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Surgical results of trabeculectomy and Ahmed valve implantation following a previous failed trabeculectomy in primary congenital glaucoma patients.

PubMed

Lee, Naeun; Ma, Kyoung Tak; Bae, Hyoung Won; Hong, Samin; Seong, Gong Je; Hong, Young Jae; Kim, Chan Yun

2015-04-01

To compare the surgical results of trabeculectomy and Ahmed glaucoma valve implantation after a previous failed trabeculectomy. A retrospective comparative case series review was performed on 31 eye surgeries in 20 patients with primary congenital glaucoma who underwent trabeculectomy or Ahmed glaucoma valve implantation after a previous failed trabeculectomy with mitomycin C. The preoperative mean intraocular pressure was 25.5 mmHg in the trabeculectomy group and 26.9 mmHg in the Ahmed glaucoma valve implantation group (p = 0.73). The 48-month postoperative mean intraocular pressure was 19.6 mmHg in the trabeculectomy group and 20.2 mmHg in the Ahmed glaucoma valve implantation group (p = 0.95). The 12-month trabeculectomy success rate was 69%, compared with 64% for Ahmed glaucoma valve implantation, and the 48-month success rates were 42% and 36% for trabeculectomy and valve implantation, respectively. The success rates following the entire follow-up period were not significantly different between the two groups (p > 0.05 by log rank test). Postoperative complications occurred in 25% of the trabeculectomy-operated eyes and 9% of the Ahmed-implanted eyes (p = 0.38). There was no significant difference in surgical outcome between the trabeculectomy and Ahmed glaucoma valve implantation groups, neither of which had favorable results. However, the trabeculectomy group demonstrated a higher prevalence of adverse complications such as post-operative endophthalmitis.

The impact of Arizona Highways Magazine on tourism.

DOT National Transportation Integrated Search

2012-03-01

The purpose of this study was to: 1) examine the effect of Arizona Highways Magazine (AHM) on tourism, 2) determine trip : characteristics of AHM subscribers traveling in Arizona, and 3) calculate a benefit/cost ratio for AHM based on the : magazine...

Surgical Results of Trabeculectomy and Ahmed Valve Implantation Following a Previous Failed Trabeculectomy in Primary Congenital Glaucoma Patients

PubMed Central

Lee, Naeun; Ma, Kyoung Tak; Bae, Hyoung Won; Hong, Samin; Seong, Gong Je; Hong, Young Jae

2015-01-01

Purpose To compare the surgical results of trabeculectomy and Ahmed glaucoma valve implantation after a previous failed trabeculectomy. Methods A retrospective comparative case series review was performed on 31 eye surgeries in 20 patients with primary congenital glaucoma who underwent trabeculectomy or Ahmed glaucoma valve implantation after a previous failed trabeculectomy with mitomycin C. Results The preoperative mean intraocular pressure was 25.5 mmHg in the trabeculectomy group and 26.9 mmHg in the Ahmed glaucoma valve implantation group (p = 0.73). The 48-month postoperative mean intraocular pressure was 19.6 mmHg in the trabeculectomy group and 20.2 mmHg in the Ahmed glaucoma valve implantation group (p = 0.95). The 12-month trabeculectomy success rate was 69%, compared with 64% for Ahmed glaucoma valve implantation, and the 48-month success rates were 42% and 36% for trabeculectomy and valve implantation, respectively. The success rates following the entire follow-up period were not significantly different between the two groups (p > 0.05 by log rank test). Postoperative complications occurred in 25% of the trabeculectomy-operated eyes and 9% of the Ahmed-implanted eyes (p = 0.38). Conclusions There was no significant difference in surgical outcome between the trabeculectomy and Ahmed glaucoma valve implantation groups, neither of which had favorable results. However, the trabeculectomy group demonstrated a higher prevalence of adverse complications such as post-operative endophthalmitis. PMID:25829827

Comparative study of encapsulated blebs following Ahmed glaucoma valve implantation and trabeculectomy with mitomycin-C.

PubMed

Bae, Kunho; Suh, Wool; Kee, Changwon

2012-08-01

To compare the histopathologic and morphologic findings of encapsulated blebs following Ahmed glaucoma valve implantation and primary standard trabeculectomy with mitomycin-C. We reviewed the records of patients with otherwise uncontrollable glaucoma who had undergone Ahmed glaucoma valve implantation or trabeculectomy with mitomycin-C. Five eyes that underwent Ahmed valve implantation and three eyes that underwent trabeculectomy needed surgical revision of the initial surgery due to encapsulated bleb development with total loss of function. The surgically removed encapsulated blebs were analyzed macroscopically and microscopically. Removal of the encapsulated bleb was performed at a mean follow-up time of 26.6 ± 19.4 weeks in the Ahmed valve implantation group and 12.0 ± 11.4 weeks in the trabeculectomy group. The fibrotic wall of the encapsulated blebs had an overall thickness of 2.48 ± 0.42 mm in the Ahmed valve implantation group and 1.62 ± 0.37 mm in the trabeculectomy group. Macroscopically, the coconut flesh-like smooth surface was split into two layers, and the wall of the capsule was thicker in the Ahmed valve implantation group than in the trabeculectomy group. Histopathologically, the fibrotic capsule was composed of an inner fibrodegenerative layer and an outer fibrovascular layer, and there were no histopathological differences between the two groups. The fibrotic capsule wall was thicker in the Ahmed valve group, but there were no differences in histological findings between the two groups.

Histological observation of hairless mice skin after exposure to Simulated Solar Light: Comparison between the histological findings with different methodologies and 3R principle correlations.

PubMed

Hossy, Bryan Hudson; Leitão, Alvaro Augusto da Costa; Torres, Renata Bosco; Ramos-E-Silva, Marcia; Miguel, Nádia Campos de Oliveira; de Pádula, Marcelo

2018-03-01

Albino hairless mouse (AHM) has been used as a biological model in photodermatology. However, the experimental landscape is diverse to follow and need particular attention. Irradiation parameters were investigated for the development of a protocol to assess alterations in the AHM skin using Simulated Solar Light (SSL). The present study was compared with published articles (last 15 years) according to irradiation protocols, morphological findings to minimize animal suffering and UV exposure. Three groups: Control (G1), experimental - sunburn (G2) and skin photodamage assay (G3). G2 were immobilized and exposed to SSL once for 15, 30 and 45min. G3 were exposed to SSL, without immobilization, for 15min once a day for one week. The dorsal skin was analyzed using hematoxylin and eosin technique. G2 displayed different sunburn degrees. Based on the profile of the observed morphological alterations, a 15min irradiation was chosen as the exposure time to expose G3, without immobilization, for 5 consecutive days. These conditions produced the same morphological changes in the AHM with a shorter solar exposure time, without immobilizing the animals but using environmental exposure fluences, conforming to 3R (reduction - refinement - replacement) recommendations. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Assessing the Impact of Social Media on the 25 January 2011 Egyptian Revolution

DTIC Science & Technology

2012-03-01

Ahmed Maher to support workers of Mahalla al Kubra. The group used the Internet (social media and blogs), mobile telephones, and word of mouth to...especially the poor, were united by their collective struggle. As a result, the word of mouth went viral and brought tens of thousands of Egyptians...distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words ) In the light of the dramatic events of the 25 January 2011

The Ahmed Versus Baerveldt Study: Five-Year Treatment Outcomes.

PubMed

Christakis, Panos G; Kalenak, Jeffrey W; Tsai, James C; Zurakowski, David; Kammer, Jeffrey A; Harasymowycz, Paul J; Mura, Juan J; Cantor, Louis B; Ahmed, Iqbal I K

2016-10-01

To compare 2 frequently used aqueous shunts for the treatment of glaucoma. International, multicenter, randomized trial. Patients aged 18 years or older with uncontrolled glaucoma despite maximum tolerated medical therapy, many of whom had failed or were at high risk of failing trabeculectomy. Eligible patients were randomized to receive an Ahmed-FP7 valve implant (New World Medical, Inc, Rancho Cucamonga, CA) or a Baerveldt-350 implant (Abbott Medical Optics, Inc, Santa Ana, CA) using a standardized surgical technique. The primary outcome was failure, defined as intraocular pressure (IOP) outside the target range (5-18 mmHg) or reduced <20% from baseline for 2 consecutive visits after 3 months, severe vision loss, or de novo glaucoma surgery. Secondary outcomes measures included IOP, medication use, visual acuity, complications, and interventions. A total of 238 patients were randomized; 124 received the Ahmed-FP7 implant, and 114 received the Baerveldt-350 implant. Baseline characteristics were similar between groups. Mean preoperative IOP was 31.4±10.8 mmHg on 3.1±1.0 glaucoma medications. At 5 years, the cumulative failure rate was 53% in the Ahmed group and 40% in the Baerveldt group (P = 0.04). The main reason for failure in both groups was high IOP, and the cumulative de novo glaucoma reoperation rate was 18% in the Ahmed group and 11% in the Baerveldt group (P = 0.22). Hypotony resulted in failure in 5 patients (4%) in the Baerveldt group compared with none in the Ahmed group (P = 0.02). Mean IOP was 16.6±5.9 mmHg in the Ahmed group (47% reduction) and 13.6±5.0 mmHg in the Baerveldt group (57% reduction, P = 0.001). Mean medication use was 1.8±1.5 mmHg in the Ahmed group (44% reduction) and 1.2±1.3 mmHg in the Baerveldt group (61% reduction, P = 0.03). The 2 groups had similar complication rates (Ahmed 63%, Baerveldt 69%) and intervention rates (Ahmed 41%, Baerveldt 41%). Most complications were transient, and most interventions were slit-lamp procedures. Both implants were effective in reducing IOP and the need for glaucoma medications. The Baerveldt group had a lower failure rate and a lower IOP on fewer medications than the Ahmed group, but had a small risk of hypotony that was not seen in the Ahmed group. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

U.S. Post-Conflict Integration Policy of Militias in Iraq

DTIC Science & Technology

2008-03-01

2 Hashim, 300. 3 Ahmed Hashim, Insurgency and Counter-Insurgency in Iraq (Ithaca: Cornell University...have earned acceptance and legitimacy through 19 Migdal, 296. 20 Ahmed Hashim, Insurgency and...Kennedy School of Government, Harvard University,[2006]). 41 Ahmed Hashim, Insurgency and Counter-Insurgency in Iraq (Ithaca: Cornell University

Antihyperglycemic Medication Use Among Medicare Beneficiaries With Heart Failure, Diabetes Mellitus, and Chronic Kidney Disease.

PubMed

Patel, Priyesh A; Liang, Li; Khazanie, Prateeti; Hammill, Bradley G; Fonarow, Gregg C; Yancy, Clyde W; Bhatt, Deepak L; Curtis, Lesley H; Hernandez, Adrian F

2016-07-01

Diabetes mellitus, heart failure (HF), and chronic kidney disease are common comorbidities, but overall use and safety of antihyperglycemic medications (AHMs) among patients with these comorbidities are poorly understood. Using Get With the Guidelines-Heart Failure and linked Medicare Part D data, we assessed AHM use within 90 days of hospital discharge among HF patients with diabetes mellitus discharged from Get With the Guidelines-Heart Failure hospitals between January 1, 2006, and October 1, 2011. We further summarized use by renal function and assessed renal contraindicated AHM use for patients with estimated glomerular filtration rate <30 mL/min/1.73m(2). Among 8791 patients meeting inclusion criteria, the median age was 77 (interquartile range 71-83), 62.3% were female, median body mass index was 29.7 (interquartile range 25.5-35.3), median hemoglobin A1c was 6.8 (interquartile range 6.2-7.8), and 34% had ejection fraction <40%. 74.9% of patients filled a prescription for an AHM, with insulin (39.5%), sulfonylureas (32.4%), and metformin (17%) being the most commonly used AHMs. Insulin use was higher and sulfonylurea/metformin use was lower among patients with lower renal function classes. Among 1512 patients with estimated glomerular filtration rate <30 mL/min/1.73m(2), 35.4% filled prescriptions for renal contraindicated AHMs per prescribing information, though there was a trend toward lower renal contraindicated AHM use over time (Cochran-Mantel-Haenszel row-mean score test P=0.048). Although use of other AHMs was low overall, thiazolidinediones were used in 6.6% of HF patients, and dipeptidyl peptidase-4 inhibitors were used in 5.1%, with trends for decreasing thiazolidinedione use and increased dipeptidyl peptidase-4 inhibitor use over time (P<0.001). Treatment of diabetes mellitus in patients with HF and chronic kidney disease is complex, and these patients are commonly treated with renal contraindicated AHMs, including over 6% receiving a thiazolidinedione, despite known concerns regarding HF. More research regarding safety and efficacy of various AHMs among HF patients is needed. © 2016 American Heart Association, Inc.

The Afghan National Police: Turning a Counterinsurgency Problem into a Solution

DTIC Science & Technology

2009-12-01

27 “Special Forces groups are organized in small teams of 12 men — a.k.a. Operational Detachment Alpha (ODA). A typical Green Beret’s Team structure...Human Progress, 98. 162 Akbar S. Ahmed and David M. Hart, Islam in Tribal Societies: From the Atlas to the Indus (London; Boston: Routledge & Kegan ...Boston: Routledge & Kegan Paul, 1984. Al Jazeera. “Taliban Issue Code of Conduct.” Al Jazeera English Central/S. Asia (July 27, 2009), http

77 FR 42546 - In the Matter of the Designation of Ahmed Abdulrahman Sihab Ahmed Sihab as a Specially Designated...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-19

... DEPARTMENT OF STATE [Public Notice 7957] In the Matter of the Designation of Ahmed Abdulrahman... Sihab, committed, or poses a significant risk of committing, acts of terrorism that threaten the security of U.S. nationals or the national security, foreign policy, or economy of the United States...

Propionibacterium acnes endophthalmitis in Ahmed glaucoma valve.

PubMed

Gutiérrez-Díaz, E; Montero-Rodríguez, M; Mencía-Gutiérrez, E; Fernández-González, M C; Pérez-Blázquez, E

2001-01-01

To report a case of Propionibacterium acnes endophthalmitis in a patient with an Ahmed glaucoma valve. A nine-year-old boy with bilateral congenital glaucoma, with an Ahmed glaucoma valve implanted in the left eye, had recurrent conjunctival dehiscence and endophthalmitis. Vitreous cultures demonstrated the presence of Propionibacterium acnes. This is the first reported case of Propionibacterium acnes endophthalmitis in an Ahmed glaucoma valve and the second one in a glaucoma drainage device. We strongly recommend using a patch graft to prevent and treat tube exposure. Conjunctival grafts may be useful to close the conjunctiva when there is marked scarring to prevent patch exposure and melting or extrusion.

Delayed-onset streptococcus pyogenes endophthalmitis following Ahmed glaucoma valve implantation.

PubMed

Bayraktar, Zerrin; Kapran, Ziya; Bayraktar, Sükrü; Acar, Nur; Unver, Yaprak Banu; Gök, Kemran

2005-01-01

To report a case of delayed-onset Streptococcus pyogenes endophthalmitis following implantation of an Ahmed glaucoma valve. A 10-year-old patient presented with acute endophthalmitis 1 year after Ahmed glaucoma valve implantation. The conjunctiva and Tenon's capsule over the valve plate had been penetrated by one of the polypropylene fixation sutures. The valve was removed, and pars plana vitrectomy was performed. Vitreous specimens and removal of the discharge over the plate revealed Streptococcus pyogenes. This is the first documented case of Streptococcus pyogenes endophthalmitis following Ahmed glaucoma valve implantation. We think the conjunctival buttonhole caused by the polypropylene suture provided an entry site for the infection. (c) Japanese Ophthalmological Society 2005.

Ahmed glaucoma valve implant: surgical technique and complications.

PubMed

Riva, Ivano; Roberti, Gloria; Oddone, Francesco; Konstas, Anastasios Gp; Quaranta, Luciano

2017-01-01

Implantation of Ahmed glaucoma valve is an effective surgical technique to reduce intraocular pressure in patients affected with glaucoma. While in the past, the use of this device was reserved to glaucoma refractory to multiple filtration surgical procedures, up-to-date mounting experience has encouraged its use also as a primary surgery for selected cases. Implantation of Ahmed glaucoma valve can be challenging for the surgeon, especially in patients who already underwent previous multiple surgeries. Several tips have to be acquired by the surgeon, and a long learning curve is always needed. Although the valve mechanism embedded in the Ahmed glaucoma valve decreases the risk of postoperative hypotony-related complications, it does not avoid the need of a careful follow-up. Complications related to this type of surgery include early and late postoperative hypotony, excessive capsule fibrosis around the plate, erosion of the tube or plate edge, and very rarely infection. The aim of this review is to describe surgical technique for Ahmed glaucoma valve implantation and to report related complications.

Ahmed glaucoma valve implant: surgical technique and complications

PubMed Central

Riva, Ivano; Roberti, Gloria; Oddone, Francesco; Konstas, Anastasios GP; Quaranta, Luciano

2017-01-01

Implantation of Ahmed glaucoma valve is an effective surgical technique to reduce intraocular pressure in patients affected with glaucoma. While in the past, the use of this device was reserved to glaucoma refractory to multiple filtration surgical procedures, up-to-date mounting experience has encouraged its use also as a primary surgery for selected cases. Implantation of Ahmed glaucoma valve can be challenging for the surgeon, especially in patients who already underwent previous multiple surgeries. Several tips have to be acquired by the surgeon, and a long learning curve is always needed. Although the valve mechanism embedded in the Ahmed glaucoma valve decreases the risk of postoperative hypotony-related complications, it does not avoid the need of a careful follow-up. Complications related to this type of surgery include early and late postoperative hypotony, excessive capsule fibrosis around the plate, erosion of the tube or plate edge, and very rarely infection. The aim of this review is to describe surgical technique for Ahmed glaucoma valve implantation and to report related complications. PMID:28255226

Potential of Iraqi Local Councils to facilitate Iraqi National Unity

DTIC Science & Technology

2009-06-12

U.S. forces to form a multi-tribal grassroots council involving both sects. Abu Ahmed currently serves as a local contractor in Baghdad. He has...worked with local councils and supported their efforts in reconstruction. Abu Ahmed offers insight into local councils from a unique third...responded on average in agreement when asked whether reform was more effective if local leaders sought to achieve it. Abu Ahmed , a prominent

Association of Antihypertensive Medication Adherence With Healthcare Use and Medicaid Expenditures for Acute Cardiovascular Events.

PubMed

Yang, Zhuo; Howard, David H; Will, Julie; Loustalot, Fleetwood; Ritchey, Matthew; Roy, Kakoli

2016-05-01

We assessed the impact of antihypertensive medication (AHM) adherence on the incidence and associated Medicaid costs of acute cardiovascular disease (CVD) events among Medicaid beneficiaries. The study cohort (n=59,037) consists of nonelderly adults continuously enrolled (36 mo and above) in a Medicaid fee-for-service program. AHM adherence was calculated using the medication possession ratio (MPR) and stratified to low (MPR<60%), moderate (60%≤MPR<80%), and high (MPR≥80%) levels. We used a proportional hazard model to estimate risk for acute CVD events and generalized linear models to estimate Medicaid per-patient-per-year costs. Low and moderate adherence subgroups had about 1.8 and 1.4 times higher risk of acute CVD events, compared with high adherence subgroup. By adherence level, Medicaid per-patient per-year costs for (1) CVD-related emergency department visits and hospitalizations were $661 (low), $479 (moderate), and $343 (high) and (2) AHMs were $430 (low), $604 (moderate), and $664 (high). Costs for CVD events and AHMs combined were similar across adherence subgroups. Lower adherence to AHM was associated with progressively higher CVD risk. The increase in medication cost from higher AHM adherence was offset solely by reduced Medicaid spending on acute CVD events.

The effect of intravitreal bevacizumab injection before Ahmed valve implantation in patients with neovascular glaucoma.

PubMed

Kang, Jung Youb; Nam, Ki Yup; Lee, Sang Joon; Lee, Seung Uk

2014-08-01

To evaluate the effect of intravitreal bevacizumab (IVB) before Ahmed valve implantation for treatment of neovascular glaucoma (NVG). This study is a retrospective, comparative, consecutive case series. The study group consisted of 27 eyes of 26 patients with NVG who underwent an Ahmed valve implantation. Thirteen eyes were treated with Ahmed valve implantation alone (control group), and 14 eyes were treated with a combination of preoperative IVB injection and Ahmed valve implantation (IVB group). Visual acuity, intraocular pressure (IOP), number of anti-glaucoma medications, surgical complications, and success rate were compared between the two groups. There were no significant differences in preoperative characteristics between the two groups. Visual acuity at 1, 2 weeks, and 1 month after surgery were significantly better in the IVB group (p = 0.038, 0.034, and 0.032, respectively). Hyphema associated with Ahmed valve implantation occurred significantly less in the IVB group (p = 0.016). On the other hand, the mean IOP and number of anti-glaucoma medications at all follow-up periods were similar between the two groups. Kaplan-Meier survival analysis showed the probability of success 6 months after surgery as 71.4 % in the IVB group and 84.6 % in the control group. No significant difference in success rate was found between the groups (p = 0.422). IVB before Ahmed valve implantation for treatment of NVG reduced the incidence of hyphema. In this retrospective study, IVB provided better visual outcome in the early postoperative periods but did not significantly improve mean IOP, number of anti-glaucoma medications, or success rate.

Trabeculectomy versus Ahmed Glaucoma Valve implantation in neovascular glaucoma

PubMed Central

Shen, Christopher C; Salim, Sarwat; Du, Haiming; Netland, Peter A

2011-01-01

Purpose: To compare surgical outcomes in neovascular glaucoma patients who underwent trabeculectomy with mitomycin C versus Ahmed Glaucoma Valve implantation. Patients and methods: This was a retrospective comparative case series. We reviewed 40 eyes of 39 patients with underlying diagnosis of neovascular glaucoma, divided into two groups: Ahmed Glaucoma Valve (N = 20) and trabeculectomy with mitomycin C (N = 20). Surgical success was defined as 6 mm Hg ≤ intraocular pressure ≤21 mm Hg, with or without the use of glaucoma medications, with no further glaucoma surgery, and light perception or better vision. Early postoperative hypotony was defined as intraocular pressure <5 mm Hg during the first postoperative week. Results: The average follow-up was 31 months (range 6–87 months) for the Ahmed Glaucoma Valve group and 25 months (6–77 months) for the trabeculectomy group. Although the mean number of postoperative intraocular pressure-lowering medications was significantly higher in the trabeculectomy group compared with the Ahmed Glaucoma Valve group at 3 and 6 month time points, there was no statistically significant difference at any other time point. There was no statistically significant difference between both groups in postoperative visual acuity and intraocular pressure. Success was 70% and 65% at 1 year and 60% and 55% at 2 years after Ahmed Glaucoma Valve and trabeculectomy, respectively. Kaplan–Meier survival curve analysis showed no significant difference in success between the two groups (P = 0.815). Hyphema was the most common complication in both groups. Conclusion: We found similar results after trabeculectomy with mitomycin C and Ahmed Glaucoma Valve implantation in eyes with neovascular glaucoma. PMID:21468334

The Ahmed versus Baerveldt study: three-year treatment outcomes.

PubMed

Christakis, Panos G; Tsai, James C; Kalenak, Jeffrey W; Zurakowski, David; Cantor, Louis B; Kammer, Jeffrey A; Ahmed, Iqbal I K

2013-11-01

To compare 2 commonly used aqueous drainage devices for the treatment of refractory glaucoma. International, multicenter, randomized trial. Patients aged 18 years or older with uncontrolled or high-risk glaucoma refractory to maximum medical therapy, many of whom had failed trabeculoplasty and trabeculectomy. Eligible patients were randomized to an Ahmed-FP7 valve implant (New World Medical, Inc., Rancho Cucamonga, CA) or a Baerveldt-350 implant (Abbott Medical Optics, Inc., Santa Ana, CA) using a standardized surgical technique. The primary outcome was failure, defined as intraocular pressure (IOP) outside of the target range (5-18 mmHg, with ≥20% reduction from baseline) for 2 consecutive visits after 3 months, vision-threatening complications, de novo glaucoma procedures, or loss of light perception. Secondary outcome measures include IOP, medication use, visual acuity, complications, and interventions. A total of 238 patients were enrolled and randomized; 124 received the Ahmed implant and 114 received the Baerveldt implant. Baseline characteristics were similar in both groups. Half the study group had secondary glaucoma, and 37% had previously failed trabeculectomy. The mean preoperative IOP was 31.4±10.8 mmHg on 3.1±1.0 glaucoma medications. Median baseline Snellen visual acuity was 20/100. At 3 years, the cumulative probability of failure was 51% in the Ahmed group and 34% in the Baerveldt group (P = 0.03). Mean IOP was 15.7±4.8 mmHg in the Ahmed group (49% reduction) and 14.4±5.1 mmHg in the Baerveldt group (55% reduction; P = 0.09). Mean number of glaucoma medications was 1.8±1.4 in the Ahmed group (42% reduction) and 1.1±1.3 in the Baerveldt group (65% reduction; P = 0.002). There was a moderate but similar decrease in visual acuity in both groups (P< 0.001). The 2 groups had similar complication rates (52% Ahmed, 62% Baerveldt; P = 0.12); however, the Baerveldt group had a higher rate of hypotony-related vision-threatening complications (0% Ahmed, 6% Baerveldt; P = 0.005). More interventions were required in the Baerveldt group, although the difference did not reach statistical significance (38% Ahmed, 50% Baerveldt; P = 0.07). Most complications were transient, and most interventions were slit-lamp procedures. Both devices were effective in reducing IOP and glaucoma medications. The Baerveldt group had a lower failure rate and required fewer medications than the Ahmed group after 3 years, but it experienced more hypotony-related vision-threatening complications. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

The Ahmed Versus Baerveldt study: one-year treatment outcomes.

PubMed

Christakis, Panos G; Kalenak, Jeffrey W; Zurakowski, David; Tsai, James C; Kammer, Jeffrey A; Harasymowycz, Paul J; Ahmed, Iqbal I K

2011-11-01

To report the 1-year treatment outcomes of the Ahmed Versus Baerveldt (AVB) Study. Multicenter randomized clinical trial. A total of 238 patients were enrolled in the study, including 124 in the Ahmed group and 114 in the Baerveldt group. Patients aged 18 years or older with uncontrolled glaucoma refractory to medicinal, laser, and surgical therapy were randomized to undergo implantation of an Ahmed-FP7 valve (New World Medical, Inc., Rancho Cucamonga, CA) or a Baerveldt-350 implant (Abbott Medical Optics, Inc., Santa Ana, CA), to be followed for 5 years. The primary outcome measure was failure, defined as intraocular pressure (IOP) out of target range (5-18 mmHg with ≥ 20% reduction from baseline) for 2 consecutive visits after 3 months, vision-threatening complications, additional glaucoma procedures, or loss of light perception. Secondary outcome measures included IOP, medication use, visual acuity, complications, and interventions. There were no significant differences in baseline ocular or demographic characteristics between the study groups with the exception of sex. Preoperatively, the study group had a mean IOP of 31.4 ± 10.8 mmHg on a mean of 3.1 ± 1.0 glaucoma medications with a median Snellen acuity of 20/100. The cumulative probability of failure a 1-year was 43% in the Ahmed group and 28% in the Baerveldt group (P = 0.02). The mean IOP at 1 year was 16.5 ± 5.3 mmHg in the Ahmed group and 13.6 ± 4.8 mmHg in the Baerveldt group (P < 0.001). The mean number of glaucoma medications required was 1.6 ± 1.3 in the Ahmed group and 1.2 ± 1.3 in the Baerveldt group (P = 0.03). Visual acuity was similar in both groups at all visits in the first year (P = 0.66). In the first year after surgery, there were a similar number of patients who experienced postoperative complications in the 2 groups (45% Ahmed, 54% Baerveldt, P = 0.19), but a greater number of patients in the Baerveldt group required interventions (26% Ahmed vs. 42% Baerveldt, P = 0.009). The Baerveldt-350 group had a higher success rate than the Ahmed-FP7 group after 1 year of follow-up, but required a greater number of interventions. Proprietary or commercial disclosure may be found after the references. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Chain Dynamic Formulations for Multibody System Tracked Vehicles (Preprint)

DTIC Science & Technology

2013-03-06

Michael Wallin 1 Ahmed K. Aboubakr 1 Paramsothy Jayakumar 2 Michael D. Letherwood 2 Ashraf Hamed 1 Ahmed A. Shabana 1...5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Michael Wallin; Ahmed Aboubakr; Paramsothy Jayakumar ; Michael Letherwood; Ashraf Hamed 5d...Taylor & Francis/CRC, Boca Raton, Florida. 16. Shabana, A. A., Hamed, A. M., Mohamed, A. A., Jayakumar , P., and Letherwood, M. D. 2012, “Use of B

A Novel Surgical Technique for Ahmed Valves in Refractory Glaucoma With Silicone Oil Endotamponade.

