachiasmatic and infrachiasmatic space.

Effects of Pleistocene environmental changes on the distribution and community structure of the mammalian fauna of Mexico

NASA Astrophysics Data System (ADS)

Ceballos, Gerardo; Arroyo-Cabrales, Joaquín; Ponce, Eduardo

2010-05-01

Biological communities in Mexico experienced profound changes in species composition and structure as a consequence of the environmental fluctuations during the Pleistocene. Based on the recent and fossil Mexican mammal checklists, we determine the distribution, composition, diversity, and community structure of late Pleistocene mammalian faunas, and analyze extinction patterns and response of individual species to environmental changes. We conclude that (1) differential extinctions occurred at family, genus, and species level, with a major impact on species heavier than 100 kg, including the extinction all proboscideans and several ruminants; (2) Pleistocene mammal communities in Mexico were more diverse than recent ones; and (3) the current assemblages of species are relatively young. Furthermore, Pleistocene relicts support the presence of biogeographic corridors; important refugia existed as well as centers of speciation in isolated regions. We identified seven corridors: eastern USA-Sierra Madre Oriental corridor, Rocky Mountains-Sierra Madre Occidental corridor, Central United States-Northern Mexico corridor, Transvolcanic Belt-Sierra Madre del Sur corridor, western USA-Baja California corridor, Tamaulipas-Central America gulf lowlands corridor, and Sonora-Central America Pacific lowlands corridor. Our study suggests that present mammalian assemblages are very different than the ones in the late Pleistocene.

Secure corridor for infraacetabular screws in acetabular fracture fixation-a 3-D radiomorphometric analysis of 124 pelvic CT datasets.

PubMed

Arlt, Stephan; Noser, Hansrudi; Wienke, Andreas; Radetzki, Florian; Hofmann, Gunther Olaf; Mendel, Thomas

2018-05-21

Acetabular fracture surgery is directed toward anatomical reduction and stable fixation to allow for the early functional rehabilitation of an injured hip joint. Recent biomechanical investigations have shown the superiority of using an additional screw in the infraacetabular (IA) region, thereby transfixing the separated columns to strengthen the construct by closing the periacetabular fixation frame. However, the inter-individual existence and variance concerning secure IA screw corridors are poorly understood. This computer-aided 3-D radiomorphometric study examined 124 CT Digital Imaging and Communications in Medicine (DICOM) datasets of intact human pelves (248 acetabula) to visualize the spatial IA corridors as the sum of all intraosseous screw positions. DICOM files were pre-processed using the Amira® 4.2 visualization software. Final corridor computation was accomplished using a custom-made software algorithm. The volumetric measurement data of each corridor were calculated for further statistical analyses. Correlations between the volumetric values and the biometric data were investigated. Furthermore, the influence of hip dysplasia on the IA corridor configuration was analyzed. The IA corridors consistently showed a double-cone shape with the isthmus located at the acetabular fovea. In 97% of male and 91% of female acetabula, a corridor for a 3.5-mm screw could be found. The number of IA corridors was significantly lower in females for screw diameters ≥ 4.5 mm. The mean 3.5-mm screw corridor volume was 16 cm 3 in males and 9.2 cm 3 in female pelves. Corridor volumes were significantly positively correlated with body height and weight and with the diameter of Köhler's teardrop on standard AP pelvic X-rays. No correlation was observed between hip dysplasia and the IA corridor extent. IA corridors are consistently smaller in females. However, 3.5-mm small fragment screws may still be used as the standard implant because sex-specific differences are significant only with screw diameters ≥ 4.5 mm. Congenital hip dysplasia does not affect secure IA screw insertion. The described method allows 3-D shape analyses with highly reliable results. The visualization of secure IA corridors may support the spatial awareness of surgeons. Volumetric data allow the reliable assessment of individual IA corridors using standard AP X-ray views, which aids preoperative planning.

An experimental test of whether habitat corridors affect pollen transfer.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Townsend, Patricia A.; Levey, Douglas J.

Abstract. Negative effects of habitat fragmentation are thought to be diminished when habitat patches are joined by a corridor. A key assumption is that corridors facilitate exchange rates of organisms between otherwise isolated patches. If the organisms are pollinators, corridors may be important for maintaining genetically viable populations of the plants that they pollinate. We tested the hypothesis that corridors increase the movement of insect pollinators into patches of habitat and thereby increase pollen transfer for two species of plants, one pollinated by butterflies (Lantana camara) and the other by bees and wasps (Rudbeckia hirta). We worked in an experimentalmore » landscape consisting of 40 greater than or equal to 1-ha patches of early-successional habitat in a matrix of forest. Within each of eight experimental units, two patches were connected by a corridor (150 X 25 m), and three were not. Patch shape varied to control for the area added by the presence of a corridor. Differences in patch shape also allowed us to test alternative hypotheses of how corridors might function. The Traditional Corridor Hypothesis posits that corridors increase immigration and emigration by functioning as movement conduits between patches. The Drift Fence Hypothesis posits that corridors function by ‘‘capturing’’ organisms dispersing through the matrix, redirecting them into associated habitat patches. Using fluorescent powder to track pollen, we found that pollen transfer by butterflies between patches connected by a corridor was significantly higher than between unconnected patches (all values mean plus or minus 1 SE: 59% plus or minus 9.2% vs. 25% plus or minus 5.2% of flowers receiving pollen). Likewise, pollen transfer by bees and wasps was significantly higher between connected patches than between unconnected patches (30% plus or minus 4.2% vs. 14.5% plus or minus 2.2%). These results support the Traditional Corridor Hypothesis. There was little support, however, for the Drift Fence Hypothesis. To generalize our results to a larger scale, we measured the probability of pollen transfer by butterflies as a function of distance along a 2000 X 75 m corridor. Pollen transfer probability exponentially declined with respect to distance and successfully predicted pollen transfer probability on the scale of our previous experiment. These results suggest that corridors facilitate pollen transfer in fragmented landscapes.« less

45 CFR 800.204 - Reinsurance, risk corridors, and risk adjustment.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 3 2013-10-01 2013-10-01 false Reinsurance, risk corridors, and risk adjustment... Adjustment § 800.204 Reinsurance, risk corridors, and risk adjustment. (a) Transitional reinsurance program... transitional reinsurance program for the individual market. (b) Temporary risk corridors program. An MSPP...

45 CFR 800.204 - Reinsurance, risk corridors, and risk adjustment.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 3 2014-10-01 2014-10-01 false Reinsurance, risk corridors, and risk adjustment... Adjustment § 800.204 Reinsurance, risk corridors, and risk adjustment. (a) Transitional reinsurance program... transitional reinsurance program for the individual market. (b) Temporary risk corridors program. An MSPP...

UNICOR: a species connectivity and corridor network simulator

Treesearch

E. L. Landguth; B. K. Hand; J. Glassy; S. A. Cushman; M. A. Sawaya

2012-01-01

We introduce UNIversal CORridor network simulator (UNICOR), a species connectivity and corridor identifi cation tool. UNICOR applies Dijkstra's shortest path algorithm to individual-based simulations. Outputs can be used to designate movement corridors, identify isolated populations, and prioritize conservation plans to promote species persistence. The key...

China Pakistan Economic Corridor (CPEC): Benefits For Pakistan And Comparison With Suez And Panama Canals

DTIC Science & Technology

2017-12-01

ECONOMIC CORRIDOR (CPEC): BENEFITS FOR PAKISTAN AND COMPARISON WITH SUEZ AND PANAMA CANALS by Hanif Ullah Khan December 2017 Thesis...DATE December 2017 3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE CHINA PAKISTAN ECONOMIC CORRIDOR (CPEC): BENEFITS FOR...The China Pakistan Economic Corridor (CPEC) is part of China’s “One Belt, One Road” initiative and joins two major economic corridors: The Silk Road

Identification of functional corridors with movement characteristics of brown bears on the Kenai Peninsula, Alaska

USGS Publications Warehouse

Graves, T.A.; Farley, S.; Goldstein, M.I.; Servheen, C.

2007-01-01

We identified primary habitat and functional corridors across a landscape using Global Positioning System (GPS) collar locations of brown bears (Ursus arctos). After deriving density, speed, and angular deviation of movement, we classified landscape function for a group of animals with a cluster analysis. We described areas with high amounts of sinuous movement as primary habitat patches and areas with high amounts of very directional, fast movement as highly functional bear corridors. The time between bear locations and scale of analysis influenced the number and size of corridors identified. Bear locations should be collected at intervals ???6 h to correctly identify travel corridors. Our corridor identification technique will help managers move beyond the theoretical discussion of corridors and linkage zones to active management of landscape features that will preserve connectivity. ?? 2007 Springer Science+Business Media, Inc.

Designing large-scale conservation corridors for pattern and process.

PubMed

Rouget, Mathieu; Cowling, Richard M; Lombard, Amanda T; Knight, Andrew T; Kerley, Graham I H

2006-04-01

A major challenge for conservation assessments is to identify priority areas that incorporate biological patterns and processes. Because large-scale processes are mostly oriented along environmental gradients, we propose to accommodate them by designing regional-scale corridors to capture these gradients. Based on systematic conservation planning principles such as representation and persistence, we identified large tracts of untransformed land (i.e., conservation corridors) for conservation that would achieve biodiversity targets for pattern and process in the Subtropical Thicket Biome of South Africa. We combined least-cost path analysis with a target-driven algorithm to identify the best option for capturing key environmental gradients while considering biodiversity targets and conservation opportunities and constraints. We identified seven conservation corridors on the basis of subtropical thicket representation, habitat transformation and degradation, wildlife suitability, irreplaceability of vegetation types, protected area networks, and future land-use pressures. These conservation corridors covered 21.1% of the planning region (ranging from 600 to 5200 km2) and successfully achieved targets for biological processes and to a lesser extent for vegetation types. The corridors we identified are intended to promote the persistence of ecological processes (gradients and fixed processes) and fulfill half of the biodiversity pattern target. We compared the conservation corridors with a simplified corridor design consisting of a fixed-width buffer along major rivers. Conservation corridors outperformed river buffers in seven out of eight criteria. Our corridor design can provide a tool for quantifying trade-offs between various criteria (biodiversity pattern and process, implementation constraints and opportunities). A land-use management model was developed to facilitate implementation of conservation actions within these corridors.

Dispersal corridors for plant species in the Poyang Lake Basin of southeast China identified by integration of phylogeographic and geospatial data.

PubMed

Fan, Dengmei; Sun, Zhixia; Li, Bo; Kou, Yixuan; Hodel, Richard G J; Jin, Zhinong; Zhang, Zhiyong

2017-07-01

Measuring the dispersal of wildlife through landscapes is notoriously difficult. Recently, the categorical least cost path algorithm that integrates population genetic data with species distribution models has been applied to reveal population connectivity. In this study, we use this method to identify the possible dispersal corridors of five plant species ( Castanopsis tibetana , Schima superba , Cyclocarya paliurus , Sargentodoxa cuneata , Eomecon chionantha ) in the Poyang Lake Basin (PLB, largely coinciding with Jiangxi Province), China, in the late Quaternary. The results showed that the strongest population connectivity for the five species occurred in the Wuyi Mountains and the Yu Mountains of the eastern PLB (East Corridor) during the late Quaternary. In the western PLB, populations of the five species were connected by the Luoxiao Mountains and the Jiuling Mountains (West Corridor) but with a lower degree of connectivity. There were some minor connections between the eastern and the western populations across the Gannan Hills. When the corridors of five species were overlaid, the East Corridor and the West Corridor were mostly shared by multiple species. These results indicate that plant species in the PLB could have responded to the Quaternary climate changes by moving along the East Corridor and the West Corridor. Given that dispersal corridors have seldom been considered in the governmental strategies of biodiversity conservation in the PLB, preserving and restoring natural vegetation along these corridors should be prioritized to mitigate the effects of anthropogenic climate change by facilitating migration of plant species and other biota.

Bison phylogeography constrains dispersal and viability of the Ice Free Corridor in western Canada

PubMed Central

Froese, Duane; Ives, John W.; Zazula, Grant D.; Letts, Brandon; Andrews, Thomas D.; Driver, Jonathan C.; Hall, Elizabeth; Hare, P. Gregory; Jass, Christopher N.; MacKay, Glen; Southon, John R.; Stiller, Mathias; Woywitka, Robin; Suchard, Marc A.

2016-01-01

The Ice Free Corridor has been invoked as a route for Pleistocene human and animal dispersals between eastern Beringia and more southerly areas of North America. Despite the significance of the corridor, there are limited data for when and how this corridor was used. Hypothetical uses of the corridor include: the first expansion of humans from Beringia into the Americas, northward postglacial expansions of fluted point technologies into Beringia, and continued use of the corridor as a contact route between the north and south. Here, we use radiocarbon dates and ancient mitochondrial DNA from late Pleistocene bison fossils to determine the chronology for when the corridor was open and viable for biotic dispersals. The corridor was closed after ∼23,000 until 13,400 calendar years ago (cal y BP), after which we find the first evidence, to our knowledge, that bison used this route to disperse from the south, and by 13,000 y from the north. Our chronology supports a habitable and traversable corridor by at least 13,000 cal y BP, just before the first appearance of Clovis technology in interior North America, and indicates that the corridor would not have been available for significantly earlier southward human dispersal. Following the opening of the corridor, multiple dispersals of human groups between Beringia and interior North America may have continued throughout the latest Pleistocene and early Holocene. Our results highlight the utility of phylogeographic analyses to test hypotheses about paleoecological history and the viability of dispersal routes over time. PMID:27274051

Bison phylogeography constrains dispersal and viability of the Ice Free Corridor in western Canada.

PubMed

Heintzman, Peter D; Froese, Duane; Ives, John W; Soares, André E R; Zazula, Grant D; Letts, Brandon; Andrews, Thomas D; Driver, Jonathan C; Hall, Elizabeth; Hare, P Gregory; Jass, Christopher N; MacKay, Glen; Southon, John R; Stiller, Mathias; Woywitka, Robin; Suchard, Marc A; Shapiro, Beth

2016-07-19

The Ice Free Corridor has been invoked as a route for Pleistocene human and animal dispersals between eastern Beringia and more southerly areas of North America. Despite the significance of the corridor, there are limited data for when and how this corridor was used. Hypothetical uses of the corridor include: the first expansion of humans from Beringia into the Americas, northward postglacial expansions of fluted point technologies into Beringia, and continued use of the corridor as a contact route between the north and south. Here, we use radiocarbon dates and ancient mitochondrial DNA from late Pleistocene bison fossils to determine the chronology for when the corridor was open and viable for biotic dispersals. The corridor was closed after ∼23,000 until 13,400 calendar years ago (cal y BP), after which we find the first evidence, to our knowledge, that bison used this route to disperse from the south, and by 13,000 y from the north. Our chronology supports a habitable and traversable corridor by at least 13,000 cal y BP, just before the first appearance of Clovis technology in interior North America, and indicates that the corridor would not have been available for significantly earlier southward human dispersal. Following the opening of the corridor, multiple dispersals of human groups between Beringia and interior North America may have continued throughout the latest Pleistocene and early Holocene. Our results highlight the utility of phylogeographic analyses to test hypotheses about paleoecological history and the viability of dispersal routes over time.

43 CFR 2802.11 - How does BLM designate corridors?

Code of Federal Regulations, 2013 CFR

2013-10-01

... air, water, soil, fish, wildlife, and vegetation; (3) Physical effects and constraints on corridor... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false How does BLM designate corridors? 2802.11... POLICY MANAGEMENT ACT Lands Available for FLPMA Grants § 2802.11 How does BLM designate corridors? (a...

43 CFR 2802.11 - How does BLM designate corridors?

Code of Federal Regulations, 2012 CFR

2012-10-01

... air, water, soil, fish, wildlife, and vegetation; (3) Physical effects and constraints on corridor... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false How does BLM designate corridors? 2802.11... POLICY MANAGEMENT ACT Lands Available for FLPMA Grants § 2802.11 How does BLM designate corridors? (a...

43 CFR 2802.11 - How does BLM designate corridors?

Code of Federal Regulations, 2011 CFR

2011-10-01

... air, water, soil, fish, wildlife, and vegetation; (3) Physical effects and constraints on corridor... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false How does BLM designate corridors? 2802.11... POLICY MANAGEMENT ACT Lands Available for FLPMA Grants § 2802.11 How does BLM designate corridors? (a...

Analysis of Florida Department of Transportation transit corridor program/projects : technical memorandum number one - review and summary of transit corridor plans

DOT National Transportation Integrated Search

2001-05-01

The purpose of this project was to undertake a consolidated comprehensive review of the Florida Department of Transportation Transit Corridor Program. Technical Memorandum Number One provides a summary of all transit corridor projects either under wa...

14 CFR 93.321 - Transfer and termination of allocations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... commercial air tours outside the Dragon and Zuni Point corridors may not be transferred into the Dragon and Zuni Point corridors. Allocations authorizing commercial air tours within the Dragon and Zuni Point corridors may be transferred outside of the Dragon and Zuni Point corridors. (iii) A certificate holder must...

14 CFR 93.321 - Transfer and termination of allocations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... commercial air tours outside the Dragon and Zuni Point corridors may not be transferred into the Dragon and Zuni Point corridors. Allocations authorizing commercial air tours within the Dragon and Zuni Point corridors may be transferred outside of the Dragon and Zuni Point corridors. (iii) A certificate holder must...

46 CFR 92.10-30 - Dead end corridors.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Dead end corridors. 92.10-30 Section 92.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 92.10-30 Dead end corridors. (a) Dead end corridors, or the...

46 CFR 92.10-30 - Dead end corridors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Dead end corridors. 92.10-30 Section 92.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 92.10-30 Dead end corridors. (a) Dead end corridors, or the...

46 CFR 92.10-30 - Dead end corridors.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Dead end corridors. 92.10-30 Section 92.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 92.10-30 Dead end corridors. (a) Dead end corridors, or the...

46 CFR 108.161 - Dead end corridors.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Dead end corridors. 108.161 Section 108.161 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.161 Dead end corridors. No dead end corridor...

46 CFR 108.161 - Dead end corridors.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Dead end corridors. 108.161 Section 108.161 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.161 Dead end corridors. No dead end corridor...

46 CFR 108.161 - Dead end corridors.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Dead end corridors. 108.161 Section 108.161 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.161 Dead end corridors. No dead end corridor...

46 CFR 92.10-30 - Dead end corridors.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Dead end corridors. 92.10-30 Section 92.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 92.10-30 Dead end corridors. (a) Dead end corridors, or the...

46 CFR 108.161 - Dead end corridors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Dead end corridors. 108.161 Section 108.161 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.161 Dead end corridors. No dead end corridor...

46 CFR 92.10-30 - Dead end corridors.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Dead end corridors. 92.10-30 Section 92.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 92.10-30 Dead end corridors. (a) Dead end corridors, or the...

46 CFR 108.161 - Dead end corridors.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Dead end corridors. 108.161 Section 108.161 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.161 Dead end corridors. No dead end corridor...

4. Corridor B. Perspective of west side as viewed from ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Corridor B. Perspective of west side as viewed from roof of Building No. 9982. The flat-roof building that joins Corridor B is Building No. 9981, Receiving and Evacuation Building. - Madigan Hospital, Corridors & Ramps, Bounded by Wilson & McKinley Avenues & Garfield & Lincoln Streets, Tacoma, Pierce County, WA

14 CFR 93.321 - Transfer and termination of allocations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... commercial air tours outside the Dragon and Zuni Point corridors may not be transferred into the Dragon and Zuni Point corridors. Allocations authorizing commercial air tours within the Dragon and Zuni Point corridors may be transferred outside of the Dragon and Zuni Point corridors. (iii) A certificate holder must...