PubMed

Davo-Cabrera, Juan Maria; Lanzagorta-Aresti, Aitor; Alcocer Yuste, Pablo

2017-10-01

The purpose of the study is to describe a novel technique to implant Ahmed valves in patients with refractory glaucoma because of silicone oil (SO) endotamponade PATIENTS:: Three patients with glaucoma without SO removal were used as an example for this technique. Technique report. We introduce a standard technique modification for Ahmed valves in patients with SO. This modification consists on locating the Ahmed valve more tangential to the limbus curvature instead of the usual perpendicular position and inserting the tube in the posterior chamber. The tube can be longer and run parallel to pupil. This technique allows use superotemporal quadrant (fewer complications), avoid corneal touch and decrease SO loss through the tube to subconjunctival space.

Ahmed Midhat and Adnan Adivar on history of science and civilizations.

PubMed

Kilinc, Berna

2008-01-01

I analyze the contrasting visions of history of science in the works respectively of an Ottoman and a Turkish man of letters, Ahmed Midhat and Adnan Adivar, and claim that they perceived the link between science and cultural identity in different terms. Ahmed Midhat conceived of science as closely tied to its cultural matrix, whereas Adivar settled for a less holistic view. Both authors saw science as the harbinger of a new social existence, but they evaluated the prospects of this existence in rather divergent ways. Ahmed Midhat was concerned with the detrimental effects of an unquestioning appropriation of European scientific traditions, while Adivar had no such qualms, and celebrated the universalism and progressiveness of reason as revealed in history of science. I suggest that these differences in their outlooks presented their readers with civilizational choices.

Electrical Stimulation of Artificial Heart Muscle: A Look Into the Electrophysiologic and Genetic Implications.

PubMed

Mohamed, Mohamed A; Islas, Jose F; Schwartz, Robert J; Birla, Ravi K

Development of tissue-engineered hearts for treatment of myocardial infarction or biologic pacemakers has been hindered by the production of mostly arrhythmic or in-synergistic constructs. Electrical stimulation (ES) of these constructs has been shown to produce tissues with greater twitch force and better adrenergic response. To further our understanding of the mechanisms underlying the effect of ES, we fabricated a bioreactor capable of delivering continuous or intermittent waveforms of various types to multiple constructs simultaneously. In this study, we examined the effect of an intermittent biphasic square wave on our artificial heart muscle (AHM) composed of neonatal rat cardiac cells and fibrin gel. Twitch forces, spontaneous contraction rates, biopotentials, gene expression profiles, and histologic observations were examined for the ES protocol over a 12 day culture period. We demonstrate improved consistency between samples for twitch force and contraction rate, and higher normalized twitch force amplitudes for electrically stimulated AHMs. Improvements in electrophysiology within the AHM were noted by higher conduction velocities and lower latency in electrical response for electrically stimulated AHMs. Genes expressing key electrophysiologic and structural markers peaked at days 6 and 8 of culture, only a few days after the initiation of ES. These results may be used for optimization strategies to establish protocols for producing AHMs capable of replacing damaged heart tissue in either a contractile or electrophysiologic capacity. Optimized AHMs can lead to alternative treatments to heart failure and alleviate the limited donor supply crisis.

Electrical Stimulation of Artificial Heart Muscle: a look into the electrophysiological and genetic implications

PubMed Central

Mohamed, Mohamed A; Islas, Jose F; Schwartz, Robert J; Birla, Ravi K

2016-01-01

Development of tissue-engineered hearts for treatment of myocardial infarction or biological pacemakers has been hindered by the production of mostly arrhythmic or in-synergistic constructs. Electrical stimulation (ES) of these constructs has been shown to produce tissues with greater twitch force and better adrenergic response. In order to further our understanding of the mechanisms underlying the effect of ES, we fabricated a bioreactor capable of delivering continuous or intermittent waveforms of various types to multiple constructs simultaneously. In this study, we examined the effect of an intermittent biphasic square wave on our artificial heart muscle (AHM) composed of neonatal rat cardiac cells and fibrin gel. Twitch forces, spontaneous contraction rates, biopotentials, gene expression profiles, and histological observations were examined for the ES protocol over a 12 day culture period. We demonstrate improved consistency between samples for twitch force and contraction rate, and higher normalized twitch force amplitudes for electrically stimulated AHM. Improvements in electrophysiology within the AHM was noted by higher conduction velocities and lower latency in electrical response for electrically stimulated AHM. Genes expressing key electrophysiological and structural markers peaked at days 6 and 8 of culture, only a few days after the initiation of ES. These results may be used for optimization strategies to establish protocols for producing AHM capable of replacing damaged heart tissue in either a contractile or electrophysiological capacity. Optimized AHM can lead to alternative treatments to heart failure and alleviate the limited donor supply crisis. PMID:28459744

Prescribing and deprescribing antihypertensive medication in older people by Dutch general practitioners: a qualitative study

PubMed Central

van Middelaar, Tessa; Ivens, Sophie D; van Peet, Petra G; Poortvliet, Rosalinde K E; Richard, Edo; Pols, A Jeannette; Moll van Charante, Eric P.

2018-01-01

Objectives To explore general practitioners’ (GPs) routines and considerations on (de)prescribing antihypertensive medication (AHM) in older patients, their judgement on usability of the current guideline and needs for future support. Design Semistructured interviews. Setting Dutch general practice. Participants Fifteen GPs were purposively sampled based on level of experience and practice characteristics until saturation was reached. Results GPs appeared reluctant to start AHM, especially in patient >80 years. High systolic blood pressure and history of cardiovascular disease or diabetes were enablers to start or intensify treatment. Reasons to refrain from this were frailty and patient preference. GPs described a tendency to continue AHM regimens unchanged, influenced by daily time constraints, automated prescription routines and anticipating discomfort when disturbing patients’ delicate balance. GPs were only inclined to deprescribe AHM in terminally ill patients or after prolonged achievement of target levels in combination with side effects or patient preference. Deprescription was facilitated when GPs had experience with patients showing increased quality of life after deprescription and was withheld by anticipated regret (ie, GPs’ fear of a stroke after deprescribing). GPs felt insufficient guidance from current guidelines, especially on deprescription. Conclusions GPs are reluctant to start or deprescribe AHM in older people and have a propensity to continue AHM within a daily routine that insufficiently supports critical medication review. (De)prescription is influenced by patient preferences and anticipated regret and current guidelines provide insufficient guidance. PMID:29678989

Effects of intense aerobic exercise and/or antihypertensive medication in individuals with metabolic syndrome.

PubMed

Ramirez-Jimenez, M; Morales-Palomo, F; Ortega, J F; Mora-Rodriguez, R

2018-05-17

We studied the blood pressure lowering effects of a bout of exercise and/or antihypertensive medicine with the goal of studying if exercise could substitute or enhance pharmacologic hypertension treatment. Twenty-three hypertensive metabolic syndrome patients chronically medicated with angiotensin II receptor 1 blockade antihypertensive medicine underwent 24-hr monitoring in four separated days in a randomized order; a) after taking their habitual dose of antihypertensive medicine (AHM trial), b) substituting their medicine by placebo medicine (PLAC trial), c) placebo medicine with a morning bout of intense aerobic exercise (PLAC+EXER trial) and d) combining the exercise and antihypertensive medicine (AHM+EXER trial). We found that in trials with AHM subjects had lower plasma aldosterone/renin activity ratio evidencing treatment compliance. Before exercise, the trials with AHM displayed lower systolic (130±16 vs 133±15 mmHg; P=0.018) and mean blood pressures (94±11 vs 96±10 mmHg; P=0.036) than trials with placebo medication. Acutely (i.e., 30 min after treatments) combining AHM+EXER lowered systolic blood pressure (SBP) below the effects of PLAC+EXER (-8.1±1.6 vs -4.9±1.5 mmHg; P=0.015). Twenty-four hour monitoring revealed no differences among trials in body motion. However, PLAC+EXER and AHM lowered SBP below PLAC during the first 10 hours, time at which PLAC+EXER effects faded out (i.e., at 19 PM). Adding exercise to medication (i.e., AHM+EXER) resulted in longer reductions in SBP than with exercise alone (PLAC+EXER). In summary, one bout of intense aerobic exercise in the morning cannot substitute the long-lasting effects of antihypertensive medicine in lowering blood pressure, but their combination is superior to exercise alone. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Comparison of polypropylene and silicone Ahmed Glaucoma Valves.

PubMed

Ishida, Kyoko; Netland, Peter A; Costa, Vital P; Shiroma, Lineu; Khan, Baseer; Ahmed, Iqbal Ike K

2006-08-01

To evaluate and compare the clinical outcomes after implantation of the silicone plate and the polypropylene plate Ahmed Glaucoma Valves. Prospective, multicenter, comparative series. A total of 132 patients with uncontrolled glaucoma were treated with either the silicone or polypropylene Ahmed Glaucoma Valve implant. Success was defined according to 2 criteria: (1) intraocular pressure (IOP) of 6 mmHg or more or 21 mmHg or less, and (2) IOP reduction of at least 30% relative to preoperative values. Eyes requiring further glaucoma surgery, including cyclophotocoagulation, or showing loss of light perception were classified as failures. Average follow-up was 12.8 months (range, 6-30 months) for the silicone plate group and 14.5 months (range, 6-30 months) for the polypropylene plate group (P = 0.063). At the last follow-up examination, the mean IOP was 13.8+/-3.9 mmHg and 17.3+/-6.5 mmHg (P<0.0001) and the mean number of antiglaucoma medications was 1.9+/-1.3 and 2.1+/-1.4 (P = 0.48) in the silicone plate and polypropylene plate groups, respectively. The life-table success rates for the silicone plate and polypropylene plate groups were 94.2% and 83.2% at 12 months and 82.4% and 56.7% at 24 months by definition 1, respectively (P = 0.035). When an IOP reduction of at least 30% was used for success criterion (definition 2), probabilities of success were 89.5% and 71.7% at 12 months and 78.3% and 68.5% at 24 months in the silicone and the polypropylene plate groups, respectively (P = 0.012). Visual outcomes were comparable between the 2 groups. However, complications including Tenon's cyst were observed more frequently in the polypropylene plate than in the silicone plate group (P<0.05). The silicone Ahmed Glaucoma Valve (model FP7) showed improved IOP reduction compared with the polypropylene (model S2) implant. Differences observed in mean IOP, success rate, and complications suggest that plate material may influence clinical outcome.

The impact of Arizona Highways Magazine's facebook page.

DOT National Transportation Integrated Search

2014-02-01

This project examined the relationship between use of the Arizona Highways magazine (AHM) Facebook Page and the decision to : travel to or within Arizona. Key purposes were to: (1) provide a thorough understanding of AHM Facebook Page users, includin...

Maritime Strategy in Pakistan

DTIC Science & Technology

2004-12-01

69 Shamim Ahmed Rizvi, “New Measures in the Shipping Policy,” Pakistan and Gulf Economist (22- 28 April, 2002) http...2003. Rizvi, Shamim Ahmed. “New Measures in the Shipping Policy,” Pakistan and Gulf Economist (22-28 April, 2002) http

Antifibrotic effect of aloe vera in viral infection-induced hepatic periportal fibrosis

PubMed Central

Hegazy, Sahar K; El-Bedewy, Mohamed; Yagi, Akira

2012-01-01

AIM: To investigate the anti-oxidative and anti-fibrotic effects of aloe vera in patients with liver fibrosis. METHODS: Aloe vera high molecular weight fractions (AHM) were processed by patented hyper-dry system in combination of freeze-dry technique with microwave and far infrared-ray radiation. Fifteen healthy volunteers as the control group and 40 patients were included. The patients were randomly subdivided into two equal groups: the conventional group was treated with placebo (starch), and AHM group was treated with 0.15 gm/d AHM, both for 12 consecutive weeks. The patients were investigated before and after treatment. Serum activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), hyaluronic acid (HA), transforming growth factor-β (TGF-β) and matrixmetalloproteinase-2 (MMP-2) were determined. The reduced glutathione (GSH) and malondialdehyde (MDA) levels in liver were assayed and the expression of hepatic α-smooth muscle actin (α-SMA) was identified by immunohistochemistry. RESULTS: At the start of the study, the hematoxylin and eosin staining revealed fibro-proliferated bile ductules, thick fibrous septa and dense inflammatory cellular infiltration in the patients before treatment. The use of AHM for 12 wk significantly ameliorated the fibrosis, inhibited the inflammation, and resulted in minimal infiltration and minimal fibrosis compared to the conventional group. The enzyme activities of the liver (ALT, AST and ALP) were attenuated after treatment in both groups, and the decrease in the AHM group was more significant as compared with the conventional group. Similar to the AST, the MDA levels were significantly higher before treatment, and were attenuated after treatment in both groups. In contrast, the hepatic glutathione content in the patients were decreased significantly in the AHM group compared to the controls. The serum levels of the fibrosis markers (HA, TGF-β and MMP-2) were also reduced significantly after treatment. The expression of α-SMA was modified in patients before and after treatment as compared with the normal controls. In the conventional group, there was only thin and incomplete parenchymal α-SMA positive septum joining the thickened centrilobular veins, while in the AHM group, few α-SMA positive cells were present in sinusoid and lobule after treatment. CONCLUSION: Oral supplementation with AHM could be helpful in alleviating the fibrosis and inflammation of hepatic fibrosis patients. PMID:22563189

Chain Dynamic Formulations for Multibody System Tracked Vehicles

DTIC Science & Technology

2012-08-07

Chicago Paramsothy Jayakumar , Mike Letherwood US Army RDECOM TARDEC 7 August 2012 UNCLASSIFIED: Distribution Statement A. Approved for...GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Michael Wallin; Paramsothy Jayakumar ; Mike Letherwood; Ahmed Aboubakr; Ahmed Shabana 5d

Wavelet Analysis for Molecular Dynamics

DTIC Science & Technology

2015-06-01

Research Directorate, ARL Jaydeep P Bardhan Dept. of Mechanical and Industrial Engineering, Northeastern University Boston, MA Ahmed E Ismail Dept. of...Rinderspacher, Jaydeep P Bardhan , and Ahmed E Ismail ARL-MR-0891 Approved for public release; distribution is unlimited. October 2013–September 2014 US Army

Application of 5-Fluorouracil-Polycaprolactone Sustained-Release Film in Ahmed Glaucoma Valve Implantation Inhibits Postoperative Bleb Scarring in Rabbit Eyes.

PubMed

Bi, Xiu-Zeng; Pan, Wei-Hua; Yu, Xin-Ping; Song, Zong-Ming; Ren, Zeng-Jin; Sun, Min; Li, Cong-Hui; Nan, Kai-Hui

2015-01-01

This study was designed to investigate whether 5-fluorouracil (5-Fu)-polycaprolactone sustained-release film in Ahmed glaucoma valve implantation inhibits postoperative bleb scarring in rabbit eyes. Eighteen New Zealand white rabbits were randomly divided into three groups (A, B and C; n = 6 per group). Group A received combined 5-Fu-polycaprolactone sustained-release film application and Ahmed glaucoma valve implantation, group B received local infiltration of 5-Fu and Ahmed glaucoma valve implantation, and group C received Ahmed glaucoma valve implantation. Postoperative observations were made of the anterior segment, intraocular pressure, central anterior chamber depth, blebs, drainage tube, and accompanying ciliary body detachment. The pathology of the blebs and surrounding tissues were observed at month 3 postoperatively. We revealed that the 5-Fu-polycaprolactone sustained-release film maintained a release concentration range of 13.7 ± 0.12 to 37.41 ± 0.47 μg/ml over three months in vitro. Postoperatively, diffuse blebs with ridges were found in all eyes in group A, two blebs were observed in group B, and no bleb formation was present in group C. The postoperative central anterior chamber depth in group A was significantly less than that of the other two groups. The postoperative intraocular pressure of group A stabilized at 6.33-8.67 mmHg, whereas that of group C gradually remained at 7.55-10.02 mmHg. The histopathology showed that the fibrous tissue thickness of the blebs in group A was significantly thinner than that of the other groups. We conclude that the 5-Fu-polycaprolactone sustained-release film had a sustained drug release effect, which promoted the inhibition of bleb scarring after Ahmed glaucoma valve implantation.

A bio-inspired device for drag reduction on a three-dimensional model vehicle.

PubMed

Kim, Dongri; Lee, Hoon; Yi, Wook; Choi, Haecheon

2016-03-10

In this paper, we introduce a bio-mimetic device for the reduction of the drag force on a three-dimensional model vehicle, the Ahmed body (Ahmed et al 1984 SAE Technical Paper 840300). The device, called automatic moving deflector (AMD), is designed inspired by the movement of secondary feathers on bird's wing suction surface: i.e., secondary feathers pop up when massive separation occurs on bird's wing suction surface at high angles of attack, which increases the lift force at landing. The AMD is applied to the rear slanted surface of the Ahmed body to control the flow separation there. The angle of the slanted surface considered is 25° at which the drag coefficient on the Ahmed body is highest. The wind tunnel experiment is conducted at Re H  = 1.0 × 10(5)-3.8 × 10(5), based on the height of the Ahmed body (H) and the free-stream velocity (U ∞). Several AMDs of different sizes and materials are tested by measuring the drag force on the Ahmed body, and showed drag reductions up to 19%. The velocity and surface-pressure measurements show that AMD starts to pop up when the pressure in the thin gap between the slanted surface and AMD is much larger than that on the upper surface of AMD. We also derive an empirical formula that predicts the critical free-stream velocity at which AMD starts to operate. Finally, it is shown that the drag reduction by AMD is mainly attributed to a pressure recovery on the slanted surface by delaying the flow separation and suppressing the strength of the longitudinal vortices emanating from the lateral edges of the slanted surface.

Reusable Rocket Engine Advanced Health Management System. Architecture and Technology Evaluation: Summary

NASA Technical Reports Server (NTRS)

Pettit, C. D.; Barkhoudarian, S.; Daumann, A. G., Jr.; Provan, G. M.; ElFattah, Y. M.; Glover, D. E.

1999-01-01

In this study, we proposed an Advanced Health Management System (AHMS) functional architecture and conducted a technology assessment for liquid propellant rocket engine lifecycle health management. The purpose of the AHMS is to improve reusable rocket engine safety and to reduce between-flight maintenance. During the study, past and current reusable rocket engine health management-related projects were reviewed, data structures and health management processes of current rocket engine programs were assessed, and in-depth interviews with rocket engine lifecycle and system experts were conducted. A generic AHMS functional architecture, with primary focus on real-time health monitoring, was developed. Fourteen categories of technology tasks and development needs for implementation of the AHMS were identified, based on the functional architecture and our assessment of current rocket engine programs. Five key technology areas were recommended for immediate development, which (1) would provide immediate benefits to current engine programs, and (2) could be implemented with minimal impact on the current Space Shuttle Main Engine (SSME) and Reusable Launch Vehicle (RLV) engine controllers.

The Development and Validation of Audiovisual Simulated Performance Tests Using 35mm Slides

DTIC Science & Technology

1979-05-01

is not observed, the data of Group A And B permit the investigation of a further comparison, i.e., whether an AVS tesi is less valid...CM» Ali(A NtU U trMcKklMt «tin MrU •■ Orlttr «M Cl^ In»«rt Sen« tat Um* TlfklM Oktal* AHM «rMtk UMft IM* Str*a «M TlfklM S*cur*lr MylM* TMI

Surgical Outcome of Ahmed Valve Implantation in Mexican Patients with Neovascular Glaucoma.

PubMed

Hernandez-Oteyza, Alejandra; Lazcano-Gomez, Gabriel; Jimenez-Roman, Jesus; Hernandez-Garciadiego, Carlos

2014-01-01

To describe clinical results of Ahmed glaucoma valve implantation in Mexican patients with neovascular glaucoma (NVG). We reviewed records of 60 eyes of 60 patients with NVG who underwent Ahmed valve implantation, with a follow-up period of 1 year. We identified successful and failed cases and compared baseline and follow-up characteristics to identify possible differences between both groups. We classified 36 eyes (60%) as successful and 24 (40%) as failed cases. We found a significant difference in success rate in patients who had a hypertensive phase at any time during the follow-up period (OR = 5.15, CI = 1.49-20.15, p = 0.004). Patients in the success group showed a statistically significant decrease in the number of glaucoma medications 1 year after surgery (p <0.0001). We found a statistically significant difference in success rate in patients who had preoperative best corrected visual acuity (BCVA) better than logmar 0.70 (odds ratio 4.31, CI = 1.1-19.3, p = 0.03086). A hypertensive postoperative phase and a preoperative BCVA worse or equal to 20/100 seem to be risk factors for Ahmed valve surgical failure in patients with NVG. How to cite this article: Hernandez-Oteyza A, Lazcano-Gomez G, Jimenez-Roman J, Hernandez-Garciadiego C. Surgical Outcome of Ahmed Valve Implantation in Mexican Patients with Neovascular Glaucoma. J Curr Glaucoma Pract 2014;8(3):86-90.

Usefulness of an ability-based health model in work ability assessments provided by psychiatrists and psychology specialists writing social security certificates.

PubMed

Solli, Hans Magnus; Barbosa da Silva, António; Egeland, Jens

2015-01-01

To investigate whether adding descriptions of the health factors "ability," "environment" and "intentions/goals" to the officially sanctioned biomedical disability model (BDM) would improve assessments of work ability for social security purposes. The study was based on a theoretical design consisting of textual analysis and interpretation. Two further work ability models were defined: the mixed health model (MHM), which describes health factors without assessing a person's abilities in context, and the ability-based health model (AHM), which assesses abilities in a concrete context of environment and intention. Eighty-six social security certificates, written by psychiatrists and psychology specialists in a Norwegian hospital-based mental health clinic, were analysed in relation to the three work ability/disability models. In certificates based on the BDM, a general pattern was found of "gradual work training". The MHM added health factors, but without linking them together in a concrete way. With the AHM, work ability was assessed in terms of a concrete unified evaluation of the claimant's abilities, environments and intentions/goals. Applying the AHM in work ability assessments, in comparison with the BDM and the MHM, is useful because this foregrounds claimants' abilities in a context of concrete goals and work-related opportunities, as a unity. Implications for Rehabilitation A concept of health should include ability, environment and intentions/goals as components. When all three of these components are described in concrete terms in a work ability assessment, an integrated picture of the individual's abilities in the context of his/her particular intentions/goals and work opportunities comes to the fore. This kind of assessment makes it possible to meet the individual's needs for individual follow-up in a work environment.

Fuzzy Logic for Determination of Crack Severity in Defense Applications

DTIC Science & Technology

2010-03-31

FUZZY LOGIC FOR DETERMINATION OF CRACK SEVERITY IN DEFENSE APPLICATIONS Vijay Sharma , Harpreet Singh, Arati M. Dixit, Ahmed Mekki Department of... Vijay Sharma ; Harpreet Singh; Arati M. Dixit; Ahmed Mekki 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S

Possible hypoglycemic effect of Aloe vera L. high molecular weight fractions on type 2 diabetic patients

PubMed Central

Yagi, Akira; Hegazy, Sahar; Kabbash, Amal; Wahab, Engy Abd-El

2009-01-01

Aloe vera L. high molecular weight fractions (AHM) containing less than 10 ppm of barbaloin and polysaccharide (MW: 1000 kDa) with glycoprotein, verectin (MW: 29 kDa), were prepared by patented hyper-dry system in combination of freeze–dry technique with microwave and far infrared radiation. AHM produced significant decrease in blood glucose level sustained for 6 weeks of the start of the study. Significant decrease in triglycerides was only observed 4 weeks after treatment and continued thereafter. No deterious effects on kidney and liver functions were apparent. Treatment of diabetic patients with AHM may relief vascular complications probably via activation of immunosystem. PMID:23964163

Defeating Stereotypes of Muslim Women

ERIC Educational Resources Information Center

Smith, Susan E.

2007-01-01

Dr. Leila Ahmed's memoir, "A Border Passage: From Cairo to America--A Woman's Journey", pulses with a theme of many women's stories: the struggle to define oneself in the face of social restraints. The 1999 book by Ahmed, the first professor of women's studies in religion at Harvard's Divinity School, came long before the recent wave of memoirs…

Ab interno management of blocked Ahmed valve in the posterior segment.

PubMed

Odrich, Steven; Wald, Kenneth; Sperber, Laurence

2013-01-01

To report a case of late failure of a posterior segment placed Ahmed valve in a uveitic eye with a corneal graft and a minimally invasive, ab interno approach in restoring valve function, pressure control, and preservation of vision. Case report. A 25 gauge trans-conjunctival 3-port pars plana vitrectomy was performed to inspect and clean the ostium of the Ahmed valve of any vitreous debris. The Ahmed valve was not disturbed externally and conjunctival dissection was not performed. A 27-gauge blunt cannula was introduced through the vitrector site and used to cannulate the tube and flush it with balanced salt solution. A bleb was immediately re-established and all instruments were removed requiring no sutures. Intraocular pressure returned to target levels and a filtration bleb was re-established. Corneal graft clarity was restored with resolution of preoperative microcystic edema. Postoperative inflammation was minimal and vision was restored. A nonfunctioning tube shunt residing in the vitreous cavity may be revised ab interno without disturbing the shunt placement or the conjunctiva under which it resides to re-establish filtration.

Follow-up of the original cohort with the Ahmed glaucoma valve implant.

PubMed

Topouzis, F; Coleman, A L; Choplin, N; Bethlem, M M; Hill, R; Yu, F; Panek, W C; Wilson, M R

1999-08-01

To study the long-term results of the Ahmed glaucoma valve implant in patients with complicated glaucoma in whom short-term results have been reported. In this multicenter study, we analyzed the long-term outcome of a cohort of 60 eyes from 60 patients in whom the Ahmed glaucoma valve was implanted. Failure was characterized by at least one of the following: intraocular pressure greater than 21 mm Hg at both of the last two visits less than 6 mm Hg at both of the last two visits, loss of light perception, additional glaucoma surgery, devastating complications, and removal or replacement of the Ahmed glaucoma valve implant. Devastating complications included chronic hypotony, retinal detachment, malignant glaucoma, endophthalmitis, and phthisis bulbi; we also report results that add corneal complications (corneal decompensation or edema, corneal graft failure) as defining a devastating complication. The mean follow-up time for the 60 eyes was 30.5 months (range, 2.1 to 63.5). When corneal complications were included in the definition of failure, 26 eyes (43%) were considered failures. Cumulative probabilities of success at 1, 2, 3, and 4 years were 76%, 68%, 54%, and 45%, respectively. When corneal complications were excluded from the definition of failure, 13 eyes (21.5%) were considered failures. Cumulative probabilities of success at 1, 2, 3, and 4 years were 87%, 82%, 76%, and 76%, respectively. Most of the failures after 12 months of postoperative follow-up were because of corneal complications. The long-term performance of the Ahmed glaucoma valve implant is comparable to other drainage devices. More than 12 months after the implantation of the Ahmed glaucoma valve implant, the most frequent adverse outcome was corneal decompensation or corneal graft failure. These corneal problems may be secondary to the type of eyes that have drainage devices or to the drainage device itself. Further investigation is needed to identify the reasons that corneal problems follow drainage device implantation.

Intravitreal ranibizumab injection combined trabeculectomy versus Ahmed valve surgery in the treatment of neovascular glaucoma: assessment of efficacy and complications.

PubMed

Liu, Lan; Xu, Yongfeng; Huang, Zhu; Wang, Xiaoyu

2016-05-26

Researches have shown anti-vascular endothelial growth factor (VEGF) agent is effective in treating neovascular eye diseases. The purpose of this study is to evaluate the efficacy and safety of intravitreal ranibizumab (IVR) injection combined trabeculectomy in the treatment of neovascular glaucoma (NVG), and compared it with Ahmed valve surgery. Thirty-six NVG patients (37 eyes) from the First Affiliated Hospital of Zhejiang medical college, between January 1, 2014 and January 31, 2015, were included in this prospective, interventional clinical study. Eighteen NVG eyes were given IVR injection one week before trabeculectomy. Ahmed valve implantation surgery was performed in nineteen eyes. Ocular pain, best corrected visual acuity (BCVA), intraocular pressure (IOP) and surgical complications were evaluated before and after the surgery. IOP was significantly decreased following IVR injection combined trabeculectomy treatment (baseline 57.1 ± 8.9 mmHg; week 1, 15.2 ± 4.3 mmHg p = 0.000; month 1, 16.9 ± 2.1 mmHg p = 0.000; month 3, 20.3 ± 7.7 mmHg p = 0.000; month 6, 19.7 ± 7.3 mmHg p = 0.000). There was a significant, though modest, BCVA improvement in sighted eyes of IVR group (baseline 2.42 ± 0.68, W1 1.80 ± 0.91, P = 0.013; M1 1.77 ± 0.93, p = 0.011). IVR injection combined trabeculectomy had less postoperative complications and lower failure ratio than Ahmed surgery (IVR 5.6 %, Ahmed 31.6 %). The study revealed that IVR injection combined trabeculectomy was an effective and safe treatment for NVG. Compared with Ahmed surgery, IVR injection combined trabeculectomy had less complications and higher success ratio. (Chinese Clinical Registry, TRN ChiCTR-OPN-16008147, 3/24/2016, retrospectively registered).

Clinical Experience with the M4 Ahmed Glaucoma Drainage Implant.

PubMed

Sluch, Ilya; Gudgel, Brett; Dvorak, Justin; Anne Ahluwalia, Mary; Ding, Kai; Vold, Steve; Sarkisian, Steven

2017-01-01

To evaluate the safety and efficacy of the M4 (porous polyethylene plate) Ahmed Glaucoma Valve (AGV) drainage implant in a multicenter retrospective study. A retrospective chart review of medical records of patients who had undergone the M4 Ahmed valve was performed from January 2013 to April 2015. The primary outcome measure was surgical failure defined as: Less than a 20% reduction in baseline intraocular pressure (IOP) to last follow-up visit, final IOP less than 5 mm Hg or greater than 18 mm Hg, reoperation for glaucoma, or loss of light perception vision. All eyes not meeting the above criteria were defined as success. A total of 291 eyes met all study inclusion criteria. The average follow-up in the study was 6 months (±7.6 months) with 112 patients achieving 12-month follow-up (38.5%). 208 eyes (71.5%) met the study success criteria at final follow-up. No statistically significant spikes in postoperative IOP at 1 and 4 months were detected. The average preoperative IOP was 26.0 on an average of 2.8 medications. At 6 months, the average IOP dropped to 16.7 on 0.9 medications and stayed relatively stable at 15.8 on 1.2 medications at 12-month follow-up. The M4 valve appears to have less of a hypertensive phase compared with the other Ahmed class valves with a similar safety profile. While 71.5% success rate was achieved at final follow-up, the failure rate steadily increased over time. While the M4 production has been discontinued, the porous design of the M4 may avoid a pressure spike in the Ahmed valve class and warrants future investigation for valve design. How to cite this article: Sluch I, Gudgel B, Dvorak J, Ahluwalia MA, Ding K, Vold S, Sarkisian S. Clinical Experience with the M4 Ahmed Glaucoma Drainage Implant. J Curr Glaucoma Pract 2017;11(3):92-96.

Institutional Statements of Commitment and Widening Participation Policy in Australia

ERIC Educational Resources Information Center

Chapman, Amy; Mangion, Antoine; Buchanan, Rachel

2015-01-01

This article describes ways in which the equity agenda, as outlined in the Bradley Review of Higher Education (Bradley et al., 2008), is translated into action in one Australian university. Drawing on the conceptual work of Ahmed (2012) to elaborate institutional life, we investigate the effects of the widening participation policy. Ahmed (2012)…

[Results of fistulizing and Ahmed valve surgery for treatment of refractory glaucoma].

PubMed

Bikbov, M M; Babushkin, A E; Chaĭka, O V; Orenburkina, O I; Matiukhina, E N

2014-01-01

Surgical results of 76 patients (76 eyes) aged 25-79 years with secondary refractory glaucoma were analyzed. The best hypotensive effect and visual functions integrity were achieved with Ahmed valve implantation (86.7% and 83.3% of cases respectively); after conventional fistulizing surgery the hypotensive effect was observed in 45.5%, noncompromised vision--in 54.5% of cases. Tunnel trabeculectomy with iridocycloretraction led to normalization of intraocular pressure and stabilization of visual functions in 81.3% and 68.8% of cases respectively and thus can be considered as an alternative to fistulizing surgery in patients with secondary refractory glaucoma. Uveal glaucoma is a relative contraindication to Ahmed valve implantation, while neovascular glaucoma is that to tunnel trabeculectomy with iridocycloretraction.

Proceedings of the Annual Midwest Research-to-Practice Conference in Adult, Continuing and Community Education (20th, Charleston, Illinois, September 26-28, 2001).

ERIC Educational Resources Information Center

Hine, William C., Ed.

The following 22 research papers are included in this proceedings: "Relationships between Scholarly Activities of Teaching and the Scholarly Activities of Research" (Ahmed Khaled Ahmed and James McElhinney); "Making the Invisible Visible: British Caribbean Immigrant Women & Their Learning Experiences in Institutions of Higher Learning" (Mary V.…

Investigating the Islamic Perspective on Homosexuality.

PubMed

Jahangir, Junaid B; Abdul-Latif, Hussein

2016-07-01

In his 2006 article in the Journal of the Islamic Medical Association of North America (JIMA), Dr. Ahmed qualified the predominant psychiatric view on homosexuality by recourse to opinions prevalent within reparative therapy circles. Conservative Muslim thinkers, online counselors, and other professionals continue to hold opinions similar to those delineated by Dr. Ahmed in his journal article. We use his article as a focal point to critique the general opinions upheld by conservative Muslim thinkers by alluding to the harms associated with reparative therapy and by rejecting the unreasonable prescription of permanent celibacy. We critique Dr. Ahmed's association of homosexuality with mental health issues, fatal diseases, alcoholism, and illicit sexual intercourse. Investigating the Muslim tradition, we encourage conservative Muslim leaders to facilitate Muslim gays and lesbians in their legitimate human need for intimacy, affection, and companionship.

75 FR 29601 - In the Matter of the Designation of Taleb Nail; Also Known as Djaafar Abou Mohamed; Also Known as...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-26

... DEPARTMENT OF STATE [Public Notice 7029] In the Matter of the Designation of Taleb Nail; Also Known as Djaafar Abou Mohamed; Also Known as Abou Mouhadji; Also Known as Mohamed Ould Ahmed Ould Ali... known as Djaafar Abou Mohamed, also known as Abou Mouhadji, also known as Mohamed Ould Ahmed Ould Ali...

Extreme Sensitivity of Botulinum Neurotoxin Domains Toward Mild Agitation

DTIC Science & Technology

2009-09-01

Department Molecular Biology, Integrated Toxicology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick...hydroxyethylpiperazine-N0-2-ethanesulfo- cular dichroism. AL OF PHARMACEUTICAL SCIENCES, VOL. 98, NO. 9, SEPTapplications. Botulinum neurotoxins (BoNTs) are...Dr. S. Ashraf Ahmed (Telephone: 301- 619-6299; Fax: 301-619-2348; E-mail: syed.ahmed@amedd.army.mil) Journal of Pharmaceutical Sciences, Vol. 98

Effect of mitomycin c and 5-flurouracil adjuvant therapy on the outcomes of Ahmed glaucoma valve implantation.

PubMed

Cui, Qi N; Hsia, Yen C; Lin, Shan C; Stamper, Robert L; Rose-Nussbaumer, Jennifer; Mehta, Nitisha; Porco, Travis C; Naseri, Ayman; Han, Ying

2017-03-01

To examine the effect of mitomycin c and 5-flurouracil on treatment outcomes following Ahmed glaucoma valve implantation. Retrospective consecutive case series. Fifty patients who received Ahmed glaucoma valve implantation from 1999 to 2013 in the San Francisco Veterans Administration Hospital. The +INJECTION group received intraoperative mitomycin c followed by postoperative mitomycin c and/or 5-flurouracil, whereas the -INJECTION group did not. Primary outcome was treatment success at 1 year post-implantation. Intraocular pressure, hypertensive phase, and the number of glaucoma medications were also examined. Twenty-six patients/eyes in the +INJECTION group and 24 patients/eyes in the -INJECTION group were included. Treatment success was higher in the +INJECTION compared with the -INJECTION group (86 vs. 58%; P = 0.04). Intraocular pressure was lower in the +INJECTION compared with the -INJECTION group at 1, 3, 6 and 12 months (P ≪ 0.00001, P = 0.00003, 0.0008 and 0.024). Hypertensive phase occurred less often in the +INJECTION compared with the -INJECTION group (3.8 vs. 54%; P = 0.021). The +INJECTION group required fewer medications compared with the -INJECTION group (P = 0.02, 0.002, 0.003 and 0.008 at 1, 3, 6 and 12 months). Complication rates were comparable between groups (46.2 and 54.2%; P = 0.63). Adjuvant treatment with antifibrotics following Ahmed glaucoma valve implantation decreased the hypertensive phase and improved surgical outcomes without impacting complication rates at 1 year. This study postulates a role for antifibrotics in the postoperative management of Ahmed glaucoma valves. © 2016 Royal Australian and New Zealand College of Ophthalmologists.

Surgical Outcomes of Ahmed or Baerveldt Tube Shunt Implantation for medically Uncontrolled Traumatic Glaucoma.

PubMed

Yadgarov, Arkadiy; Liu, Dan; Crane, Elliot S; Khouri, Albert S

2017-01-01

To describe postoperative surgical success of either Ahmed or Baerveldt tube shunt implantation for eyes with medically uncontrolled traumatic glaucoma. A review was carried out to identify patients with traumatic glaucoma that required tube shunt implantation between 2009 and 2015 at Rutgers University in Newark, New Jersey, USA. Seventeen eyes from 17 patients met inclusion criteria, including at least 3-month postoperative follow-up. The main outcome measure was surgical success at 1-year follow-up after tube implantation. Mean preoperative intraocular pressure (IOP) was 34.1 ± 8.2 mm Hg on 3.1 ± 1.6 ocular hypotensive medications. Nine eyes (53%) sustained closed globe injury. Ten eyes (59%) received an Ahmed valve shunt and seven eyes (41%) received a Baerveldt tube shunt. Surgical success rate at 1 year postoperatively was 83%. Compared to preoperative, the mean postoperative IOP was significantly lower (16.1 ± 3.5 mm Hg, p < 0.001) on significantly fewer ocular hypertensive medications (1.3 ± 1.6, p = 0.001) at a mean follow-up of 10 months. Mean IOP reduction at last follow-up was 49%. There were three cases of surgical failures: One case of hypotony, one case of tube extrusion with subsequent explan-tation, and one case requiring second tube insertion for IOP control. Implantation of an Ahmed or Baerveldt tube shunt provided successful control of IOP in patients with medically uncontrollable traumatic glaucoma. Yadgarov A, Liu D, Crane ES, Khouri AS. Surgical Outcomes of Ahmed or Baerveldt Tube Shunt Implantation for medically Uncontrolled Traumatic Glaucoma. J Curr Glaucoma Pract 2017;11(1):16-21.

The Ahmed Glaucoma Valve in Refractory Glaucoma: Experiences in Southwest Ethiopia.

PubMed

Gessesse, Girum W

2015-07-01

The management of refractory glaucoma is a challenging task for any glaucoma surgeon. This study is aimed to evaluate the efficacy of Ahmed Glaucoma Valve implantation in refractory glaucomas in South-West Ethiopia. A retrospective review was conducted on the charts of consecutive patients treated with Ahmed glaucoma valve implantation at Jimma University Specialized Hospital between August 2012 and August 2014. Success was defined as Intraocular Pressure (IOP) less than 22 mm Hg and greater than 5mm Hg at 6 months, with at least 30% reduction from baseline, without medical therapy (complete success) or either with or without medication (qualified successes). A total of 12 eyes of 11 patients were included. The mean age of patients was 40.7 (SD= 19.0) years; 63.6% of them were males. The main types of glaucoma were pseudoexfoliative (3 eyes), uveitic (2 eyes), chronic angle closure (2 eyes) and Juvenile Open Angle (JOAG) (2 eyes). The mean IOP was reduced from preoperative level (32.75±7.14 mmHg) to (15.75 ±4.35 mmHg) at six postoperative months, (P<0.001); 66.7% eyes had complete successes while 83.3% had qualified success. Intra-operative complications were encountered in 2(16.7%) eyes, while 5/12 (41.7%) eyes had post-operative complications-hypotony (one with choroidal effusion) and progression of cataract in 2 eyes each. Hypertensive phase was diagnosed in 2(16.7%) eyes. The Ahmed glaucoma valve implant appears to be effective and relatively safe for treating complicated glaucomas with success rate comparable with those reported from other studies. Ahmed glaucoma valve, refractory glaucoma, complications, Ethiopia.

[Late endophthalmitis following Ahmed valve].

PubMed

del-Hierro-Zarzuelo, A; Vico-Ruiz, E; Martínez-de-la-Casa, J M; García-Feijoó, J; Castillo-Martín, A; García-Sánchez, J

2005-11-01

A 71-year-old woman with a history of aphakic glaucoma underwent implantation of an Ahmed valve and scleral grafting in her right eye. Postoperative visual acuity was 0.5 and intraocular pressure was 12 mmHg during treatment with brimonidine tartrate (0.2%). Nine months after implantation she suffered a conjunctival infection which was treated with hygienic measures and topical antibiotic therapy. Four days later, she developed an endophthalmitis which was treated with topical, intravitreous and intravenous vancomycin and ceftazidime. The Ahmed drainage implant was replaced at 72 hours. Laboratory culture yielded Haemophilus influenzae. Four days later, the eye was enucleated. Endophthalmitis is an uncommon complication of glaucoma drainage implant surgery. Exposure of the drainage tube represents the greatest risk factor for this condition. Removal of the implant in the first 24 hours is recommended if a good visual prognosis is to be achieved.

Early postoperative endophthalmitis after pars plana Ahmed valve placement with persistent extraocular infection.

PubMed

Park, Susanna S; Rabowsky, Jeffrey

2007-01-01

This article presents a case of early postoperative endophthalmitis that occurred after vitrectomy and Ahmed Glaucoma Valve (New World Medical, Inc., Rancho Cucamonga, CA) placement and was treated with intravitreal antibiotics. Intravenous vancomycin was started after aqueous culture grew methicillin-resistant Staphylococcus aureus. The endophthalmitis improved, but new purulent discharge around the peritomy was noted 10 days after presentation, requiring removal of the valve.

Bilateral Ocular Decompression Retinopathy after Ahmed Valve Implantation for Uveitic Glaucoma.

PubMed

Flores-Preciado, Javier; Ancona-Lezama, David Arturo; Valdés-Lara, Carlos Andrés; Díez-Cattini, Gian Franco; Coloma-González, Itziar

2016-01-01

We report the case of a 29-year-old man who underwent Ahmed valve implantation in both eyes as treatment for uveitic glaucoma, subsequently presenting with bilateral ocular decompression retinopathy in the postoperative period. Ocular decompression retinopathy is a rare complication of filtering surgery in patients with glaucoma; however, the course is benign in most cases, with spontaneous resolution of bleedings and improvement of visual acuity.

Ahmed Hilmi Pasha (1839-1905): A remarkable Ottoman physician and medical translator.

PubMed

Tekiner, Halil

2016-09-15

Besides being a founding member of the Ottoman Medical Society (est. 1867) and general director of the Imperial Military and Civil medical schools in Istanbul, Dr Ahmed Hilmi Pasha offered a pathology course for the first time in the Ottoman Empire. He also translated various medical textbooks from French, and he paved the way for using Turkish in Ottoman medical education. © The Author(s) 2016.

Pars plana Ahmed valve and vitrectomy in patients with glaucoma associated with posterior segment disease.

PubMed

Wallsh, Josh O; Gallemore, Ron P; Taban, Mehran; Hu, Charles; Sharareh, Behnam

2013-01-01

To assess the safety and efficacy of a modified technique for pars plana placement of the Ahmed valve in combination with pars plana vitrectomy in the treatment of glaucoma associated with posterior segment disease. Thirty-nine eyes with glaucoma associated with posterior segment disease underwent pars plana vitrectomy combined with Ahmed valve placement. All valves were placed in the pars plana using a modified technique, without the pars plana clip, and using a scleral patch graft. The 24 eyes diagnosed with neovascular glaucoma had an improvement in intraocular pressure from 37.6 mmHg to 13.8 mmHg and best-corrected visual acuity from 2.13 logarithm of minimum angle of resolution to 1.40 logarithm of minimum angle of resolution. Fifteen eyes diagnosed with steroid-induced glaucoma had an improvement in intraocular pressure from 27.9 mmHg to 14.1 mmHg and best-corrected visual acuity from 1.38 logarithm of minimum angle of resolution to 1.13 logarithm of minimum angle of resolution. Complications included four cases of cystic bleb formation and one case of choroidal detachment and explantation for hypotony. Ahmed valve placement through the pars plana during vitrectomy is an effective option for managing complex cases of glaucoma without the use of the pars plana clip.

Amnesty, Reconciliation and Reintegration: The International Community and the Rwandan Process

DTIC Science & Technology

2008-05-22

Egypt, the Secretary General of the OAU, Dr. Salim Ahmed SALIM, the Secretary General of the United Nations, Dr. Boutros Boutros GHALI and Observers...the Mediator, His Excellency Faustin BIRINDWA, Prime Minister of Zaire; - Dr. Salim Ahmed SALIM, Secretary General of the OAU; - The...2005. Disarmament as Part of Reconciliation in Rwanda. Institute of Security Studies 108 (June): 1-16. Ali- Dinar , Ali B. PhD Ed. 1999. DRC

Essential Services in Support of the Counterinsurgency during Operation Iraq Freedom

DTIC Science & Technology

2006-10-23

local populace working on rebuilding their own country can be found to be particularly disturbing. However, Dr. Ahmed Hashim has clearly depicted...critical to success. Dr. Ahmed Hashim infers that the lack of awareness of the cultural significance of our behavior toward the local Iraqi population...currency, the New Iraqi Dinar , which should also help strengthen confidence in the use of this currency by the local population.24 CERP permits the shift

Dr Ahmed Zaky Abushady: author, beekeeper, doctor and poet.

PubMed

Wright, David

2013-12-01

Ahmed Zaky Abushady, (1892-1955) was an author, beekeeper, doctor and poet. This paper follows his life from his upbringing in Egypt and his time as a medical student in England to his later life as a pathologist working in Alexandria and Cairo and finally his years in the United States of America. It emphasises his contributions in several fields not directly related to medicine and looks at his continuing influence.

Bilateral Ocular Decompression Retinopathy after Ahmed Valve Implantation for Uveitic Glaucoma

PubMed Central

Flores-Preciado, Javier; Ancona-Lezama, David Arturo; Valdés-Lara, Carlos Andrés; Díez-Cattini, Gian Franco; Coloma-González, Itziar

2016-01-01

Case Report We report the case of a 29-year-old man who underwent Ahmed valve implantation in both eyes as treatment for uveitic glaucoma, subsequently presenting with bilateral ocular decompression retinopathy in the postoperative period. Discussion Ocular decompression retinopathy is a rare complication of filtering surgery in patients with glaucoma; however, the course is benign in most cases, with spontaneous resolution of bleedings and improvement of visual acuity. PMID:27920718

Pakistan’s Domestic Political Developments

DTIC Science & Technology

2005-09-19

Daily Times (Lahore), Aug. 29, 2005; Aamer Ahmed Khan, “Musharraf Under Fire After Local elections,” BBC News, Aug. 30, 2005; Husain Haqqani, “Hit... Ahmed serves as MMA president. Another long-standing Islamist party is the Jamiat Ulema-i-Islam faction led by Maulana Fazlur Rehman (JUI-F). The JUI...Harper Collins India, 2000), p. 135. 37 Pakistani Ambassador to the United States Ashraf Jehangir Qazi, “Transition in Pakistan” (letter), New York

From structure to structural dynamics: Ahmed Zewail's legacy.

PubMed

Chergui, Majed; Thomas, John Meurig

2017-07-01

In this brief tribute to Ahmed Zewail, we highlight and place in the historical context, several of the major achievements that he and his colleagues have made in Femtochemistry (of which he was the principal instigator) and his introduction of ultrafast electron scattering, diffraction, microscopy and spectroscopy. By achieving a sub-picosecond temporal resolution, coupled with a picometer spatial resolution, he revolutionised our understanding of the corpus of chemical, physical, biological and materials science systems.

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

Use of rumination and activity monitoring for the identification of dairy cows with health disorders: Part I. Metabolic and digestive disorders.

PubMed

Stangaferro, M L; Wijma, R; Caixeta, L S; Al-Abri, M A; Giordano, J O

2016-09-01

The objectives of this study were to evaluate (1) the performance of an automated health-monitoring system (AHMS) to identify cows with metabolic and digestive disorders-including displaced abomasum, ketosis, and indigestion-based on an alert system (health index score, HIS) that combines rumination time and physical activity; (2) the number of days between the first HIS alert and clinical diagnosis (CD) of the disorders by farm personnel; and (3) the daily rumination time, physical activity, and HIS patterns around CD. Holstein cattle (n=1,121; 451 nulliparous and 670 multiparous) were fitted with a neck-mounted electronic rumination and activity monitoring tag (HR Tags, SCR Dairy, Netanya, Israel) from at least -21 to 80 d in milk (DIM). Raw data collected in 2-h periods were summarized per 24 h as daily rumination and activity. A HIS (0 to 100 arbitrary units) was calculated daily for individual cows with an algorithm that used rumination and activity. A positive HIS outcome was defined as a HIS of <86 during at least 1 d from -5 to 2 d after CD. Blood concentrations of nonesterified fatty acids, β-hydroxybutyrate, total calcium, and haptoglobin were determined in a subgroup of cows (n=459) at -11±3, -4±3, 0, 3±1, 7±1, 14±1, and 28±1 DIM. The sensitivity of the HIS was 98% [95% confidence interval (CI): 93, 100] for displaced abomasum (n=41); 91% (95% CI: 83, 99) for ketosis (n=54); 89% (95% CI: 68, 100) for indigestion (n=9); and 93% (95% CI: 89, 98) for all metabolic and digestive disorders combined (n=104). Days (mean and 95% CI) from the first positive HIS <86 and CD were -3 (-3.7, -2.3), -1.6 (-2.3, -1.0), -0.5 (-1.5, 0.5), and -2.1 (-2.5, -1.6) for displaced abomasum, ketosis, indigestion, and all metabolic and digestive disorders, respectively. The patterns of rumination, activity, and HIS for cows flagged by the AHMS were characterized by lower levels than for cows without a health disorder and cows not flagged by the AHMS from -5 to 5 d after CD, depending on the disorder and parameter. Differences between cows without health disorders and those flagged by the AHMS for blood markers of metabolic and health status confirmed the observations of the CD and AHMS alerts. The overall sensitivity and timing of the AHMS alerts for cows with metabolic and digestive disorders indicated that AHMS that combine rumination and activity could be a useful tool for identifying cows with metabolic and digestive disorders. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Global U(1 ) Y⊗BRST symmetry and the LSS theorem: Ward-Takahashi identities governing Green's functions, on-shell T -matrix elements, and the effective potential in the scalar sector of the spontaneously broken extended Abelian Higgs model

NASA Astrophysics Data System (ADS)

Lynn, Bryan W.; Starkman, Glenn D.

2017-09-01

The weak-scale U (1 )Y Abelian Higgs model (AHM) is the simplest spontaneous symmetry breaking (SSB) gauge theory: a scalar ϕ =1/√{2 }(H +i π )≡1/√{2 }H ˜ei π ˜/⟨H ⟩ and a vector Aμ. The extended AHM (E-AHM) adds certain heavy (MΦ2,Mψ2˜MHeavy2≫⟨H ⟩2˜mWeak2 ) spin S =0 scalars Φ and S =1/2 fermions ψ . In Lorenz gauge, ∂μAμ=0 , the SSB AHM (and E-AHM) has a global U (1 )Y conserved physical current, but no conserved charge. As shown by T. W. B. Kibble, the Goldstone theorem applies, so π ˜ is a massless derivatively coupled Nambu-Goldstone boson (NGB). Proof of all-loop-orders renormalizability and unitarity for the SSB case is tricky because the Becchi-Rouet-Stora-Tyutin (BRST)-invariant Lagrangian is not U (1 )Y symmetric. Nevertheless, Slavnov-Taylor identities guarantee that on-shell T-matrix elements of physical states Aμ,ϕ , Φ , ψ (but not ghosts ω , η ¯ ) are independent of anomaly-free local U (1 )Y gauge transformations. We observe here that they are therefore also independent of the usual anomaly-free U (1 )Y global/rigid transformations. It follows that the associated global current, which is classically conserved only up to gauge-fixing terms, is exactly conserved for amplitudes of physical states in the AHM and E-AHM. We identify corresponding "undeformed" [i.e. with full global U (1 )Y symmetry] Ward-Takahashi identities (WTI). The proof of renormalizability and unitarity, which relies on BRST invariance, is undisturbed. In Lorenz gauge, two towers of "1-soft-pion" SSB global WTI govern the ϕ -sector, and represent a new global U (1 )Y⊗BRST symmetry not of the Lagrangian but of the physics. The first gives relations among off-shell Green's functions, yielding powerful constraints on the all-loop-orders ϕ -sector SSB E-AHM low-energy effective Lagrangian and an additional global shift symmetry for the NGB: π ˜→π ˜+⟨H ⟩θ . A second tower, governing on-shell T-matrix elements, replaces the old Adler self-consistency conditions with those for gauge theories, further severely constrains the effective potential, and guarantees infrared finiteness for zero NGB (π ˜) mass. The on-shell WTI include a Lee-Stora-Symanzik theorem, also for gauge theories. This enforces the strong condition mπ2=0 on the pseudoscalar π (not just the much weaker condition mπ˜2=0 on the NGB π ˜), and causes all relevant-operator contributions to the effective Lagrangian to vanish exactly. In consequence, certain heavy C P -conserving Φ , ψ matter decouple completely in the mHe a v y 2/mwe a k 2→∞ limit. We prove four new low-energy heavy-particle decoupling theorems that are more powerful than the usual Appelquist-Carazzone decoupling theorem: including all virtual ϕ and ψ loop contributions, relevant operators operators vanish exactly due to the exact U (1 )Y symmetry of 1-soft-π Adler-self-consistency relations governing on-shell T-matrix elements. Underlying our results is that global U (1 )Y transformations δU (1 )Y,and nilpotent s2=0 BRST transformations, commute: we prove [δU (1 )Y,s ] in G. 't Hooft's Rξ gauges. With its on-shell T-matrix constraints, SSB E-AHM physics therefore has more symmetry than does its BRST-invariant Lagrangian LE-AHM Rξ : i.e. global U (1 )Y⊗BRST symmetry. The NGB π ˜ decouples from the observable particle spectrum Bμ,h ˜, Φ ˜, ψ ˜ in the usual way, when the observable vector Bμ≡Aμ+1/e ⟨H ⟩ ∂μπ ˜ absorbs it, as if it were a gauge transformation, hiding both towers of U (1 )Y WTI from observable particle physics.