14 CFR 93.321 - Transfer and termination of allocations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... commercial air tours outside the Dragon and Zuni Point corridors may not be transferred into the Dragon and Zuni Point corridors. Allocations authorizing commercial air tours within the Dragon and Zuni Point corridors may be transferred outside of the Dragon and Zuni Point corridors. (iii) A certificate holder must...

Integrated corridor management : analysis, modeling, and simulation for the U.S.-75 corridor in Dallas, Texas – post-deployment assessment report.

DOT National Transportation Integrated Search

2016-11-01

The U.S. Department of Transportation Integrated Corridor Management (ICM) Initiative aims to advance the state of the practice in transportation corridor operations to manage congestion. Through the deployment of ICM at the two selected Demonstratio...

Integrated corridor management analysis, modeling, and simulation for the I-15 corridor in San Diego, California post-deployment assessment report.

DOT National Transportation Integrated Search

2016-12-01

The U.S. Department of Transportation Integrated Corridor Management (ICM) Initiative aims to advance the state of the practice in transportation corridor operations to manage congestion. Through the deployment of ICM at the two selected Demonstratio...

Corridor Length and Patch Colonization by a Butterfly, Junonia coenia

Treesearch

Nick Haddad

2000-01-01

Corridors have been proposed to reduce isolation and increase population persistence in fragmented landscapes, yet little research has evaluated the types of landscapes in which corridors will be most effective. I tested the hypothesis that corridors increase patch colonization by a butterfly, Junonia coenia, regardless of the butterfly's...

77 FR 55265 - Environmental Impact Statement for the Northeast Corridor Between Washington, DC, New York, NY...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-07

... the Northeast Corridor Between Washington, DC, New York, NY, and Boston, MA AGENCY: Federal Railroad... ). SUPPLEMENTARY INFORMATION: FRA is leading the planning and environmental evaluation of the Northeast Corridor (NEC) in close coordination with the involved states, Northeast Corridor Infrastructure and Operations...

76 FR 29290 - Environmental Impact Statement: Interstate 64 Hampton Roads Bridge Tunnel Corridor, Virginia

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-20

...: Interstate 64 Hampton Roads Bridge Tunnel Corridor, Virginia AGENCY: Federal Highway Administration (FHWA... Interstate 64 Hampton Roads Bridge Tunnel (HRBT) corridor in Virginia. FOR FURTHER INFORMATION CONTACT... Interstate 64 Hampton Roads Bridge Tunnel (HRBT) corridor in Virginia. The approximate limits of the study...

A novel flexible microfluidic meshwork to reduce fibrosis in glaucoma surgery.

PubMed

Amoozgar, Behzad; Wei, Xiaoling; Hui Lee, Jun; Bloomer, Michele; Zhao, Zhengtuo; Coh, Paul; He, Fei; Luan, Lan; Xie, Chong; Han, Ying

2017-01-01

Fibrosis and hence capsule formation around the glaucoma implants are the main reasons for glaucoma implant failure. To address these issues, we designed a microfluidic meshwork and tested its biocompatibility in a rabbit eye model. The amount of fibrosis elicited by the microfluidic meshwork was compared to the amount elicited by the plate of conventional glaucoma drainage device. Six eyes from 3 New Zealand albino rabbits were randomized to receive either the novel microfluidic meshwork or a plate of Ahmed glaucoma valve model PF7 (AGV PF7). The flexible microfluidic implant was made from negative photoresist SU-8 by using micro-fabrication techniques. The overall size of the meshwork was 7 mm × 7 mm with a grid period of 100 μm. Both implants were placed in the subtenon space at the supratemporal quadrant in a standard fashion. There was no communication between the implants and the anterior chamber via a tube. All animal eyes were examined for signs of infection and implant erosion on days 1, 3, 7, and 14 and then monthly. Exenterations were performed in which the entire orbital contents were removed at 3 months. Histology slides of the implant and the surrounding tissues were prepared and stained with hematoxylin-eosin. Thickness of the fibrous capsules beneath the implants were measured and compared with paired student's t-test between the two groups. The gross histological sections showed that nearly no capsule formed around the microfluidic meshwork in contrast to the thick capsule formed around the plate of AGV PF7. Thickness of the fibrotic capsules beneath the AGV PF7 plate from the 3 rabbit eyes was 90μm, 82μm, and 95 μm, respectively. The thickness at the bottom of fibrotic capsules around the new microfluidic implant were 1μm, 2μm, and 1μm, respectively. The difference in thickness of capsule between the two groups was significant (P = 0.002). No complications were noticed in the 6 eyes, and both implants were tolerated well by all rabbits. The microfluidic meshwork elicited minimal fibrosis and capsule formation after 3-months implantation in a rabbit model. This provides promising evidence to aid in future development of a new glaucoma drainage implant that will elicit minimal scar formation and provide better long-term surgical outcomes.

How Corridors Reduce Indigo Bunting Nest Success.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weldon, Aimee, J.

2006-08-01

Abstract: Corridors are a popular strategy to conserve biodiversity and promote gene flow in fragmented landscapes. Corridor effectiveness has been bolstered by the fact that no empirical field studies have shown negative effects on populations or communities. I tested the hypothesis that corridors increase nest predation in connected habitat fragments relative to unconnected fragments. I evaluated this hypothesis in a large-scale experimental system of open-habitat fragments that varied in shape and connectivity. Corridors increased nest predation rates in connected fragments relative to unconnected fragments with lower edge:area ratios. Nest predation rates were similar between connected and unconnected fragments with highermore » edge:area ratios. These results suggest that the increase in predator activity is largely attributable to edge effects incurred through the addition of a corridor. This is the first field study to demonstrate that corridors can negatively impact animal populations occupying connected fragments.« less

Towards a definition of biological corridor

Treesearch

D.K. Rosenberg; B.R. Noon; E.C. Meslow

1995-01-01

Lack of clear, unambiguous criteria that distinguishes a linear habitat patch as a corridor contributes to controversy over the value of corridors for wildlife conservation. The definitions of biological corridors have been vague or inconsistent, and often they confound form and function. Explicit criteria that can differentiate between a linear habitat patch and a...

46 CFR 190.10-30 - Dead end corridors.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Dead end corridors. 190.10-30 Section 190.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 190.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more...

46 CFR 190.10-30 - Dead end corridors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Dead end corridors. 190.10-30 Section 190.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 190.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more...

46 CFR 72.10-30 - Dead end corridors.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 3 2010-10-01 2010-10-01 false Dead end corridors. 72.10-30 Section 72.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 72.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more than 40...

46 CFR 72.10-30 - Dead end corridors.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 3 2013-10-01 2013-10-01 false Dead end corridors. 72.10-30 Section 72.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 72.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more than 40...

46 CFR 190.10-30 - Dead end corridors.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Dead end corridors. 190.10-30 Section 190.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 190.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more...

46 CFR 72.10-30 - Dead end corridors.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 3 2012-10-01 2012-10-01 false Dead end corridors. 72.10-30 Section 72.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 72.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more than 40...

46 CFR 190.10-30 - Dead end corridors.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Dead end corridors. 190.10-30 Section 190.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 190.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more...

46 CFR 72.10-30 - Dead end corridors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 3 2011-10-01 2011-10-01 false Dead end corridors. 72.10-30 Section 72.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 72.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more than 40...

46 CFR 190.10-30 - Dead end corridors.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Dead end corridors. 190.10-30 Section 190.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 190.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more...

46 CFR 72.10-30 - Dead end corridors.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 3 2014-10-01 2014-10-01 false Dead end corridors. 72.10-30 Section 72.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 72.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more than 40...

View looking south along the main corridor on the third ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View looking south along the main corridor on the third floor of the south wing. The openings along the top of the corridor walls allowed for the movement of air and light between the corridor and the resident rooms. - U. S. Naval Asylum, Biddle Hall, Gray's Ferry Avenue, Philadelphia, Philadelphia County, PA

24. Interior view of entrance corridor looking down east corridor; ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

24. Interior view of entrance corridor looking down east corridor; showing unoccupied corner office space and stairs going down to lower floor; center of main section of building on main floor; view to northeast. - Ellsworth Air Force Base, Group Administration & Secure Storage Building, 2372 Westover Avenue, Blackhawk, Meade County, SD

76 FR 31009 - Iowa Northern Railway Company-Operation Exemption-North Central Iowa Rail Corridor, LLC

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-27

... Railway Company--Operation Exemption--North Central Iowa Rail Corridor, LLC Iowa Northern Railway Company...) Docket No. FD 35507, North Central Iowa Rail Corridor, LLC--Acquisition Exemption--Union Pacific Railroad Company, in which North Central Iowa Rail Corridor, LLC seeks to acquire from Union Pacific Railroad...

78 FR 32007 - Environmental Impact Statement for Tulsa-Oklahoma City Passenger Rail Corridor, Oklahoma, Lincoln...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-28

... Environmental Policy Act of 1969 (NEPA) for the State of Oklahoma High-Speed Rail Initiative: Tulsa--Oklahoma... South Central High Speed Rail Corridor and is a federally-designated high-speed rail (HSR) corridor...-Speed Rail Initiative: Tulsa--Oklahoma City Passenger Rail Corridor Investment Plan. The proposed route...

Conservation value of remnant riparian forest corridors of varying quality for amazonian birds and mammals.

PubMed

Lees, Alexander C; Peres, Carlos A

2008-04-01

Forest corridors are often considered the main instrument with which to offset the effects of habitat loss and fragmentation. Brazilian forestry legislation requires that all riparian zones on private landholdings be maintained as permanent reserves and sets fixed minimum widths of riparian forest buffers to be retained alongside rivers and perennial streams. We investigated the effects of corridor width and degradation status of 37 riparian forest sites (including 24 corridors connected to large source-forest patches, 8 unconnected forest corridors, and 5 control riparian zones embedded within continuous forest patches) on bird and mammal species richness in a hyper-fragmented forest landscape surrounding Alta Floresta, Mato Grosso, Brazil. We used point-count and track-sampling methodology, coupled with an intensive forest-quality assessment that combined satellite imagery and ground truthed data. Vertebrate use of corridors was highly species-specific, but broad trends emerged depending on species life histories and their sensitivity to disturbance. Narrow and/or highly disturbed riparian corridors retained only a depauperate vertebrate assemblage that was typical of deforested habitats, whereas wide, well-preserved corridors retained a nearly complete species assemblage. Restriction of livestock movement along riparian buffers and their exclusion from key areas alongside deforested streams would permit corridor regeneration and facilitate restoration of connectivity.

75 FR 45695 - Final Federal Agency Actions on Trans-Texas Corridor 35 (TTC-35) in Texas

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-03

...-Texas Corridor 35 (TTC-35) in Texas AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice...-modal corridor to meet the transportation challenges of the I-35 corridor. EIS No. 20100133. The actions.... Land: Section 4(f) of the Department of Transportation Act of 1966 [49 U.S.C. 303]. 4. Wildlife...

75 FR 64741 - Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-20

... Corridor Commission: Notice of Meeting Notice is hereby given in accordance with Section 552b of Title 5... Corridor Commission will be held on Friday, November 19, 2010. The Commission was established pursuant to... Corridor. The meeting will convene on November 19, 2010 at 9 a.m. at Brigham Hill Community Barn located at...

75 FR 2885 - Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-19

... Corridor Commission: Notice of Meeting Notice is hereby given in accordance with Section 552b of Title 5... Corridor Commission will be held on Thursday, February 25, 2010. The Commission was established pursuant to... Corridor. The meeting will convene on February 25, 2010 at 9 a.m. at the Woonsocket City Hall located at...

14 CFR 93.81 - Applicability and description of area.

Code of Federal Regulations, 2011 CFR

2011-01-01

... as follows: (a) North-South Corridor. The North-South Corridor includes the airspace extending upward...°29′02″ N., Longitude 86°38′02″ W.; to point of beginning. (b) East-West Corridor—The East-West Corridor is divided into three sections to accommodate the different altitudes as portions of the corridor...

14 CFR 93.81 - Applicability and description of area.

Code of Federal Regulations, 2014 CFR

2014-01-01

... as follows: (a) North-South Corridor. The North-South Corridor includes the airspace extending upward...°29′02″ N., Longitude 86°38′02″ W.; to point of beginning. (b) East-West Corridor—The East-West Corridor is divided into three sections to accommodate the different altitudes as portions of the corridor...

14 CFR 93.81 - Applicability and description of area.

Code of Federal Regulations, 2013 CFR

2013-01-01

... as follows: (a) North-South Corridor. The North-South Corridor includes the airspace extending upward...°29′02″ N., Longitude 86°38′02″ W.; to point of beginning. (b) East-West Corridor—The East-West Corridor is divided into three sections to accommodate the different altitudes as portions of the corridor...

14 CFR 93.81 - Applicability and description of area.

Code of Federal Regulations, 2010 CFR

2010-01-01

... as follows: (a) North-South Corridor. The North-South Corridor includes the airspace extending upward...°29′02″ N., Longitude 86°38′02″ W.; to point of beginning. (b) East-West Corridor—The East-West Corridor is divided into three sections to accommodate the different altitudes as portions of the corridor...

14 CFR 93.81 - Applicability and description of area.

Code of Federal Regulations, 2012 CFR

2012-01-01

... as follows: (a) North-South Corridor. The North-South Corridor includes the airspace extending upward...°29′02″ N., Longitude 86°38′02″ W.; to point of beginning. (b) East-West Corridor—The East-West Corridor is divided into three sections to accommodate the different altitudes as portions of the corridor...

75 FR 48359 - Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-10

... Corridor Commission: Notice of Meeting Notice is hereby given in accordance with Section 552b of Title 5... Corridor Commission will be held on Thursday, September 16, 2010. The Commission was established pursuant... waters within the Corridor. The meeting will convene on September 16, 2010 at 9 a.m. at Slater Mill...

18. Readiness Crew Building interior, lower level corridor. This corridor ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

18. Readiness Crew Building interior, lower level corridor. This corridor is located in the southwest side of the building and runs from southeast to northwest; view looking northwest from the exit door at the southeast end. Lyon - Whiteman Air Force Base, Bomber Alert Facility S-6, 1300 Alert Road, Knob Noster, Johnson County, MO

78 FR 52602 - Notice To Rescind a Notice of Intent and Draft Environmental Impact Statement: I-17 Corridor...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-23

... and Draft Environmental Impact Statement: I-17 Corridor Improvement Study; Maricopa County, Arizona... Corridor Improvement Study was published in the Federal Register on January 6, 2010. FOR FURTHER... Corridor is located in the city of Phoenix, and the study area limits for the EIS consisted of...

Effects of weighting schemes on the identification of wildlife corridors generated with least-cost methods

Treesearch

Sean A. Parks; Kevin S. McKelvey; Michael K. Schwartz

2012-01-01

The importance of movement corridors for maintaining connectivity within metapopulations of wild animals is a cornerstone of conservation. One common approach for determining corridor locations is least-cost corridor (LCC) modeling, which uses algorithms within a geographic information system to search for routes with the lowest cumulative resistance between target...

Resection of a Pediatric Thalamic Juvenile Pilocytic Astrocytoma with Whole Brain Tractography

PubMed Central

Weiner, Howard L

2017-01-01

The resection of deep-seated brain tumors has been associated with morbidity due to injury to critical neural structures during the approach. Recent technological advancements in navigation and stereotaxy, surgical planning, brain tractography and minimal-access brain ports present the opportunity to overcome such limitations. Here, we present the case of a pediatric patient with a left thalamic/midbrain juvenile pilocytic astrocytoma (JPA). The tumor displaced the corticospinal fibers posteriorly and resulted in hemiparesis. Using whole brain tractography to plan a corridor for the approach, neuronavigation, a tubular retractor and an exoscope for visualization, we obtained gross total resection of the tumor, while minimizing injury to white matter bundles, including the corticospinal fibers. We propose that surgical planning with whole brain tractography is essential for reducing morbidity while accessing deep-lying brain lesions via retractor tubes, by means of sparing critical fiber tracts. PMID:29234572

China national space remote sensing infrastructure and its application

NASA Astrophysics Data System (ADS)

Li, Ming

2016-07-01

Space Infrastructure is a space system that provides communication, navigation and remote sensing service for broad users. China National Space Remote Sensing Infrastructure includes remote sensing satellites, ground system and related systems. According to the principle of multiple-function on one satellite, multiple satellites in one constellation and collaboration between constellations, series of land observation, ocean observation and atmosphere observation satellites have been suggested to have high, middle and low resolution and fly on different orbits and with different means of payloads to achieve a high ability for global synthetically observation. With such an infrastructure, we can carry out the research on climate change, geophysics global surveying and mapping, water resources management, safety and emergency management, and so on. I This paper gives a detailed introduction about the planning of this infrastructure and its application in different area, especially the international cooperation potential in the so called One Belt and One Road space information corridor.

Critical dimensions of trans-sacral corridors assessed by 3D CT models: Relevance for implant positioning in fractures of the sacrum.

PubMed

Wagner, Daniel; Kamer, Lukas; Sawaguchi, Takeshi; Geoff Richards, R; Noser, Hansrudi; Uesugi, Masafumi; Ossendorf, Christian; Rommens, Pol M

2017-11-01

Trans-sacral implants can be used alternatively to sacro-iliac screws in the treatment of osteoporosis-associated fragility fractures of the pelvis and the sacrum. We investigated trans-sacral corridor dimensions, the number of individuals amenable to trans-sacral fixation, as well as the osseous boundaries and shape of the S1 corridor. 3D models were reconstructed from pelvic CT scans from 92 Europeans and 64 Japanese. A corridor of <12 mm was considered critical for trans-sacral implant positioning, and <8 mm as impossible. A statistical model of trans-sacral corridor S1 was computed. The limiting cranio-caudal diameter was 11.6 mm (±5.4) for S1 and 14 mm (±2.4) for S2. Trans-sacral implant positioning was critical in 52% of cases for S1, and in 21% for S2. The S1 corridor was impossible in 26%, with no impossible corridor in S2. Antero-superiorly, the S1 corridor was limited not only by the sacrum but in 40% by the iliac fossa. The statistical model demonstrated a consistent oval shape of the trans-section of corridor S1. Considering the variable in size and shape of trans-sacral corridors in S1, a thorough anatomical knowledge and preoperative planning are mandatory using trans-sacral implants. In critical cases, S2 is a veritable alternative. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2577-2584, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Strategies for obstacle avoidance during walking in the cat.

PubMed

Chu, Kevin M I; Seto, Sandy H; Beloozerova, Irina N; Marlinski, Vladimir

2017-08-01

Avoiding obstacles is essential for successful navigation through complex environments. This study aimed to clarify what strategies are used by a typical quadruped, the cat, to avoid obstacles during walking. Four cats walked along a corridor 2.5 m long and 25 or 15 cm wide. Obstacles, small round objects 2.5 cm in diameter and 1 cm in height, were placed on the floor in various locations. Movements of the paw were recorded with a motion capture and analysis system (Visualeyez, PTI). During walking in the wide corridor, cats' preferred strategy for avoiding a single obstacle was circumvention, during which the stride direction changed while stride duration and swing-to-stride duration ratio were preserved. Another strategy, stepping over the obstacle, was used during walking in the narrow corridor, when lateral deviations of walking trajectory were restricted. Stepping over the obstacle involved changes in two consecutive strides. The stride preceding the obstacle was shortened, and swing-to-stride ratio was reduced. The obstacle was negotiated in the next stride of increased height and normal duration and swing-to-stride ratio. During walking on a surface with multiple obstacles, both strategies were used. To avoid contact with the obstacle, cats placed the paw away from the object at a distance roughly equal to the diameter of the paw. During obstacle avoidance cats prefer to alter muscle activities without altering the locomotor rhythm. We hypothesize that a choice of the strategy for obstacle avoidance is determined by minimizing the complexity of neuro-motor processes required to achieve the behavioral goal. NEW & NOTEWORTHY In a study of feline locomotor behavior we found that the preferred strategy to avoid a small obstacle is circumvention. During circumvention, stride direction changes but length and temporal structure are preserved. Another strategy, stepping over the obstacle, is used in narrow walkways. During overstepping, two strides adjust. A stride preceding the obstacle decreases in length and duration. The following stride negotiating the obstacle increases in height while retaining normal temporal structure and nearly normal length. Copyright © 2017 the American Physiological Society.