The Report of the Independent Commission on the Security Forces of Iraq

DTIC Science & Technology

2007-09-06

Jday’l Ayfan Facilitator Abdallah Ahmad Isma’il Ibrahim AQI External Facilitator Imad Abd Abbas Nassir AQI Weapons Facilitator Ahmed Sancar AQI Foreign...example, a minimum of three bids are required for any contract above 25 million dinars (about $20,000). MOD officials told the Commission that if fewer...Ministry of Defense headquarters in Baghdad and by an operational commander, Commander Ahmed Maarij, in Umm Qasr; its leadership reports to the Iraqi

Political and Economic Trends in North Africa,

DTIC Science & Technology

1975-01-01

placing one of his principal aides, Ahmed Kaid, in the post of S;cretarry Gi:neral. The last significant instances of political violence in Algeria were...Ministry at the height of his popularity in 1970 and purged from the Political Bureau the following year; Ahmed Mestiri was ousted from the Cabinet in...lavish -- scholarships. (Thus in 1971 60% of all university students held scholarships, which ranged between 350 and 450 dinars ($700 to $900), i.e. two to

A Computing Platform for Parallel Sparse Matrix Computations

DTIC Science & Technology

2016-01-05

REPORT NUMBER 19a. NAME OF RESPONSIBLE PERSON 19b. TELEPHONE NUMBER Ahmed Sameh Ahmed H. Sameh, Alicia Klinvex, Yao Zhu 611103 c. THIS PAGE The...PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: Discipline Yao Zhu 0.50 Alicia Klinvex 0.10 0.60 2 Names of Post Doctorates Names of Faculty Supported...PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: NAME Total Number: NAME Total Number: Yao Zhu Alicia Klinvex 2 ...... ...... Sub Contractors (DD882) Names of other

A Finite Difference Approximation for a Coupled System of Nonlinear Size-Structured Populations

DTIC Science & Technology

2000-01-01

are available. For a classical Lotka - Volterra competition model which is represented by a system of N di erential equations, conditions on the growth...Methods Appl. Sci., 9 (1999), 1379-1391. [5] S. Ahmed, Extinction of Species in Nonautonomous Lotka - Volterra Systems, Proc. Amer. Math. Soc., 127 (1999...Walter DeGruyter, Berlin, 1995. [7] S. Ahmed and F. Montes de Oca, Extinction in Nonautonomous T -periodic Lotka - Volterra System, Appl. Math. Comput

Coupling of HRT II and AS-OCT to evaluate corneal endothelial cell loss and in vivo visualization of the Ahmed glaucoma valve implant.

PubMed

Mendrinos, E; Dosso, A; Sommerhalder, J; Shaarawy, T

2009-09-01

To report corneal endothelial cell loss and in vivo visualization of the Ahmed glaucoma valve implant in eyes with refractory glaucoma. Ten eyes underwent Ahmed valve implant surgery and were followed-up for 12 months. Data collected included intraocular pressure (IOP), number of antiglaucoma medications and surgery-related complications. At 6 and 12 months postoperatively, the intracameral length of the drainage tube (ICL) and the distance between the tube and the cornea (T-C distance), and the iris (T-I distance) were assessed using anterior segment optical coherence tomography (AS-OCT). Heidelberg cornea tomograph II (HRT II) was used to measure the corneal endothelial cell density. Mean (+/-SEM) preoperative IOP was 29.5+/-4 mmHg. Mean postoperative IOP was 11.6+/-2 at 12 months (P<0.01). Over a 6-month period, mean corneal endothelial loss was 7.9%+/-2.5 in the central and 7.5%+/-2.4 in the peripheral cornea (P<0.01). There was no correlation between central or peripheral corneal endothelial cell loss and the T-C, T-I distance or the ICL of the tube. Corneal endothelial cell loss occurs following Ahmed valve implant surgery, this appears to be multifactorial. AS-OCT and HRT II are promising methods for the follow-up of patients with a glaucoma drainage device.

Efficacy of intravitreal ranibizumab combined with Ahmed glaucoma valve implantation for the treatment of neovascular glaucoma.

PubMed

Tang, Min; Fu, Yang; Wang, Ying; Zheng, Zhi; Fan, Ying; Sun, Xiaodong; Xu, Xun

2016-01-09

Neovascular glaucoma is a refractive glaucoma. Recently, anti-VEGF factors have been used alone or in combination for the treatment of neovascular glaucoma. However, the medium- and long-term efficacy of such drugs remains to be evaluated. This study was to determine the efficacy of intravitreal ranibizumab combined with Ahmed glaucoma valve implantation for the treatment of neovascular glaucoma. In this prospective non-randomized study, 43 neovascular glaucoma patients (43 eyes) were assigned to receive either 0.5 mg intravitreal ranibizumab for three to 14 days before Ahmed glaucoma valve implantation (injection group, n = 21) or Ahmed glaucoma valve implantation alone (control group, n = 22). The patients were followed up for six to 12 months. Differences in surgical success rate, intraocular pressure, best corrected visual acuity, anti-glaucoma medications and postoperative complications were compared between the two groups. Surgical success was defined as IOP > = 6 mm Hg and < = 21 mm Hg, with or without the use of anti-glaucoma medications, and without severe complications or reoperation. Of the 43 patients, 40 completed the 6-month follow-up and 37 completed the 1-year follow-up. Success rate was 73.7% vs. 71.4% at six months and 72.2% vs. 68.4% at 12 months in the injection group and the control group respectively. No significant difference was noted between the two groups (six months: P = 0.87, 12 months: P = 1.00). There were no significant differences in the two groups with respect to intraocular pressure, best corrected visual acuity, anti-glaucoma medications or postoperative complications at six months or 12 months. Single intravitreal ranibizumab (0.5 mg) before surgery has no significant effect on the medium- or long-term outcomes of neovascular glaucoma treated with Ahmed glaucoma valve implantation. Chinese Clinical Trial Registry ( ChiCTR-OOC-14005709, Trial registration date: 2014-12-01).

Correction of a Space Telescope Active Primary Mirror Using Adaptive Optics in a Woofer-Tweeter Configuration

DTIC Science & Technology

2015-09-01

shows the elements of an AHM. The substrate is a rib-stiffened silicon carbide ( SiC ) structure cast to meet the required optical figure. The...right) 2. SMT Three Point Linearity Test The active mirror under study is a 1-meter hexagonal SiC AHM mirror with 156 face sheet actuators. The...CORRECTION OF A SPACE TELESCOPE ACTIVE PRIMARY MIRROR USING ADAPTIVE OPTICS IN A WOOFER-TWEETER CONFIGURATION by Matthew R. Allen September 2015

Characterization of the Murine Salmonella Typhimurium-Specific Primary B-Cell Repertoire

DTIC Science & Technology

1984-04-27

B cells which express the Lyb 3> 5, and 7 differentiation antigens (Huber ejt aJ., 1977; Ahmed _et_ al., 1977; Subbarao _et_ al., 1979)- However, T... k k k IgCH Allotype"*̂ J J d b a) (Staats, 1972) b ) (Lieberman, 1978) 79 and macrophage help for stimulation of TML-specific B cells in...associated with the absence of a mature subpopulation of B cells (Huber ejt al., 1977; Ahmed et_ al., 1977; Subbarao _et al., 1979; Metcalf ejt

Computational Investigations on the Aerodynamics of a Generic Car Model in Proximity to a Side Wall

NASA Astrophysics Data System (ADS)

Mallapragada, Srivatsa

A moving road vehicle is subjected to many fluid interferences caused by a number of external agents apart from the vehicle itself. Vehicles moving in proximity to a side wall is an interesting aspect that has been little investigated in the literature. This is of great interest in motorsports, more specifically in NASCAR racing. The aim of this thesis is to develop a Computational Fluid Dynamics (CFD) model that can simulate the motion of a race car moving close to a side wall with an objective of understanding the influence of this side barrier on the overall aerodynamic characteristics of the vehicle, like the force and moment coefficients. Additionally, flow visualization tools are used to gain insights into the flow field and to explain the causes of the observed aerodynamic characteristics of the vehicle. This is accomplished by using a generic car model, a 25-degree slant angle Ahmed Body, in proximity to a side wall in a virtual wind tunnel where the vehicle body is allowed to move at constant velocity. This methodology is different from the traditional CFD approach where the air is blown over a stationary vehicle. The simulation process used in this thesis requires the use of a recently developed meshing methodology called the Overset mesh. All simulations were run using a commercial finite volume CFD code called StarCCM+ where the Unsteady Reynolds Averaged Navier-Stokes URANS fluid flow solver was used to model turbulence. However, the existing literature suggests that no URANS model can correctly predict the flow field around a 25-degree slant Ahmed body model; all models under-predict turbulence in the initial separated shear layer and over-predict the separation region. Subsequently, the first phase of this thesis involved the determination of a modeling methodology that can accurately predict the flow-field over a 25-degree Ahmed body. Two two-equation eddy-viscosity turbulence models, the AKN and SST preferred by many researchers for CFD simulations of massively separated flows, were tested. It turned out that only the latter with modified model coefficients was capable of reproducing the experimental results with a reasonable accuracy. Compared to the eddy viscosity CFD simulations of an isolated 25-degree slant angle Ahmed body seen in existing literature, the results presented in this thesis show significantly better correlations with experiments. The wall proximity studies show a strong influence of the presence of the wall on the overall aerodynamic characteristics of the vehicle body. When compared with the experimental studies, although both show similar trends, however, there exists a significant difference between the experimental and CFD predicted results which tend to worsen as one approaches the wall. These differences can be attributed to fact that the CFD emulation of the flow around the side-wall is more realistic compared to the experimental implementation.

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

NONE

White Oak Dam is located in the White Oak Creek watershed which provides the primary surface drainage for Oak Ridge National Laboratory. A stability analysis was made on the dam by Syed Ahmed in January 1994 which included an evaluation of the liquefaction potential of the embankment and foundation. This report evaluates the stability of the dam and includes comments on the report prepared by Ahmed. Slope stability analyses were performed on the dam and included cases for sudden drawdown, steady seepage, partial pool and earthquake. Results of the stability analyses indicate that the dam is stable and failure ofmore » the structure would not occur for the cases considered. The report prepared by Ahmed leads to the same conclusions as stated above. Review of the report finds that it is complete, well documented and conservative in its selection of soil parameters. The evaluation of the liquefaction potential is also complete and this report is in agreement with the findings that the dam and foundation are not susceptible to liquefaction.« less

[Management of corneal endothelial decompensation with Descemet's membrane endothelial keratoplasty in a patient with Ahmed glaucoma valve implant].

PubMed

Röck, T; Bartz-Schmidt, K-U; Röck, D; Yoeruek, E

2014-05-01

Currently, the main causes for developing bullous keratopathy are from problems related to intraocular surgery, trauma, infection, Fuchs' endothelial dystrophy and chronically elevated intraocular pressure. In the 1990s penetrating keratoplasty was once considered the therapy of choice for treatment of bullous keratopathy but in recent years it has been replaced by posterior lamellar keratoplasty. The Descemet membrane endothelial keratoplasty (DMEK) procedure represents the final development of posterior lamellar keratoplasty. The question now arises whether DMEK can be used in patients with bullous keratopathy and Ahmed glaucoma valve implant. A 72-year-old man was referred to our hospital for further evaluation with the diagnosis of bullous keratopathy and pseudoexfoliative glaucoma. The bullous keratopathy was caused by a variety of previous operations as well as decompensation of intraocular pressure. This article describes the therapy of bullous keratopathy by DMEK with existing Ahmed glaucoma valve implant. After surgery the cornea became clear and the best-corrected visual acuity improved from hand movement to 0.2. The intraocular pressure remained normal (10-14 mmHg) without antiglaucoma medication and the endothelial cell count decreased only slightly over a follow-up of 13 months. No complications were encountered. The DMEK surgical procedure seems to be possible in patients with Ahmed glaucoma valve implant and endothelial decompensation. However, further studies with a larger number of patients should follow to validate the replacement of penetrating keratoplasty and other posterior lamellar procedures by DMEK.

Multilevel learning in the adaptive management of waterfowl harvests: 20 years and counting

USGS Publications Warehouse

Johnson, Fred A.; Boomer, G. Scott; Williams, Byron K.; Nichols, James D.; Case, David J.

2015-01-01

In 1995, the U.S. Fish and Wildlife Service implemented an adaptive harvest management program (AHM) for the sport harvest of midcontinent mallards (Anas platyrhynchos). The program has been successful in reducing long-standing contentiousness in the regulatory process, while integrating science and policy in a coherent, rigorous, and transparent fashion. After 20 years, much has been learned about the relationship among waterfowl populations, their environment, and hunting regulations, with each increment of learning contributing to better management decisions. At the same time, however, much has been changing in the social, institutional, and environmental arenas that provide context for the AHM process. Declines in hunter numbers, competition from more pressing conservation issues, and global-change processes are increasingly challenging waterfowl managers to faithfully reflect the needs and desires of stakeholders, to account for an increasing number of institutional constraints, and to (probabilistically) predict the consequences of regulatory policy in a changing environment. We review the lessons learned from the AHM process so far, and describe emerging challenges and ways in which they may be addressed. We conclude that the practice of AHM has greatly increased an awareness of the roles of social values, trade-offs, and attitudes toward risk in regulatory decision-making. Nevertheless, going forward the waterfowl management community will need to focus not only on the relationships among habitat, harvest, and waterfowl populations, but on the ways in which society values waterfowl and how those values can change over time. 

A new genus and new species of Cicadettini (Hemiptera: Cicadidae: Cicadettinae) from Pakistan.

PubMed

Sanborn, Allen F; Ahmed, Zubair

2017-03-02

Pakistan contains parts of the Indomalayan and Palaearctic ecozones. As a result, there is a diversity of habitats that has led to diversity in the cicada fauna. We reviewed the Pakistani cicada fauna (Ahmed and Sanborn 2010) but new records and new species continue to be found (Ahmed et al. 2010; 2012; 2013; 2014). This work continues to expand the knowledge of the Pakistani cicada fauna with the description of a new genus and new species of cicada provided to the second author from his contacts.

Clinical outcomes of Ahmed glaucoma valve implantation in pediatric glaucoma.

PubMed

Pakravan, Mohammad; Esfandiari, Hamed; Yazdani, Shahin; Doozandeh, Azadeh; Dastborhan, Zahra; Gerami, Ebrahim; Kheiri, Bahareh; Pakravan, Parastou; Yaseri, Mehdi; Hassanpour, Kiana

2018-03-01

To evaluate the outcomes of Ahmed glaucoma valve implantation in refractory primary congenital glaucoma as well as primary procedure in aphakic glaucoma. In this retrospective study, medical records of patients who underwent Ahmed glaucoma valve implantation for refractory glaucoma and aphakic glaucoma were reviewed. Primary outcome measures were the surgical success defined as intraocular pressure ≤21 mm Hg and decreased ≥20% and no secondary glaucoma surgery. Secondary outcome measures were the number of glaucoma medications, complications, best corrected visual acuity, and intraocular pressure. A total of 62 eyes of refractory primary congenital glaucoma patients (group 1) and 33 eyes of aphakic glaucoma patients (group 2) were included in our study. Mean follow-up was 51 ± 33 months in group 1 and 49 ± 41 months in group 2 (p = 0.82). The cumulative probability of success was 90% in both groups at the first year; however, the success rate was 52.5% in group 1 and 71.5% in group 2 at 5 years' follow-up visit. In group 1, the mean intraocular pressure ± standard deviation was 33.1 ± 8.6 mm Hg at the baseline and decreased to 17.1 ± 5.3 mm Hg at 1 year and 18.5 ± 6.4 at 3 years postoperatively (all p's < 0.001). Corresponding values for group 2 were 28.9 ± 6.1, 15.2 ± 4.6, and 16.0 ± 5.9 mm Hg, respectively (all p's < 0.001). The baseline number of glaucoma medications was 3 ± 0.7 that decreased to 2 ± 0.8 at final follow-up (p = 0.02). Ahmed glaucoma valve implantation has a moderate success rate in the management of refractory primary congenital glaucoma with an increased chance of tube-related complications. The surgical success rate is higher in case of primary Ahmed glaucoma valve implant for aphakic glaucoma with acceptable safety profile.

Non-indexed medical journals in the Web: new perspectives in the medical literature.

PubMed

Germenis, A E; Kokkinides, P A; Stavropoulos-Giokas, C

1997-11-01

Many medical journals, publishing in national languages, meet serious financial problems and difficulties when they attempt to become indexed in the international indices. Obviously, this not only affects the scientific quality of non-indexed medical journals (NIMJs) but also affects the awareness of the scientific community of topics with apparently local but potentially broader scientific significance. This is a reality for over 100 Greek medical journals, none of which has a life longer than 30 years or more than 2000 subscribers. Among them, the 'Archives of Hellenic Medicine' (AHM) is published and sponsored by the Athens Medical Society (the oldest medical society in Greece founded in 1835). This peer-reviewed Journal is being published for 13 years, bimonthly, in Greek. Attempting to overcome the above mentioned problems and to be involved in the process of discovering the most effective way of scientific 'skywriting', 2 years ago, the AHM entered full-text in the Web and it was decided that up to 500% of its volume should be covered by English-language papers. As a result, the AHM are now included in the main Web lists of medical journals and their home page is linked in many academic pages having approximately 500 hits/month. Furthermore, 45 retrievals of AHM's English-language papers or English abstracts of Greek-language articles were reported by e-mail response from abroad. Considered apart from the paper-publishing, the expenses of the digital publishing of the AHM are about half of those of paper-publishing, as they were before the appearance of the Journal in the Web. Up to now, about 40% of the Journal's digital publishing cost is covered by advertisements included in its pages and by a modification of its paper-publishing policy. It is concluded that the international scientific community is not indifferent for information published in NIMJs. Medical national minorities working abroad express special interest for this type of information. The Web makes the NIMJs accessible to these potential readers, who would never have the chance to acquire them in their printed form.

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.

Experimental aerodynamic study of a car-type bluff body

NASA Astrophysics Data System (ADS)

Conan, Boris; Anthoine, Jérôme; Planquart, Philippe

2011-05-01

The Ahmed body is used as a reference model for fundamental studies of car-type bluff body aerodynamics, in particular focused on the influence of the rear slant angle on the drag coefficient. The objectives of the present work are to obtain reliable drag coefficient comparable to the literature and to explain, based on the nature of the flow, its variation when changing the rear slant angle from 10° to 40°. The drag coefficients measured in both an open and a closed test sections differ by less than 0.5% which proves the reliability and reproducibility of the results. The sensitivity of the drag coefficient to some parameters such as the model roughness or the oncoming boundary layer and the lack of precise information on these parameters in the literature could explain the difference observed with the Ahmed drag coefficient data. The various types of measurement techniques used in the study underline their complementarity. The combination of particle image velocimetry and oil visualization provides a deeper understanding of the flow behaviour around the Ahmed body and a physical interpretation of the drag coefficient evolution.

Glaucoma in modified osteo-odonto-keratoprosthesis eyes: role of additional stage 1A and Ahmed glaucoma drainage device-technique and timing.

PubMed

Iyer, Geetha; Srinivasan, Bhaskar; Agarwal, Shweta; Shetty, Roshni; Krishnamoorthy, Sripriya; Balekudaru, Shantha; Vijaya, Lingam

2015-03-01

To report the technique, timing, and outcomes of the Ahmed glaucoma drainage device in eyes with the modified osteo-odonto-keratoprosthesis (MOOKP) and the role of an additional stage 1A to the Rome-Vienna protocol. Retrospective interventional case series. Case records of 22 eyes of 20 patients with high intraocular pressure at various stages of the MOOKP procedure performed in 85 eyes of 82 patients were studied. Stage 1A, which includes total iridodialysis, intracapsular cataract extraction, and anterior vitrectomy, was done in all eyes as the primary stage. Seventeen Ahmed glaucoma drainage devices were implanted in 15 eyes of 14 patients (chemical injury in 9 [10 eyes] and Stevens-Johnson syndrome in 5 patients). Implantation was performed during and after stage 1A in 2 and 7 eyes, respectively, after stage 1B+1C in 1 eye, and after stage 2 in 6 eyes. Eleven of 15 eyes (73.3%) remained stable with adequate control of intraocular pressure over a mean follow-up period of 33.68 months (1-90 months). Complications related to the drainage device were hypotony in 1 eye and vitreous block of the tube in 1 eye. It is ideal to place the Ahmed glaucoma drainage device prior to the mucosal graft when the anatomy of the ocular surface is least altered with best outcomes. The technique of placement of the drainage device during the various stages of the MOOKP procedure has been described. The intraocular pressure stabilized in three quarters of the eyes with pre-existing glaucoma. Copyright © 2015 Elsevier Inc. All rights reserved.

Efficacy and safety of intravitreal bevacizumab in eyes with neovascular glaucoma undergoing Ahmed glaucoma valve implantation: 2-year follow-up.

PubMed

Arcieri, Enyr S; Paula, Jayter S; Jorge, Rodrigo; Barella, Kleyton A; Arcieri, Rafael S; Secches, Danilo J; Costa, Vital P

2015-02-01

To evaluate the efficacy and safety of intravitreal bevacizumab (IVB) in eyes with neovascular glaucoma (NVG) undergoing Ahmed glaucoma valve (AGV) implantation. This was a multicentre, prospective, randomized clinical trial that enrolled 40 patients with uncontrolled neovascular glaucoma that had undergone panretinal photocoagulation and required glaucoma drainage device implantation. Patients were randomized to receive IVB (1.25 mg) or not during Ahmed valve implant surgery. Injections were administered intra-operatively, and 4 and 8 weeks after surgery. After a mean follow-up of 2.25 ± 0.67 years (range 1.5-3 years), both groups showed a significant decrease in IOP (p < 0.05). There was no difference in IOP between groups except at the 18-month interval, when IOP in IVB group was significantly lower (14.57 ± 1.72 mmHg vs. 18.37 ± 1.06 mmHg - p = 0.0002). There was no difference in survival success rates between groups. At 24 months, there was a trend to patients treated with IVB using less antiglaucoma medications than the control group (p = 0.0648). Complete regression of rubeosis iridis was significantly more frequent in the IVB group (80%) than in the control group (25%) (p = 0.0015). Intravitreal bevacizumab may lead to regression of new vessels both in the iris and in the anterior chamber angle in patients with neovascular glaucoma undergoing Ahmed glaucoma valve implantation. There is a trend to slightly lower IOPs and number of medications with IVB use during AGV implantation for neovascular glaucoma. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Bleb Analysis and Short-Term Results of Biodegradable Collagen Matrix-Augmented Ahmed Glaucoma Valve Implantation: 6-Month Follow-up.

PubMed

Rho, Seungsoo; Sung, Youngje; Ma, Kyoung Tak; Rho, Sae Heun; Kim, Chan Yun

2015-09-01

To evaluate the short-term efficacy of a biodegradable collagen matrix (BCM) as an adjuvant for Ahmed valve implantation surgery to prevent the hypertensive phase. This prospective study included 43 refractory glaucoma eyes, all followed for 6 months. Refractory glaucoma was defined as an IOP higher than 20 mm Hg with antiglaucoma eye drops without previous glaucoma surgery. Conventional method was performed in 21 eyes and BCM-augmented Ahmed valve implantation (BAAVI) in 22 eyes. In the BAAVI group, a 10 × 10 × 2-mm BCM was sutured on an Ahmed glaucoma valve FP7 model. Complete success was defined as an IOP of 21 mm Hg or lower (target IOP 1) or 17 mm Hg or lower (target IOP 2) without antiglaucoma medications and qualified success as an IOP of 21 mm Hg or lower with or without medications. Maximal bleb thickness was measured using anterior segment optical coherence tomography images. The preoperative IOPs and numbers of preoperative antiglaucoma medications were similar for both groups. Complete target IOP 1 success rates were 38.1% and 86.4%, complete target IOP 2 success rates were 19.0% and 59.1%, and qualified success rates were 52.4% and 90.9% in the conventional and BAAVI groups, respectively (P < 0.05). The hypertensive phase rate was lower in the BAAVI group (4.5% vs. 47.6%, P = 0.002). Maximal bleb thickness was increased in the BAAVI group on postoperative days 30 and 180 (P < 0.05). Success rates were higher in the BAAVI group than in the conventional group with the change of bleb morphology. Furthermore, use of BCM significantly decreased the need for antiglaucoma medications for at least 6 months postoperatively.

The use of Ahmed glaucoma valve in the management of pediatric glaucoma.

PubMed

Balekudaru, Shantha; Vadalkar, Juhie; George, Ronnie; Vijaya, Lingam

2014-08-01

To assess the intraocular pressure control (IOP), changes in visual acuity, complications, reoperation rates and risk factors for failure following Ahmed glaucoma valve implantation in pediatric eyes with glaucoma. The medical records of consecutive patients with glaucoma who underwent Ahmed glaucoma valve implantation from January 2000 to December 2009) were retrospectively reviewed. Only one eye of each patient was included. Subgroup analysis was performed in three groups; group 1 included phakic eyes with primary congenital glaucoma, juvenile open-angle glaucoma, or glaucoma associated with ocular anomalies; group 2 included eyes with glaucoma in aphakia or pseudophakia; group 3 included eyes with other diagnoses. A successful outcome was defined as final IOP between 6 mm Hg and 18 mm Hg without loss of light perception or reoperation for glaucoma. A total of 71 eyes in 71 patients: 15 (21%) in group 1, 47 (66%) in group 2, and 9 (13%) in group 3 were included Successful IOP control was achieved in 44 eyes of 44 patients (62%). Cumulative probabilities of success by Kaplan-Meier analysis at 12 and 24 months was 97% and 80% for the entire group, 100% and 82% for group 1, 95% and 86% for group 2, and 90% and 42% for group 3. Reoperation was necessary for 18 patients (25%), either for tube-related complications or for IOP control. The only significant risk factor for failure was the category of diagnosis (P = 0.029). Ahmed glaucoma valve implantation is an option in the management of pediatric glaucoma; however, reoperations for tube related complications or for persistent elevated IOP is frequently needed. Copyright © 2014 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

[Long-term outcomes of Ahmed glaucoma valve implantation for treating refractory glaucoma].

PubMed

Xu, Yumei; Hong, Tao; Li, Wanming

2015-02-10

To explore the efficacies and complications of Ahmed glaucoma valve implantation for treating refractory glaucoma. A retrospective study of case series was conducted for 24 patients (26 eyes) with refractory glaucoma from February 2001 to July 2008 at our hospital. Ahmed glaucoma valve implantation was performed. Pre- and post-operative best spectacle-corrected visual acuity (BSCVA), intraocular pressure (IOP), number of medications and complications were recorded and analyzed. The follow-up period was 58-159 months. The post-operative values of IOP were 13.02+/-6.79, 11.43+/-5.24 and 18.56+/-6.43 mmHg at 1 day, 1 month and the last follow-up respectively. There were significant difference when compared with pre-operative IOP (37.59+/-10.76 mmHg, P < 0.01). And 65.38% of eyes maintained or gained ≥ 1 line of BSCVA. But there was no significant difference with pre-operative BSCVA (P = 0.110). Twenty eyes required anti-glaucoma drugs after glaucoma valve implantation and the average number of medication was 1.72+/-0.98. There was significant difference with the pre-operative medication number 2.7 ± 0.7 (P = 0.001). The surgical success rate was 73.1%. And the causes of failure were endophthalmitis, corneal endothelial decompensation, persistent conjunctival wound non-healing, glaucoma valve exposure and loss of light perception.Early postoperative complications were ocular hypotony, shallow anterior chamber, hyphema, transient high IOP and tube occlusion. And long-term complications included encapsulated cyst formation, tube exposure, corneal endothelial decompensation and endophthalmitis. Ahmed glaucoma valve implantation is efficacious for refractory glaucoma.However, clinicians should pay attention to the prevention and treatment of complications.

Combined Phacoemulsification and Ahmed Glaucoma Drainage Implant Surgery for Patients With Refractory Glaucoma and Cataract.

PubMed

Valenzuela, Felipe; Browne, Andrew; Srur, Miguel; Nieme, Carlos; Zanolli, Mario; López-Solís, Remigio; Traipe, Leonidas

2016-02-01

To examine the indications, safety, efficacy, and complications of combined phacoemulsification and Ahmed glaucoma drainage implant surgery. A retrospective case review of 35 eyes (31 patients) subjected to combined phacoemulsification and Ahmed glaucoma drainage implant surgery. Demographic characteristics of the study population, indications for combined surgery, and operative and postoperative complications were recorded. Visual acuity, intraocular pressure (IOP), and number of glaucoma medications were evaluated preoperatively and postoperatively. Complete success was defined as IOP ≤ 21 mm Hg without medication, qualified success if IOP ≤ 21 mm Hg with ≥ 1 medications, and failure if IOP>21 mm Hg or ≤ 5 mm Hg on ≥ 2 consecutive visits. Mean follow-up was 29.5 months (range, 6 to 87 mo). The most common indication for combined surgery was a history of prior failed trabeculectomy (60%). Postoperative visual acuity improved in 30 of 35 eyes (85%) (P<0.01) regardless of the indication for combined surgery. IOP was reduced from a mean of 24.7 to 15.0 mm Hg at the last follow-up visit (P<0.01). The number of IOP-lowering medications was reduced from a median of 3.1 preoperatively to 1.7 at the last follow-up (P<0.01). Overall, there were 31 eyes (89%) classified as qualified success and 4 eyes (11%) as complete success. The most common postoperative complication was a hypertensive phase in 18 eyes (51%). Combined phacoemulsification and Ahmed glaucoma drainage implant surgery seems to be a safe and effective surgical option, providing good visual rehabilitation and control of IOP for patients with refractory glaucoma and cataract.

Intravitreal ranibizumab as an adjunct for Ahmed valve surgery in open-angle glaucoma: a pilot study.

PubMed

Desai, Rajen U; Singh, Kuldev; Lin, Shan C

2013-03-01

To determine the safety and efficacy of intravitreal ranibizumab therapy before and after Ahmed tube insertion for open-angle glaucoma as a means of optimizing postoperative intraocular pressure control. Randomized, controlled trial. Open-angle glaucoma patients scheduled for Ahmed tube insertion, randomized to ranibizumab or control groups. Ranibizumab (0.5 mg in 0.05 mL) was administered intravitreally at three time points: 9 days prior to surgery, 1 month post-surgery and 2 months post-surgery. Control patients underwent the same procedure without ranibizumab. Success at 6 months postoperatively was defined as intraocular pressure <18 mmHg with no adjunctive medications or intraocular pressure <15 mmHg with one adjunctive medication. The study and control arms included six and five subjects, respectively, with four in each arm undergoing combined cataract surgery. In the ranibizumab arm, the preoperative and postoperative intraocular pressure/medication usage was 21.0 ± 6.7 mmHg on 3.2 ± 1.5 medications and 14.7 ± 1.9 mmHg on 0.5 ± 0.8 medications, respectively. In the control arm, preoperative and postoperative intraocular pressure/medication usage was 18.8 ± 3.8 mmHg on 2.8 ± 1.3 medications and 16.2 ± 3.6 mmHg with 1.8 ± 1.6 medications, respectively. Success was achieved in 83% of subjects in the ranibizumab group compared with 40% in the control group (two-tailed Fisher's exact test, P = 0.24). The findings from this small pilot comparative study suggest that intravitreal ranibizumab use may be a safe and potentially effective adjunctive treatment modality in improving success after Ahmed tube placement. © 2012 The Authors. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.

Use of subconjunctival injections of 5-fluorouracil to rescue and prolong intraocular pressure reduction for a failing Ahmed glaucoma implant.

PubMed

Kaplowitz, Kevin; Khodadadeh, Sarah; Wang, Samantha; Lee, Daniel; Tsai, James C

2017-06-01

5-Fluorouracil (5-FU) has been well described for a failing trabeculectomy bleb, but not for aqueous shunts. We sought to determine whether subconjunctival 5-FU prolongs the intraocular pressure (IOP) efficacy of Ahmed shunts. We included all patients with Ahmed FP-7 implantation by one surgeon at Yale University. Patients with <3 months follow-up were excluded. Injections were done on a case-by-case basis, usually for IOP > 21 on >2 medications. Five-milligram (0.1 cc) injections were made over the plate. The control group consisted of Ahmed FP-7 patients without injections. The main outcome measure was IOP. Secondary outcome was success (IOP <21 mmHg, 20% decrease from preoperative IOP, and no reoperation). The average age of controls was 72.5 ± 16.6 years, and 63.7 ± 18.8 with 5-FU (p = 0.02). Forty-four patients received 5-FU and 45 did not. Mean preoperative IOP in controls was 31.5 ± 11 mmHg on 3.1 ± 1 medications, and 31.9 ± 9.0 mmHg (p = 0.86) on 3.3 ± 0.9 medications with 5-FU (p = 0.18). At a mean 137 days after surgery, mean pre-injection IOP was 25.3 ± 7.7 mmHg on 2.0 ± 1.3 medications. Five years following implantation, control IOPs averaged 12.9 ± 7.1 mmHg (53% decrease from preoperative IOP, p < 0.001) on 1.4 ± 1.1 medications versus 17.2 ± 4.9 mmHg (46% decrease from preoperative, 32% decrease from pre-5FU IOP, p < 0.001) on 2.7 ± 0.8 medications with 5-FU. The IOP at 5 years was statistically similar in both groups (p = 0.23). Five-year success rates trended higher with 5-FU (77 vs. 67%, p = 0.38). Subconjunctival injection of 5-FU sustained a significant long-term decline in intraocular pressures in eyes with failing Ahmed shunts. Outcomes between eyes receiving injections and controls were statistically similar.

The Ahmed Versus Baerveldt study: design, baseline patient characteristics, and intraoperative complications.

PubMed

Christakis, Panos G; Tsai, James C; Zurakowski, David; Kalenak, Jeffrey W; Cantor, Louis B; Ahmed, Iqbal I K

2011-11-01

To report the design, baseline patient characteristics, and intraoperative complications of the Ahmed Versus Baerveldt (AVB) Study. Multicenter, randomized, clinical trial. Patients were recruited from 7 international clinical sites and treated by 10 surgeons between 2005 and 2009. Inclusion criteria required that patients be at least 18 years of age and have uncontrolled glaucoma refractory to medicinal, laser, and surgical therapy. Eligible patients were randomized to undergo implantation of an Ahmed-FP7 valve (New World Medical, Inc., Rancho Cucamonga, CA) or a Baerveldt-350 implant (Abbott Medical Optics, Inc., Santa Ana, CA) using standardized surgical technique, to be followed for 5 years. The primary outcome measure was failure, defined as intraocular pressure (IOP) out of target range (5-18 mmHg with ≥ 20% reduction from baseline) for 2 consecutive visits after 3 months, vision-threatening complications, additional glaucoma procedures, or loss of light perception. Secondary outcome measures included IOP, medication use, visual acuity, complications, and interventions. A total of 238 patients were enrolled in the study; 124 received the Ahmed-FP7 valve implant and 114 received the Baerveldt-350 implant. The 2 treatment groups did not differ in any baseline characteristics with the exception of sex. The mean age of the study group was 66 ± 16 years, and 55% were women, with a greater proportion in the Baerveldt group (P=0.01). The mean baseline IOP of the study group was 31.4 ± 10.8 on a mean of 3.1 ± 1.0 glaucoma medications. The median Snellen visual acuity was 20/100, mean number of previous laser therapies was 0.9 ± 1.1, and mean number of previous surgeries was 1.7 ± 1.2. Five (4%) patients in the Ahmed group and 4 (4%) patients in the Baerveldt group experienced significant intraoperative complications. Aqueous drainage devices are being increasingly used for glaucoma refractory to conventional treatment, and the AVB Study compares the 2 most commonly implanted devices. The 2 groups had similar baseline characteristics, and there were a similar number of intraoperative complications for both devices. Proprietary or commercial disclosure may be found after the references. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Ahmed glaucoma valve in children: A review☆

PubMed Central

Nassiri, Nariman; Nouri-Mahdavi, Kouros; Coleman, Anne L.

2011-01-01

Pediatric glaucoma is potentially a blinding disease. Although goniotomy and trabeculotomy are associated with good early success rates, eventually 20% of these procedures fail and many children will require additional surgery to control the IOP in the long-term. In this review, we reported that adequate IOP control can be achieved with the placement of Ahmed glaucoma valve and can last 5 or more years. However, most patients will need one or more glaucoma medications at some point after surgery. In addition, the implants may be associated with pupillary irregularities, lenticular opacification as well as tube-related complications, particularly in the first year of life, as the globe is enlarging with age. PMID:23960945

Schockmed Valve: A Novel Surgical Option for Uncontrolled Glaucoma in Eyes with Poor Conjunctiva and Encircling Bands.

PubMed

Fleischman, David; Kim, Bryan

2017-01-01

Surgical management of elevated intraocular pressure (IOP) in an eye with scarred conjunctiva, an encircling band, and silicone oil has limited options. By combining the flow restrictor of the Ahmed Glaucoma Valve (New World Medical, Rancho Cucamonga, California) and the capsule of the encircling band as a conduit for aqueous flow, immediate pressure reduction could theoretically be achieved in eyes with limited conjunctival mobilization. This is a description of a surgical technique in a case of a patient with multiple ocular surgeries with uncontrolled multimechanism glaucoma despite using all available topical and oral glaucoma medications. A combination of the Ahmed valve with a modification of the Schocket shunt technique was used in this case of an encircling band and poor conjunctiva. At 10-month follow-up, the patient maintains controlled pressures on dorzolamide-timolol drops. The combined Ahmed-Schocket (or Schockmed) technique may be another surgical option for management of uncontrolled IOP in cases of scarred conjunctiva and encircling bands needing immediate pressure reduction. A novel surgical option for uncontrolled glaucoma in eyes with poor conjunctiva and encircling bands. How to cite this article: Fleischman D, Kim B. Schockmed Valve: A Novel Surgical Option for Uncontrolled Glaucoma in Eyes with Poor Conjunctiva and Encircling Bands. J Curr Glaucoma Pract 2017;11(3):120-124.

Establishing the framework to support bioartificial heart fabrication using fibrin-based three-dimensional artificial heart muscle.

PubMed

Hogan, Matthew; Mohamed, Mohamed; Tao, Ze-Wei; Gutierrez, Laura; Birla, Ravi

2015-02-01

Only 3000 heart transplants are performed in the USA every year, leaving some 30 000-70 000 Americans without proper care. Current treatment modalities for heart failure have saved many lives yet still do not correct the underlying problems of congestive heart failure. Tissue engineering represents a potential field of study wherein a combination of cells, scaffolds, and/or bioreactors can be utilized to create constructs to mimic, replace, and/or repair defective tissue. The focus of this study was to generate a bioartificial heart (BAH) model using artificial heart muscle (AHM), composed of fibrin gel and neonatal rat cardiac myocytes, and a decellularized scaffold, formed by subjecting an adult rat heart to a series of decellularization solutions. By suturing the AHM around the outside of the decellularized heart and culturing while suspended in media, we were able to retain functional cardiac cells on the scaffold as evinced by visible contractility. Observed contractility rate was correlated with biopotential measurements to confirm essential functionality of cardiac constructs. Cross-sections of the BAH show successful decellularization of the scaffold and contiguous cell-rich AHM around the perimeter of the heart. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Overview of Recent Radiation Transport Code Comparisons for Space Applications

NASA Astrophysics Data System (ADS)

Townsend, Lawrence

Recent advances in radiation transport code development for space applications have resulted in various comparisons of code predictions for a variety of scenarios and codes. Comparisons among both Monte Carlo and deterministic codes have been made and published by vari-ous groups and collaborations, including comparisons involving, but not limited to HZETRN, HETC-HEDS, FLUKA, GEANT, PHITS, and MCNPX. In this work, an overview of recent code prediction inter-comparisons, including comparisons to available experimental data, is presented and discussed, with emphases on those areas of agreement and disagreement among the various code predictions and published data.

Managing high risk glaucoma with the Ahmed valve implant: 20 years of experience

PubMed Central

Rotsos, Tryfon; Tsioga, Anastasia; Andreanos, Konstantinos; Diagourtas, Andreas; Petrou, Petros; Georgalas, Ilias; Papaconstantinou, Dimitrios

2018-01-01

AIM To estimate the efficacy and safety of the Ahmed implant in patients with high risk for failure after glaucoma surgery. METHODS In 342 eyes of 342 patients with refractory glaucoma, even with application of medical treatment, the Ahmed valve was introduced for intraocular pressure (IOP) control, in the period of the last 20y. The nature of glaucoma was neovascular in 162 eyes, pseudophakic or aphakic in 49 eyes, inflammatory in 29 eyes and non working previous antiglaucomatic surgical interventions in 102 eyes. RESULTS Follow-up ranged from 18 to 120mo with a mean follow-up of 63.2mo. IOP before the operation decreased from 31.6±10.4 mm Hg to 18.3±5.4 mm Hg (no systemic treatment) at the end of follow up period. When we compared the IOP values before the operation using ANOVA showed statistically significant difference (P<0.001). The success rate was 85.2% during the first semester, 76.8% at 12mo and 50.3% at the end of follow up period (18 to 120mo after implantation). Success rate was 25.7% in neovascular glaucoma, 63.2% in aphakic glaucoma and 73.8% in non working previous antiglaucomatic surgical interventions. Complications due to the implant were: serous choroidal detachment in 14.8%, blockage of the tube in 2.8%, malposition of the tube in 4.9%, suprachoroidal hemorrhage in 2.1%, cataract progression in 39.6% (phakic eyes), shallow anterior chamber in 9.2%, hyphaema in 28.9%, exposure of valve in 2.6%, exposure of tube in 9.3%, hypotony in 4.9% and conjunctival fibrosis in 41.5%. CONCLUSION Despite the fact that Ahmed valve implant had suchlike results as other implants concerning the IOP control, complications rate due to hypotony or over filtration in the first days after the intervention are not that frequent as with other valve implants. PMID:29487813

Managing high risk glaucoma with the Ahmed valve implant: 20 years of experience.

PubMed

Rotsos, Tryfon; Tsioga, Anastasia; Andreanos, Konstantinos; Diagourtas, Andreas; Petrou, Petros; Georgalas, Ilias; Papaconstantinou, Dimitrios

2018-01-01

To estimate the efficacy and safety of the Ahmed implant in patients with high risk for failure after glaucoma surgery. In 342 eyes of 342 patients with refractory glaucoma, even with application of medical treatment, the Ahmed valve was introduced for intraocular pressure (IOP) control, in the period of the last 20y. The nature of glaucoma was neovascular in 162 eyes, pseudophakic or aphakic in 49 eyes, inflammatory in 29 eyes and non working previous antiglaucomatic surgical interventions in 102 eyes. Follow-up ranged from 18 to 120mo with a mean follow-up of 63.2mo. IOP before the operation decreased from 31.6±10.4 mm Hg to 18.3±5.4 mm Hg (no systemic treatment) at the end of follow up period. When we compared the IOP values before the operation using ANOVA showed statistically significant difference ( P <0.001). The success rate was 85.2% during the first semester, 76.8% at 12mo and 50.3% at the end of follow up period (18 to 120mo after implantation). Success rate was 25.7% in neovascular glaucoma, 63.2% in aphakic glaucoma and 73.8% in non working previous antiglaucomatic surgical interventions. Complications due to the implant were: serous choroidal detachment in 14.8%, blockage of the tube in 2.8%, malposition of the tube in 4.9%, suprachoroidal hemorrhage in 2.1%, cataract progression in 39.6% (phakic eyes), shallow anterior chamber in 9.2%, hyphaema in 28.9%, exposure of valve in 2.6%, exposure of tube in 9.3%, hypotony in 4.9% and conjunctival fibrosis in 41.5%. Despite the fact that Ahmed valve implant had suchlike results as other implants concerning the IOP control, complications rate due to hypotony or over filtration in the first days after the intervention are not that frequent as with other valve implants.

Active technique by suction to control the flow structure over a van model

NASA Astrophysics Data System (ADS)

Harinaldi, Budiarso, Warjito, Kosasih, Engkos A.; Tarakka, Rustan; Simanungkalit, Sabar P.

2012-06-01

Today research trend in car aerodynamics are carried out from the point of view of the durable development. Some car companies have the objective to develop control solution that enable to reduce the aerodynamic drag of vehicle. It provides the possibility to modify the flow separation to reduce the development of the swirling structures around the vehicle. In this study, a family van is modeled with a modified form of Ahmed's body by changing the orientation of the flow from its original form (modified/reversed Ahmed Body). This model is equipped with a suction on the rear side to comprehensively examine the pressure field modifications that occur. The investigation combines computational and experimental work. The computational simulation used is k-epsilon flow turbulence model. The reversed Ahmed body used in the investigation has slant angle (φ) 35° at the front part. In the computational work, meshing type is tetra/hybrid element with hex core type and the grid number is more than 1.7 million in order to ensure detail discretization and more accurate calculation results. The boundary condition is upstream velocity of 11.1 m/s. Mean free stream at far upstream region is assumed in a steady state condition and uniform. The suction velocity is set at 1 m/s. Meanwhile in the experimental work a reversed Ahmed model is tested in a controlled wind tunnel experiments. The main measurement is the drag aerodynamic measurement at rear of the body of the model using strain gage. The results show that the application of a suction in the rear part of the van model give the effect of reducing the wake and the vortex is formed. Aerodynamic drag reduction close to 24% for the computational approach and 14.8% for the experimental approach by introducing a suction have been obtained.

Adaptive harvest management: Adjustments for SEIS 2013

USGS Publications Warehouse

Boomer, Scott; Johnson, Fred A.; Zimmerman, Guthrie S.

2015-01-01

This report provides a summary of revised methods and assessment results based on updated adaptive harvest management (AHM) protocols developed in response to the preferred alternative specified in the Final Supplemental Environmental Impact Statement on the Issuance of Annual Regulations Permitting the Hunting of Migratory Birds (SEIS; U.S. Department of the Interior 2013). We describe necessary changes to optimization procedures and decision processes for the implementation of AHM for midcontinent, eastern and western mallards (Anas platyrhynchos), northern pintails (Anas acuta), and scaup (Aythya affinis, A. marila) decision frameworks. We present this final report for communication purposes, and acknowledge that any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

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

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.

A multicenter randomized controlled evaluation of automated home monitoring and telephonic disease management in patients recently hospitalized for congestive heart failure: the SPAN-CHF II trial.

PubMed

Weintraub, Andrew; Gregory, Douglas; Patel, Ayan R; Levine, Daniel; Venesy, David; Perry, Kathleen; Delano, Christine; Konstam, Marvin A

2010-04-01

We performed a prospective, randomized investigation assessing the incremental effect of automated health monitoring (AHM) technology over and above that of a previously described nurse directed heart failure (HF) disease management program. The AHM system measured and transmitted body weight, blood pressure, and heart rate data as well as subjective patient self-assessments via a standard telephone line to a central server. A total of 188 consented and eligible patients were randomized between intervention and control groups in 1:1 ratio. Subjects randomized to the control arm received the Specialized Primary and Networked Care in Heart Failure (SPAN-CHF) heart failure disease management program. Subjects randomized to the intervention arm received the SPAN-CHF disease management program in conjunction with the AHM system. The primary end point was prespecified as the relative event rate of HF hospitalization between intervention and control groups at 90 days. The relative event rate of HF hospitalization for the intervention group compared with controls was 0.50 (95%CI [0.25-0.99], P = .05). Short-term reductions in the heart failure hospitalization rate were associated with the use of automated home monitoring equipment. Long-term benefits in this model remain to be studied. (c) 2010 Elsevier Inc. All rights reserved.

Process R&D for Particle Size Control of Molybdenum Oxide

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

Sen, Sujat; Dzwiniel, Trevor; Pupek, Krzysztof

The primary goal of this study was to produce MoO 3 powder with a particle size range of 50 to 200 μm for use in targets for production of the medical isotope 99Mo. Molybdenum metal powder is commercially produced by thermal reduction of oxides in a hydrogen atmosphere. The most common source material is MoO 3, which is derived by the thermal decomposition of ammonium heptamolybdate (AHM). However, the particle size of the currently produced MoO 3 is too small, resulting in Mo powder that is too fine to properly sinter and press into the desired target. In this study,more » effects of heating rate, heating temperature, gas type, gas flow rate, and isothermal heating were investigated for the decomposition of AHM. The main conclusions were as follows: lower heating rate (2-10°C/min) minimizes breakdown of aggregates, recrystallized samples with millimeter-sized aggregates are resistant to various heat treatments, extended isothermal heating at >600°C leads to significant sintering, and inert gas and high gas flow rate (up to 2000 ml/min) did not significantly affect particle size distribution or composition. In addition, attempts to recover AHM from an aqueous solution by several methods (spray drying, precipitation, and low temperature crystallization) failed to achieve the desired particle size range of 50 to 200 μm. Further studies are planned.« less

76 FR 30360 - Ocean Transportation Intermediary License; Applicants

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-25

.... Chaucer Freight LLC (NVO & OFF), 755 N. Rte. 83, Suite 222, Bensenville, IL 60106. Officers: Kathy...: Syed O. Ahmed, President/Corporate Secretary (Qualifying Individual). Application Type: New OFF License...

homepage of A Ismail

Science.gov Websites

@anl.gov Ahmed Ismail Research Associate at the ANL High Energy Physics Theory Group and UIC ELEMENTARY PARTICLE PHYSICS THEORY High Energy Phenomenology Updated October 2013 aismail@anl.gov

76 FR 30984 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-27

... registered with the Commission; The Securities Industry Automation Corporation (``SIAC'') and The Nasdaq... 10102, New Executive Office Building, Washington, DC 20503 or by sending an e-mail to: Shagufta_Ahmed...

76 FR 7906 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-11

... designated to act on behalf of the organization. Respondents: Private sector: Business or other for-profit..., 200 Third Street, Parkersburg, West Virginia 26106; (304) 480-8112. OMB Reviewer: Shagufta Ahmed...

75 FR 35878 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-23

...: Tip Reporting Alternative Commitment (TRAC) for Use in the Food and Beverage Industry. Abstract...., Room 6129, Washington, DC 20224; (202) 622-3634. OMB Reviewer: Shagufta Ahmed, Office of Management and...

Combustion Science for Cleaner Fuels

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

Ahmed, Musahid

2014-10-17

Musahid Ahmed discusses how he and his team use the Advanced Light Source (ALS) to study combustion chemistry at our '8 Big Ideas' Science at the Theater event on October 8th, 2014, in Oakland, California.

Combustion Science for Cleaner Fuels

ScienceCinema

Ahmed, Musahid

2018-01-16

Musahid Ahmed discusses how he and his team use the Advanced Light Source (ALS) to study combustion chemistry at our '8 Big Ideas' Science at the Theater event on October 8th, 2014, in Oakland, California.

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.

Complications and 2-year valve survival following Ahmed valve implantation during the first 2 years of life.

PubMed

Almobarak, F; Al-Mobarak, F; Khan, A O

2009-06-01

To report complications and 2-year valve survival following Ahmed valve implantation during the first 2 years of life. Retrospective institutional case series. Forty-two eyes of 36 patients with Ahmed valve implantation (without prior drainage device surgery) during the first 2 years of life and 2 years' postsurgical follow-up were identified. Most eyes had primary congenital glaucoma (28/42, 66.7%), aphakic glaucoma (5/42, 11.9%) or Peters anomaly (5/42, 11.9%). All but three eyes had prior ocular surgery. Surgery was at a mean age of 11.83 months (m) (SD 5.63). The most common significant postoperative complications were tube malpositioning requiring intervention (11/42, 26.2%), endophthalmitis (3/42, 7.1%; one with tube exposure) and retinal detachment (3/42, 7.1%). Thirty-six eyes (85.8%) required resumption of antiglaucoma medications to maintain intraocular pressure (IOP) < or =22 mm Hg a mean of 7.2 m (SD 6.8) postoperatively. Cumulative probabilities of valve survival (IOP< or =22 mm Hg with or without medication) by Kaplan-Meier analysis were 73.8% and 63.3% at 12 months and 24 months, respectively. Postoperative tube malpositioning that required surgical revision was common in this age group. Infectious endophthalmitis and retinal detachment are known potential complications following any incisional surgery for advanced buphthalmos; however, tube exposure is a unique potential problem following aqueous shunt implantation that can lead to intraocular infection. Cumulative valve survival 2 years following implantation was 63.3%.

Pretest aerosol code comparisons for LWR aerosol containment tests LA1 and LA2

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

Wright, A.L.; Wilson, J.H.; Arwood, P.C.

The Light-Water-Reactor (LWR) Aerosol Containment Experiments (LACE) are being performed in Richland, Washington, at the Hanford Engineering Development Laboratory (HEDL) under the leadership of an international project board and the Electric Power Research Institute. These tests have two objectives: (1) to investigate, at large scale, the inherent aerosol retention behavior in LWR containments under simulated severe accident conditions, and (2) to provide an experimental data base for validating aerosol behavior and thermal-hydraulic computer codes. Aerosol computer-code comparison activities are being coordinated at the Oak Ridge National Laboratory. For each of the six LACE tests, ''pretest'' calculations (for code-to-code comparisons) andmore » ''posttest'' calculations (for code-to-test data comparisons) are being performed. The overall goals of the comparison effort are (1) to provide code users with experience in applying their codes to LWR accident-sequence conditions and (2) to evaluate and improve the code models.« less

Genetics Home Reference: phosphoribosylpyrophosphate synthetase superactivity

MedlinePlus

... Sources for This Page Ahmed M, Taylor W, Smith PR, Becker MA. Accelerated transcription of PRPS1 in ... 11):7482-8. Citation on PubMed Becker MA, Smith PR, Taylor W, Mustafi R, Switzer RL. The ...

Combined trabeculotomy-trabeculectomy versus Ahmed valve implantation for refractory primary congenital glaucoma in Egyptian patients: a long-term follow-up

PubMed Central

Helmy, Hazem

2016-01-01

Introduction Primary congenital glaucoma (PCG) is the most common type of glaucoma in pediatric patients. The aim of this study was to compare the effectiveness of combined trabeculotomy-trabeculectomy versus Ahmed valve implantation for cases of PCG refractory to traditional incisional angle surgery (goniotomy and trabeculotomy) in the Egyptian population. Methods The study was conducted in the Glaucoma Clinic of the Research Institute of Ophthalmology (Egypt). The study included 66 eyes of 66 patients (in two groups) with advanced PCG who had previous failed goniotomy, trabeculotomy, or both. Group 1 included 33 patients who underwent trabeculotomy-trabeculectomy procedures; group 2 included 33 patients who underwent FP 8 Ahmed valve implantation. The main outcome measures were intraocular pressure (IOP) reduction, corneal diameter, and axial length stability in both groups. Secondary outcome measures included detection of complications in both groups. Results The average ages of the patients were 13.5 ± 3.9 months and 15.3 ± 5.8 months in groups 1 and 2, respectively. Ten patients (30.3%) in group 1 and 9 patients (27.3%) in group 2 had family histories of PCG. Positive consanguinity was present in 26 patients (78.8%) in group 1 and in 27 patients (81.8%) in group 2. In group 1, the mean intraocular pressure (IOP) value decreased from 33.6 ± 3.4 mmHg preoperatively to 13.8 ± 0.6, 16.9 ± 1.5, 18.2 ± 2.5, 19.8 ± 3.6, and 20.2 ± 3.1 mmHg in the first postoperative month and after years 1, 2, 3, and 4, respectively (p < 0.001). In group 2, the mean IOP value decreased from 33.4 ± 4.5 mmHg preoperatively to 13.3 ± 1.1, 16.3 ± 1.6, 18.1 ± 1.0, 19.1 ± 3.5, and 19.9 ± 3.7 mmHg in the first postoperative month and after years 1, 2, 3, and 4, respectively (p < 0.001). The average number of medications decreased from 2.2 ± 0.4 preoperatively to 1.8 ± 0.4 postoperatively in group 1, while it decreased from 2.1 ± 0.4 preoperatively to 1.9 ± 0.3 postoperatively in group 2. The success rate in group 1 was 97, 91, 76, and 61% in years 1, 2, 3, and 4, respectively, whereas the success rate in group 2 was 97, 93, 81, and 66% in years 1, 2, 3, and 4, respectively. Conclusion Both procedures, i.e., combined trabeculotomy-trabeculectomy and Ahmed valve implantation are suitable options in advanced PCG with failed trabeculotomy and goniotomy. Ahmed valve implanation has a better long-term survival, but trabeculotomy-trabeculectomy provides a second chance for surgical intervention. PMID:27053995

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

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

Evaluation of the tightness of contact between 
limbal sclera tunnel and tube following Ahmed 
glaucoma valve implantation.