CT scan based determination of optimal bone corridor for atlantoaxial ventral screw fixation in miniature breed dogs.

PubMed

Vizcaíno Revés, Núria; Stahl, Cristina; Stoffel, Michael; Bali, Monty; Forterre, Franck

2013-10-01

To describe the most reliable insertion angle, corridor length and width to place a ventral transarticular atlantoaxial screw in miniature breed dogs. Retrospective CT imaging study. Cervical CT scans of toy breed dogs (n = 21). Dogs were divided into 2 groups--group 1: no atlantoaxial abnormalities; group 2: atlantoaxial instability. Insertion angle in medial to lateral and ventral to dorsal direction was measured in group 1. Corridor length and width were measured in groups 1 and 2. Corridor width was measured at 3 points of the corridor. Each variable was measured 3 times and the mean used for statistical analysis. Mean ± SD optimal transarticular atlantoaxial insertion angle was determined to be 40 ± 1° in medial to lateral direction from the midline and 20 ± 1° in ventral to dorsal direction from the floor of the neural canal of C2. Mean corridor length was 7 mm (range, 4.5-8.0 mm). Significant correlation was found between corridor length, body weight, and age. Mean bone corridor width ranged from 3 to 5 mm. Statistically significant differences were found between individuals, gender and measured side. Optimal placement of a transarticular screw for atlantoaxial joint stabilization is very demanding because the screw path corridor is very narrow. © Copyright 2013 by The American College of Veterinary Surgeons.

75 FR 17756 - Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

... Corridor Commission: Notice of Meeting Notice is hereby given in accordance with Section 552b of Title 5... Corridor Commission will be held on Thursday, May 20, 2010. The Commission was established pursuant to... Corridor. The meeting will convene on May 20, 2010 at 9 a.m. at Atria Draper Place located at 25 Hopedale...

Mapping mountain torrent hazards in the Hexi Corridor using an evidential reasoning approach

NASA Astrophysics Data System (ADS)

Ran, Youhua; Liu, Jinpeng; Tian, Feng; Wang, Dekai

2017-02-01

The Hexi Corridor is an important part of the Silk Road Economic Belt and a crucial channel for westward development in China. Many important national engineering projects pass through the corridor, such as highways, railways, and the West-to-East Gas Pipeline. The frequent torrent disasters greatly impact the security of infrastructure and human safety. In this study, an evidential reasoning approach based on Dempster-Shafer theory is proposed for mapping mountain torrent hazards in the Hexi Corridor. A torrent hazard map for the Hexi Corridor was generated by integrating the driving factors of mountain torrent disasters including precipitation, terrain, flow concentration processes, and the vegetation fraction. The results show that the capability of the proposed method is satisfactory. The torrent hazard map shows that there is high potential torrent hazard in the central and southeastern Hexi Corridor. The results are useful for engineering planning support and resource protection in the Hexi Corridor. Further efforts are discussed for improving torrent hazard mapping and prediction.

Landscape corridors can increase invasion by an exotic species and reduce diversity of native species.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Resasco, Julian; et al,

2014-04-01

Abstract. Landscape corridors are commonly used to mitigate negative effects of habitat fragmentation, but concerns persist that they may facilitate the spread of invasive species. In a replicated landscape experiment of open habitat, we measured effects of corridors on the invasive fire ant, Solenopsis invicta, and native ants. Fire ants have two social forms: polygyne, which tend to disperse poorly but establish at high densities, and monogyne, which disperse widely but establish at lower densities. In landscapes dominated by polygyne fire ants, fire ant abundance was higher and native ant diversity was lower in habitat patches connected by corridors thanmore » in unconnected patches. Conversely, in landscapes dominated by monogyne fire ants, connectivity had no influence on fire ant abundance and native ant diversity. Polygyne fire ants dominated recently created landscapes, suggesting that these corridor effects may be transient. Our results suggest that corridors can facilitate invasion and they highlight the importance of considering species’ traits when assessing corridor utility.« less

Sex-specific differences of the infraacetabular corridor: a biomorphometric CT-based analysis on a database of 523 pelves.

PubMed

Gras, Florian; Gottschling, Heiko; Schröder, Manuel; Marintschev, Ivan; Reimers, Nils; Burgkart, Rainer

2015-01-01

An infraacetabular screw path facilitates the closure of a periacetabular fixation frame to increase the plate fixation strength in acetabular fractures up to 50%. Knowledge of the variance in corridor sizes and axes has substantial surgical relevance for safe screw placement. (1) What proportion of healthy pelvis specimens have an infraacetabular corridor that is 5 mm or larger in diameter? (2) Does a universal corridor axis and specific screw entry point exist? (3) Are there sex-specific differences in the infraacetabular corridor size or axis and are these correlated with anthropometric parameters like age, body weight and height, or the acetabular diameter? A template pelvis with a mean shape from 523 segmented pelvis specimens was generated using a CT-based advanced image analyzing system. Each individual pelvis was registered to the template using a free-form registration algorithm. Feasible surface regions for the entry and exit points of the infraacetabular corridor were marked on the template and automatically mapped to the individual samples to perform a measurement of the maximum sizes and axes of the infraacetabular corridor on each specimen. A minimum corridor diameter of at least 5 mm was defined as a cutoff for placing a 3.5-mm cortical screw in clinical settings. In 484 of 523 pelves (93%), an infraacetabular corridor with a diameter of at least 5 mm was found. Using the mean axis angulations (54.8° [95% confidence interval {CI}, 0.6] from anterocranial to posterocaudal in relation to the anterior pelvic plane and 1.5° [95% CI, 0.4] from anteromedial to posterolateral in relation to the sagittal midline plane), a sufficient osseous corridor was present in 64% of pelves. Allowing adjustment of the three-dimensional axis by another 5° included an additional 25% of pelves. All corridor parameters were different between females and males (corridor diameter, 6.9 [95% CI, 0.2] versus 7.7 [95% CI, 0.2] mm; p<0.001; corridor length, 96.2 [95% CI, 0.7] versus 106.4 [95% CI, 0.6] mm; p<0.001; anterior pelvic plane angle, 54.0° [95% CI, 0.9] versus 55.3° [95% CI, 0.8]; p<0.01; sagittal midline plane angle, 4.3° [95% CI, 0.6] versus -0.3° [95% CI, 0.5]; p<0.001). This study provided reference values for placement of a 3.5-mm cortical screw in the infraacetabular osseous corridor in 90% of female and 94% of male pelves. Based on the sex-related differences in corridor axes, the mean screw trajectory is approximately parallel to the sagittal midline plane in males but has to be tilted from medial to lateral in females. Considering the narrow corridor diameters, we suggest an individual preoperative CT scan analysis for fine adjustments in each patient.

Integrated corridor management : ICM implementation guide

DOT National Transportation Integrated Search

2006-04-12

This Implementation Guidance for Integrated Corridor Management (ICM) has been developed as part of Phase 1 (Foundational Research) for the Federal Highway Administration and the Federal Transit Administration Integrated Corridor Management Initiativ...

Comprehensive highway corridor planning with sustainability indicators.

DOT National Transportation Integrated Search

2011-10-01

"The Maryland State Highway Administration (SHA) has initiated major planning efforts to improve transportation : efficiency, safety, and sustainability on critical highway corridors through its Comprehensive Highway Corridor : (CHC) program. This pr...

Comprehensive highway corridor planning with sustainability indicators.

DOT National Transportation Integrated Search

2013-04-01

The Maryland State Highway Administration (SHA) has initiated major planning efforts to improve transportation : efficiency, safety, and sustainability on critical highway corridors through its Comprehensive Highway Corridor : (CHC) program. This pro...

75 FR 22758 - Intent To Prepare a Draft Environmental Impact Statement for Improvements to the U.S. 17 and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-30

... Environmental Impact Statement for Improvements to the U.S. 17 and Market Street (U.S. 17 Business) Corridor in... and Market Street (U.S. 17 Business) corridor in northern New Hanover and southern Pender Counties... are being evaluated as part of the U.S. 17 Corridor Study. The purpose of the U.S. 17 Corridor Study...

77 FR 74729 - Notice To Rescind a Notice of Intent and Draft Environmental Impact Statement: I-10 Corridor...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-17

... and Draft Environmental Impact Statement: I-10 Corridor Improvement Study; Maricopa County, AZ AGENCY..., Arizona. A NOI to prepare an EIS for the I-10 Corridor Improvement Study was published in the Federal..., Arizona. The I-10 Corridor is in or adjacent to the cities of Phoenix, Tempe, and Chandler, as well as the...

Uncertainty analysis of least-cost modeling for designing wildlife linkages.

PubMed

Beier, Paul; Majka, Daniel R; Newell, Shawn L

2009-12-01

Least-cost models for focal species are widely used to design wildlife corridors. To evaluate the least-cost modeling approach used to develop 15 linkage designs in southern California, USA, we assessed robustness of the largest and least constrained linkage. Species experts parameterized models for eight species with weights for four habitat factors (land cover, topographic position, elevation, road density) and resistance values for each class within a factor (e.g., each class of land cover). Each model produced a proposed corridor for that species. We examined the extent to which uncertainty in factor weights and class resistance values affected two key conservation-relevant outputs, namely, the location and modeled resistance to movement of each proposed corridor. To do so, we compared the proposed corridor to 13 alternative corridors created with parameter sets that spanned the plausible ranges of biological uncertainty in these parameters. Models for five species were highly robust (mean overlap 88%, little or no increase in resistance). Although the proposed corridors for the other three focal species overlapped as little as 0% (mean 58%) of the alternative corridors, resistance in the proposed corridors for these three species was rarely higher than resistance in the alternative corridors (mean difference was 0.025 on a scale of 1 10; worst difference was 0.39). As long as the model had the correct rank order of resistance values and factor weights, our results suggest that the predicted corridor is robust to uncertainty. The three carnivore focal species, alone or in combination, were not effective umbrellas for the other focal species. The carnivore corridors failed to overlap the predicted corridors of most other focal species and provided relatively high resistance for the other focal species (mean increase of 2.7 resistance units). Least-cost modelers should conduct uncertainty analysis so that decision-makers can appreciate the potential impact of model uncertainty on conservation decisions. Our approach to uncertainty analysis (which can be called a worst-case scenario approach) is appropriate for complex models in which distribution of the input parameters cannot be specified.

Solidification Structure Synthesis in Undercooled Liquids

DTIC Science & Technology

1993-10-18

Diagrams 32 1. Supersaturation in Sn-Sb Alloys 32 2. Microstructural Transitions in Fe-Ni alloys 33 E. Droplet Nucleation Kinetics 36 F . Controlled...indicated as - F ,,. The curves correspond to the extrapolation of experimental data (exp.). (b) to the approximation of AGv and TAS=-O by Dubey and...Thermodynamic stability of oxide particles in Sn Oxide A Grxn1 A Grxn2 A F (XmOn) (kJ) (kJ) (°C) AI20 3 +1605 +810 144 TiO- +367 +372 142 Y203 +2119 +1067 136

INTERIOR VIEW, EASTWEST CORRIDOR SEEN THROUGH EAST SIDE ENTRY (NOTE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

INTERIOR VIEW, EAST-WEST CORRIDOR SEEN THROUGH EAST SIDE ENTRY (NOTE GLASS BLOCK TRANSOM PROVIDING LIGHT INTO CORRIDOR) - Greenbelt Community Building, 15 Crescent Road, Greenbelt, Prince George's County, MD

Effective strategies for comprehensive corridor management

DOT National Transportation Integrated Search

2004-10-01

Despite the increasing importance of comprehensive corridor management at the state and local government level, questions remain regarding effective methods for developing and implementing corridor management plans. Further insight is also needed int...

78 FR 23815 - Northeast Corridor Safety Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-22

.... 6] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of the Northeast Corridor Safety Committee (NECSC) Meeting. [[Page 23816

Evaluating the intersection of a regional wildlife connectivity network with highways.

PubMed

Cushman, Samuel A; Lewis, Jesse S; Landguth, Erin L

2013-01-01

Reliable predictions of regional-scale population connectivity are needed to prioritize conservation actions. However, there have been few examples of regional connectivity models that are empirically derived and validated. The central goals of this paper were to (1) evaluate the effectiveness of factorial least cost path corridor mapping on an empirical resistance surface in reflecting the frequency of highway crossings by American black bear, (2) predict the location and predicted intensity of use of movement corridors for American black bear, and (3) identify where these corridors cross major highways and rank the intensity of these crossings. We used factorial least cost path modeling coupled with resistant kernel analysis to predict a network of movement corridors across a 30.2 million hectare analysis area in Montana and Idaho, USA. Factorial least cost path corridor mapping was associated with the locations of actual bear highway crossings. We identified corridor-highway intersections and ranked these based on corridor strength. We found that a major wildlife crossing overpass structure was located close to one of the most intense predicted corridors, and that the vast majority of the predicted corridor network was "protected" under federal management. However, narrow, linear corridors connecting the Greater Yellowstone Ecosystem to the rest of the analysis area had limited protection by federal ownership, making these additionally vulnerable to habitat loss and fragmentation. Factorial least cost path modeling coupled with resistant kernel analysis provides detailed, synoptic information about connectivity across populations that vary in distribution and density in complex landscapes. Specifically, our results could be used to quantify the structure of the connectivity network, identify critical linkage nodes and core areas, map potential barriers and fracture zones, and prioritize locations for mitigation, restoration and conservation actions.

Energy Futures Synthesis for West-Wide Section 368 Energy Corridors

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Neill, Barbara L.; Gagne, Douglas A.; Cook, Jeffrey J.

To comply with Section 368(a) of the Energy Policy Act of 2005 (EPAct), the U.S. Bureau of Land Management (BLM) and the U.S. Forest Service designated 6,000 miles of energy corridors on public and national forest lands in the western United States in 2009. The corridors, commonly referred to as 'West-wide' or 'Section 368' energy corridors, are intended as preferred locations for future siting of electric transmission and distribution lines and for oil, gas, and hydrogen pipelines. In response to a lawsuit filed by several organizations over the corridor designations, the BLM, Forest Service, and the U.S. Department of Energymore » entered into a Settlement Agreement, directing the formation of the Section 368 Interagency Workgroup to periodically review the energy corridors on a regional basis. In conducting the reviews, the Workgroup identifies new, relevant, existing, publicly available information to make recommendations for revisions, deletions, and additions to the Section 368 energy corridors. This report synthesizes information in available contemporary transmission, pipeline, and energy future studies to inform the regional reviews by providing a snapshot of what the western energy and transmission system will look like generally 10-15 years in the future. After an overview of the western grid implications, the analysis narrows to Region 2 and Region 3 of the BLM Section 368 energy corridors and focuses on the implications of potential developments in the oil, natural gas, and electricity markets in Colorado, New Mexico, Utah, and portions of Arizona and Nevada that could inform the current regional review. This analysis will help inform the Workgroup on potential development within existing corridors and the need for new corridors that have not yet been designated.« less

43 CFR 2802.11 - How does BLM designate corridors?

Code of Federal Regulations, 2014 CFR

2014-10-01

... activities located within the proposed right-of-way corridor; (7) Social and economic impacts of the right-of...) Transportation and utility corridor studies previously developed by user groups; and (9) Engineering and...

14 CFR 93.319 - Commercial air tour limitations.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., as applicable: (1) Total SFRA allocations; and (2) Dragon corridor and Zuni Point corridor... minutes east. This exception does not include operation in the Zuni Point corridor. [65 FR 17732, Apr. 4...

North side, enclosed corridor connecting buildings 511 and 515. West ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

North side, enclosed corridor connecting buildings 511 and 515. West side of corridor. - Fitzsimons General Hospital, Infirmary, Northwest Corner of East Bushnell Avenue & South Page Street, Aurora, Adams County, CO

Comprehensive highway corridor planning with sustainability indicators : [research summary].

DOT National Transportation Integrated Search

2013-04-01

The Maryland State Highway Administration (SHA) has initiated major planning : efforts to improve transportation efficiency, safety and sustainability on critical : highway corridors through its Comprehensive Highway Corridor (CHC) program. : It is i...

Corridor incident management (CIM)

DOT National Transportation Integrated Search

2007-09-01

The objective of the Corridor Incident Management (CIM) research project was to develop and demonstrate a set of multi-purpose methods, tools and databases to improve corridor incident management in Tennessee, relying primarily on resources already a...

Multimodal corridor and capacity analysis manual. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1998-12-31

This report presents the results of research carried out under NCHRP Project 8-31, Long-Term Availability of Multimodal Corridor Capacity. The report is presented as a manual on multimodal corridor and capacity analysis. Because transportation-system and corridor capacity for freight and passengers is critical for meeting current and future transportation demand, this manual will provide much needed assistance to a wide range of practitioners, particularly those engaged in performance analysis, capacity management, needs studies, systems planning, and corridor development planning--including major investment studies. It provides information regarding capacity analysis approaches for highways, rail, pipelines, and waterways and presents available options formore » enhancing corridor capacity and performance through various strategies such as new capacity development, freeing up unused capacity, or control of travel demand. Evaluation methods for these options are included.« less

Effect of course length and corridor width on the 2-minute walk test performance in geriatric patients.

PubMed

Lindemann, Ulrich; Beck, Luisa; Becker, Clemens

2017-02-01

To evaluate the effect of course length and corridor width on 2-minute walk test results in older adults. Cross-sectional and experimental study with different test conditions. Geriatric rehabilitation clinic. A total of 21 patients (median age 81 years). Patients walked two minutes on a 20 m and 40 m course with a 2 m or 1 m corridor width and on a continuous course without any turning in a corridor of 2 m width, five walks in total. The distance traveled within the 2 minutes was recorded. Compared with the 20 m course length, median walking distances measured by the 2-minute walk test in a walk way 2 m broad were better on the continuous corridor without any turn (136.9 m vs. 129.3 m, p = 0.002) and on the 40 m course (131.8 m vs. 129.3 m, p = 0.003). Walking distance on a 20 m course length was longer in a corridor of 2 m width compared with the 1 m corridor width (129.3 m vs. 119.2 m, p = 0.005). The walking distance was not affected by corridor width on the 40 m course length. Performance of elderly patients on the 2-minute walk test is influenced by the width of the corridor and the length of the course used.

"Everything Happens in the Hallways": Exploring User Activity in the Corridors at Two Rehabilitation Units.

PubMed

Colley, Jacinta; Zeeman, Heidi; Kendall, Elizabeth

2017-01-01

This research aimed to examine the role of the corridors in specialist inpatient rehabilitation units to inform future design of these spaces. In healthcare settings, such as rehabilitation units, corridors have often been designed simply as spaces allowing movement between other locations. However, research suggests that corridors may be places where important social and care-related activities take place. How corridors are used and understood by patients and staff in inpatient rehabilitation settings is unclear, and a greater understanding of the role of corridors in these settings could help to inform more supportive design of these spaces. Independent observations of user activity were conducted at a major metropolitan inpatient spinal injury unit (SIU) and brain injury unit (BIU). Interviews were conducted with SIU patients ( n = 12), and focus groups were conducted with SIU staff ( n = 23), BIU patients ( n = 12), and BIU staff ( n = 10). Results from the observations showed that the corridors were used frequently across the day, particularly by staff. Thematic analysis of staff and patient experiences found three key themes describing how corridors were used: (1) moving around, (2) delivery and experiences of quality care, and (3) a "spillover space." Results demonstrate that corridors not only have an important role as connective spaces but are also used as flexible, multipurpose spaces for delivery of quality care and patient experiences. Future design should consider how these spaces can more deliberately support and contribute to patient and staff experiences of rehabilitation.