PubMed

Holló, Gábor; Naghizadeh, Farzaneh

2013-01-01

To investigate whether the tightness of contact between the tube and the limbal sclera tunnel can be evaluated with high-magnification anterior segment optical coherence tomography (OCT) imaging following Ahmed glaucoma valve implantation. Tightness between the tube and the limbal sclera tunnel was investigated with the CAM-L cornea lens adapter of the Optovue Fourier-domain OCT (RTVue-OCT) for 21 uncomplicated Ahmed glaucoma valves implanted in 20 eyes of 19 patients with glaucoma. Nineteen valves were implanted 4 to 124 months earlier (late postoperative cases) and 2 valves 1 day prior to the imaging (early postoperative cases). All valves were introduced into the anterior chamber via a limbal sclera tunnel. The limbal intratunnel part of the tube was successfully imaged in all but 2 cases where an additional full-thickness sclera patch was used. In 14 cases, the contact was tight without tube compression. In 
5 cases, the tube was partially compressed but remained open in the limbal sclera tunnel, and redilated behind the limbus. No case with loose contact or peritubular filtration was seen. The posterior run of the tube was successfully imaged in all 19 cases without a full-thickness sclera patch. High-magnification imaging with the CAM- L anterior segment adapter of the RTVue-OCT allows detailed examination of the limbal insertion area of tubes in both the early and late postoperative periods. Therefore this method may potentially be applied for detection of complications related to tube insertion after glaucoma drainage device surgery.

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.

A new assessment method of pHEMT models by comparing relative errors of drain current and its derivatives up to the third order

NASA Astrophysics Data System (ADS)

Dobeš, Josef; Grábner, Martin; Puričer, Pavel; Vejražka, František; Míchal, Jan; Popp, Jakub

2017-05-01

Nowadays, there exist relatively precise pHEMT models available for computer-aided design, and they are frequently compared to each other. However, such comparisons are mostly based on absolute errors of drain-current equations and their derivatives. In the paper, a novel method is suggested based on relative root-mean-square errors of both drain current and its derivatives up to the third order. Moreover, the relative errors are subsequently relativized to the best model in each category to further clarify obtained accuracies of both drain current and its derivatives. Furthermore, one our older and two newly suggested models are also included in comparison with the traditionally precise Ahmed, TOM-2 and Materka ones. The assessment is performed using measured characteristics of a pHEMT operating up to 110 GHz. Finally, a usability of the proposed models including the higher-order derivatives is illustrated using s-parameters analysis and measurement at more operating points as well as computation and measurement of IP3 points of a low-noise amplifier of a multi-constellation satellite navigation receiver with ATF-54143 pHEMT.

Stress and your health

MedlinePlus

... uptight; Stress; Tension; Jitters; Apprehension Images Generalized anxiety disorder Stress and anxiety References Ahmed SM, Hershberger PJ, Lemkau ... on stress. www.nimh.nih.gov/health/publications/stress/index.shtml . Accessed ... aspects of cardiovascular disease. In: Mann DL, Zipes DP, Libby P, Bonow ...

Genetics Home Reference: Bosma arhinia microphthalmia syndrome

MedlinePlus

... Xue S, Yigit G, Filali H, Chen K, Rosin N, Yoshiura KI, Oufadem M, Beck TJ, McGowan R, ... AD, Nürnberg P, Meschede D, Mühlbauer W, Okamoto N, Varghese V, Irving R, Sigaudy S, Williams D, Ahmed ...

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

Comparison of the Ahmed and Baerveldt glaucoma shunts with combined cataract extraction.

PubMed

Rai, Amrit S; Shoham-Hazon, Nir; Christakis, Panos G; Rai, Amandeep S; Ahmed, Iqbal Ike K

2018-04-01

To compare the surgical outcomes of combined phacoemulsification with either Ahmed glaucoma valve (AGV) or Baerveldt glaucoma implant (BGI). Retrospective cohort study. A total of 104 eyes that underwent combined phacoemulsification with either AGV (PhacoAGV; n = 57) or BGI (PhacoBGI; n = 47) implantation. Failure was defined as uncontrolled intraocular pressure (IOP; <5 mm Hg, ≥18 mm Hg, or <20% reduction), additional glaucoma surgery, vision-threatening complications, or progression to no-light-perception vision. The PhacoAGV group was older (p = 0.03), had poorer baseline visual acuity (VA; p = 0.001), and had fewer previous glaucoma surgeries (p = 0.04). Both groups had similar baseline IOP (PhacoAGV: 26.4 ± 8.3 mm Hg; PhacoBGI: 25.7 ± 7.3; p = 0.66) and glaucoma medications (PhacoAGV: 3.8 ± 1.0; PhacoBGI: 3.6 ± 1.5; p = 0.54). At 2 years, failure rates were 44% in the PhacoAGV group and 23% in the PhacoBGI group (p = 0.02). Both groups had similar mean IOP reduction (PhacoAGV: 45%; PhacoBGI: 47%, p = 0.67) and medication use reduction (PhacoAGV: 47%; PhacoBGI: 58%, p = 0.38). The PhacoBGI group had higher IOP and medication use up to 1 month (p < 0.05). Both groups improved in VA from baseline (p < 0.05) and had similar overall complication rates (p = 0.31). The PhacoBGI group required more overall interventions (p < 0.0005). This comparative study found no difference in IOP, glaucoma medications, or complication rates between PhacoAGV and PhacoBGI at 2 years, despite BGIs being implanted in patients at higher risk for failure. The PhacoAGV group had higher failure rates at 2 years. Both groups had significant improvements in VA due to removal of their cataracts. The PhacoBGI group required more interventions, but most of these were minor slit-lamp procedures. Copyright © 2018. Published by Elsevier Inc.

Evaluating mallard adaptive management models with time series

USGS Publications Warehouse

Conn, P.B.; Kendall, W.L.

2004-01-01

Wildlife practitioners concerned with midcontinent mallard (Anas platyrhynchos) management in the United States have instituted a system of adaptive harvest management (AHM) as an objective format for setting harvest regulations. Under the AHM paradigm, predictions from a set of models that reflect key uncertainties about processes underlying population dynamics are used in coordination with optimization software to determine an optimal set of harvest decisions. Managers use comparisons of the predictive abilities of these models to gauge the relative truth of different hypotheses about density-dependent recruitment and survival, with better-predicting models giving more weight to the determination of harvest regulations. We tested the effectiveness of this strategy by examining convergence rates of 'predictor' models when the true model for population dynamics was known a priori. We generated time series for cases when the a priori model was 1 of the predictor models as well as for several cases when the a priori model was not in the model set. We further examined the addition of different levels of uncertainty into the variance structure of predictor models, reflecting different levels of confidence about estimated parameters. We showed that in certain situations, the model-selection process favors a predictor model that incorporates the hypotheses of additive harvest mortality and weakly density-dependent recruitment, even when the model is not used to generate data. Higher levels of predictor model variance led to decreased rates of convergence to the model that generated the data, but model weight trajectories were in general more stable. We suggest that predictive models should incorporate all sources of uncertainty about estimated parameters, that the variance structure should be similar for all predictor models, and that models with different functional forms for population dynamics should be considered for inclusion in predictor model! sets. All of these suggestions should help lower the probability of erroneous learning in mallard ABM and adaptive management in general.

Arizona Highways magazine : tracking shifts in reader habits.

DOT National Transportation Integrated Search

2016-09-01

The primary mission of Arizona Highways magazine (AHM) is to promote travel and tourism in Arizona. The magazine has conducted a subscriber survey approximately every five years since the early 1990s, with the last survey conducted in 2009. However, ...

A comparison of theoretical and experimental pressure distributions for two advanced fighter wings

NASA Technical Reports Server (NTRS)

Haney, H. P.; Hicks, R. M.

1981-01-01

A comparison was made between experimental pressure distributions measured during testing of the Vought A-7 fighter and the theoretical predictions of four transonic potential flow codes. Isolated wind and three wing-body codes were used for comparison. All comparisons are for transonic Mach numbers and include both attached and separate flows. In general, the wing-body codes gave better agreement with the experiment than did the isolated wing code but, because of the greater complexity of the geometry, were found to be considerably more expensive and less reliable.

Early Light Imaging for Biomedical Applications

DTIC Science & Technology

2000-07-01

such as prostate cancer, breast cancer, cervical cancer, glaucoma , macular degeneration, macular endema, and atherosclerosis plaques. Understanding of...harmonic- generation cross-correlation time gating", Opt. Lett., 16 1019-1021 (1991) 17. K. Yoo, Z. Zang, S. Ahmed , R. Alfano, "Imaging objects hidden

Entrepreneurship--Born, Made and Educated

ERIC Educational Resources Information Center

Burger-Helmchen, Thierry, Ed.

2012-01-01

Chapters in this book include: (1) The Psychology of Entrepreneurship (Melek Kalkan and Canani Kaygusuz); (2) Entrepreneurial Intentions: The Role of the Cognitive Variables (Jose C. Sanchez); (3) Do External Factors Influence Students' Entrepreneurial Inclination? An Evidence Based Approach (Ishfaq Ahmed, Muhammad Musarrat Nawaz and Muhammad…

Compression performance of HEVC and its format range and screen content coding extensions

NASA Astrophysics Data System (ADS)

Li, Bin; Xu, Jizheng; Sullivan, Gary J.

2015-09-01

This paper presents a comparison-based test of the objective compression performance of the High Efficiency Video Coding (HEVC) standard, its format range extensions (RExt), and its draft screen content coding extensions (SCC). The current dominant standard, H.264/MPEG-4 AVC, is used as an anchor reference in the comparison. The conditions used for the comparison tests were designed to reflect relevant application scenarios and to enable a fair comparison to the maximum extent feasible - i.e., using comparable quantization settings, reference frame buffering, intra refresh periods, rate-distortion optimization decision processing, etc. It is noted that such PSNR-based objective comparisons generally provide more conservative estimates of HEVC benefit than are found in subjective studies. The experimental results show that, when compared with H.264/MPEG-4 AVC, HEVC version 1 provides a bit rate savings for equal PSNR of about 23% for all-intra coding, 34% for random access coding, and 38% for low-delay coding. This is consistent with prior studies and the general characterization that HEVC can provide about a bit rate savings of about 50% for equal subjective quality for most applications. The HEVC format range extensions provide a similar bit rate savings of about 13-25% for all-intra coding, 28-33% for random access coding, and 32-38% for low-delay coding at different bit rate ranges. For lossy coding of screen content, the HEVC screen content coding extensions achieve a bit rate savings of about 66%, 63%, and 61% for all-intra coding, random access coding, and low-delay coding, respectively. For lossless coding, the corresponding bit rate savings are about 40%, 33%, and 32%, respectively.

Effect of glaucoma tube shunt parameters on cornea endothelial cells in patients with Ahmed valve implants.

PubMed

Koo, Euna B; Hou, Jing; Han, Ying; Keenan, Jeremy D; Stamper, Robert L; Jeng, Bennie H

2015-01-01

The aim of this study was to assess the effect of various tube parameters on corneal endothelial cell density (ECD) after insertion of Ahmed valves. Thirty-nine eyes of 33 patients with previous superotemporal (ST) Ahmed valve implantation and 20 eyes of 13 participants with previous uncomplicated phacoemulsification and intraocular lens implantation but no history of glaucoma surgery were evaluated. Various tube parameters were measured with anterior segment optical coherence tomography. ST, central, and inferonasal (IN) ECD and pachymetry were measured. Endothelial cell loss and corneal thickness in the ST cornea was compared with those in the IN cornea. The mean age of the operated patients was 58 ± 22 years, and the mean time since glaucoma surgery was 2.5 ± 2.6 years. Thirty-two of the 39 study eyes were pseudophakic. The ECD was significantly lower in the ST endothelium than in the IN endothelium in eyes with glaucoma tube surgery (P < 0.001), although this relative reduction in ST ECD was not greater than that seen in pseudophakic control eyes (P = 0.16). In univariate analysis, tube angle relative to the cornea and distance from the tip of the tube to the cornea were significant risk factors for decreased ST endothelial cell loss when assessed relative to the IN ECD (P = 0.01 and P = 0.02, respectively). In multivariate analysis, only the distance of the tube tip to the cornea remained significantly associated with ST endothelial cell loss. Although this was a retrospective study with inherent limitations, tubes that are closer to the cornea seem to lead to increased loss of adjacent endothelial cells.

Simultaneous Implantation of an Ahmed and Baerveldt Glaucoma Drainage Device for Uncontrolled Intraocular Pressure in Advanced Glaucoma.

PubMed

Rao, Veena S; Christenbury, Joseph; Lee, Paul; Allingham, Rand; Herndon, Leon; Challa, Pratap

2017-02-01

To evaluate efficacy and safety of a novel technique, simultaneous implantation of Ahmed and Baerveldt shunts, for improved control of intraocular pressure (IOP) in advanced glaucoma with visual field defects threatening central fixation. Retrospective case series; all patients receiving simultaneous Ahmed and Baerveldt implantation at a single institution between October 2004 and October 2009 were included. Records were reviewed preoperatively and at postoperative day 1, week 1, month 1, month 3, month 6, year 1, and yearly until year 5. Outcome measures included IOP, best-corrected visual acuity, visual field mean deviation, cup to disc ratio, number of glaucoma medications, and complications. Fifty-nine eyes were identified; mean (±SD) follow-up was 26±23 months. Primary open-angle glaucoma was most common (n=37, 63%). Forty-six eyes (78%) had prior incisional surgery. Mean preoperative IOP was 25.5±9.8 mm Hg. IOP was reduced 50% day 1 (P<0.001, mean 12.7±7.0 mm Hg), which persisted throughout follow-up. At year 1, cup to disc ratio and mean deviation were stable with decreased best-corrected visual acuity from logMAR 0.72±0.72(20/100) to 1.06±1.13(20/200) (P=0.007). The Kaplan-Meier survival analysis showed median and mean survival of 1205 and 829±91 days, respectively. Complication rate was 47%. IOP is markedly reduced postoperative day 1 following double glaucoma tube implantation with effects persisting over postoperative year 1 and up to year 5. Complications were higher than that seen in reports of single shunt implantation, which may be explained by patient complexity in this cohort. This technique may prove a promising novel approach for management of uncontrolled IOP in advanced glaucoma.

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.

Dual Coding, Reasoning and Fallacies.

ERIC Educational Resources Information Center

Hample, Dale

1982-01-01

Develops the theory that a fallacy is not a comparison of a rhetorical text to a set of definitions but a comparison of one person's cognition with another's. Reviews Paivio's dual coding theory, relates nonverbal coding to reasoning processes, and generates a limited fallacy theory based on dual coding theory. (PD)

Individualized Special Education with Cognitive Skill Assessment.

ERIC Educational Resources Information Center

Kurhila, Jaakko; Laine, Tei

2000-01-01

Describes AHMED (Adaptive and Assistive Hypermedia in Education), a computer learning environment which supports the evaluation of disabled children's cognitive skills in addition to supporting openness in learning materials and adaptivity in learning events. Discusses cognitive modeling and compares it to previous intelligent tutoring systems.…

Foreign Terrorist Threat to Singapore: An Assessment

DTIC Science & Technology

2001-04-01

mystical power, he impressed potential believers with the help of the yoga technique of momentary levitation. 40 Gullible followers quickly multiplied...flat rented to Ramzi Ahmed Yousef – a freelance terrorist with links to the radical Egyptian group Al-Gama’at al- Islamiyya and indicted for

Development of New Generation of Multibody System Computer Software

DTIC Science & Technology

2012-04-12

DEVELOPMENT OF NEW GENERATION OF MULTIBODY SYSTEM COMPUTER SOFTWARE Ahmed A. Shabana University of Illinois at Chicago Paramsothy Jayakumar ...Paramsothy Jayakumar ; Michael Letherwood 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES

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

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.

Communication and Integrated Rural Development.

ERIC Educational Resources Information Center

Information Center on Instructional Technology Report, 1976

1976-01-01

In discussing communication planning and integrated rural development, Philip H. Coombs, Manzoor Ahmed, and Pratima Kale of the International Council for Educational Development stress that communication planning must deal with problems in behavioral and not just technical terms. Communication planners must be able to work with experts from other…

Pakistan’s Gwadar Port - Prospects of Economic Revival

DTIC Science & Technology

2005-06-01

Ahmed , who stood by me all the time during the academic rigors involved in the completion of this thesis. They sacrificed their opportunities to... Ashraf Khan, “Pakistan Fishing Village undergoes Transformation into global mega-port,” Agence France Presse, (September 14, 2003). 107 Kux Dennis

75 FR 82146 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-29

... before January 28, 2011 to be assured of consideration. Domestic Finance/Terrorism Risk Insurance Program... Program Reauthorization Act of 2007, and by Treasury implementing regulations to pay Federal share to... Ahmed, Office of Management and Budget, New Executive Office Building, Room 10235, Washington, DC 20503...

Partial Tenon’s capsule resection with adjunctive mitomycin C in Ahmed glaucoma valve implant surgery

PubMed Central

Susanna, R

2003-01-01

Aim: To verify if partial intraoperative Tenon’s capsule resection (PTCR) with adjunctive mitomycin C is effective in developing thin, avascular blebs in eyes undergoing Ahmed glaucoma valve insertion, and to assess the efficacy and safety of this procedure. Methods: A multicentre, prospective, alternating case assignment, investigator unmasked, parallel group, comparative interventional study was conducted in four Latin American countries (Argentina, Brazil, Colombia, and Peru). Ahmed glaucoma valve implant insertion with PTCR (group A) and without PCTR (group B) was performed in neovascular glaucomatous eyes without previous surgery. Adjunctive mitomycin C (MMC) was used in both groups. Patients were examined 1 day, 10 days, 1 month, 2 months, 3 months, 6 months, and 1 year following the surgery. Intraocular pressure (IOP) and the appearance of the bleb were evaluated at each examination. Appearance of the bleb was classified at both the 1 month mark and last examinations into one of three groups: flat and vascularised; elevated avascular; or elevated and not avascular. Results: 92 eyes from 92 patients were included in the study. The preoperative mean IOP was 50.0 (SD 10.5) mm Hg in group A and 48.4 (11.7) in group B (p>0.05). Statistically significant IOP reductions were observed at all periods of follow up. 12 months after surgery, the mean IOP was 17.2 (5.0) mm Hg in group A and 18.3 (8.7) mm Hg in group B (p>0.05). A hypertensive phase occurred in 40.0% in group A and in 46.8% in group B (p>0.05). At the 1 month and the final follow up, the blebs in all eyes were considered elevated and not avascular. The success rate (IOP⩽21 mm Hg) at 1 year after surgery was 70.4% in group A and 77.7% in group B (p>0.05). Overall, 74.2% of the patients achieved an IOP ⩽21 mm Hg and 55.2% an IOP⩽17 mm Hg, with or without additional medication administered to lower IOP. The incidence of complications was similar in both groups. Conclusions: In eyes undergoing Ahmed valve implantation for neovascular glaucoma, PCTR with MMC augmentation showed no additional benefits or complications over MMC augmentation alone; no avascular bleb was obtained with this technique. The incidence of a hypertensive phase was lower than reported in previous studies. PMID:12881343

New Hires at the National Cancer Institute at Frederick | Poster

Cancer.gov

Forty-nine people joined the facility in September and October 2013. The National Cancer Institute welcomes… Aamir Akram Clarissa Alexander Robert Buckheit Brian Chan Kelly Dempsey Christopher Descalzi Ahmed Fahim Devikala Gurusamy Jaewoo Hong Rhushikesh Kulkarni James Shaum Dionysios Watson Yuheng Xi Yi Xiang Thomas Zengeya

A Call to Lead

ERIC Educational Resources Information Center

Hamilton, Kendra

2006-01-01

Imam Yahya Hendi came from afar--the occupied Palestinian Territories--to become, in 1999, the first full-time Muslim chaplain serving at a university in the United States. He is now the chaplain at Georgetown University. Rumee Ahmed, appointed earlier this year as Brown University's first Muslim chaplain, had a significantly shorter trip, moving…

Diabetes Care and Treatment Project: A Joslin Telemedicine Initiative

DTIC Science & Technology

2005-10-01

threatening process or development of optic disc changes potentially associated with the development of glaucoma . The figures below illustrate the work...Hildebrand L, Federman J, Canahan L, Kuzmak P, Peters JM, Darkins A, Ahmed J, Aiello LM, Aiello LP, Buck G, Cheng YL, Cunningham D, GoodallE, Hope N

Discipline and Pleasure: The Pedagogical Work of Disneyland

ERIC Educational Resources Information Center

Aronstein, Susan L.; Finke, Laurie A.

2013-01-01

Disneyland is work disguised as play; school disguised as vacation. While Walt Disney's curriculum deploys across all of its products, it literally engulfs the approximately 50 million "guests" who visit the Disney Parks each year. Drawing on Sarah Ahmed's phenomenological reading of orientation in Queer phenomenology, this…

78 FR 16502 - Proposed Agency Information Collection Activities; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-15

...: Board of Governors of the Federal Reserve System. SUMMARY: On June 15, 1984, the Office of Management... OMB Desk Officer, Shagufta Ahmed, Office of Information and Regulatory Affairs, Office of Management... Collection Report title: Annual Company-Run Stress Test Projections. Agency form number: FR Y-16. OMB control...

Audiovisual Mass Media and Education. TTW 27/28.

ERIC Educational Resources Information Center

van Stapele, Peter, Ed.; Sutton, Clifford C., Ed.

1989-01-01

The 15 articles in this special issue focus on learning about the audiovisual mass media and education, especially television and film, in relation to various pedagogical and didactical questions. Individual articles are: (1) "Audiovisual Mass Media for Education in Pakistan: Problems and Prospects" (Ahmed Noor Kahn); (2) "The Role of the…

Building a Flexible Nework Infrastructure for Moving Target Defense

DTIC Science & Technology

2017-10-13

testbed. We have published a paper in the CAN Workshop held in conjunction with the ACM CoNext 2016 conference [3]. ML implementations on OpenNetVM...Artificial Intelligence applications in the network Workshop held in conjunction with IEEE ICNP 2017 [4]. [1] Azeem Aqil, Karim Khalil, Ahmed Atya

CTC Sentinel. Volume 7, Issue 5

DTIC Science & Technology

2014-05-01

individuals because they would face “ultimate punishment in the afterlife .” It is possible that Shekau knew of Ansaru’s formation but decided to let...lil brother ahmed got sentenced to life…26 years minimum…. love lil bro see you in the afterlife inshallah #kasper.”44 He appears to be referring

Developing Software to Use Parallel Processing Effectively

DTIC Science & Technology

1988-10-01

Experience, Vol 15(6), June 1985, p53 Gajski85 Gajski , Daniel D. and Jih-Kwon Peir, "Essential Issues in Multiprocessor Systems", IEEE Computer, June...Treleaven (eds.), Springer-Verlag, pp. 213-225 (June 1987). Kuck83 David Kuck, Duncan Lawrie, Ron Cytron, Ahmed Sameh and Daniel Gajski , The Architecture and

A Network Design Approach to Countering Terrorism

DTIC Science & Technology

2015-09-01

2003). More and more scale-free networks have been discovered. How can such diverse systems have the same architecture and properties? Part of the...Rabei Ousmane Sayed Ahmed (a.k.a. the Egyptian ) convinced the group to pursuit jihad at home, where they had the material resources to act (Atran, 2010

Automated UMLS-Based Comparison of Medical Forms

PubMed Central

Dugas, Martin; Fritz, Fleur; Krumm, Rainer; Breil, Bernhard

2013-01-01

Medical forms are very heterogeneous: on a European scale there are thousands of data items in several hundred different systems. To enable data exchange for clinical care and research purposes there is a need to develop interoperable documentation systems with harmonized forms for data capture. A prerequisite in this harmonization process is comparison of forms. So far – to our knowledge – an automated method for comparison of medical forms is not available. A form contains a list of data items with corresponding medical concepts. An automatic comparison needs data types, item names and especially item with these unique concept codes from medical terminologies. The scope of the proposed method is a comparison of these items by comparing their concept codes (coded in UMLS). Each data item is represented by item name, concept code and value domain. Two items are called identical, if item name, concept code and value domain are the same. Two items are called matching, if only concept code and value domain are the same. Two items are called similar, if their concept codes are the same, but the value domains are different. Based on these definitions an open-source implementation for automated comparison of medical forms in ODM format with UMLS-based semantic annotations was developed. It is available as package compareODM from http://cran.r-project.org. To evaluate this method, it was applied to a set of 7 real medical forms with 285 data items from a large public ODM repository with forms for different medical purposes (research, quality management, routine care). Comparison results were visualized with grid images and dendrograms. Automated comparison of semantically annotated medical forms is feasible. Dendrograms allow a view on clustered similar forms. The approach is scalable for a large set of real medical forms. PMID:23861827

One-week habitation of two humans in an airtight facility with two goats and 23 crops Analysis of carbon, oxygen, and water circulation

NASA Astrophysics Data System (ADS)

Tako, Y.; Tsuga, S.; Tani, T.; Arai, R.; Komatsubara, O.; Shinohara, M.

Human habitation and animal holding experiments in a closed environment, the Closed Ecology Experiment Facilities (CEEF), were carried out. The CEEF were established for collecting experimental data to estimate carbon transfer in the ecosystem around Rokkasho nuclear fuel reprocessing plant. Circulation of O2 and CO2, and supply of food from crops cultivated in the CEEF were conducted for the first time in the habitation experiments. Two humans known as eco-nauts inhabited the CEEF, living and working in the Plant Module (PM) and the Animal and Habitation Module (AHM), for a week three times in 2005. On a fresh weight basis, 82% of their food was supplied from 23 crops including rice and soybean, cultivated and harvested in the PM, in the 2nd and 3rd experiments. For the goats, the animals held in the experiments, all of their feed, consisting of rice straw, soybean plant leaves, and peanut shells and peanut plant leaves, was produced in the PM in the 2nd and 3rd experiments. The O2 produced in the PM by photosynthesis of the crops was separated by the O2 separator using molecular sheaves, then accumulated, transferred, and supplied to the AHM atmosphere. The CO2 produced in the AHM by respiration of the humans and animals was separated by the CO2 separator using solid amine, then accumulated, transferred, and supplied to the PM atmosphere. The amount of O2 consumed in the AHM was 46 51% of that produced in the PM, and the amount of CO2 produced in the AHM was 43 56% of that consumed in the PM. The surplus of O2 and the shortage of CO2 was a result of the fact that waste of the goats and the crops and part of the human waste were not processed in these habitation experiments. The estimated amount of carbon ingested by the eco-nauts was 64 92% of that in the harvested edible part of the crops. The estimated amount of carbon ingested by the goats was 36 53% of that in the harvested inedible part of the crops. One week was not enough time for determination of gas exchange especially for humans and animals, because fluctuation of their gas exchange was quite high. The amount of transpired water collected as condensate was 818 938 L d-1, and it was recycled as replenishing water compensating transpiration loss of nutrient solution. The amount of waste nutrient solution discharged from the PM was 1421 1644 L d-1. The waste nutrient solutions from rice and other crops were processed through micro filters (MFs) separately. The MF filtrated solutions were processed with reverse osmosis (RO) membrane filter separately and divided into filtrated water and concentrated waste nutrient solution. The concentrated waste nutrient solution from the crops other than rice was processed through an ultra-micro filter (UF) and reused, although that from rice was discharged in 2005. Concentrations of nutritional ions in the UF filtrated solution were determined, the depleted ions were added back, the UF filtrated solution was diluted with the RO membrane filtrated water, and the nutrient solution for the crops other than rice was regenerated. The nutrient solution for rice was newly made each time, using concentrated solution from an external source and the RO membrane filtrated water. Average amounts of water used in the AHM (L d-1) were determined as follows: drinking by humans (filtrated water), 1.5; cooking, etc. (filtrated water other than for drinking), 14.3; drinking by goats, 3.8; showering (hot water), 13.2; showering (cold water), 0.1; washing of hand and face and brushing teeth, 4.1; washing of dishes, dish clothes and towels, 36.4; and washing of animal holding tools, 0.3. The waste water was processed by a RO purification system and recycled for toilet flushing and animal pens washing. A circulation experiment for water was started in 2006 and a circulation experiment for waste materials is planned for 2007. In 2006, a single duration of the air circulation experiments was 2 weeks, although the human habitants were changed after 1 week.

Comparison of SAND-II and FERRET

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

Wootan, D.W.; Schmittroth, F.

1981-01-01

A comparison was made of the advantages and disadvantages of two codes, SAND-II and FERRET, for determining the neutron flux spectrum and uncertainty from experimental dosimeter measurements as anticipated in the FFTF Reactor Characterization Program. This comparison involved an examination of the methodology and the operational performance of each code. The merits of each code were identified with respect to theoretical basis, directness of method, solution uniqueness, subjective influences, and sensitivity to various input parameters.

Transformation of two and three-dimensional regions by elliptic systems

NASA Technical Reports Server (NTRS)

Mastin, C. Wayne

1994-01-01

Several reports are attached to this document which contain the results of our research at the end of this contract period. Three of the reports deal with our work on generating surface grids. One is a preprint of a paper which will appear in the journal Applied Mathematics and Computation. Another is the abstract from a dissertation which has been prepared by Ahmed Khamayseh, a graduate student who has been supported by this grant for the last two years. The last report on surface grids is the extended abstract of a paper to be presented at the 14th IMACS World Congress in July. This report contains results on conformal mappings of surfaces, which are closely related to elliptic methods for surface grid generation. A preliminary report is included on new methods for dealing with block interfaces in multiblock grid systems. The development work is complete and the methods will eventually be incorporated into the National Grid Project (NGP) grid generation code. Thus, the attached report contains only a simple grid system which was used to test the algorithms to prove that the concepts are sound. These developments will greatly aid grid control when using elliptic systems and prevent unwanted grid movement. The last report is a brief summary of some timings that were obtained when the multiblock grid generation code was run on the Intel IPSC/860 hypercube. Since most of the data in a grid code is local to a particular block, only a small fraction of the total data must be passed between processors. The data is also distributed among the processors so that the total size of the grid can be increase along with the number of processors. This work is only in a preliminary stage. However, one of the ERC graduate students has taken an interest in the project and is presently extending these results as a part of his master's thesis.

Description of Transport Codes for Space Radiation Shielding

NASA Technical Reports Server (NTRS)

Kim, Myung-Hee Y.; Wilson, John W.; Cucinotta, Francis A.

2011-01-01

This slide presentation describes transport codes and their use for studying and designing space radiation shielding. When combined with risk projection models radiation transport codes serve as the main tool for study radiation and designing shielding. There are three criteria for assessing the accuracy of transport codes: (1) Ground-based studies with defined beams and material layouts, (2) Inter-comparison of transport code results for matched boundary conditions and (3) Comparisons to flight measurements. These three criteria have a very high degree with NASA's HZETRN/QMSFRG.

Comparison of laser anemometer measurements and theory in an annular turbine cascade with experimental accuracy determined by parameter estimation

NASA Technical Reports Server (NTRS)

Goldman, L. J.; Seasholtz, R. G.

1982-01-01

Experimental measurements of the velocity components in the blade to blade (axial tangential) plane were obtained with an axial flow turbine stator passage and were compared with calculations from three turbomachinery computer programs. The theoretical results were calculated from a quasi three dimensional inviscid code, a three dimensional inviscid code, and a three dimensional viscous code. Parameter estimation techniques and a particle dynamics calculation were used to assess the accuracy of the laser measurements, which allow a rational basis for comparison of the experimenal and theoretical results. The general agreement of the experimental data with the results from the two inviscid computer codes indicates the usefulness of these calculation procedures for turbomachinery blading. The comparison with the viscous code, while generally reasonable, was not as good as for the inviscid codes.

Libya: Unrest and U.S. Policy

DTIC Science & Technology

2011-03-29

carried a report on March 9 from the government General Bureau for Criminal Investigation offering, “A reward of half a million Libyan dinars [about...entire city to run.”52 • Ahmed al Zubayr al Sanusi. Serves as a Council member. He is known as “Libya’s longest-serving ‘prisoner of conscience

Ahmed Zewail and Femtochemistry

Science.gov Websites

lasers to observe chemical reactions as they actually happen. The ... chemist's laser-spectroscopy technique has led to a greater understanding of the nature of chemical bonds as well as the details of such -invisible intermediate stages in a chemical reaction by firing two pulses of laser light in quick succession

Rejecting Ahmed's "Melancholy Migrant": South Sudanese Australians in Higher Education

ERIC Educational Resources Information Center

Harris, Anne; Marlowe, Jay; Nyuon, Nyadol

2015-01-01

This paper draws on related research studies in two urban centres (Melbourne and Adelaide, Australia) with South Sudanese men and women engaged in varying degrees with higher education. The co-authors examine some gendered differences in the process and demands of resettlement, including within employment and education, and its implications for…

Calibrating Crash Modification Factors for Wyoming-Specific Conditions : Application of the Highway Safety Manual - Part D

DOT National Transportation Integrated Search

2017-04-01

Mohamed Ahmed, Ph.D., P.E.- orcid.org/0000-0002-1921-0724; Sherif Gaweesh, M.S. - orcid.org/0000-0001-7977-6378; Md Julfiker Hossain -orcid.org/0000-0001-7173-7040; Sadia Sharmin orcid.org/0000-0003-0947-8345; Thomas Peel orcid.org/ 0000-0002...

Willfulness and Aspirations for Young Women in Australian High Stakes Curriculum

ERIC Educational Resources Information Center

Duggan, Shane B.

2017-01-01

This paper follows recent scholarship in youth studies in suggesting that young people's aspirations for the future are deeply enmeshed within a social, cultural, and economic articulation of what constitutes a "good" life that an individual ought to orient toward. It uses Ahmed's (2014) notion of "wilfulness" to consider how…

T Cell Responses to Arenavirus Infections.

DTIC Science & Technology

1991-11-01

CLASSIFICATION OF THIS PAGE Form AAmWved REPORT DOCUMENTATION PAGE OMB No.O 70O1U ts. REPORT SECURITY CLASSIFICATION lb. RESTRICTIVE MARKINGS Unclassified Za...1991. J. Virol. 65.3001-3006. 23. Ahmed, R., L. D., Butler, and L. Bhatti. 1988. J. Virol. 62: 21 02-21 06. 24. Moskophidis 0, S. P. Cobbold , H. Waldmann

75 FR 71064 - Medicare Program; Proposed Changes to the Medicare Advantage and the Medicare Prescription Drug...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-22

... and the Medicare Prescription Drug Benefit Programs for Contract Year 2012 and Other Proposed Changes... for Contract Year 2012 and Other Proposed Changes'' which was filed for public inspection on November 10, 2010. FOR FURTHER INFORMATION CONTACT: Sabrina Ahmed, (410) 786-7499. SUPPLEMENTARY INFORMATION...

Working for Change across International Borders: The Association of Headmistresses and Education for International Citizenship

ERIC Educational Resources Information Center

Goodman, Joyce

2007-01-01

This article contributes to the retrieval of the "lost history" of interwar internationalism that is increasingly receiving attention from historians of education. It traces the involvement of the English Association of Headmistresses (AHM) in a range of organizations that networked women educationists with women's organizations, with…

Empowering Factors Among Breast Cancer Screening Compliant Underserved Populations

DTIC Science & Technology

2005-10-01

sex 17 Promiscuous sex (Multiple sexual, partnersý) 18 Chewing Tobacco 19 Being Female 20 Being Male 21 H. Barriers to Cancer Screening For each...Behavior among Preteen Black and White Children. JNMA, 96: (2) 200-208; 2004. 7. Elzey JD and Ahmed NU. A Whole New Life: an illness and a healing by

Too Distant Shores: The Strait of Gibraltar and the Space of Exception

ERIC Educational Resources Information Center

Gluhovic, Milija

2008-01-01

Focusing on "The Sheep and the Whale" ("Le mouton et la baleine," 2001) by Moroccan-Canadian playwright Ahmed Ghazali, this essay examines political and ethical issues concerning human migration from Africa to Europe. The play's representation of human rights abuses in the Strait of Gibraltar and the dilemmas facing illegal…

Kindness in Australia: an empirical critique of moral decline sociology.

PubMed

Habibis, Daphne; Hookway, Nicholas; Vreugdenhil, Anthea

2016-09-01

A new sociological agenda is emerging that interrogates how morality can be established in the absence of the moral certainties of the past but there is a shortage of empirical work on this topic. This article establishes a theoretical framework for the empirical analysis of everyday morality drawing on the work of theorists including Ahmed, Bauman and Taylor. It uses the Australian Survey of Social Attitudes to assess the state and shape of contemporary moralities by asking how kind are Australians, how is its expression socially distributed, and what are the motivations for kindness. The findings demonstrate that Australians exhibit a strong attachment and commitment to kindness as a moral value that is primarily motivated by interiorized sources of moral authority. We argue these findings support the work of theorists such as Ahmed and Taylor who argue authenticity and embodied emotion are legitimate sources of morality in today's secular societies. The research also provides new evidence that generational changes are shaping understandings and practices of kindness in unexpected ways. © London School of Economics and Political Science 2016.

Identification and molecular characterization of a new recombinant begomovirus and associated betasatellite DNA infecting Capsicum annuum in India.

PubMed

Bhatt, Bhavin S; Chahwala, Fenisha D; Rathod, Sangeeta; Singh, Achuit K

2016-05-01

Capsicum annuum (Chilli) is a perennial herbaceous plant that is cultivated as an annual crop throughout the world, including India. Chilli leaf curl disease (ChiLCD) is a major biotic constraint, causing major losses in chilli production. During 2014, leaf samples of chilli plants displaying leaf curl disease were collected from the Ahmedabad district of Gujarat, India. These samples were used to isolate, clone and sequence viral genomic DNA and an associated betasatellite DNA molecule. Sequence analysis showed 90.4 % nucleotide sequence identity to the previously reported chilli leaf curl virus-[India:Guntur:2009] (ChiLCV-[IN:Gun:09]. As per ICTV nomenclature rules, ChiLCV-Ahm represents a new species of begomovirus, and we therefore propose the name chilli leaf curl Ahmedabad virus-[India:Ahmedabad:2014] (ChiLCAV-[IN:Ahm:14]). The associated betasatellite DNA showed a maximum of 93.5 % nucleotide sequence identity to a previously reported tomato leaf curl Bangladesh betasatellite and may be named tomato leaf curl Bangladesh betasatellite-[India:Ahmedabad:Chilli:2014].

Comparison of Transport Codes, HZETRN, HETC and FLUKA, Using 1977 GCR Solar Minimum Spectra

NASA Technical Reports Server (NTRS)

Heinbockel, John H.; Slaba, Tony C.; Tripathi, Ram K.; Blattnig, Steve R.; Norbury, John W.; Badavi, Francis F.; Townsend, Lawrence W.; Handler, Thomas; Gabriel, Tony A.; Pinsky, Lawrence S.;

A retrospective study on the outcomes of Ahmed valve versus Ahmed valve combined with fluocinolone implant in uveitic glaucoma

PubMed Central

Sevgi, Duriye D.; Davoudi, Samaneh; Talcott, Katherine E.; Cho, Heeyoon; Guo, Rong; Lobo, Ann-Marie; Papaliodis, George N.; Turalba, Angela; Sobrin, Lucia; Shen, Lucy Q.

2017-01-01

Purpose To compare the intraocular pressure (IOP) outcomes of Ahmed glaucoma valve (AGV) surgery alone versus AGV with fluocinolone implant in uveitic glaucoma patients. Methods We identified uveitic glaucoma patients with AGV surgery alone and AGV surgery combined with fluocinolone implant from the Massachusetts Eye and Ear Ocular Inflammation Database. Demographic information, visual acuity, and IOP were recorded at preoperative visits and 1, 6, and 12 months after surgery. Incidence of hypertensive phase, defined as an IOP of >21 mm Hg or use of additional treatment to lower IOP occurring any time between 7 days to 6 months postoperatively, was investigated. Multilevel mixed effects models were performed to compare the outcomes between groups. Results Eighteen eyes of 13 uveitic glaucoma patients with 1-year follow-up data were included. There were 11 eyes of 9 patients (mean age, 56.5 years; 63.6% male) in the AGV group and 7 eyes of 4 patients (mean age, 61.3 years; 71.4% male) in the AGV + fluocinolone group. There was no significant difference in visual acuity change at 1 year after surgery between groups (P = 0.25), although visual acuity improvement was significant in the AGV group (P = 0.01). The hypertensive phase occurred in 91% of AGV patients and 43% of AGV + fluocinolone patients (P = 0.30), with onset of 8-40 days (mean, 18 days) after surgery. IOP and number of glaucoma medications decreased at the 1-year postoperative visits in both the AGV group (P < 0.0001, P < 0.0001) and the AGV + fluocinolone group (P = 0.001, P < 0.0001). Compared to the AGV group, the AGV + fluocinolone group used fewer glaucoma medications (0.28 vs 1.30 [P = 0.01]) and had better inflammation control (P = 0.02). The surgical complication rates were similar between groups. Conclusions In uveitic glaucoma, AGV with fluocinolone achieves a similar, desired IOP control but with fewer glaucoma medications than AGV alone. PMID:29162989

A retrospective study on the outcomes of Ahmed valve versus Ahmed valve combined with fluocinolone implant in uveitic glaucoma.

PubMed

Sevgi, Duriye D; Davoudi, Samaneh; Talcott, Katherine E; Cho, Heeyoon; Guo, Rong; Lobo, Ann-Marie; Papaliodis, George N; Turalba, Angela; Sobrin, Lucia; Shen, Lucy Q

2017-01-01

To compare the intraocular pressure (IOP) outcomes of Ahmed glaucoma valve (AGV) surgery alone versus AGV with fluocinolone implant in uveitic glaucoma patients. We identified uveitic glaucoma patients with AGV surgery alone and AGV surgery combined with fluocinolone implant from the Massachusetts Eye and Ear Ocular Inflammation Database. Demographic information, visual acuity, and IOP were recorded at preoperative visits and 1, 6, and 12 months after surgery. Incidence of hypertensive phase, defined as an IOP of >21 mm Hg or use of additional treatment to lower IOP occurring any time between 7 days to 6 months postoperatively, was investigated. Multilevel mixed effects models were performed to compare the outcomes between groups. Eighteen eyes of 13 uveitic glaucoma patients with 1-year follow-up data were included. There were 11 eyes of 9 patients (mean age, 56.5 years; 63.6% male) in the AGV group and 7 eyes of 4 patients (mean age, 61.3 years; 71.4% male) in the AGV + fluocinolone group. There was no significant difference in visual acuity change at 1 year after surgery between groups ( P = 0.25), although visual acuity improvement was significant in the AGV group ( P = 0.01). The hypertensive phase occurred in 91% of AGV patients and 43% of AGV + fluocinolone patients ( P = 0.30), with onset of 8-40 days (mean, 18 days) after surgery. IOP and number of glaucoma medications decreased at the 1-year postoperative visits in both the AGV group ( P < 0.0001, P < 0.0001) and the AGV + fluocinolone group ( P = 0.001, P < 0.0001). Compared to the AGV group, the AGV + fluocinolone group used fewer glaucoma medications (0.28 vs 1.30 [ P = 0.01]) and had better inflammation control ( P = 0.02). The surgical complication rates were similar between groups. In uveitic glaucoma, AGV with fluocinolone achieves a similar, desired IOP control but with fewer glaucoma medications than AGV alone.

1-week habitation of two people in an airtight facility, CEEF with two goats and 23 crops, conducted with 89% self-sufficiency in food and without O2-addition and CO2-release - analysis of exchange of carbon and oxygen among organisms and water circulation in the CEEF -

NASA Astrophysics Data System (ADS)

Tako, Y.; Tsuga, S.; Tani, T.; Arai, R.; Komatsubara, O.; Shinohara, M.

Three 1-week experiments were conducted from September to October of 2005 in which two human subjects named as eco-nauts were enclosed and worked in an airtight facility called Closed Ecosystem Experiment Facilities CEEF The test involved connecting a Plant Module PM with 23 crops including rice soybean peanut and sugar beet to an Animal Habitation Module AHM which included the eco-nauts and two Shiba-goats Although only 34 weight of the food consumed by the eco-nauts was produced by crops in the PM in the first experiment it was 81 in the second and third experiments As for feed to the goats 40 rice straw was produced in the PM in the first experiment and all of the feed rice straw soybean leaf and peanut shell was produced in the PM in the second and third experiments In all these experiments the crops produced more oxygen than the amount consumed by respiration of human and animals The oxygen build-up in the atmosphere of the PM from crop photosynthesis was separated and supplied to atmosphere of the AHM Carbon dioxide build-up in atmosphere of the AHM from respiration of eco-nauts and Shiba-goats was separated and supplied back to atmosphere of the PM Carbon in waste except for a part of that in human feces was withdrawn and not recycled for these experiments Therefore carbon dioxide from respiration compensated the demand for photosynthesis of the crops Amounts of carbon in edible and inedible parts of harvested crop biomass and amount of carbon taken by the eco-nauts and Shiba-goats were also estimated Water transpired through

Investigating the Sensitivity of Nucleation Parameterization on Ice Growth

NASA Astrophysics Data System (ADS)

Gaudet, L.; Sulia, K. J.

2017-12-01

The accurate prediction of precipitation from lake-effect snow events associated with the Great Lakes region depends on the parameterization of thermodynamic and microphysical processes, including the formation and subsequent growth of frozen hydrometeors. More specifically, the formation of ice hydrometeors has been represented through varying forms of ice nucleation parameterizations considering the different nucleation modes (e.g., deposition, condensation-freezing, homogeneous). These parameterizations have been developed from in-situ measurements and laboratory observations. A suite of nucleation parameterizations consisting of those published in Meyers et al. (1992) and DeMott et al. (2010) as well as varying ice nuclei data sources are coupled with the Adaptive Habit Model (AHM, Harrington et al. 2013), a microphysics module where ice crystal aspect ratio and density are predicted and evolve in time. Simulations are run with the AHM which is implemented in the Weather Research and Forecasting (WRF) model to investigate the effect of ice nucleation parameterization on the non-spherical growth and evolution of ice crystals and the subsequent effects on liquid-ice cloud-phase partitioning. Specific lake-effect storms that were observed during the Ontario Winter Lake-Effect Systems (OWLeS) field campaign (Kristovich et al. 2017) are examined to elucidate this potential microphysical effect. Analysis of these modeled events is aided by dual-polarization radar data from the WSR-88D in Montague, New York (KTYX). This enables a comparison of the modeled and observed polarmetric and microphysical profiles of the lake-effect clouds, which involves investigating signatures of reflectivity, specific differential phase, correlation coefficient, and differential reflectivity. Microphysical features of lake-effect bands, such as ice, snow, and liquid mixing ratios, ice crystal aspect ratio, and ice density are analyzed to understand signatures in the aforementioned modeled dual-polarization radar variables. Hence, this research helps to determine an ice nucleation scheme that will best model observations of lake-effect clouds producing snow off of Lake Ontario and Lake Erie, and analyses will highlight the sensitivity of the evolution of the cases to a given nucleation scheme.

Chromaticity calculations and code comparisons for x-ray lithography source XLS and SXLS rings

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

Parsa, Z.

1988-06-16

This note presents the chromaticity calculations and code comparison results for the (x-ray lithography source) XLS (Chasman Green, XUV Cosy lattice) and (2 magnet 4T) SXLS lattices, with the standard beam optic codes, including programs SYNCH88.5, MAD6, PATRICIA88.4, PATPET88.2, DIMAD, BETA, and MARYLIE. This analysis is a part of our ongoing accelerator physics code studies. 4 figs., 10 tabs.

Comparison of two computer codes for crack growth analysis: NASCRAC Versus NASA/FLAGRO

NASA Technical Reports Server (NTRS)

Stallworth, R.; Meyers, C. A.; Stinson, H. C.

1989-01-01

Results are presented from the comparison study of two computer codes for crack growth analysis - NASCRAC and NASA/FLAGRO. The two computer codes gave compatible conservative results when the part through crack analysis solutions were analyzed versus experimental test data. Results showed good correlation between the codes for the through crack at a lug solution. For the through crack at a lug solution, NASA/FLAGRO gave the most conservative results.

Computerized Dental Comparison: A Critical Review of Dental Coding and Ranking Algorithms Used in Victim Identification.

PubMed

Adams, Bradley J; Aschheim, Kenneth W

2016-01-01

Comparison of antemortem and postmortem dental records is a leading method of victim identification, especially for incidents involving a large number of decedents. This process may be expedited with computer software that provides a ranked list of best possible matches. This study provides a comparison of the most commonly used conventional coding and sorting algorithms used in the United States (WinID3) with a simplified coding format that utilizes an optimized sorting algorithm. The simplified system consists of seven basic codes and utilizes an optimized algorithm based largely on the percentage of matches. To perform this research, a large reference database of approximately 50,000 antemortem and postmortem records was created. For most disaster scenarios, the proposed simplified codes, paired with the optimized algorithm, performed better than WinID3 which uses more complex codes. The detailed coding system does show better performance with extremely large numbers of records and/or significant body fragmentation. © 2015 American Academy of Forensic Sciences.

Code-to-Code Comparison, and Material Response Modeling of Stardust and MSL using PATO and FIAT

NASA Technical Reports Server (NTRS)

Omidy, Ali D.; Panerai, Francesco; Martin, Alexandre; Lachaud, Jean R.; Cozmuta, Ioana; Mansour, Nagi N.

2015-01-01

This report provides a code-to-code comparison between PATO, a recently developed high fidelity material response code, and FIAT, NASA's legacy code for ablation response modeling. The goal is to demonstrates that FIAT and PATO generate the same results when using the same models. Test cases of increasing complexity are used, from both arc-jet testing and flight experiment. When using the exact same physical models, material properties and boundary conditions, the two codes give results that are within 2% of errors. The minor discrepancy is attributed to the inclusion of the gas phase heat capacity (cp) in the energy equation in PATO, and not in FIAT.

Driver Performance and Behavior in Adverse Weather Conditions: An Investigation Using the SHRP2 Naturalistic Driving Study Data—Phase 2

DOT National Transportation Integrated Search

2018-02-01

Ahmed (orcid.org/0000-0002-1921-0724); Ghasemzadeh (orcid.org/0000-0003-1232-251X); Hammit (orcid.org/0000-0002-8859-9075); Khan (orcid.org/0000-0001-5996-091X); Das (orcid.org/0000-0003-4674-5334); Ali (orcid.org/0000-0001-7643-7143); Eldeeb (orcid....

ACHP | Advisory Council on Historic Preservation Staff Directory

Science.gov Websites

general counsel kfanizzo@achp.gov 202-517-0193 Office of Administration Ismail D. Ahmed, senior accountant wdancingfeather@achp.gov 202-517-0195 Ira Matt, Senior Policy Analyst imatt@achp.gov 202-517-1481 Office of specialist lrichmond@achp.gov 202-517-1484 Shayla Shrieves, senior writer-editor sshrieves@achp.gov 202-517

78 FR 73173 - Endangered and Threatened Wildlife and Plants; Listing the Straight-Horned Markhor as Threatened...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-05

... Club, African Safari Club of Florida, The Conklin Foundation, Grand Slam Club/Ovis, Wild Sheep... had reached a critical level, estimated at fewer than 200 (Ahmed et al. 2001, p. 4; Johnson 1994b, p... the markhor at the species level (Capra falconeri) was transferred from CITES Appendix II to Appendix...

78 FR 78303 - Proposed Modification of Area Navigation (RNAV) Route T-265, IL

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-26

..., except Federal holidays. An informal docket may also be examined during normal business hours at the..., AHMED and START, respectively, and then re-designating the remaining waypoints in the route, BULLZ and... the flying public with an easy way to file and fly around the Chicago Class B airspace area between...

75 FR 30859 - Notice of Lodging of Consent Decree Under the Clean Air Act

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-02

... DEPARTMENT OF JUSTICE Notice of Lodging of Consent Decree Under the Clean Air Act Notice is hereby given that on May 24, 2010, a proposed Consent Decree in United States, and South Coast Air Quality Management District v. Lifoam Industries, LLC, Civil Action No. 10-CV-03825-AHM- FFM was lodged with the...

Stanford University: The Building Energy Retrofit Programs. Green Revolving Funds in Action: Case Study Series

ERIC Educational Resources Information Center

Flynn, Emily

2011-01-01

Stanford University's Energy Retrofit Program was created in 1993 to target resource reduction and conservation focused projects on campus. Fahmida Ahmed, Associate Director of the Department of Sustainability and Energy Management, says that Stanford has been investing in sustainability and energy-efficiency since the late 1970s, longer than many…

Use and Testing of the Motorcycle by the US Army April 1917 to February 1977

DTIC Science & Technology

1977-06-10

the-road capability for most of its other vehicles by converting them to four-wheel drive. According to Major General George A. Lynch, the overweight ...No Norway MAJ Ola Aabakken Yes Yes No Pakistan MAJ Najeeb Ahmed Yes Yes No Peru * MAJ Alberto Arciniega Philippines COL Mariano P. Adalem No

New Computational Framework for the Treatment of Joint Constraints and Connectivity Conditions in Finite Element/Multibody System Algorithms

DTIC Science & Technology

2014-03-21

A. Shabana University of Illinois at Chicago Paramsothy Jayakumar , Michael D. Letherwood, David J. Gorsich U.S. Army TARDEC Disclaimer...ALGORITMS 5a. CONTRACT NUMBER W56hzv-13-c-0032 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Ahmed Shabana; Paramsothy Jayakumar ; Michael

"Who Wants to Be Sad Over and Over Again?": Emotion Ideologies in Contemporary German Education about the Holocaust

ERIC Educational Resources Information Center

Krieg, Lisa Jenny

2015-01-01

Based on an ethnographic field study in Cologne, this article discusses the connection between memory practices and emotion ideologies in Holocaust education, using Sara Ahmed's concept of affective economies. Moral goals, political demands, and educators' care for their students lead to tensions in the education process. Two case studies…

Combinatorial neural codes from a mathematical coding theory perspective.

PubMed

Curto, Carina; Itskov, Vladimir; Morrison, Katherine; Roth, Zachary; Walker, Judy L

2013-07-01

Shannon's seminal 1948 work gave rise to two distinct areas of research: information theory and mathematical coding theory. While information theory has had a strong influence on theoretical neuroscience, ideas from mathematical coding theory have received considerably less attention. Here we take a new look at combinatorial neural codes from a mathematical coding theory perspective, examining the error correction capabilities of familiar receptive field codes (RF codes). We find, perhaps surprisingly, that the high levels of redundancy present in these codes do not support accurate error correction, although the error-correcting performance of receptive field codes catches up to that of random comparison codes when a small tolerance to error is introduced. However, receptive field codes are good at reflecting distances between represented stimuli, while the random comparison codes are not. We suggest that a compromise in error-correcting capability may be a necessary price to pay for a neural code whose structure serves not only error correction, but must also reflect relationships between stimuli.

Planned Comparisons as Better Alternatives to ANOVA Omnibus Tests.

ERIC Educational Resources Information Center

Benton, Roberta L.

Analyses of data are presented to illustrate the advantages of using a priori or planned comparisons rather than omnibus analysis of variance (ANOVA) tests followed by post hoc or posteriori testing. The two types of planned comparisons considered are planned orthogonal non-trend coding contrasts and orthogonal polynomial or trend contrast coding.…

MOCCA code for star cluster simulation: comparison with optical observations using COCOA

NASA Astrophysics Data System (ADS)

Askar, Abbas; Giersz, Mirek; Pych, Wojciech; Olech, Arkadiusz; Hypki, Arkadiusz

2016-02-01

We introduce and present preliminary results from COCOA (Cluster simulatiOn Comparison with ObservAtions) code for a star cluster after 12 Gyr of evolution simulated using the MOCCA code. The COCOA code is being developed to quickly compare results of numerical simulations of star clusters with observational data. We use COCOA to obtain parameters of the projected cluster model. For comparison, a FITS file of the projected cluster was provided to observers so that they could use their observational methods and techniques to obtain cluster parameters. The results show that the similarity of cluster parameters obtained through numerical simulations and observations depends significantly on the quality of observational data and photometric accuracy.

MCNP and GADRAS Comparisons

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

Klasky, Marc Louis; Myers, Steven Charles; James, Michael R.