Experiences with Acquiring Highly Redundant Spatial Data to Support Driverless Vehicle Technologies

NASA Astrophysics Data System (ADS)

Koppanyi, Z.; Toth, C. K.

2018-05-01

As vehicle technology is moving towards higher autonomy, the demand for highly accurate geospatial data is rapidly increasing, as accurate maps have a huge potential of increasing safety. In particular, high definition 3D maps, including road topography and infrastructure, as well as city models along the transportation corridors represent the necessary support for driverless vehicles. In this effort, a vehicle equipped with high-, medium- and low-resolution active and passive cameras acquired data in a typical traffic environment, represented here by the OSU campus, where GPS/GNSS data are available along with other navigation sensor data streams. The data streams can be used for two purposes. First, high-definition 3D maps can be created by integrating all the sensory data, and Data Analytics/Big Data methods can be tested for automatic object space reconstruction. Second, the data streams can support algorithmic research for driverless vehicle technologies, including object avoidance, navigation/positioning, detecting pedestrians and bicyclists, etc. Crucial cross-performance analyses on map database resolution and accuracy with respect to sensor performance metrics to achieve economic solution for accurate driverless vehicle positioning can be derived. These, in turn, could provide essential information on optimizing the choice of geospatial map databases and sensors' quality to support driverless vehicle technologies. The paper reviews the data acquisition and primary data processing challenges and performance results.

Is less always better? Keyhole and standard subtemporal approaches: evaluation of temporal lobe retraction and surgical volume with and without zygomatic osteotomy in a cadaveric model.

PubMed

Ercan, Serdar; Scerrati, Alba; Wu, Phengfei; Zhang, Jun; Ammirati, Mario

2017-07-01

OBJECTIVE The subtemporal approach is one of the surgical routes used to reach the interpeduncular fossa. Keyhole subtemporal approaches and zygomatic arch osteotomy have been proposed in an effort to decrease the amount of temporal lobe retraction. However, the effects of these modified subtemporal approaches on temporal lobe retraction have never been objectively validated. METHODS A keyhole and a classic subtemporal craniotomy were executed in 4 fresh-frozen silicone-injected cadaver heads. The target was defined as the area bordered by the superior cerebellar artery, the anterior clinoid process, supraclinoid internal carotid artery, and the posterior cerebral artery. Once the target was fully visualized, the authors evaluated the amount of temporal lobe retraction by measuring the distance between the base of the middle fossa and the temporal lobe. In addition, the volume of the surgical and anatomical corridors was assessed as well as the surgical maneuverability using navigation and 3D moldings. The same evaluation was conducted after a zygomatic osteotomy was added to the two approaches. RESULTS Temporal lobe retraction was the same in the two approaches evaluated while the surgical corridor and the maneuverability were all greater in the classic subtemporal approach. CONCLUSIONS The zygomatic arch osteotomy facilitates the maneuverability and the surgical volume in both approaches, but the temporal lobe retraction benefit is confined to the lateral part of the middle fossa skull base and does not result in the retraction necessary to expose the selected target.

China Pakistan Economic Corridor (CPEC): Challenges and the Way Forward

DTIC Science & Technology

2017-06-01

ECONOMIC CORRIDOR (CPEC): CHALLENGES AND THE WAY FORWARD by Muzaffar Hussain June 2017 Thesis Advisor: Robert E. Looney Second Reader...DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE CHINA PAKISTAN ECONOMIC CORRIDOR (CPEC): CHALLENGES AND THE WAY FORWARD 5. FUNDING NUMBERS...is unlimited. 12b. DISTRIBUTION CODE 13. ABSTRACT The China-Pakistan Economic Corridor (CPEC)—the latest venture in a history of bilateral economic

23 CFR Appendix C to Subpart A of... - Policy for the Signing and Numbering of Future Interstate Corridors Designated by Section 332 of...

Code of Federal Regulations, 2014 CFR

2014-04-01

... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... signs along a federally designated future Interstate corridor only after the specific route location has...

23 CFR Appendix C to Subpart A of... - Policy for the Signing and Numbering of Future Interstate Corridors Designated by Section 332 of...

Code of Federal Regulations, 2011 CFR

2011-04-01

... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... signs along a federally designated future Interstate corridor only after the specific route location has...

23 CFR Appendix C to Subpart A of... - Policy for the Signing and Numbering of Future Interstate Corridors Designated by Section 332 of...

Code of Federal Regulations, 2013 CFR

2013-04-01

... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... signs along a federally designated future Interstate corridor only after the specific route location has...

23 CFR Appendix C to Subpart A of... - Policy for the Signing and Numbering of Future Interstate Corridors Designated by Section 332 of...

Code of Federal Regulations, 2010 CFR

2010-04-01

... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S.C. 139(b... federally designated future Interstate corridor only after the specific route location has been established...

Corridors cause differential seed predation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orrock, John L.; Damschen, Ellen I.

2005-06-01

Orrock, John, L., and Ellen I. Damschen. 2005. Corridors cause differential seed predation. Ecol. Apps. 15(3):793-798. Abstract. Corridors that connect disjunct populations are heavily debated in conservation, largely because the effects of corridors have rarely been evaluated by replicated, large-scale studies. Using large-scale experimental landscapes, we found that, in addition to documented positive effects, corridors also have negative impacts on bird-dispersed plants by affecting seed predation, and that overall predation is a function of the seeds primary consumer (rodents or arthropods). Both large-seeded Prunus serotina and small-seeded Rubus allegheniensis experienced greater predation in connected patches. However, P. serotina experienced significantlymore » less seed predation compared to R. allegheniensis in unconnected patches, due to decreased impacts of rodent seed predators on this large-seeded species. Viewed in light of previous evidence that corridors have beneficial impacts by increasing pollination and seed dispersal, this work demonstrates that corridors may have both positive and negative effects for the same plant species at different life stages. Moreover, these effects may differentially affect plant species within the same community: seeds primarily consumed by rodents suffer less predation in unconnected patches. By shifting the impact of rodent and arthropod seed predators, corridors constructed for plant conservation could lead to shifts in the seed bank.« less

An introduction to issues of habitat fragmentation relative to transportation corridors with special reference to high-speed rail (HSR)

NASA Astrophysics Data System (ADS)

de Santo, Robert S.; Smith, Dwight G.

1993-01-01

Potential environmental impacts on wildlife result from siting and construction (short-term impacts) and habitat removal and fragmentation (long-term impacts) as a consequence of transportation corridor construction. Especially in rural districts, wildlife migration corridors and dispersal orientation are altered or destroyed and wildlife populations and their gene pools are isolated. This significantly weakens the wildlife community. Prudent selection of construction corridors reduces fragmentation impacts by maximizing preserved fragment sizes, and by running parallel to, not through, natural areas. Corridor width determines the degree to which wildlife movement is restricted except that culverts, underpasses, overpasses, and one-way gates, can aid wildlife in cross movements. Minimum underpass dimensions for large wildlife should be no smaller than 14 ft×14 ft and should include natural substratum inverts. Rail corridors have four characteristics that minimize adverse environmental impacts. The railbed is dry, ballast fillters runoff, there is little runoff beyond the toe of slope, and drainage ditches serve to control sheet flow and erosion, sediment movement, and uncontrolled channel flow. Rail corridors usually occupy smaller land areas because they are narrower and are more feasible to elevate so as to allow free movement of wildlife across the corridor.

Identifying transit corridors for elephant using a long time-series

NASA Astrophysics Data System (ADS)

Pittiglio, Claudia; Skidmore, Andrew K.; van Gils, Hein A. M. J.; Prins, Herbert H. T.

2012-02-01

The role of corridors in mitigating the effects of landscape fragmentation on biodiversity is controversial. Recent studies have highlighted the need for new approaches in corridor design using long-term datasets. We present a method to identify transit corridors for elephant at a population scale over a large area and an extended period of time using long-term aerial surveys. We investigated environmental and anthropogenic factors directly and indirectly related to the wet versus dry season distribution of elephant and its transit corridors. Four environmental variables predicted the presence of elephant at the landscape scale in both seasons: distance from permanent water, protected areas and settlements and vegetation structure. Path analysis revealed that altitude and monthly average NDVI, and distance from temporary water had a significant indirect effect on elephant distribution at local scale in dry and wet seasons respectively. Five transit corridors connecting Tarangire National Park and the northern as well as south-eastern wet season dispersal areas were identified and matched the wildlife migration routes described in the 1960s. The corridors are stable over the decades, providing landscape connectivity for elephant. Our approach yielded insights how advanced spatial analysis can be integrated with biological data available from long-term datasets to identify actual transit corridors and predictors of species distribution.

The role of green corridors for wildlife conservation in urban landscape: A literature review

NASA Astrophysics Data System (ADS)

Aziz, H. A.; Rasidi, M. H.

2014-02-01

Green corridors are an attempt to mitigate negative effects of the built environment of cities and towns. The corridors act as conservation for rapidly extreme intervention and development of the urban environment. Most importantly, it enables dispersal movement of animals within city areas. Issues relate to wildlife conservation in urban areas has been studied for many years and thus, the research makes a review for how the green corridors contribute to the conservation of urban wildlife. This study reviews groups of articles in disciplines of urban landscape planning and biology conservation to discuss the relationship between elements of green corridors and urban wildlife dispersal movement behaviour in Malaysian context. Accordingly, this research is purposely studied to give understanding on how green corridors contribute to the animals' ability of moving and dispersing within the built-up areas. In advance, it is found that there are three factors contribute to the capability of colonization among urban wildlife which are individual, physical and social factor. Green corridor has been defined as one of the physical factor that influence urban wildlife behaviour movement. Consequently, safety area indicating to animals species for traversing in any time such as at night can be defined as the primary potential corridor.

Maglev guideway route alignment and right-of-way requirements

NASA Astrophysics Data System (ADS)

Carlton, S.; Andriola, T.

1992-12-01

The use of existing rights-of-way (ROW) is assessed for maglev systems by estimating trip times and land acquisition requirements for potential maglev corridors while meeting passenger comfort limits. Right-of-way excursions improve trip time but incur a cost for purchasing land. The final report documents findings of the eight tasks in establishing right-of-way feasibility by examining three city-pair corridors in detail and developing an approximation method for estimating route length and travel times in 20 additional city-pair corridor portions and 21 new corridors. The use of routes independent of existing railroad or highway right-of-way have trip time advantages and significantly reduce the need for aggressive guideway geometries on intercity corridors. Selection of the appropriate alignment is determined by many corridor specific issues. Use of existing intercity rights-of-way may be appropriate for parts of routes on a corridor-specific basis and for urban penetration where vehicle speeds are likely to be reduced by policy due to noise and safety considerations, and where land acquisition costs are high. Detailed aspects of available rights-of-way, land acquisition costs, geotechnical issues, land use, and population centers must be examined in more detail on a specific corridor basis before the proper or best maglev alignment can be chosen.

The potential of electricity transmission corridors in forested areas as bumblebee habitat.

PubMed

Hill, Bruce; Bartomeus, Ignasi

2016-11-01

Declines in pollinator abundance and diversity are not only a conservation issue, but also a threat to crop pollination. Maintained infrastructure corridors, such as those containing electricity transmission lines, are potentially important wild pollinator habitat. However, there is a lack of evidence comparing the abundance and diversity of wild pollinators in transmission corridors with other important pollinator habitats. We compared the diversity of a key pollinator group, bumblebees ( Bombus spp.), between transmission corridors and the surrounding semi-natural and managed habitat types at 10 sites across Sweden's Uppland region. Our results show that transmission corridors have no impact on bumblebee diversity in the surrounding area. However, transmission corridors and other maintained habitats such as roadsides have a level of bumblebee abundance and diversity comparable to semi-natural grasslands and host species that are important for conservation and ecosystem service provision. Under the current management regime, transmission corridors already provide valuable bumblebee habitat, but given that host plant density is the main determinant of bumblebee abundance, these areas could potentially be enhanced by establishing and maintaining key host plants. We show that in northern temperate regions the maintenance of transmission corridors has the potential to contribute to bumblebee conservation and the ecosystem services they provide.

The potential of electricity transmission corridors in forested areas as bumblebee habitat

PubMed Central

Hill, Bruce

2016-01-01

Declines in pollinator abundance and diversity are not only a conservation issue, but also a threat to crop pollination. Maintained infrastructure corridors, such as those containing electricity transmission lines, are potentially important wild pollinator habitat. However, there is a lack of evidence comparing the abundance and diversity of wild pollinators in transmission corridors with other important pollinator habitats. We compared the diversity of a key pollinator group, bumblebees (Bombus spp.), between transmission corridors and the surrounding semi-natural and managed habitat types at 10 sites across Sweden's Uppland region. Our results show that transmission corridors have no impact on bumblebee diversity in the surrounding area. However, transmission corridors and other maintained habitats such as roadsides have a level of bumblebee abundance and diversity comparable to semi-natural grasslands and host species that are important for conservation and ecosystem service provision. Under the current management regime, transmission corridors already provide valuable bumblebee habitat, but given that host plant density is the main determinant of bumblebee abundance, these areas could potentially be enhanced by establishing and maintaining key host plants. We show that in northern temperate regions the maintenance of transmission corridors has the potential to contribute to bumblebee conservation and the ecosystem services they provide. PMID:28018640

The role of corridors in conservation: Solution or bandwagon?

PubMed

Hobbs, R J

1992-11-01

Corridors are currently a major buzzword in conservation biology and landscape ecology. These linear landscape features may perform numerous functions, but it is their role in facilitating movement of fauna that has attracted much recent debate. The database supporting the idea of corridors acting as faunal conduits is remarkably small, and few studies have actually demonstrated that movement along corridors is important for any given species. Such data are very difficult to obtain, and conservation biologists are thus faced with the problem of whether to recommend the allocation of resources to corridors on the assumption that they may be important. Copyright © 1992. Published by Elsevier Ltd.

Magellan aerobraking periapse corridor design

NASA Technical Reports Server (NTRS)

Cook, Richard A.; Lyons, Daniel T.

1992-01-01

One extended mission idea for the Magellan project uses aerobraking techniques to circularize the current orbit. A major technical issue in this proposal is the design of the periapse altitude corridor. Aerobraking would cause a number of significant side effects on both the spacecraft and ground system. Heating and aerodynamic torques on the spacecraft are key issues, as are the corridor control maneuver frequency and aerobrake duration. Spacecraft and ground systems operational limits have been identified in an attempt to constrain the corridor design. A simulation program has been developed to model the aerobraking corridor control process. This paper presents study results using this program which relate to the feasibility of this aerobraking concept.

Transsacral Osseous Corridor Anatomy Is More Amenable To Screw Insertion In Males: A Biomorphometric Analysis of 280 Pelves.

PubMed

Gras, Florian; Gottschling, Heiko; Schröder, Manuel; Marintschev, Ivan; Hofmann, Gunther O; Burgkart, Rainer

2016-10-01

Percutaneous iliosacral screw placement is the standard procedure for fixation of posterior pelvic ring lesions, although a transsacral screw path is being used more frequently in recent years owing to increased fracture-fixation strength and better ability to fix central and bilateral sacral fractures. However, biomorphometric data for the osseous corridors are limited. Because placement of these screws in a safe and effective manner is crucial to using transsacral screws, we sought to address precise sacral anatomy in more detail to look for anatomic variation in the general population. We asked: (1) What proportion of healthy pelvis specimens have no transsacral corridor at the level of the S1 vertebra owing to sacral dysmorphism? (2) If there is no safe diameter for screw placement in the transsacral S1 corridor, is an increased and thus safe diameter of the transsacral S2 corridor expected? (3) Are there sex-specific differences in sacral anatomy and are these correlated with known anthropometric parameters? CT scans of pelves of 280 healthy patients acquired exclusively for medical indications such as polytrauma (20%), CT angiography (70%), and other reasons (10%), were segmented manually. Using an advanced CT-based image analysis system, the mean shape of all segmented pelves was generated and functioned as a template. On this template, the cylindric transsacral osseous corridor at the level of the S1 and S2 vertebrae was determined manually. Each pelvis then was registered to the template using a free-form registration algorithm to measure the maximum screw corridor diameters on each specimen semiautomatically. Thirty of 280 pelves (11%) had no transsacral S1 corridor owing to sacral dysmorphism. The average of maximum cylindrical diameters of the S1 corridor for the remaining 250 pelves was 12.8 mm (95% CI, 12.1-13.5 mm). A transverse corridor for S2 was found in 279 of 280 pelves, with an average of maximum cylindrical diameter of 11.6 mm (95% CI, 11.3-11.9 mm). Decreasing transsacral S1 corridor diameters are correlated with increasing transsacral S2 corridor diameters (R value for females, -0.260, p < 0.01; for males, -0.311, p < 0.001). Female specimens were more likely to have sacral dysmorphism (defined as a pelvis without a transsacral osseous corridor at the level of the S1 vertebra) than were male specimens (females, 16%; males, 7%; p < 0.003). Furthermore female pelves had smaller-corridor diameters than did male pelves (females versus males for S1: 11.7 mm [95% CI, 10.6-12.8 mm] versus 13.5 mm [95% CI, 12.6-14.4 mm], p < 0.01; and for S2: 10.6 mm [95% CI, 10.1-11.1 mm] versus 12.2 mm [95% CI, 11.8-12.6 mm ], p < 0.0001). Narrow corridors and highly individual, sex-dependent variance of morphologic features of the sacrum make transsacral implant placement technically demanding. Individual preoperative axial-slice CT scan analyses and orthogonal coronal and sagittal reformations are recommended to determine the prevalence of sufficient-sized osseous corridors on both levels for safe screw placements, especially in female patients, owing to their smaller corridor diameters and higher rate of sacral dysmorphism.

3. DODGEVILLE MILL COMPLEX ADJACENT TO NORTHEAST CORRIDOR DODGEVILLE, BRISTOL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. DODGEVILLE MILL COMPLEX ADJACENT TO NORTHEAST CORRIDOR DODGEVILLE, BRISTOL CO., MA. Sec. 4116, MP 195.55. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

1. HEBRONVILLE MILL COMPLEX ADJACENT TO NORTHEAST CORRIDOR. HEBRONVILLE, BRISTOL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. HEBRONVILLE MILL COMPLEX ADJACENT TO NORTHEAST CORRIDOR. HEBRONVILLE, BRISTOL CO., MA. Sec. 4116, MP 193.75. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

Delaware's transportation agenda in the northeast corridor.

DOT National Transportation Integrated Search

2009-10-01

The fractionated governance structure of the entire Northeast Corridor (Warren 2009) is also : evidenced within the Baltimore-to-Philadelphia portion, which contains the entire extent of : Delawares claim to the corridor. Though comprising only a ...

24. View looking north up corridor from Charles Street Bridge. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

24. View looking north up corridor from Charles Street Bridge. Providence, Providence Co., RI. Sec. 4116, mp 186.44. - Northeast Railroad Corridor, Amtrak route between CT & MA state lines, Providence, Providence County, RI

35. OUTER DRAWBRIDGE, ENTRY TO THE PROTECTIVE CORRIDOR BETWEEN THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

35. OUTER DRAWBRIDGE, ENTRY TO THE PROTECTIVE CORRIDOR BETWEEN THE RAVELIN AND THE CASTILLO, AS SEEN FROM WITHIN THE CORRIDOR - Castillo de San Marcos, 1 Castillo Drive, Saint Augustine, St. Johns County, FL

I-95 Corridor Crash Data Reporting Methods

DOT National Transportation Integrated Search

2010-06-01

Access to timely and accurate crash data is essential to improving safety and efficiency on the I-95 Corridor's transportation network. Crash data are used throughout the corridor by law enforcement, departments of transportation, licensing agencies ...

Corridor management and preservation in Texas : 2010 workshops

DOT National Transportation Integrated Search

2010-01-01

2007 RMC Project 05606 : Report 56061, Creating Partnerships with Local Communities to Manage and Preserve Corridors Basis for Workshop; 5606P1, Guidelines on Corridor Management and Preservation; 5606S, Summary Report. Workshop is an ...

ICMS concept of operations for a generic corridor

DOT National Transportation Integrated Search

2006-04-18

This Generic Concept of Operations for Integrated Corridor Management (ICM) has been developed as part of Phase 1 (Foundational Research) for the Federal Highway Administration and the Federal Transit Administration (FHWA/FTA) Integrated Corridor Man...

METHODS FOR MULTI-SPATIAL SCALE CHARACTERIZATION OF RIPARIAN CORRIDORS

EPA Science Inventory

This paper describes the application of aerial photography and GIS technology to develop flexible and transferable methods for multi-spatial scale characterization and analysis of riparian corridors. Relationships between structural attributes of riparian corridors and indicator...

Final report : Dallas Integrated Corridor Management (ICM) Demonstration Project.

DOT National Transportation Integrated Search

2015-08-01

The Dallas Area Rapid Transit (DART) is leading the US-75 Integrated Corridor Management (ICM) Demonstration Project for the Dallas region. Coordinated corridor operations and management is predicated on being able to share transportation information...

Test report : Dallas Integrated Corridor Management (ICM) demonstration project.

DOT National Transportation Integrated Search

2015-05-01

The Dallas Area Rapid Transit (DART) is leading the US 75 Integrated Corridor Management (ICM) Demonstration Project for the Dallas region. Coordinated corridor operations and management is predicated on being able to share transportation information...

23. Looking N up corridor from Chick Interlocking Tower. Boston, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. Looking N up corridor from Chick Interlocking Tower. Boston, Suffolk Co., MA. Sec. 4116, MP 227.09. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

Training plan : Dallas Integrated Corridor Management (ICM) demonstration project.

DOT National Transportation Integrated Search

2013-01-01

The Dallas Area Rapid Transit (DART) is leading the US 75 Integrated Corridor Management (ICM) Demonstration Project for the Dallas region. Coordinated corridor operations and management is predicated on being able to share transportation information...

90-94 ITS Intercity Corridor Study - Strategic Deployment Plan

DOT National Transportation Integrated Search

1996-12-01

PUBLIC-PRIVATE PARTNERSHIP, COMMERCIAL VEHICLES OPERATIONS OR CVO : THE IH 90/94 ITS INTERCITY CORRIDOR STRATEGIC DEPLOYMENT PLAN IS AN APPROACH FOR IMPLEMENTING INTELLIGENT TRANSPORTATION SYSTEMS (ITS) IN THE IH 90/94 CORRIDORS THAT TRAVERSE THE ...

76 FR 31008 - North Central Iowa Rail Corridor, LLC-Acquisition Exemption-Union Pacific Railroad Company

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-27

... Rail Corridor, LLC--Acquisition Exemption-- Union Pacific Railroad Company North Central Iowa Rail Corridor, LLC (NCIRC), a noncarrier, has filed a verified notice of exemption under 49 [[Page 31009

13. I95 bridge crossing corridor with Providence Station in background. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. I-95 bridge crossing corridor with Providence Station in background. Providence, Providence County, RI. sec. 4116, mp 185.15. - Northeast Railroad Corridor, Amtrak route between CT & MA state lines, Providence, Providence County, RI

Integrated corridor management : implementation guide and lessons learned.

DOT National Transportation Integrated Search

2012-02-01

This implementation guide is intended for use by adopters of integrated corridor management (ICM) approaches and strategies to address congestion and travel time reliability issues within specific travel corridors. It introduces the topic of ICM and ...

Silicon Valley Smart Corridor : final evaluation report

DOT National Transportation Integrated Search

2003-08-01

This document summarizes the findings from the evaluation of the integrated freeway, arterial, and incident management system known as the Silicon Valley Smart Corridor (SVSC). Centered along the Highway 17/Interstate 880 corridor in San Jose, Califo...

77 FR 73734 - Northeast Corridor Safety Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-11

.... 5] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of a Northeast Corridor Safety... Committee is made up of stakeholders operating on the [[Page 73735

Using collaborative tools for energy corridor planning.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuiper, J. A.; Cantwell, B.; Hlohowskyj, I.

2008-01-01

In November 2007, the Draft Programmatic Environmental Impact Statement on Designation of Energy Corridors on Federal Land in the Western 11 States was released. The draft proposes a network of 6055 miles of energy corridors on lands managed by seven different federal agencies. Determining the proposed locations of the corridors was a large collaborative effort among the agencies and included local, state, and federal land managers. To connect this geographically dispersed group of people, the project team employed a variety of approaches to communicate corridor siting issues, including sharing GIS layers and electronic maps, a downloadable GIS database and ArcReadermore » project, workshops, and Internet webcast teleconferences. This collaborative approach allowed difficult siting issues to be understood and discussed from many perspectives, which resulted in rapid and effective decision making. The result was a proposed corridor system that avoids many sensitive resources and protected lands while accommodating expected energy development.« less

Moving shadows contribute to the corridor illusion in a chimpanzee (Pan troglodytes).

PubMed

Imura, Tomoko; Tomonaga, Masaki

2009-08-01

Previous studies have reported that backgrounds depicting linear perspective and texture gradients influence relative size discrimination in nonhuman animals (known as the "corridor illusion"), but research has not yet identified the other kinds of depth cues contributing to the corridor illusion. This study examined the effects of linear perspective and shadows on the responses of a chimpanzee (Pan troglodytes) to the corridor illusion. The performance of the chimpanzee was worse when a smaller object was presented at the farther position on a background reflecting a linear perspective, implying that the corridor illusion was replicated in the chimpanzee (Imura, Tomonaga, & Yagi, 2008). The extent of the illusion changed as a function of the position of the shadows cast by the objects only when the shadows were moving in synchrony with the objects. These findings suggest that moving shadows and linear perspective contributed to the corridor illusion in a chimpanzee. Copyright 2009 APA, all rights reserved.

Abort-once-around entry dispersion corridor analysis. [for space shuttle reentry

NASA Technical Reports Server (NTRS)

Kyle, H. C.

1975-01-01

Abort-Once-Around (AOA) entry dispersion corridors were determined for Shuttle Mission 3A. These corridors are presented as plots of entry interface flight path angle versus range to target. The methods used to determine the corridors are discussed. Major dispersion sources are discussed and results presented. While specific trajectory inputs and constraints are subject to change, the dispersion corridors show the trends under consideration. The corridors presented show the delta V advantage of the two-burn over the one-burn AOA. The atmospheric dispersion study illustrates the need to target for the seasonal atmosphere. The 40 deg/30 deg angle of attack (alpha) (TPS design) profile did not provide adequate crossrange capability with worst case aerodynamic dispersions. This problem was alleviated with the change to a 38 deg/28 deg alpha profile. The backface temperatures calculated were generally higher than the present limits.

Endemic and threatened tetrapods in the restingas of the biodiversity corridors of Serra do Mar and of the Central da Mata Atlântica in eastern Brazil.

PubMed

Rocha, C F D; Van Sluys, M; Bergallo, H G; Alves, M A S

2005-02-01

Biodiversity corridors comprise a mosaic of land uses connecting fragments of natural forest across a landscape. Two such corridors have been established along the eastern coast of Brazil: the Serra do Mar and the Central da Mata Atlântica corridors, along which most of the coastal plains are restinga areas. In this study, we analyze the present status of the endemic and endangered terrestrial vertebrates of both corridors. We sampled 10 restingas in both corridors, recording species of amphibians, reptiles, birds, and mammals. Some restingas harbor a relatively large number of endemic species,and two main regions of endemism can be identified along the restingas of both corridors: the coastal restingas from northern Espirito Santo State to southern Bahia State (between Linhares, ES, and Tarancoso, BA), and the coastal region between the restingas of Maricá and Jurubatiba, Rio de Janeiro State. Six species of terrestrial vertebrates considered threatened with extinction are found in the restingas of Serra do Mar and Central da Mata Atlântica biodiversity corridors (Liolaemus lutzae, Formicivora littoralis, Mimus gilvus, Schistochlamys melanopis, and Trinomys eliasi). The region located between the restinga of Maricá and that of Jurubatiba is of special relevance for the conservation of vertebrate species of the restingas of the corridors because a considerable number of threatened species of terrestrial vertebrates are found there. We strongly recommend efforts to develop checklists of threatened faunas for the States of Espirito Santo and Bahia.

[Identification of ecological corridors for Tibetan antelope and assessment of their human disturbances in the alpine desert of Qinghai-Tibet Plateau].

PubMed

Zhuge, Hai-jin; Lin, Dan-qi; Li, Xiao-wen

2015-08-01

The alpine desert of Qinghai-Tibet Plateau (QTP) provides the largest habitats for those endangered ungulates (e.g., Tibetan antelope, Tibetan Kiang and wild yak) on the earth. However, human disturbance especially infrastructure constructions (e.g., railway & highway) has increasingly fragmented the habitats of those endangered ungulates by disturbing and interrupting their ecological corridors for their seasonal migration. Aiming at identifying the potential ecological corridors for Tibetan antelope, a GIS-based model-Linkage Mapper was used to model and detect the potential ecological corridors of Tibetan antelope based on the principle of least cost path. Three categories of ecological corridors, i. e., closed (inside reserves), linking (linking the reserves) and open (starting from reserve but ending outside) corridors were distinguished by their spatial interactions with existing major national nature reserves (i.e., Altun, Kekexili and Qiangtang NNRs) in the alpine desert of QTP, and their spatial patterns, conservation status associated with human disturbance were also examined. Although our research indicated a general ecological integration of both habitats and ecological corridors in the alpine desert ecosystem, increasing human disturbance should not be ignored, which particularly partially undermined the functioning of those ecological corridors linking the nature reserves. Considering disadvantages of prevailing separate administrative structure of nature reserve on the effective conservation of ecological corridors for those endangered ungulates, a coordinative conservation network among these major national nature reserves should be established to ensure the unified trans-boundary conservation efforts and to enhance its overall conservation efficacy by sharing information, knowledge and optimizing conservation resources.

Riparian corridors enhance movement of a forest specialist bird in fragmented tropical forest.

PubMed

Gillies, Cameron S; St Clair, Colleen Cassady

2008-12-16

Riparian corridors and fencerows are hypothesized to increase the persistence of forest animals in fragmented landscapes by facilitating movement among suitable habitat patches. This function may be critically important for forest birds, which have declined dramatically in fragmented habitats. Unfortunately, direct evidence of corridor use has been difficult to collect at landscape scales and this limits support for corridors in conservation planning. Using telemetry and handheld GPS units, we examined the movement of forest birds by translocating territorial individuals of barred antshrikes (Thamnophilus doliatus; a forest specialist) and rufous-naped wrens (Campylorhynchus rufinucha; a forest generalist) 0.7-1.9 km from their territories in the highly fragmented tropical dry forest of Costa Rica. In each translocation, the directly intervening habitat comprised 1 of 3 treatments: forested riparian corridor, linear living fencerow, or open pasture. Antshrikes returned faster and with greater success in riparian corridors relative to pasture treatments. This species also traveled more directly in riparian corridor treatments, detoured to use forested routes in the other 2 treatments, and did not use fencerows even when they led directly to their home territories. By contrast, wrens were more likely to use fencerows when returning, and return time and success were equivalent among the 3 treatments. Both species crossed fewer gaps in tree cover during riparian corridor treatments than in fencerow or pasture treatments. We conclude that antshrikes, which may be representative of other forest specialists, use forested corridors for movement in this landscape and that fencerows are avoided as movement conduits.

Urban Power Line Corridors as Novel Habitats for Grassland and Alien Plant Species in South-Western Finland

PubMed Central

Lampinen, Jussi; Ruokolainen, Kalle; Huhta, Ari-Pekka

2015-01-01

Regularly managed electric power line corridors may provide habitats for both early-successional grassland plant species and disturbance-dependent alien plant species. These habitats are especially important in urban areas, where they can help conserve native grassland species and communities in urban greenspace. However, they can also provide further footholds for potentially invasive alien species that already characterize urban areas. In order to implement power line corridors into urban conservation, it is important to understand which environmental conditions in the corridors favor grassland species and which alien species. Likewise it is important to know whether similar environmental factors in the corridors control the species composition of the two groups. We conducted a vegetation study in a 43 kilometer long urban power line corridor network in south-western Finland, and used generalized linear models and distance-based redundancy analysis to determine which environmental factors best predict the occurrence and composition of grassland and alien plant species in the corridors. The results imply that old corridors on dry soils and steep slopes characterized by a history as open areas and pastures are especially suitable for grassland species. Corridors suitable for alien species, in turn, are characterized by productive soils and abundant light and are surrounded by a dense urban fabric. Factors controlling species composition in the two groups are somewhat correlated, with the most important factors including light abundance, soil moisture, soil calcium concentration and soil productivity. The results have implications for grassland conservation and invasive alien species control in urban areas. PMID:26565700

Urban Power Line Corridors as Novel Habitats for Grassland and Alien Plant Species in South-Western Finland.

PubMed

Lampinen, Jussi; Ruokolainen, Kalle; Huhta, Ari-Pekka

2015-01-01

Regularly managed electric power line corridors may provide habitats for both early-successional grassland plant species and disturbance-dependent alien plant species. These habitats are especially important in urban areas, where they can help conserve native grassland species and communities in urban greenspace. However, they can also provide further footholds for potentially invasive alien species that already characterize urban areas. In order to implement power line corridors into urban conservation, it is important to understand which environmental conditions in the corridors favor grassland species and which alien species. Likewise it is important to know whether similar environmental factors in the corridors control the species composition of the two groups. We conducted a vegetation study in a 43 kilometer long urban power line corridor network in south-western Finland, and used generalized linear models and distance-based redundancy analysis to determine which environmental factors best predict the occurrence and composition of grassland and alien plant species in the corridors. The results imply that old corridors on dry soils and steep slopes characterized by a history as open areas and pastures are especially suitable for grassland species. Corridors suitable for alien species, in turn, are characterized by productive soils and abundant light and are surrounded by a dense urban fabric. Factors controlling species composition in the two groups are somewhat correlated, with the most important factors including light abundance, soil moisture, soil calcium concentration and soil productivity. The results have implications for grassland conservation and invasive alien species control in urban areas.

Concept of operations : Dallas Integrated Corridor Management (ICM) demonstration project.

DOT National Transportation Integrated Search

2010-06-01

This concept of operations (Con Ops) for the US-75 Integrated Corridor Management (ICM) Program has been developed as part of the US Department of Transportation Integrated Corridor Management Initiative, which is an innovative research initiative th...

High-speed surface transportation corridor : a conceptual framework, final report.

DOT National Transportation Integrated Search

2009-10-08

Efficient transportation is indispensable for economic growth and prosperity. In this study we propose the development of a high-speed surface corridor and compatible vehicles. We present a conceptual framework for this corridor and vehicle. This pro...

Potential metrics for designating and monitoring oversize/overweight corridors : final report.

DOT National Transportation Integrated Search

2016-11-11

This report: - Discusses how oversize/overweight (OS/OW) corridors are currently designated in Texas. - Provides information on OS/OW corridors as detailed in the Texas Transportation Code. - Lists potential metrics (as identified by stakeholder work...

3. GENERAL VIEW OF CORRIDOR AROUND TRENTON STATION. TRENTON, MERCER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. GENERAL VIEW OF CORRIDOR AROUND TRENTON STATION. TRENTON, MERCER CO., NJ. Sec. 1401, MP 56.70. - Northeast Railroad Corridor, Amtrak Route between Pennsylvania/New Jersey & New Jersey/New York State Lines, Newark, Essex County, NJ

45 CFR 153.10 - Basis and scope.

Code of Federal Regulations, 2012 CFR

2012-10-01

... RELATED TO REINSURANCE, RISK CORRIDORS, AND RISK ADJUSTMENT UNDER THE AFFORDABLE CARE ACT General... program for individual market in each State. (3) Section 1342. Establishment of risk corridors for plans... risk corridors program, and a permanent risk adjustment program. ...

Interior view of main corridor, with doors to shell, powder, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Interior view of main corridor, with doors to shell, powder, and plotting rooms visible. Corridor to southeast gun chamber on the right - U.S. Naval Base, Pearl Harbor, Battery Adair, Princeton Place, Pearl City, Honolulu County, HI

45 CFR 153.10 - Basis and scope.

Code of Federal Regulations, 2014 CFR

2014-10-01

... RELATED TO REINSURANCE, RISK CORRIDORS, AND RISK ADJUSTMENT UNDER THE AFFORDABLE CARE ACT General... program for individual market in each State. (3) Section 1342. Establishment of risk corridors for plans... risk corridors program, and a permanent risk adjustment program. ...

45 CFR 153.10 - Basis and scope.

Code of Federal Regulations, 2013 CFR

2013-10-01

... RELATED TO REINSURANCE, RISK CORRIDORS, AND RISK ADJUSTMENT UNDER THE AFFORDABLE CARE ACT General... program for individual market in each State. (3) Section 1342. Establishment of risk corridors for plans... risk corridors program, and a permanent risk adjustment program. ...

Traffic analysis toolbox volume XIII : integrated corridor management analysis, modeling, and simulation guide

DOT National Transportation Integrated Search

2017-02-01

As part of the Federal Highway Administration (FHWA) Traffic Analysis Toolbox (Volume XIII), this guide was designed to help corridor stakeholders implement the Integrated Corridor Management (ICM) Analysis, Modeling, and Simulation (AMS) methodology...

78 FR 77550 - Integrated Corridor Management Deployment Planning Grants

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-23

... of this program is to promote the integrated management and operations of the transportation system... DEPARTMENT OF TRANSPORTATION Federal Highway Administration Integrated Corridor Management... the Integrated Corridor Management Deployment Planning Grants. The purpose of this notice was to...

Missouri River freight corridor assessment & development plan.

DOT National Transportation Integrated Search

2011-09-01

The purpose of the Missouri River Freight Corridor Development effort is to redevelop the river as a freight corridor with logical market nodes and reliable service that supports a sustainable market and logistics system. Four focus areas have been i...

400 SOUTH CORRIDOR ASSESSMENT [2014

DOT National Transportation Integrated Search

2014-09-22

The goal of the 400 S Corridor Assessment study is to evaluate current and future traffic and transit performance along the new light rail line corridors and at major intersections in Salt Lake Citys Downtown and University of Utah areas. The fiel...

Traffic analysis toolbox volume XIII : integrated corridor management analysis, modeling, and simulation guide.

DOT National Transportation Integrated Search

2017-02-01

As part of the Federal Highway Administration (FHWA) Traffic Analysis Toolbox (Volume XIII), this guide was designed to help corridor stakeholders implement the Integrated Corridor Management (ICM) Analysis, Modeling, and Simulation (AMS) methodology...

System acceptance test plan : Dallas Integrated Corridor Management (ICM) demonstration project.

DOT National Transportation Integrated Search

2013-02-01

The Dallas Area Rapid Transit (DART) is leading the US 75 Integrated Corridor Management (ICM) Demonstration Project for the Dallas region. Coordinated corridor operations and management is predicated on being able to share transportation information...

Interior, looking corridor connecting 511 to 515 into Medical Research ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Interior, looking corridor connecting 511 to 515 into Medical Research Library in 516. - Fitzsimons General Hospital, Central Service Building, North of Building No. 511, East of corridor connecting Building 511 to Building 515, Aurora, Adams County, CO

South Carolina southeast high speed rail corridor improvement study

DOT National Transportation Integrated Search

2001-02-01

The Southeast Rail Corridor was originally designated as a high-speed corridor in Section 1010 of the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991. More specifically, it involved the high-speed grade-crossing improvement program o...

Efficient Bifacial Semitransparent Perovskite Solar Cells Using Ag/V2O5 as Transparent Anodes.

PubMed

Pang, Shangzheng; Li, Xueyi; Dong, Hang; Chen, Dazheng; Zhu, Weidong; Chang, Jingjing; Lin, Zhenhua; Xi, He; Zhang, Jincheng; Zhang, Chunfu; Hao, Yue

2018-04-18

Bifacial semitransparent inverted planar structured perovskite solar cells (PSCs) based on Cs 0.05 FA 0.3 MA 0.7 PbI 2.51 Br 0.54 using an Ag thin film electrode and V 2 O 5 optical coupling layer are investigated theoretically and experimentally. It is shown that the introduction of the cesium (Cs) ions in the perovskite could obviously improve the device performance and stability. When only the bare Ag film electrode is used, the PSCs show a bifacial performance with the power conversion efficiency (PCE) of 14.62% illuminated from the indium tin oxide (ITO) side and 5.45% from the Ag film side. By introducing a V 2 O 5 optical coupling layer, the PCE is enhanced to 8.91% illuminated from the Ag film side, which is 63% improvement compared with the bare Ag film electrode, whereas the PCE illuminated from the ITO side remains almost unchanged. Moreover, when a back-reflector is employed, the PCE of device could be further improved to 15.39% by illumination from the ITO side and 12.44% by illumination from the Ag side. The devices also show superior semitransparent properties and exhibit negligible photocurrent hysteresis, irrespective of the side from which the light is illuminated. In short, the Ag/V 2 O 5 double layer is a promising semitransparent electrode due to its low cost and simple preparation process, which also point to a new direction for the bifacial PSCs and tandem solar cells.

Control and Diagnosis in Integrated Product Development - Observations during the Development of an AGV

NASA Astrophysics Data System (ADS)

Stetter, R.; Simundsson, A.

2015-11-01

This paper is concerned with the integration of control and diagnosis functionalities into the development of complete systems which include mechanical, electrical and electronic subsystems. For the development of such systems the strategies, methods and tools of integrated product development have attracted significant attention during the last decades. Today, it is generally observed that product development processes of complex systems can only be successful if the activities in the different domains are well connected and synchronised and if an ongoing communication is present - an ongoing communication spanning the technical domains and also including functions such as production planning, marketing/distribution, quality assurance, service and project planning. Obviously, numerous approaches to tackle this challenge are present in scientific literature and in industrial practice, as well. Today, the functionality and safety of most products is to a large degree dependent on control and diagnosis functionalities. Still, there is comparatively little research concentrating on the integration of the development of these functionalities into the overall product development processes. The main source of insight of the presented research is the product development process of an Automated Guided Vehicle (AGV) which is intended to be used on rough terrain. The paper starts with a background describing Integrated Product Development. The second section deals with the product development of the sample product. The third part summarizes some insights and formulates first hypotheses concerning control and diagnosis in Integrated Product Development.

Fuzzy logic control of an AGV

NASA Astrophysics Data System (ADS)

Kelkar, Nikhal; Samu, Tayib; Hall, Ernest L.

1997-09-01

Automated guided vehicles (AGVs) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research on the design of a modular autonomous mobile robot controller. The controller incorporates a fuzzy logic approach for steering and speed control, a neuro-fuzzy approach for ultrasound sensing (not discussed in this paper) and an overall expert system. The advantages of a modular system are related to portability and transportability, i.e. any vehicle can become autonomous with minimal modifications. A mobile robot test-bed has been constructed using a golf cart base. This cart has full speed control with guidance provided by a vision system and obstacle avoidance using ultrasonic sensors. The speed and steering fuzzy logic controller is supervised by a 486 computer through a multi-axis motion controller. The obstacle avoidance system is based on a micro-controller interfaced with six ultrasonic transducers. This micro- controller independently handles all timing and distance calculations and sends a steering angle correction back to the computer via the serial line. This design yields a portable independent system in which high speed computer communication is not necessary. Vision guidance is accomplished with a CCD camera with a zoom lens. The data is collected by a vision tracking device that transmits the X, Y coordinates of the lane marker to the control computer. Simulation and testing of these systems yielded promising results. This design, in its modularity, creates a portable autonomous fuzzy logic controller applicable to any mobile vehicle with only minor adaptations.

43. Dressing rooms and corridor in basement on west side ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

43. Dressing rooms and corridor in basement on west side of building, looking south. (July 1991) A nearly identical corridor with dressing rooms ran along the east side of the basement, and the two corridors were connected by a short hallway at the north end. The theatre seats seen in hallway in this photo are from Seattle's Orpheum Theatre which was demolished in 1967. - Fox Theater, Seventh Avenue & Olive Way, Seattle, King County, WA

Carbon stock corridors to mitigate climate change and promote biodiversity in the tropics

NASA Astrophysics Data System (ADS)

Jantz, Patrick; Goetz, Scott; Laporte, Nadine

2014-02-01

A key issue in global conservation is how biodiversity co-benefits can be incorporated into land use and climate change mitigation activities, particularly those being negotiated under the United Nations to reduce emissions from tropical deforestation and forest degradation. Protected areas have been the dominant strategy for tropical forest conservation and they have increased substantially in recent decades. Avoiding deforestation by preserving carbon stored in vegetation between protected areas provides an opportunity to mitigate the effects of land use and climate change on biodiversity by maintaining habitat connectivity across landscapes. Here we use a high-resolution data set of vegetation carbon stock to map corridors traversing areas of highest biomass between protected areas in the tropics. The derived corridors contain 15% of the total unprotected aboveground carbon in the tropical region. A large number of corridors have carbon densities that approach or exceed those of the protected areas they connect, suggesting these are suitable areas for achieving both habitat connectivity and climate change mitigation benefits. To further illustrate how economic and biological information can be used for corridor prioritization on a regional scale, we conducted a multicriteria analysis of corridors in the Legal Amazon, identifying corridors with high carbon, high species richness and endemism, and low economic opportunity costs. We also assessed the vulnerability of corridors to future deforestation threat.

A Continental-scale River Corridor Model to Synthesize Understanding and Prioritize Management of Water Purification Functions and Ecological Services in Large Basins

NASA Astrophysics Data System (ADS)

Harvey, J. W.; Gomez-Velez, J. D.; Scott, D.; Boyer, E. W.; Schmadel, N. M.; Alexander, R. B.; Eng, K.; Golden, H. E.; Kettner, A.; Konrad, C. P.; Moore, R. B.; Pizzuto, J. E.; Schwarz, G. E.; Soulsby, C.

2017-12-01

The functional values of rivers depend on more than just wetted river channels. Instead, the river channel exchanges water and suspended materials with adjacent riparian, floodplain, hyporheic zones, and ponded waters such as lakes and reservoirs. Together these features comprise a larger functional unit known as the river corridor. The exchange of water, solutes, and sediments within the river corridor alters downstream water quality and ecological functions, but our understanding of the large-scale, cumulative impacts is inadequate and has limited advancements in sustainable management practices. A problem with traditional watershed, groundwater, and river water quality models is that none of them explicitly accounts for river corridor storage and processing, and the exchanges of water, solutes, and sediments that occur many times between the channel and off-channel environments during a river's transport to the sea. Our River Corridor Working Group at the John Wesley Powell Center is quantifying the key components of river corridor functions. Relying on foundational studies that identified floodplain, riparian, and hyporheic exchange flows and resulting enhancement of chemical reactions at river reach scales, we are assembling the datasets and building the models to upscale that understanding onto 2.6 million river reaches in the U.S. A principal goal of the River Corridor Working group is to develop a national-scale river corridor model for the conterminous U.S. that will reveal, perhaps for the first time, the relative influences of hyporheic, riparian, floodplain, and ponded waters at large spatial scales. The simple but physically-based models are predictive for changing conditions and therefore can directly address the consequences and effectiveness of management actions in sustaining valuable river corridor functions. This presentation features interpretation of useful river corridor connectivity metrics and ponded water influences on nutrient and sediment processing in river networks of the Mid-Atlantic and Northeastern U.S. This research is a product of the John Wesley Powell Center River Corridor Working Group https://powellcenter.usgs.gov/view-project

78 FR 7477 - Multistate Corridor Operations and Management Program

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-01

... in the Multistate Corridor Operations and Management Program authorized by the Safe, Accountable... projects to improve multimodal transportation system management and operations. This notice seeks... Multistate Corridor Operations and Management (MCOM) programs and projects. The purpose of these investments...

Integrated corridor management : implementation guide and lessons learned (final report version 2.0).

DOT National Transportation Integrated Search

2015-09-01

This implementation guide is intended for use by adopters of integrated corridor management (ICM) approaches and strategies to address congestion and travel time reliability issues within specific travel corridors. It introduces the topic of ICM and ...

Transportation policy and governance in the northeast corridor : an overview of major public agencies.

DOT National Transportation Integrated Search

2009-08-01

One of the most consistent topics of discussion about the Northeast Corridor (hereafter : NEC or the Corridor), particularly the central portion between Boston and Washington, : D.C., is the viability and efficiency of its transportation ...

General view looking SE at corridor and Pennsylvania Station. Baltimore, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view looking SE at corridor and Pennsylvania Station. Baltimore, Baltimore City, MD. Sec. 1201, MP 93.23. - Northeast Railroad Corridor, Amtrak route between District of Columbia/Maryland state line & Maryland/Delaware state line, Baltimore, Independent City, MD

North Carolina "Sealed Corridor" Phase I, II, and III Assessment

DOT National Transportation Integrated Search

2009-10-01

The Federal Railroad Administration (FRA) tasked the John A. Volpe National Transportation Systems Center to document the further success of the North Carolina DOT "Sealed Corridor" project through Phases I, II, and III. The Sealed Corridor is the se...

MOSAIC : Model Of Sustainability And Integrated Corridors, phase 3 : comprehensive model calibration and validation and additional model enhancement.

DOT National Transportation Integrated Search

2015-02-01

The Maryland State Highway Administration (SHA) has initiated major planning efforts to improve transportation : efficiency, safety, and sustainability on critical highway corridors through its Comprehensive Highway Corridor : (CHC) program. This pro...

Concept of operations for the US-75 integrated corridor in Dallas, Texas

DOT National Transportation Integrated Search

2008-04-30

This Concept of Operations (Con Ops) for the US-75 Integrated Corridor Management (ICM) Program has been developed as part of the Federal Highway Administration, the Federal Transit Administration, and RITA (FHWA/FTA/RITA) Integrated Corridor Managem...

System requirement specification for the IH-10 Integrated Corridor Management System (ICMS) in San Antonio, Texas

DOT National Transportation Integrated Search

2008-03-31

This Requirements Specification Document (RSD) was developed under the project titled TransGuide Integrated Corridor Management Stage 1 as part of the United States Department of Transportation (USDOT) Integrated Corridor Management (ICM) p...

Multi-Modal Traveler Information System - VMS/HAR State-of-the-Practice

DOT National Transportation Integrated Search

1997-05-30

The Gary-Chicago-Milwaukee (GCM) Corridor is one of the four "Priority Corridors" established by the United States Congress in the Inter-Modal Surface Transportation Efficiency Act (ISTEA). These corridors have been selected for special federal trans...

Corridors and some ecological and evolutionary consequences of connectivity.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orrock, John L

2004-07-01

Abstract - By connecting disjunct patches, corridors may offset the effects of fragmentation by promoting gene flow and population persistence. However, the ultimate effect of corridors on a focal species may hinge upon two considerations: how corridors may affect ecological interactions that impinge upon that species, and how corridors might affect the fixation of novel alleles that ultimately determine fitness and persistence. Using an experimental landscape, I show that corridor-mediated changes in patch shape change seed predation in connected and unconnected patches, and shift the behavior, abundance, and distribution of seed predators. Rodent seed predators removed more seeds in connectedmore » patches, arthropod seed predators removed more seeds in rectangular patches, and avian seed predation did not differ due to patch type. Rodent foraging was greater in the interior of connected patches because changes in patch shape influenced risk perceived by rodents while foraging. Ant communities were also affected by changes in patch shape caused by corridors, rather than corridor effects per se. The distribution and abundance of ants differed among edge-rich areas (corridors and wings), edges, and the patch interior. In rectangular patches, fire ants (Solenopsis spp.) had negative impacts on other ant species. By changing the activity of rodents, and the composition of ant communities, corridors may have important impacts on seeds. Bird-dispersed seeds may benefit from increased dispersal among connected patches, but connected patches also have greater predation risk. Using a simulation model, I demonstrate that gene flow between a stable population and a population that experiences local extinction or a reduction in size (e.g. due to natural or anthropogenic disturbance) can dramatically affect fixation of alleles in the stable population. Alone or in concert, frequent disturbance, high rates of movement, and low habitat quality make it more likely that connectivity-mediated fixation will promote fixation of harmful alleles and reduce fixation of beneficial alleles.« less

Blood Parasites of Blue-winged Teal ( Anas discors ) from Two Migratory Corridors, in the Southern USA.

PubMed

Garvon, Jason M; Mott, Joanna B; Jacobs, Sandy Serio; Fedynich, Alan M

2016-07-01

We collected 180 Blue-winged Teal ( Anas discors ) in September and October 2002 from Florida, US (n=100, representing the eastern migratory corridor) and the Louisiana-Texas, US, border (n=80, representing the western migratory corridor) and examined for blood parasites using thin heart-blood smears. Leucocytozoon simondi, Haemoproteus nettionis, and microfilariae were found in 16, 23, and 27 birds, respectively. Prevalence of L. simondi and H. nettionis did not vary by migratory corridor, but the prevalence of microfilariae was higher in the western corridor (23%) than the eastern corridor (9%). No differences in prevalence of L. simondi, H. nettionis, and microfilariae were observed by host age or sex. The mean density of L. simondi and H. nettionis averaged 1.5±0.3 and 2.3±0.4 (±SE per 3,000 erythrocytes), respectively. Ranked abundance models for main and interactive effects of corridor, age, and sex were not statistically significant for L. simondi or H. nettionis. Low prevalence and abundance of hematozoa in early autumn migrants reflects the likelihood of low exposure probabilities of Blue-winged Teal on the breeding grounds, compared to their congeners.

Role of buccal corridor in smile esthetics and its correlation with underlying skeletal and dental structures.

PubMed

Tikku, Tripti; Khanna, Rohit; Maurya, R P; Ahmad, Nabeel

2012-01-01

This study was designed to evaluate the buccal corridor in smile esthetics and to correlate it with underlying hard tissues. Posed smiling frontal photographs, digital posterior-anterior (PA) cephalograms, and study models of 25 males and 25 females in age range of 18-25 years were taken. Photographs were evaluated for smile esthetics by eight orthodontists, eight plastic surgeons, eight beauticians and eight lay people to group them into three groups with least attractive, average and attractive smile and buccal corridor width was measured. Digital PA cephalograms were transferred on Nemo-tech software for frontal facial analysis. Intercanine and intermolar widths were measured on upper study model with the help of a digital calliper. The buccal corridor width was least in attractive smile group and maximum in least attractive smile group. The buccal corridor width had a negligible correlation with hard tissues and a mild to moderate inverse correlation with intercanine and intermolar widths within the groups. As the amount of buccal corridor display was increased, smiling images were scored less attractive by the evaluators. The buccal corridor is not influenced by underlying skeletal hard tissues but have mild to moderate inverse correlation with the intercanine and intermolar width.

Energy transport corridors: the potential role of Federal lands in states identified by the Energy Policy Act of 2005, section 368(b).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krummel, J.; Hlohowskyj, I.; Kuiper, J.

2011-09-01

On August 8, 2005, the President signed the Energy Policy Act of 2005 (EPAct) into law. In Subtitle F of EPAct, Congress set forth various provisions that would change the way certain federal agencies (Agencies) coordinate to authorize the use of land for a variety of energy-related purposes. As part of Subtitle F of EPAct, Section 368 addresses the issue of energy transportation corridors on federal land for oil, gas, and hydrogen pipelines, as well as electricity transmission and distribution facilities. Because of the critical importance of improving the nation's electrical transmission grid, Congress recognized that electricity transmission issues shouldmore » receive added attention when the Agencies address corridor location and analysis issues. In Section 368, Congress specifically directed the Agencies to consider the need for upgraded and new facilities to deliver electricity: In carrying out [Section 368], the Secretaries shall take into account the need for upgraded and new electricity transmission and distribution facilities to (1) improve reliability; (2) relieve congestion; and (3) enhance capability of the national grid to deliver electricity. Section 368 does not require the Agencies to consider or approve specific projects, applications for rights-of-way (ROWs), or other permits within designated energy corridors. Importantly, Section 368 does not direct, license, or otherwise permit any on-the-ground activity of any sort. If an applicant is interested in obtaining an authorization to develop a project within any corridor designated under Section 368, the applicant would have to apply for a ROW authorization and applicable permits. The Agencies would consider each application by applying appropriate project-specific reviews under requirements of laws and related regulations, including, but not limited to, the National Environmental Policy Act (NEPA), the Clean Water Act, the Clean Air Act, Section 7 of the Endangered Species Act (ESA), and Section 106 of the National Historic Preservation Act (NHPA). Under Section 368, Congress divided the United States into two groups of states: the 11 contiguous western states and the remaining states. Direction for energy transportation corridor analysis and selection in the 11 western states was addressed in Section 368(a) of EPAct, while direction for energy transportation corridor analysis and selection in all other states was addressed under Section 368(b) of EPAct. It was clearly the priority of Congress to conduct corridor location studies and designation first on federal lands in the western states. Under Section 368(a), the Agencies produced a programmatic environmental impact statement (EIS), Designation of Energy Corridors on Federal Land in the 11 Western States (DOE and DOI 2008), that was used in part as the basis for designating more than 6,000 mi (9,656 km) of energy transportation corridors on federal land in 11 western states. Under Section 368(a) of EPAct, Congress clearly stated the Agencies needed to (1) designate energy transportation corridors on federal land, (2) conduct the necessary environmental review of the designated corridors, and (3) incorporate the designated corridors into the appropriate land use plans. Congressional direction under Section 368(b) of EPAct differs from that provided under Section 368(a). Specifically, Section 368(b) requires the secretaries of the Agencies, in consultation with the Federal Energy Regulatory Commission (FERC), affected utility industries, and other interested persons, to jointly: (1) Identify corridors for oil, gas, and hydrogen pipelines and electricity transmission and distribution facilities on federal land in states other than the 11 western states identified under Section 368(a) of EPAct, and (2) Schedule prompt action to identify, designate, and incorporate the corridors into the applicable land use plans. While Section 368(a) clearly directs designation as a necessary first step for energy transportation corridors in the 11 western states, Section 368(b) directs the Agencies to first identify corridors and then schedule prompt action to identify, designate, and incorporate the corridors into applicable land use plans. To comply with the congressional direction provided in Section 368(b), the Agencies investigated corridor identification issues in the Section 368(b) states; this report to Congress provides information that could be relevant to possible future designation of energy corridors. Future designations, if appropriate and necessary, would occur when the Agencies undertake revisions and/or updates to land use plans that guide management decisions on lands located within individual administrative units, such as specific National Forests, National Parks, or Wildlife Refuges. At this time, the Agencies are not proposing any actions or decisions related directly or indirectly to designating energy corridors on federal land under Section 368(b) of EPAct.« less

Evaluation plan for the I-95 CC ATIS (Corridor-TravTips) program

DOT National Transportation Integrated Search

1999-03-01

The Boston-to-New York travel corridor is one of the busiest travel corridors in the country and, typical of such developed areas, is experiencing congestion and safety problems and other travel-related inefficiencies along its transportation systems...

Integrated corridor management, concept development and foundational research. Task 5.5, identification of analysis needs.

DOT National Transportation Integrated Search

2006-08-28

Task 5 - Identify Corridor Types, Operational Approaches and Strategies, and Analysis Tools - is part of the overall foundational research to further the understanding of various aspects of Integrated Corridor Management (ICM) and to identify integra...

Project management plan : Dallas Integrated Corridor Management (ICM) demonstration project.

DOT National Transportation Integrated Search

2010-12-01

The Dallas Integrated Corridor Management System Demonstration Project is a multi-agency, de-centralized operation which will utilize a set of regional systems to integrate the operations of the corridor. The purpose of the Dallas ICM System is to im...

Northeast rail corridor : information on users, funding sources, and expenditures

DOT National Transportation Integrated Search

1996-06-27

This report describes data on the users of the Northeast Corridor and the : funding needed for its operations and maintenance. It includes the relative use : of the corridor by Amtrak and the commuter and freight railroads, the sources of : funding f...

50. View looking SE down corridor with Hillside Lane Bridge ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

50. View looking SE down corridor with Hillside Lane Bridge in center. Mamaroneck, Westchester Co., NY. Sec. 9108, MP 20.75. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

STREAM CORRIDOR RESTORATION AND ITS POTENTIAL TO IMPROVE WATER QUALITY

EPA Science Inventory

Watershed stream corridors are being degraded by anthropogenic impacts of increased flow from runoff, sediment loading from erosion and contaminants such as nitrate from non-point sources. One solution is to restore stream corridors with bank stabilization and energy dissipation ...

9. INTERIOR, SECOND FLOOR, NORTHSOUTH CORRIDOR IN WEST WING, FROM ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. INTERIOR, SECOND FLOOR, NORTH-SOUTH CORRIDOR IN WEST WING, FROM ITS INTERSECTION WITH MAIN EAST-WEST CORRIDOR AND NEAR STAIRWELL, LOOKING NORTH. - Oakland Naval Supply Center, Lodge-Cafeteria, East of Fifth Street, between D & E Streets, Oakland, Alameda County, CA

5. Corridor A and Building No. 9962A (with white door). ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. Corridor A and Building No. 9962-A (with white door). In upper left is east side of Building No. 9952-B. - Madigan Hospital, Corridors & Ramps, Bounded by Wilson & McKinley Avenues & Garfield & Lincoln Streets, Tacoma, Pierce County, WA

US-75 ICM system design document : Dallas Integrated Corridor Management (ICM) demonstration project.

DOT National Transportation Integrated Search

2013-06-01

This System Design document for the US-75 Integrated Corridor Management (ICM) Program has been developed as part of the US Department of Transportation Integrated Corridor Management Initiative. The basic premise behind the ICM initiative is that in...

Integrated corridor management initiative: survey Dallas traveler response panel

DOT National Transportation Integrated Search

2017-03-01

This report presents findings from the Integrated Corridor Management (ICM) traveler behavior surveys, a set of panel surveys of US-75 corridor users, conducted before and after the deployment of ICM. The purpose of the surveys was to measure the imp...

The Performance of a Tight Ins/gnss/photogrammetric Integration Scheme for Land Based MMS Applications in Gnss Denied Environments

NASA Astrophysics Data System (ADS)

Chu, Chien-Hsun; Chiang, Kai-Wei

2016-06-01

The early development of mobile mapping system (MMS) was restricted to applications that permitted the determination of the elements of exterior orientation from existing ground control. Mobile mapping refers to a means of collecting geospatial data using mapping sensors that are mounted on a mobile platform. Research works concerning mobile mapping dates back to the late 1980s. This process is mainly driven by the need for highway infrastructure mapping and transportation corridor inventories. In the early nineties, advances in satellite and inertial technology made it possible to think about mobile mapping in a different way. Instead of using ground control points as references for orienting the images in space, the trajectory and attitude of the imager platform could now be determined directly. Cameras, along with navigation and positioning sensors are integrated and mounted on a land vehicle for mapping purposes. Objects of interest can be directly measured and mapped from images that have been georeferenced using navigation and positioning sensors. Direct georeferencing (DG) is the determination of time-variable position and orientation parameters for a mobile digital imager. The most common technologies used for this purpose today are satellite positioning using the Global Navigation Satellite System (GNSS) and inertial navigation using an Inertial Measuring Unit (IMU). Although either technology used along could in principle determine both position and orientation, they are usually integrated in such a way that the IMU is the main orientation sensor, while the GNSS receiver is the main position sensor. However, GNSS signals are obstructed due to limited number of visible satellites in GNSS denied environments such as urban canyon, foliage, tunnel and indoor that cause the GNSS gap or interfered by reflected signals that cause abnormal measurement residuals thus deteriorates the positioning accuracy in GNSS denied environments. This study aims at developing a novel method that uses ground control points to maintain the positioning accuracy of the MMS in GNSS denied environments. At last, this study analyses the performance of proposed method using about 20 check-points through DG process.

Monitoring the Diversity of Hunting Ants (Hymenoptera: Formicidae) on a Fragmented and Restored Andean Landscape.

PubMed

Herrera-Rangel, J; Jiménez-Carmona, E; Armbrecht, I

2015-10-01

Hunting ants are predators of organisms belonging to different trophic levels. Their presence, abundance, and diversity may reflect the diversity of other ants and contribute to evaluate habitat conditions. Between 2003 and 2005 the restoration of seven corridors in an Andean rural landscape of Colombia was performed. The restoration took place in lands that were formerly either forestry plantations or pasturelands. To evaluate restoration progress, hunting ants were intensely sampled for 7 yr, using sifted leaf litter and mini-Winkler, and pitfall traps in 21 plots classified into five vegetation types: forests, riparian forests, two types of restored corridors, and pasturelands. The ant communities were faithful to their habitat over time, and the main differences in ant composition, abundance, and richness were due to differences among land use types. The forests and riparian forests support 45% of the species in the landscape while the restored corridors contain between 8.3-25%. The change from forest to pasturelands represents a loss of 80% of the species. Ant composition in restored corridors was significantly different than in forests but restored corridors of soil of forestry plantations retained 16.7% more species than restored corridors from pasturelands. Ubiquitous hunting ants, Hypoponera opacior (Forel) and Gnamptogenys ca andina were usually associated with pastures and dominate restored corridors. Other cryptic, small, and specialized hunting ants are not present in the restored corridors. Results suggest that the history of land use is important for the biodiversity of hunting ants but also that corridors have not yet effectively contributed toward conservation goals. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Opportunities of habitat connectivity for tiger (Panthera tigris) between Kanha and Pench National Parks in Madhya Pradesh, India.

PubMed

Rathore, Chinmaya S; Dubey, Yogesh; Shrivastava, Anurag; Pathak, Prasad; Patil, Vinayak

2012-01-01

The Tiger (Panthera tigris) population in India has undergone a sharp decline during the last few years. Of the number of factors attributed to this decline, habitat fragmentation has been the most worrisome. Wildlife corridors have long been a subject of discussion amongst wildlife biologists and conservationists with contrasting schools of thought arguing their merits and demerits. However, it is largely believed that wildlife corridors can help minimize genetic isolation, offset fragmentation problems, improve animal dispersal, restore ecological processes and reduce man animal conflict. This study attempted to evaluate the possibilities of identifying a suitable wildlife corridor between two very important wildlife areas of central India--the Kanha National Park and the Pench National Park--with tiger as the focal species. Geographic Information System (GIS) centric Least Cost Path modeling was used to identify likely routes for movement of tigers. Habitat suitability, perennial water bodies, road density, railway tracks, human settlement density and total forest edge were considered as key variables influencing tiger movement across the Kanha-Pench landscape. Each of these variables was weighted in terms of relative importance through an expert consultation process. Using different importance scenarios, three alternate corridor routes were generated of which one was identified as the most promising for tiger dispersal. Weak links--where cover and habitat conditions are currently sub-optimal--were flagged on the corridor route. Interventions aimed at augmenting the identified corridor route have been suggested using accepted wildlife corridor design principles. The involvement of local communities through initiatives such as ecotourism has been stressed as a crucial long term strategy for conservation of the Kanha-Pench wildlife corridor. The results of the study indicate that restoration of the identified wildlife corridors between the two protected areas is technically feasible.

A small mammal community in a forest fragment, vegetation corridor and coffee matrix system in the Brazilian Atlantic forest.

PubMed

Rocha, Mariana Ferreira; Passamani, Marcelo; Louzada, Júlio

2011-01-01

The objective of our work was to verify the value of the vegetation corridor in the conservation of small mammals in fragmented tropical landscapes, using a model system in the southeastern Minas Gerais. We evaluated and compared the composition and structure of small mammals in a vegetation corridor, forest fragments and a coffee matrix. A total of 15 species were recorded, and the highest species richness was observed in the vegetation corridor (13 species), followed by the forest fragments (10) and the coffee matrix (6). The absolute abundance was similar between the vegetation corridor and fragments (F = 22.94; p = 0.064), and the greatest differences occurred between the vegetation corridor and the matrix (F = 22.94; p = 0.001) and the forest fragments and the matrix (F = 22.94; p = 0.007). Six species showed significant habitat preference possibly related to the sensitivity of the species to the forest disturbance. Marmosops incanus was the species most sensitive to disturbance; Akodon montensis, Cerradomys subflavus, Gracilinanus microtarsus and Rhipidomys sp. displayed little sensitivity to disturbance, with a high relative abundance in the vegetation corridor. Calomys sp. was the species least affected by habitat disturbance, displaying a high relative abundance in the coffee matrix. Although the vegetation corridors are narrow (4 m width), our results support the hypothesis in which they work as a forest extension, share most species with the forest fragment and support species richness and abundance closer to forest fragments than to the coffee matrix. Our work highlights the importance and cost-effectiveness of these corridors to biodiversity management in the fragmented Atlantic Forest landscapes and at the regional level.

A Small Mammal Community in a Forest Fragment, Vegetation Corridor and Coffee Matrix System in the Brazilian Atlantic Forest

PubMed Central

Rocha, Mariana Ferreira; Passamani, Marcelo; Louzada, Júlio

2011-01-01

The objective of our work was to verify the value of the vegetation corridor in the conservation of small mammals in fragmented tropical landscapes, using a model system in the southeastern Minas Gerais. We evaluated and compared the composition and structure of small mammals in a vegetation corridor, forest fragments and a coffee matrix. A total of 15 species were recorded, and the highest species richness was observed in the vegetation corridor (13 species), followed by the forest fragments (10) and the coffee matrix (6). The absolute abundance was similar between the vegetation corridor and fragments (F = 22.94; p = 0.064), and the greatest differences occurred between the vegetation corridor and the matrix (F = 22.94; p = 0.001) and the forest fragments and the matrix (F = 22.94; p = 0.007). Six species showed significant habitat preference possibly related to the sensitivity of the species to the forest disturbance. Marmosops incanus was the species most sensitive to disturbance; Akodon montensis, Cerradomys subflavus, Gracilinanus microtarsus and Rhipidomys sp. displayed little sensitivity to disturbance, with a high relative abundance in the vegetation corridor. Calomys sp. was the species least affected by habitat disturbance, displaying a high relative abundance in the coffee matrix. Although the vegetation corridors are narrow (4 m width), our results support the hypothesis in which they work as a forest extension, share most species with the forest fragment and support species richness and abundance closer to forest fragments than to the coffee matrix. Our work highlights the importance and cost-effectiveness of these corridors to biodiversity management in the fragmented Atlantic Forest landscapes and at the regional level. PMID:21912591

Spirit of place of Merdeka corridor in Selatpanjang City

NASA Astrophysics Data System (ADS)

Aldy, Pedia; Dharma, S. Mira

2018-03-01

Historical city area was developing by an accumulation of developmental stages which influenced by various factors. The factors are political, economic, social, cultural, and modernization. The research will discuss the spirit of place of Merdeka corridor in Selatpanjang city, Meranti Islands. The purpose is to identify the spirit of place of Merdeka corridor and to find out the tourism concept by characters that support urban tourism in Selatpanjang city. The research method used is qualitative research method with the rationalistic paradigm. Based on cultural history, physical building, and spatial pattern, Merdeka corridor has unique characteristic, and it persists if compared by another in Selatpanjang city. However, damage of corridor, physical changes, and functions can slowly happen due to modernization and cannot avoid.

78 FR 73559 - Moose-Wilson Corridor Comprehensive Management Plan, Environmental Impact Statement, Grand Teton...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-06

...-Wilson Corridor Comprehensive Management Plan, Environmental Impact Statement, Grand Teton National Park... is preparing a Comprehensive Management Plan and Environmental Impact Statement (EIS) for the Moose...; (2) distinguish the corridor's fundamental and other important resources and values; (3) clearly...

US-75 ICM system as-built design : Dallas Integrated Corridor Management (ICM) demonstration project.

DOT National Transportation Integrated Search

2015-05-01

This As-Built document for the US-75 Integrated Corridor Management (ICM) Program has been developed as part of the US Department of Transportation Integrated Corridor Management Initiative. The basic premise behind the ICM initiative is that indepen...

Integrated corridor management I-15 San Diego, California : analysis plan.

DOT National Transportation Integrated Search

2010-02-01

This AMS Analysis Plan for the I-15 Corridor outlines the various tasks associated with the application of the ICM AMS tools and strategies to this corridor in order to support benefit-cost assessment for the successful implementation of ICM. The rep...

Integrated corridor management initiative : overview of the Dallas traveler response panel survey.

DOT National Transportation Integrated Search

2017-03-01

This report presents findings from the Integrated Corridor Management (ICM) traveler behavior surveys, a set of panel surveys of US-75 corridor users, conducted before and after the deployment of ICM. The purpose of the surveys was to measure the imp...

Developing guidelines for incorporating managing demand into WSDOT planning and programming: transportation demand management guidance for corridor planning studies.

DOT National Transportation Integrated Search

2016-02-01

The Washington State Department of Transportation (WSDOT) regional planning programs address current and forecasted deficiencies of State highways through the conduct of corridor studies. This Guidance for the conduct of corridor planning studies is ...

I-95 corridor coalition evaluation of the advanced traveler information system field operational test (TravTIPS)

DOT National Transportation Integrated Search

2001-01-01

The transportation agencies along the I-95 corridor have historically collected static and real-time transportation and travel information focused primarily on their own states or regional state groupings. Access to this information on a corridor-wid...

Evaluation of the Corridor Safety Improvement Program : phase 1 final report.

DOT National Transportation Integrated Search

1997-09-01

This project is an analysis of Oregon's Corridor Safety Improvement Programs implemented on Oregon Route 22 and Oregon Route 34. Improvements were : made along each corridor in 1993. : The project used a mail-out survey to determine the level of awar...

System requirement specification for the I-15 integrated corridor management system (ICMS) in San Diego, California.

DOT National Transportation Integrated Search

2008-03-31

This document presents a System Requirement Specification for an Integrated Corridor Management System (ICMS) in the I-15 Corridor in San Diego, California. The ICMS will consist of two major subsystems: the existing Intermodal Transportation Managem...

The EmX Franklin Corridor BRT project evaluation : final report, April 2009.

DOT National Transportation Integrated Search

2009-04-01

Lane Transit District began BRT service on its Franklin Corridor EmX in January 14, 2007. The four mile long route connects downtown Eugene and downtown Springfield, the two main hubs for LTDs system. The corridor, which has the greatest ridership...

Trucking and Size and Weight Regulations in the Mid-Continent Corridor

DOT National Transportation Integrated Search

1996-11-01

This thesis is an empirical analysis of trucking and truck size and weight (TS&W) regulations in the Mid-continent corridor. Based on this analysis, it compares and contrasts plausible near term TS&W policy options relating to this corridor. The appr...

Integrated corridor management analysis, modeling, and simulation for the I–15 corridor in San Diego, California—post-deployment analysis plan.

DOT National Transportation Integrated Search

2016-11-01

Post-Deployment Analysis, Modeling, and Simulation (AMS) activities focus on identifying impacts and benefits of the as-deployed Integrated Corridor Management (ICM) system. The as-deployed ICM strategies may differ from as-planned ...

Integrated corridor management : analysis, modeling, and simulation for the U.S.-15 corridor in Dallas, Texas—post-deployment analysis plan.

DOT National Transportation Integrated Search

2016-10-01

Post-Deployment Analysis, Modeling, and Simulation (AMS) activities focus on identifying impacts and benefits of the as-deployed Integrated Corridor Management (ICM) system. The as-deployed ICM strategies may differ from as-planned ...

New York in the new world economy : the I-90 corridor study : final report

DOT National Transportation Integrated Search

2002-12-01

The I-90 Corridor in upstate New York is a classic example of the de-industrialization of the Northeastern United States. With few exceptions, all counties along the corridor have experienced marked declined in manufacturing employment over the past ...

Helminth Community Dynamics in Populations of Blue-Winged Teal (Anas discors) Using Two Distinct Migratory Corridors.

PubMed

Garvon, Jason M; Fedynich, Alan M; Peterson, Markus J; Pence, Danny B

2011-01-01

The influence of spatially distinct host subpopulations on helminth community structure and pattern was examined in a migratory avian host species. Forty helminth species represented by 24,082 individuals were collected from 184 blue-winged teal (Anas discors; BWT) from 2 primary migratory corridors in Florida (eastern migratory corridor; EMC) and Louisiana and Texas (western migratory corridor; WMC). Mean species richness was greater in BWT from the WMC (x̅±SE = 10.2 ± 0.3 species) than the EMC (8.6 ± 0.2). The helminth community from the WMC had higher abundances of 6 common/intermediate species. Corridor helminth communities were similar in species composition but less similar when incorporating abundances of those species. Overlapping distributions of phylogenetically related host species that share generalist helminth species across ecologically similar habitats seem to mitigate the isolating mechanisms that are necessary for the distinct coevolutionary pathways to develop between adjacent corridors.

Corridors restore animal-mediated pollination in fragmented tropical forest landscapes

PubMed Central

Kormann, Urs; Scherber, Christoph; Tscharntke, Teja; Klein, Nadja; Larbig, Manuel; Valente, Jonathon J.; Hadley, Adam S.; Betts, Matthew G.

2016-01-01

Tropical biodiversity and associated ecosystem functions have become heavily eroded through habitat loss. Animal-mediated pollination is required in more than 94% of higher tropical plant species and 75% of the world's leading food crops, but it remains unclear if corridors avert deforestation-driven pollination breakdown in fragmented tropical landscapes. Here, we used manipulative resource experiments and field observations to show that corridors functionally connect neotropical forest fragments for forest-associated hummingbirds and increase pollen transfer. Further, corridors boosted forest-associated pollinator availability in fragments by 14.3 times compared with unconnected equivalents, increasing overall pollination success. Plants in patches without corridors showed pollination rates equal to bagged control flowers, indicating pollination failure in isolated fragments. This indicates, for the first time, that corridors benefit tropical forest ecosystems beyond boosting local species richness, by functionally connecting mutualistic network partners. We conclude that small-scale adjustments to landscape configuration safeguard native pollinators and associated pollination services in tropical forest landscapes. PMID:26817765

Smallholder farms as stepping stone corridors for crop-raiding elephant in northern Tanzania: integration of Bayesian expert system and network simulator.

PubMed

Pittiglio, Claudia; Skidmore, Andrew K; van Gils, Hein A M J; McCall, Michael K; Prins, Herbert H T

2014-03-01

Crop-raiding elephants affect local livelihoods, undermining conservation efforts. Yet, crop-raiding patterns are poorly understood, making prediction and protection difficult. We hypothesized that raiding elephants use corridors between daytime refuges and farmland. Elephant counts, crop-raiding records, household surveys, Bayesian expert system, and least-cost path simulation were used to predict four alternative categories of daily corridors: (1) footpaths, (2) dry river beds, (3) stepping stones along scattered small farms, and (4) trajectories of shortest distance to refuges. The corridor alignments were compared in terms of their minimum cumulative resistance to elephant movement and related to crop-raiding zones quantified by a kernel density function. The "stepping stone" corridors predicted the crop-raiding patterns. Elephant presence was confirmed along these corridors, demonstrating that small farms located between refuges and contiguous farmland increase habitat connectivity for elephant. Our analysis successfully predicted elephant occurrence in farmland where daytime counts failed to detect nocturnal presence. These results have conservation management implications.

Low-altitude remote sensing dataset of DEM and RGB mosaic for AB corridor on July 13 2013 and L2 corridor on July 21 2013

DOE Data Explorer

Baptiste Dafflon

2015-04-07

Low-altitude remote sensing dataset including DEM and RGB mosaic for AB (July 13 2013) and L2 corridor (July 21 2013).Processing flowchart for each corridor:Ground control points (GCP, 20.3 cm square white targets, every 20 m) surveyed with RTK GPS. Acquisition of RGB pictures using a Kite-based platform. Structure from Motion based reconstruction using hundreds of pictures and GCP coordinates. Export of DEM and RGB mosaic in geotiff format (NAD 83, 2012 geoid, UTM zone 4 north) with pixel resolution of about 2 cm, and x,y,z accuracy in centimeter range (less than 10 cm). High-accuracy and high-resolution inside GCPs zone for L2 corridor (500x20m), AB corridor (500x40) DEM will be updated once all GCPs will be measured. Only zones between GCPs are accurate although all the mosaic is provided.

Dynamic network expansion, contraction, and connectivity in the river corridor of mountain stream network

NASA Astrophysics Data System (ADS)

Ward, A. S.; Schmadel, N.; Wondzell, S. M.

2017-12-01

River networks are broadly recognized to expand and contract in response to hydrologic forcing. Additionally, the individual controls on river corridor dynamics of hydrologic forcing and geologic setting are well recognized. However, we currently lack tools to integrate our understanding of process dynamics in the river corridor and make predictions at the scale of river networks. In this study, we develop a perceptual model of the river corridor in mountain river networks, translate this into a reduced-complexity mechanistic model, and implement the model in a well-studied headwater catchment. We found that the river network was most sensitive to hydrologic dynamics under the lowest discharges (Qgauge < 1 L s-1). We also demonstrate a discharge-dependence on the dominant controls on network expansion, contraction, and river corridor exchange. Finally, we suggest this parsimonious model will be useful to managers of water resources who need to estimate connectivity and flow initiation location along the river corridor over broad, unstudied catchments.

Landscape connectivity promotes plant biodiversity spillover into non-target habitats.

PubMed

Brudvig, Lars A; Damschen, Ellen I; Tewksbury, Joshua J; Haddad, Nick M; Levey, Douglas J

2009-06-09

Conservation efforts typically focus on maximizing biodiversity in protected areas. The space available for reserves is limited, however, and conservation efforts must increasingly consider how management of protected areas can promote biodiversity beyond reserve borders. Habitat corridors are considered an important feature of reserves because they facilitate movement of organisms between patches, thereby increasing species richness in those patches. Here we demonstrate that by increasing species richness inside target patches, corridors additionally benefit biodiversity in surrounding non-target habitat, a biodiversity "spillover" effect. Working in the world's largest corridor experiment, we show that increased richness extends for approximately 30% of the width of the 1-ha connected patches, resulting in 10-18% more vascular plant species around patches of target habitat connected by corridors than around unconnected but otherwise equivalent patches of habitat. Furthermore, corridor-enhanced spillover into non-target habitat can be predicted by a simple plant life-history trait: seed dispersal mode. Species richness of animal-dispersed plants in non-target habitat increased in response to connectivity provided by corridors, whereas species richness of wind-dispersed plants was unaffected by connectivity and increased in response to changes in patch shape--higher edge-to-interior ratio--created by corridors. Corridors promoted biodiversity spillover for native species of the threatened longleaf pine ecosystem being restored in our experiment, but not for exotic species. By extending economically driven spillover concepts from marine fisheries and crop pollination systems, we show how reconnecting landscapes amplifies biodiversity conservation both within and beyond reserve borders.

Perceptions of brachyfacial, mesofacial and dolichofacial individuals with regard to the buccal corridor in different facial types

PubMed Central

PITHON, Matheus Melo; da MATA, Kayure Rocha; ROCHA, Karina Silva; COSTA, Brenda do Nascimento; NEVES, Fernando; BARBOSA, George Caique Gouveia; COQUEIRO, Raildo da Silva

2014-01-01

Objective Evaluate the esthetic perception and attractiveness of the smile with regard to the buccal corridor in different facial types by brachyfacial, mesofacial and dolichofacial individuals. Material and Methods The image of a smiling individual with a mesofacial type of face was changed to create three different facial types with five different buccal corridors (2%, 10%, 15%, 22% and 28%). To achieve this effect, a photo editing software was used (Adobe Photoshop, Adobe Systems Inc, San Francisco, CA, EUA). The images were submitted to evaluators with brachyfacial, mesofacial and dolichofacial types of faces, who evaluated the degree of esthetic perception and attractiveness by means of a visual analog scale measuring 70 mm. The differences between evaluators were verified by the Mann-Whitney test. All statistics were performed with a confidence level of 95%. Results Brachyfacial individuals perceived mesofacial and dolichofacial types of faces with buccal corridor of 2% as more attractive. Mesofacial individuals perceived mesofacial and dolichofacial types of faces with buccal corridor of 2%, 10% and 15% as more attractive. Dolichofacial individuals perceived the mesofacial type of face with buccal corridor of 2% as more attractive. Evaluators of the female sex generally attributed higher scores than the male evaluators. Conclusion To achieve an enhanced esthetic smile it is necessary to observe the patient's facial type. The preference for narrow buccal corridors is an esthetic characteristic preferred by men and women, and wide buccal corridors are less attractive. PMID:25466472

Perceptions of brachyfacial, mesofacial and dolichofacial individuals with regard to the buccal corridor in different facial types.

PubMed

Pithon, Matheus Melo; Mata, Kayure Rocha da; Rocha, Karina Silva; Costa, Brenda do Nascimento; Neves, Fernando; Barbosa, George Caique Gouveia; Coqueiro, Raildo da Silva

2014-01-01

Evaluate the esthetic perception and attractiveness of the smile with regard to the buccal corridor in different facial types by brachyfacial, mesofacial and dolichofacial individuals. The image of a smiling individual with a mesofacial type of face was changed to create three different facial types with five different buccal corridors (2%, 10%, 15%, 22% and 28%). To achieve this effect, a photo editing software was used (Adobe Photoshop, Adobe Systems Inc, San Francisco, CA, EUA). The images were submitted to evaluators with brachyfacial, mesofacial and dolichofacial types of faces, who evaluated the degree of esthetic perception and attractiveness by means of a visual analog scale measuring 70 mm. The differences between evaluators were verified by the Mann-Whitney test. All statistics were performed with a confidence level of 95%. Brachyfacial individuals perceived mesofacial and dolichofacial types of faces with buccal corridor of 2% as more attractive. Mesofacial individuals perceived mesofacial and dolichofacial types of faces with buccal corridor of 2%, 10% and 15% as more attractive. Dolichofacial individuals perceived the mesofacial type of face with buccal corridor of 2% as more attractive. Evaluators of the female sex generally attributed higher scores than the male evaluators. To achieve an enhanced esthetic smile it is necessary to observe the patient's facial type. The preference for narrow buccal corridors is an esthetic characteristic preferred by men and women, and wide buccal corridors are less attractive.

Hospital staff corridor conversations: work in passing.

PubMed

González-Martínez, Esther; Bangerter, Adrian; Lê Van, Kim; Navarro, Cécile

2016-03-01

First, to document the prevalence of corridor occupations and conversations among the staff of a hospital clinic, and their main features. Second, to examine the activities accomplished through corridor conversations and their interactional organization. Despite extensive research on mobility in hospital work, we still know fairly little about the prevalence and features of hospital staff corridor conversations and how they are organized. We conducted a study combining descriptive statistical analysis and multimodal conversation analysis of video recordings of staff corridor practices in a hospital outpatient clinic in Switzerland. In 2012, we collected 59 hours of video recordings in a corridor of a hospital clinic. We coded and statistically analysed the footage that showed the clinic staff exclusively. We also performed qualitative multimodal conversation analysis on a selection of the recorded staff conversations. Corridor occupations by the clinic staff are frequent and brief and rarely involve stops. Talk events (which include self-talk, face-to-face conversations and telephone conversations) during occupations are also brief and mobile, overwhelmingly focus on professional topics and are particularly frequent when two or more staff members occupy the corridor. The conversations present several interactional configurations and comprise an array of activities consequential to the provision of care and work organization. These practices are related to the fluid work organization of a spatially distributed team in a fast-paced, multitasking environment and should be taken into consideration in any undertaking aimed at improving hospital units' functioning. © 2015 John Wiley & Sons Ltd.

Maxillary arch width and buccal corridor changes with Damon and conventional brackets: A retrospective analysis.

PubMed

Shook, Corey; Kim, Sohyon Michelle; Burnheimer, John

2016-07-01

To evaluate the effect of Damon self-ligating and conventional bracket systems on buccal corridor widths and areas. A retrospective sample of consecutively treated patients using either conventional (CG, n  =  45) or Damon self-ligating (SL, n  =  39) brackets was analyzed to determine any differences in buccal corridor widths and areas both within and between groups. Pretreatment and posttreatment frontal photographs were transferred to Photoshop CC, standardized using intercanthal width, and linear and area measurements were performed with tools in Photoshop CC. Ratios were then calculated for statistical analysis. Relationships between arch widths and buccal corridors were also examined. There were no significant differences in the posttreatment intercanine or intermolar widths either within or between the CG and SL groups. There were no significant differences in any buccal corridor width or area measurement either within or between the CG and SL groups. There were strong correlations with the intercanine width and the corresponding buccal corridor smile width measurements. There was an inverse correlation with the buccal corridor area in relation to the canine and the total smile width. It is likely that posttreatment increases in arch width can be seen in patients treated with either a conventional bracket system or the Damon system. It is highly unlikely that there is any significant difference in buccal corridor width or area in patients treated with the Damon self-ligating system or a conventional bracket system.

Grizzly bears and calving caribou: What is the relation with river corridors?

USGS Publications Warehouse

Young, Donald D.; McCabe, Thomas R.

1998-01-01

Researchers have debated the effect of the Trans-Alaska Pipeline (TAP) and associated developments to caribou (Rangifer tarandus) of the central Arctic herd (CAH) since the 1970s. Several studies have demonstrated that cows and calves of the CAH avoided the TAP corridor because of disturbance associated with the pipeline, whereas others have indicated that female caribou of the CAH avoided riparian habitats closely associated with the pipeline. This avoidance was explained as a predator-avoidance strategy. We investigated the relation between female caribou and grizzly bear (Ursus arctos) use of river corridors on the yet undisturbed calving grounds of the Porcupine caribou herd (PCH) in northeastern Alaska. On the coastal plain, caribou were closer to river corridors than expected (P = 0.038), but bear use of river corridors did not differ from expected (P = 0.740). In the foothills, caribou use of river corridors did not differ from expected (P = 0.520), but bears were farther from rivers than expected (P = 0.001). Our results did not suggest an avoidance of river corridors by calving caribou or a propensity for bears to be associated with riparian habitats, presumably for stalking or ambush cover. We propose that PCH caribou reduce the risks of predation to neonates by migrating to a common calving grounds, where predator swamping is the operational antipredator strategy. Consequently, we hypothesize that nutritional demands, not predator avoidance strategies, ultimately regulate habitat use patterns (e.g., use of river corridors) of calving PCH caribou.

Technical report on the potential impacts on business revenues during construction of the central corridor light rail project

DOT National Transportation Integrated Search

2011-02-01

This report investigates the potential impacts to business revenues along the Central Corridor resulting from the construction of the Central Corridor Light Rail Project. This study addresses the potential loss of revenue by local businesses during t...

PEL and Corridor Planning: State of the Practice Review of Planning and Environment Linkages Implementation in Corridor Planning

DOT National Transportation Integrated Search

2014-07-01

The Federal Highway Administration (FHWA) commissioned a review of transportation corridor plans to determine the extent to which these plans have utilized FHWA's Planning and Environment Linkages (PEL) approach, as described in the FHWA Guidance on ...

14 CFR 93.83 - Aircraft operations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Aircraft operations. (a) North-South Corridor. Unless otherwise authorized by ATC (including the Eglin Radar Control Facility), no person may operate an aircraft in flight within the North-South Corridor designated in § 93.81(b)(1) unless— (1) Before operating within the corridor, that person obtains a clearance...

Integrated corridor management analysis, modeling, and simulation experimental plan for the test corridor.

DOT National Transportation Integrated Search

2008-03-01

This document, the AMS Experimental Plan, lays out the scope of analysis that will be conducted through the application of the AMS methodology to the Test Corridor. The specific objectives of the Experimental Plan are: create an AMS framework that id...

14 CFR 93.83 - Aircraft operations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Aircraft operations. (a) North-South Corridor. Unless otherwise authorized by ATC (including the Eglin Radar Control Facility), no person may operate an aircraft in flight within the North-South Corridor designated in § 93.81(b)(1) unless— (1) Before operating within the corridor, that person obtains a clearance...

Courtyard. Left wall is corridor from 511 to 515. Right ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Courtyard. Left wall is corridor from 511 to 515. Right wall is the south side of 517. - Fitzsimons General Hospital, Physiotherapy & Electrocardiograph Department Building, North of Building No. 516, East of corridor connecting Building No. 511 to Building No. 515, Aurora, Adams County, CO

14 CFR 93.83 - Aircraft operations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Aircraft operations. (a) North-South Corridor. Unless otherwise authorized by ATC (including the Eglin Radar Control Facility), no person may operate an aircraft in flight within the North-South Corridor designated in § 93.81(b)(1) unless— (1) Before operating within the corridor, that person obtains a clearance...

The future of rail in Washington state : options for passenger rail in the Pacific Northwest Rail Corridor

DOT National Transportation Integrated Search

1995-01-01

This document, as its title states, is an Options Report for the entire corridor. Until now, portions of : the corridor have been analyzed separately, and improvement strategies developed for distinct : segments. This report presents an overview of t...

45 CFR 153.510 - Risk corridors establishment and payment methodology.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 1 2013-10-01 2013-10-01 false Risk corridors establishment and payment methodology. 153.510 Section 153.510 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES REQUIREMENTS....510 Risk corridors establishment and payment methodology. (a) General requirement. A QHP issuer must...

45 CFR 153.540 - Compliance with risk corridors standards.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Section 153.540 Public Welfare Department of Health and Human Services REQUIREMENTS RELATING TO HEALTH CARE ACCESS STANDARDS RELATED TO REINSURANCE, RISK CORRIDORS, AND RISK ADJUSTMENT UNDER THE AFFORDABLE CARE ACT Health Insurance Issuer Standards Related to the Risk Corridors Program § 153.540 Compliance...

76 FR 5203 - Draft Environmental Impact Statement, Stehekin River Corridor Implementation Plan, North Cascades...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-28

... Statement, Stehekin River Corridor Implementation Plan, North Cascades National Park Service Complex; Chelan... public comment period. SUMMARY: The National Park Service, in cooperation with the Federal Highway Administration, has prepared a combined Stehekin River Corridor Implementation Plan, Lake Chelan National...

Staff corridor (room 206, representing rooms 301, 305, 401, 405, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Staff corridor (room 206, representing rooms 301, 305, 401, 405, 501, and 505), looking south towards the staff corridor vestibule (room 206A, representing rooms 305A, 405A, and 505A). - California State Office Building No. 1, 915 Capitol Mall, Sacramento, Sacramento County, CA

Calculating Toxic Corridors.

DTIC Science & Technology

1980-11-01

59 programmable calculator . Method 1 will most likely be used if there is a toxic corridor length table for the chemical; Method 2 if there is no table...experience of the forecaster in making this forecast, availability of a toxic corridor length table for the released chemical, and availability of a TI

Proceedings of the Annual Academic Apparel Research Conference on Advanced Apparel Manufacturing Technology Demonstration (1st) Held in Philadelphia, Pennsylvania on 14-16 February 1990. Volume 2

DTIC Science & Technology

1990-02-16

Philadelphia, PA by Dr. Leo E. Hanifin, Director Center for Manufacturing Productivity and Technology Transfer and Co-Principal Investigator Background In...Is coordinated by Dr. Leo E. Hanifin and Involves an additional four graduate students, two programmers, one engineer and one technician. In addition...the transfer bit5 - Whether the transfer is a load or unload * 4 bit4 - Which side of the AGV to perform the transfer bit3 through bitO - The number of

Soil quality and the solar corridor crop system

USDA-ARS?s Scientific Manuscript database

The solar corridor crop system (SCCS) is designed for improved crop productivity based on highly efficient use of solar radiation by integrating row crops with drilled or solid-seeded crops in broad strips (corridors) that also facilitate establishment of cover crops for year-round soil cover. The S...

Soil Quality and the Solar Corridor Crop System

USDA-ARS?s Scientific Manuscript database

The solar corridor crop system (SCCS) is designed for improved crop productivity based on highly efficient use of solar radiation by integrating row crops with drilled or solid-seeded crops in broad strips (corridors) that also facilitate establishment of cover crops for year-round soil cover. The S...

78 FR 16036 - Service Level Environmental Impact Statement for the Texas Oklahoma Passenger Rail Study Corridor...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-13

... planning for projects to implement the service. Alternatives under consideration will include a No Action..., at a corridor planning level, the infrastructure and equipment investment requirements for the... describe, at a corridor planning level, the potential environmental consequences (benefits and adverse...

14 CFR 420.27 - Launch site location review-information requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... corridor, and each impact range and impact dispersion area for each launch point; (b) Each launch vehicle... the analysis; (f) Each populated area located within a flight corridor or impact dispersion area; (g) The estimated casualty expectancy calculated for each populated area within a flight corridor or...

Landscape corridors can increase invasion by an exotic species and reduce diversity of native species

USDA-ARS?s Scientific Manuscript database

Although corridors have become commonplace in conservation to mitigate negative effects of habitat fragmentation, concerns persist that they may facilitate spread of invasive species. In a large-scale experiment, we measured effects of corridors on invasive fire ants, Solenopsis invicta, and on comm...

14 CFR 420.27 - Launch site location review-information requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... corridor, and each impact range and impact dispersion area for each launch point; (b) Each launch vehicle... the analysis; (f) Each populated area located within a flight corridor or impact dispersion area; (g) The estimated casualty expectancy calculated for each populated area within a flight corridor or...

23 CFR 450.212 - Transportation planning studies and project development.

Code of Federal Regulations, 2014 CFR

2014-04-01

... transportation operator(s) may undertake a multimodal, systems-level corridor or subarea planning study as part... part 771 and 40 CFR parts 1500-1508). Specifically, these corridor or subarea studies may result in... objective statement(s); (2) General travel corridor and/or general mode(s) definition (e.g., highway...

23 CFR 450.212 - Transportation planning studies and project development.

Code of Federal Regulations, 2012 CFR

2012-04-01

... transportation operator(s) may undertake a multimodal, systems-level corridor or subarea planning study as part... part 771 and 40 CFR parts 1500-1508). Specifically, these corridor or subarea studies may result in... objective statement(s); (2) General travel corridor and/or general mode(s) definition (e.g., highway...