To facilitate the timely execution of System Threat Reviews (STRs) for DNDO, and also to develop a methodology for performing STRs, LANL performed comparisons of several radiation transport codes (MCNP, GADRAS, and Gamma-Designer) that have been previously utilized to compute radiation signatures. While each of these codes has strengths, it is of paramount interest to determine the limitations of each of the respective codes and also to identify the most time efficient means by which to produce computational results, given the large number of parametric cases that are anticipated in performing STR's. These comparisons serve to identify regions of applicabilitymore » for each code and provide estimates of uncertainty that may be anticipated. Furthermore, while performing these comparisons, examination of the sensitivity of the results to modeling assumptions was also examined. These investigations serve to enable the creation of the LANL methodology for performing STRs. Given the wide variety of radiation test sources, scenarios, and detectors, LANL calculated comparisons of the following parameters: decay data, multiplicity, device (n,γ) leakages, and radiation transport through representative scenes and shielding. This investigation was performed to understand potential limitations utilizing specific codes for different aspects of the STR challenges.« less

Calculation of inviscid flow over shuttle-like vehicles at high angles of attack and comparisons with experimental data

NASA Technical Reports Server (NTRS)

Weilmuenster, K. J.; Hamilton, H. H., II

1983-01-01

A computer code HALIS, designed to compute the three dimensional flow about shuttle like configurations at angles of attack greater than 25 deg, is described. Results from HALIS are compared where possible with an existing flow field code; such comparisons show excellent agreement. Also, HALIS results are compared with experimental pressure distributions on shuttle models over a wide range of angle of attack. These comparisons are excellent. It is demonstrated that the HALIS code can incorporate equilibrium air chemistry in flow field computations.

Validation of the NCC Code for Staged Transverse Injection and Computations for a RBCC Combustor

NASA Technical Reports Server (NTRS)

Ajmani, Kumud; Liu, Nan-Suey

2005-01-01

The NCC code was validated for a case involving staged transverse injection into Mach 2 flow behind a rearward facing step. Comparisons with experimental data and with solutions from the FPVortex code was then used to perform computations to study fuel-air mixing for the combustor of a candidate rocket based combined cycle engine geometry. Comparisons with a one-dimensional analysis and a three-dimensional code (VULCAN) were performed to assess the qualitative and quantitative performance of the NCC solver.

Comparisons of time explicit hybrid kinetic-fluid code Architect for Plasma Wakefield Acceleration with a full PIC code

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

Massimo, F., E-mail: francesco.massimo@ensta-paristech.fr; Dipartimento SBAI, Università di Roma “La Sapienza“, Via A. Scarpa 14, 00161 Roma; Atzeni, S.

Architect, a time explicit hybrid code designed to perform quick simulations for electron driven plasma wakefield acceleration, is described. In order to obtain beam quality acceptable for applications, control of the beam-plasma-dynamics is necessary. Particle in Cell (PIC) codes represent the state-of-the-art technique to investigate the underlying physics and possible experimental scenarios; however PIC codes demand the necessity of heavy computational resources. Architect code substantially reduces the need for computational resources by using a hybrid approach: relativistic electron bunches are treated kinetically as in a PIC code and the background plasma as a fluid. Cylindrical symmetry is assumed for themore » solution of the electromagnetic fields and fluid equations. In this paper both the underlying algorithms as well as a comparison with a fully three dimensional particle in cell code are reported. The comparison highlights the good agreement between the two models up to the weakly non-linear regimes. In highly non-linear regimes the two models only disagree in a localized region, where the plasma electrons expelled by the bunch close up at the end of the first plasma oscillation.« less

Binary Star Orbits. 4. Orbits of 18 Southern Interferometric Pairs

DTIC Science & Technology

2010-09-01

Horch et al. 2010; Balega et al. 2007; Docobo et al. 2008; Hartkopf & Mason 2009; McAlister et al. 1996; Prieur et al. 2009), their southern...Kubat, J. 1997, A&A, 322, 565 Horch , E. P., Falta, D., Anderson, L. M., DeSousa, M. D., Miniter, C. M., Ahmed, T., & van Altena, W. F. 2010, AJ, 139, 205

Oman shows vision in leading Middle Eastern drilling

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

Ahmed-al Shanfari, S.B.

1989-12-01

Oman produced more than 600,000 bopd for the first time in 1988. The country led the Middle East in total wells drilled for the third consecutive year. This article presents an interview with H.E. Said bin Ahmed al-Shanfari, Oman's Minister of Petroleum and Minerals. Topics discussed include Oman's future production plans, Opec, future exploratory areas, and petroleum export levels.

78 FR 14622 - Designation of 1 Individual Pursuant to Executive Order 13224 of September 23, 2001, “Blocking...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-06

...; a.k.a. SHAH, Maulawi Ahmed; a.k.a. SHAH, Mullah Mohammed), Quetta, Pakistan; DOB 01 Jan 1985; alt. DOB 1981; POB Quetta, Pakistan; Passport NC5140251 (Pakistan) issued 23 Oct 2009 expires 22 Oct 2014; National ID No. 5440122880259 (Pakistan) (individual) [SDGT]. Dated: February 26, 2013. Adam J. Szubin...

Usability Studies in Virtual and Traditional Computer Aided Design Environments for Fault Identification

DTIC Science & Technology

2017-08-08

Usability Studies In Virtual And Traditional Computer Aided Design Environments For Fault Identification Dr. Syed Adeel Ahmed, Xavier University...virtual environment with wand interfaces compared directly with a workstation non-stereoscopic traditional CAD interface with keyboard and mouse. In...the differences in interaction when compared with traditional human computer interfaces. This paper provides analysis via usability study methods

Special Inspector General for Iraq Reconstruction. Quarterly Report to the United States Congress

DTIC Science & Technology

2011-04-30

LAW Human Rights), under the control of the CoM— in essence , under the Offi ce of the Prime Minis- ter. Aft er meeting with public opposition from...28/2006 Christopher Joseph Cahill 11/9/2006 Ahmed Hassan Dayekh 9/26/2006 Diaa Ahmen Abdul Latif Salem 5/14/2009, 6/2/2006 Jasmine International

Proceedings of the Annual Midwest Research-to-Practice Conference in Adult, Continuing and Community Education (17th, Muncie, Indiana, October 8-10, 1998).

ERIC Educational Resources Information Center

Wood, George S., Ed.; Webber, Mary Margaret, Ed.

This proceedings contains 30 papers: "What Matters in Planning a Conference" (Ahmed et al.); "Faculty Motivations for Learning To Teach at a Distance with Instructional Technology" (Armstrong); "The Use of Literature in Qualitative Research" (Austin, Babchuk); "Reading Women's Lives" (Baker-Clark); "Faculty Perceptions of Adult Students and Their…

Paralympics 2012 Legacy: Accessible Housing and Disability Equality or Inequality?

ERIC Educational Resources Information Center

Ahmed, Nadia

2013-01-01

The golden summer of sport is now over, but what is the legacy of London 2012 for disabled people? Nadia Ahmed, a disabled student, discusses the difficulties she has faced in finding accessible accommodation in London. She argues that while the Games are over, the United Kingdom still has lots of hurdles to leap when it comes to disability. The…

Driver performance and behavior in adverse weather conditions : an investigation using the SHRP2 naturalistic driving study data--phase 1.

DOT National Transportation Integrated Search

2015-12-01

Mohamed M. Ahmed, Ph.D., P.E. (orcid.org/0000-0002-1921-0724) : Ali Ghasemzadeh, M.Sc. (orcid.org/0000-0003-1232-251X) : Hesham Eldeeb, Ph.D. : Sherif Gaweesh, M.Sc. (orcid.org/0000-0001-7977-6378) : Joshua Clapp, Ph.D. : Khaled Ksaibati, Ph.D., P.E....

Vocational High School Cooperation with PT Astra Honda Motor to Prepare Skilled Labor in Industries

ERIC Educational Resources Information Center

Yoto; Widiyanti

2017-01-01

SMK Nasional as a secondary vocational education institution contribute in creating skilled labor to meet the needs of the industry. Motorcycle Engineering expertise program at the SMK Nasional in improving the graduate's quality carries out industrial class education with PT Astra Honda Motor (PT AHM); it is intended so that there is a link and…

Comment on ‘The paradoxical zero reflection at zero energy’

NASA Astrophysics Data System (ADS)

van Dijk, W.; Nogami, Y.

2017-05-01

We point out that the anomalous threshold effect in one dimension occurs when the reflection probability at zero energy R(0) has some other value than unity, rather than R(0)=0 or R(0)\\ll 1 as implied by Ahmed et al in their paper entitled ‘The paradoxical zero reflection at zero energy’ (2017 Eur. J. Phys. 38 025401).

On the Image of Hate in Education: Desirable Emotions, Learning, and the Visibility of Bodies in Educational Relations

ERIC Educational Resources Information Center

Ryther, Cathrine

2016-01-01

In this article I explore how images of hate from the work of feminist, psychoanalytical educational thinkers Deborah Britzman and Alice Pitt, and from Sara Ahmed's investigation into the cultural politics of emotion, function to shift the ideal-image of pedagogically desired emotions and complicate the emotional landscape of educational…

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

Using direct current resistivity sounding and geostatistics to aid in hydrogeological studies in the Choshuichi alluvial fan, Taiwan.

PubMed

Yang, Chieh-Hou; Lee, Wei-Feng

2002-01-01

Ground water reservoirs in the Choshuichi alluvial fan, central western Taiwan, were investigated using direct-current (DC) resistivity soundings at 190 locations, combined with hydrogeological measurements from 37 wells. In addition, attempts were made to calculate aquifer transmissivity from both surface DC resistivity measurements and geostatistically derived predictions of aquifer properties. DC resistivity sounding data are highly correlated to the hydraulic parameters in the Choshuichi alluvial fan. By estimating the spatial distribution of hydraulic conductivity from the kriged well data and the cokriged thickness of the correlative aquifer from both resistivity sounding data and well information, the transmissivity of the aquifer at each location can be obtained from the product of kriged hydraulic conductivity and computed thickness of the geoelectric layer. Thus, the spatial variation of the transmissivities in the study area is obtained. Our work is more comparable to Ahmed et al. (1988) than to the work of Niwas and Singhal (1981). The first "constraint" from Niwas and Singhal's work is a result of their use of linear regression. The geostatistical approach taken here (and by Ahmed et al. [1988]) is a natural improvement on the linear regression approach.

Wind turbine design codes: A comparison of the structural response

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

Buhl, M.L. Jr.; Wright, A.D.; Pierce, K.G.

2000-03-01

The National Wind Technology Center (NWTC) of the National Renewable Energy Laboratory is continuing a comparison of several computer codes used in the design and analysis of wind turbines. The second part of this comparison determined how well the programs predict the structural response of wind turbines. In this paper, the authors compare the structural response for four programs: ADAMS, BLADED, FAST{_}AD, and YawDyn. ADAMS is a commercial, multibody-dynamics code from Mechanical Dynamics, Inc. BLADED is a commercial, performance and structural-response code from Garrad Hassan and Partners Limited. FAST{_}AD is a structural-response code developed by Oregon State University and themore » University of Utah for the NWTC. YawDyn is a structural-response code developed by the University of Utah for the NWTC. ADAMS, FAST{_}AD, and YawDyn use the University of Utah's AeroDyn subroutine package for calculating aerodynamic forces. Although errors were found in all the codes during this study, once they were fixed, the codes agreed surprisingly well for most of the cases and configurations that were evaluated. One unresolved discrepancy between BLADED and the AeroDyn-based codes was when there was blade and/or teeter motion in addition to a large yaw error.« less

Use of rumination and activity monitoring for the identification of dairy cows with health disorders: Part III. Metritis.

PubMed

Stangaferro, M L; Wijma, R; Caixeta, L S; Al-Abri, M A; Giordano, J O

2016-09-01

The objectives of this study were to evaluate (1) the performance of an automated health-monitoring system (AHMS) to identify cows with metritis based on an alert system (health index score, HIS) that combines rumination time and physical activity; (2) the number of days between the first HIS alert and clinical diagnosis (CD) of metritis by farm personnel; and (3) the daily rumination time, physical activity, and HIS patterns around CD. In this manuscript, the overall performance of HIS to detect cows with all disorders of interest in this study [ketosis, displaced abomasum, indigestion (companion paper, part I), mastitis (companion paper, part II), and metritis] is also reported. Holstein cattle (n=1,121; 451 nulliparous and 670 multiparous) were fitted with a neck-mounted electronic rumination and activity monitoring tag (HR Tags, SCR Dairy, Netanya, Israel) from at least -21 to 80 d in milk (DIM). Raw data collected in 2-h periods were summarized per 24 h as daily rumination and activity. An HIS (0 to 100 arbitrary units) was calculated daily for individual cows with an algorithm that used rumination and activity. A positive HIS outcome was defined as an HIS of <86 units during at least 1 d from -5 to 2 d after CD. Blood concentrations of nonesterified fatty acids, β-hydroxybutyrate, total calcium, and haptoglobin were determined in a subgroup of cows (n=459) at -11±3, -4±3, 0, 3±1, 7±1, 14±1, and 28±1 DIM. The overall sensitivity of HIS was 55% for all cases of metritis (n=349), but it was greater for cows with metritis and another disorder (78%) than for cows with metritis only (53%). Cows diagnosed with metritis and flagged based on HIS had substantial alterations in their rumination, activity, and HIS patterns around CD, alterations of blood markers of metabolic and health status around calving, reduced milk production, and were more likely to exit the herd than cows not flagged based on the HIS and cows without disease, suggesting that cows flagged based on the HIS had a more severe episode of metritis. Including all disorders of interest for this study, the overall sensitivity was 59%, specificity was 98%, positive predictive value was 58%, negative predictive value was 98%, and accuracy was 96%. The AHMS was effective for identifying cows with severe cases of metritis, but less effective for identifying cows with mild cases of metritis. Also, the overall accuracy and timing of the AHMS alerts for cows with health disorders indicated that AHMS that combine rumination and activity could be a useful tool for identifying cows with metabolic and digestive disorders, and more severe cases of mastitis and metritis. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Comparison of Measured and Block Structured Simulations for the F-16XL Aircraft

NASA Technical Reports Server (NTRS)

Boelens, O. J.; Badcock, K. J.; Elmilgui, A.; Abdol-Hamid, K. S.; Massey, S. J.

2008-01-01

This article presents a comparison of the predictions of three RANS codes for flight conditions of the F-16XL aircraft which feature vortical flow. The three codes, ENSOLV, PMB and PAB3D, solve on structured multi-block grids. Flight data for comparison was available in the form of surface pressures, skin friction, boundary layer data and photographs of tufts. The three codes provided predictions which were consistent with expectations based on the turbulence modelling used, which was k- , k- with vortex corrections and an Algebraic Stress Model. The agreement with flight data was good, with the exception of the outer wing primary vortex strength. The confidence in the application of the CFD codes to complex fighter configurations increased significantly through this study.

The trellis complexity of convolutional codes

NASA Technical Reports Server (NTRS)

Mceliece, R. J.; Lin, W.

1995-01-01

It has long been known that convolutional codes have a natural, regular trellis structure that facilitates the implementation of Viterbi's algorithm. It has gradually become apparent that linear block codes also have a natural, though not in general a regular, 'minimal' trellis structure, which allows them to be decoded with a Viterbi-like algorithm. In both cases, the complexity of the Viterbi decoding algorithm can be accurately estimated by the number of trellis edges per encoded bit. It would, therefore, appear that we are in a good position to make a fair comparison of the Viterbi decoding complexity of block and convolutional codes. Unfortunately, however, this comparison is somewhat muddled by the fact that some convolutional codes, the punctured convolutional codes, are known to have trellis representations that are significantly less complex than the conventional trellis. In other words, the conventional trellis representation for a convolutional code may not be the minimal trellis representation. Thus, ironically, at present we seem to know more about the minimal trellis representation for block than for convolutional codes. In this article, we provide a remedy, by developing a theory of minimal trellises for convolutional codes. (A similar theory has recently been given by Sidorenko and Zyablov). This allows us to make a direct performance-complexity comparison for block and convolutional codes. A by-product of our work is an algorithm for choosing, from among all generator matrices for a given convolutional code, what we call a trellis-minimal generator matrix, from which the minimal trellis for the code can be directly constructed. Another by-product is that, in the new theory, punctured convolutional codes no longer appear as a special class, but simply as high-rate convolutional codes whose trellis complexity is unexpectedly small.

An Efficient Method for Verifying Gyrokinetic Microstability Codes

NASA Astrophysics Data System (ADS)

Bravenec, R.; Candy, J.; Dorland, W.; Holland, C.

2009-11-01

Benchmarks for gyrokinetic microstability codes can be developed through successful ``apples-to-apples'' comparisons among them. Unlike previous efforts, we perform the comparisons for actual discharges, rendering the verification efforts relevant to existing experiments and future devices (ITER). The process requires i) assembling the experimental analyses at multiple times, radii, discharges, and devices, ii) creating the input files ensuring that the input parameters are faithfully translated code-to-code, iii) running the codes, and iv) comparing the results, all in an organized fashion. The purpose of this work is to automate this process as much as possible: At present, a python routine is used to generate and organize GYRO input files from TRANSP or ONETWO analyses. Another routine translates the GYRO input files into GS2 input files. (Translation software for other codes has not yet been written.) Other python codes submit the multiple GYRO and GS2 jobs, organize the results, and collect them into a table suitable for plotting. (These separate python routines could easily be consolidated.) An example of the process -- a linear comparison between GYRO and GS2 for a DIII-D discharge at multiple radii -- will be presented.

Comparison of DAC and MONACO DSMC Codes with Flat Plate Simulation

NASA Technical Reports Server (NTRS)

Padilla, Jose F.

2010-01-01

Various implementations of the direct simulation Monte Carlo (DSMC) method exist in academia, government and industry. By comparing implementations, deficiencies and merits of each can be discovered. This document reports comparisons between DSMC Analysis Code (DAC) and MONACO. DAC is NASA's standard DSMC production code and MONACO is a research DSMC code developed in academia. These codes have various differences; in particular, they employ distinct computational grid definitions. In this study, DAC and MONACO are compared by having each simulate a blunted flat plate wind tunnel test, using an identical volume mesh. Simulation expense and DSMC metrics are compared. In addition, flow results are compared with available laboratory data. Overall, this study revealed that both codes, excluding grid adaptation, performed similarly. For parallel processing, DAC was generally more efficient. As expected, code accuracy was mainly dependent on physical models employed.

Comparisons of 'Identical' Simulations by the Eulerian Gyrokinetic Codes GS2 and GYRO

NASA Astrophysics Data System (ADS)

Bravenec, R. V.; Ross, D. W.; Candy, J.; Dorland, W.; McKee, G. R.

2003-10-01

A major goal of the fusion program is to be able to predict tokamak transport from first-principles theory. To this end, the Eulerian gyrokinetic code GS2 was developed years ago and continues to be improved [1]. Recently, the Eulerian code GYRO was developed [2]. These codes are not subject to the statistical noise inherent to particle-in-cell (PIC) codes, and have been very successful in treating electromagnetic fluctuations. GS2 is fully spectral in the radial coordinate while GYRO uses finite-differences and ``banded" spectral schemes. To gain confidence in nonlinear simulations of experiment with these codes, ``apples-to-apples" comparisons (identical profile inputs, flux-tube geometry, two species, etc.) are first performed. We report on a series of linear and nonlinear comparisons (with overall agreement) including kinetic electrons, collisions, and shaped flux surfaces. We also compare nonlinear simulations of a DIII-D discharge to measurements of not only the fluxes but also the turbulence parameters. [1] F. Jenko, et al., Phys. Plasmas 7, 1904 (2000) and refs. therein. [2] J. Candy, J. Comput. Phys. 186, 545 (2003).

Usability Studies In Virtual And Traditional Computer Aided Design Environments For Spatial Awareness

DTIC Science & Technology

2017-08-08

Usability Studies In Virtual And Traditional Computer Aided Design Environments For Spatial Awareness Dr. Syed Adeel Ahmed, Xavier University of...virtual environment with wand interfaces compared directly with a workstation non-stereoscopic traditional CAD interface with keyboard and mouse. In...navigate through a virtual environment. The wand interface provides a significantly improved means of interaction. This study quantitatively measures the

Biological Response to the Dynamic Spectral-Polarized Underwater Light Field

DTIC Science & Technology

2012-09-30

deployment of a comprehensive optical suite including underwater video- polarimetry (full Stokes vector video-imaging camera custom-built Cummings; and...During field operations, we couple polarimetry measurements of live, free-swimming animals in their environments with a full suite of optical...Seibel, Ahmed). We also restrain live, awake animals to take polarimetry measurements (in the field and laboratory) under a complete set of

Performance Assessment of High and Low Income Families through "Online RAW Achievement Battery Test" of Primary Grade Students

ERIC Educational Resources Information Center

Ahmed, Tamim; Hanif, Maria

2016-01-01

This study is intended to investigate student's achievement capability among two families i.e. Low and High income families and designed for primary level learners. A Reading, Arithmetic and Writing (RAW) Achievement test that was developed as a part of another research study (Tamim Ahmed Khan, 2015) was adopted for this study. Both English medium…

Why Critical Literacy Should Turn to "The Affective Turn": Making a Case for Critical Affective Literacy

ERIC Educational Resources Information Center

Anwaruddin, Sardar M.

2016-01-01

The central argument of this essay is that critical literacy with a rationalistic bent may not enable us to cope with ethical dilemmas in our responsiveness to human sufferings. I argue that critical literacy education would benefit from turning to the recent scholarship on affect/emotion studies. I draw upon the works of Sara Ahmed--one of the…

Using Center of Gravity Analysis to Defeat Violent Extremist Organizations

DTIC Science & Technology

2016-04-04

elephant . They know a definition exists, but they describe it according to their own experiences.”9 Eikmeier notes “Centers of Gravity are not self... Elephant Pass demonstrated the LTTE’s ability to conduct conventional military operations.21 16...the Battle of Elephant Pass see Ahmed Hashim’s When Counterinsurgency Wins, 99- 100. 15 Analysis Both sides reached culmination leading to the

Diversity, Replication, Pathogenicity and Cell Biology of Crimean Congo Hemorrhagic Fever Virus

DTIC Science & Technology

2007-10-01

Crimean Congo Hemorrhagic Fever Virus PRINCIPAL INVESTIGATOR: Adolfo García-Sastre, Ph.D. CONTRACTING...Diversity, Replication, Pathogenicity and Cell Biology of Crimean Congo Hemorrhagic Fever Virus 5b. GRANT NUMBER W81XWH-04-1-0876 5c. PROGRAM ELEMENT...localization and antigenic characterization of Crimean - Congo hemorrhagic fever virus glycoproteins. J.Virol. 79: 6152-61. Ahmed, A., McFalls,

Case Studies for Management Development in Bangladesh. Fourth Book. Parepared for the World Bank/Bangladesh Management Education and Training Project.

ERIC Educational Resources Information Center

McLean, Gary N.

This document contains five case studies of management and finance situations in Bangladesh, which are intended to foster classroom discussion and thereby advance management development in that country. One to four discussion questions follow each case study. The titles and authors of the case studies on management are: "Azir Ahmed & Co.,…

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.

Use of the Attribute Hierarchy Method for Development of Student Cognitive Models and Diagnostic Assessments in Geoscience Education

NASA Astrophysics Data System (ADS)

Corrigan, S.; Brodsky, L. M.; Loper, S.; Brown, N.; Curley, J.; Baker, J.; Goss, M.; Castek, J.; Barber, J.

2010-12-01

There is a recognized need to better understand student learning in the geosciences (Stofflet, 1994; Zalles, Quallmalz, Gobert and Pallant, 2007). Educators, cognitive psychologists and practicing scientists have also called for instructional approaches that support deep conceptual development (Manduca, Mogk and Stillings, 2004, Libarkin and Kurdziel, 2006). In both cases there is an important role for educational measures that can generate descriptions of how student understanding develops over time and inform instruction. The presenters will suggest one way of responding to these needs by describing the Attribute Hierarchy Method (AHM) of assessment (Leighton, Gierl and Hunka, 2004; Gierl, Cui, Wang and Zhou, 2008) as enacted in a large-scale earth science curriculum development project funded by the Bill and Melinda Gates Foundation. The AHM is one approach to criterion referenced, diagnostic assessment that ties measure design to cognitive models of student learning in order to support justified inferences about students’ understanding and the knowledge required for continued development. The Attribute Hierarchy Method bears potential for researchers and practitioners interested in learning progressions and solves many problems associated with making meaningful, justified inferences about students’ understanding based on their assessment performances. The process followed to design and develop the project’s cognitive models as well as a description of how they are used in subsequent assessment task design will be emphasized in order to demonstrate how the AHM may be applied in the context of geoscience education. Results from over twenty student cognitive interviews, and two hypothesized cognitive models -- one describing a student pathway for understanding rock formation and a second describing a student pathway for increasingly sophisticated use of maps and models in the geosciences - are also described. Sample assessment items will be provided as indications of the final assessment measures. The project’s efforts to create an on-line geoscience curriculum for use in the middle school grades that adapts to student performances by customizing whole lessons, grouping assignments or student feedback will provide a broader context for the discussion.

A validation of LTRAN2 with high frequency extensions by comparisons with experimental measurements of unsteady transonic flows

NASA Technical Reports Server (NTRS)

Hessenius, K. A.; Goorjian, P. M.

1981-01-01

A high frequency extension of the unsteady, transonic code LTRAN2 was created and is evaluated by comparisons with experimental results. The experimental test case is a NACA 64A010 airfoil in pitching motion at a Mach number of 0.8 over a range of reduced frequencies. Comparisons indicate that the modified code is an improvement of the original LTRAN2 and provides closer agreement with experimental lift and moment coefficients. A discussion of the code modifications, which involve the addition of high frequency terms of the boundary conditions of the numerical algorithm, is included.

Comparison of two- and three-dimensional flow computations with laser anemometer measurements in a transonic compressor rotor

NASA Technical Reports Server (NTRS)

Chima, R. V.; Strazisar, A. J.

1982-01-01

Two and three dimensional inviscid solutions for the flow in a transonic axial compressor rotor at design speed are compared with probe and laser anemometers measurements at near-stall and maximum-flow operating points. Experimental details of the laser anemometer system and computational details of the two dimensional axisymmetric code and three dimensional Euler code are described. Comparisons are made between relative Mach number and flow angle contours, shock location, and shock strength. A procedure for using an efficient axisymmetric code to generate downstream pressure input for computationally expensive Euler codes is discussed. A film supplement shows the calculations of the two operating points with the time-marching Euler code.

There is no MacWilliams identity for convolutional codes. [transmission gain comparison

NASA Technical Reports Server (NTRS)

Shearer, J. B.; Mceliece, R. J.

1977-01-01

An example is provided of two convolutional codes that have the same transmission gain but whose dual codes do not. This shows that no analog of the MacWilliams identity for block codes can exist relating the transmission gains of a convolutional code and its dual.

Error control techniques for satellite and space communications

NASA Technical Reports Server (NTRS)

Costello, Daniel J., Jr.

1991-01-01

Shannon's capacity bound shows that coding can achieve large reductions in the required signal to noise ratio per information bit (E sub b/N sub 0 where E sub b is the energy per bit and (N sub 0)/2 is the double sided noise density) in comparison to uncoded schemes. For bandwidth efficiencies of 2 bit/sym or greater, these improvements were obtained through the use of Trellis Coded Modulation and Block Coded Modulation. A method of obtaining these high efficiencies using multidimensional Multiple Phase Shift Keying (MPSK) and Quadrature Amplitude Modulation (QAM) signal sets with trellis coding is described. These schemes have advantages in decoding speed, phase transparency, and coding gain in comparison to other trellis coding schemes. Finally, a general parity check equation for rotationally invariant trellis codes is introduced from which non-linear codes for two dimensional MPSK and QAM signal sets are found. These codes are fully transparent to all rotations of the signal set.

PFLOTRAN-RepoTREND Source Term Comparison Summary.

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

Frederick, Jennifer M.

Code inter-comparison studies are useful exercises to verify and benchmark independently developed software to ensure proper function, especially when the software is used to model high-consequence systems which cannot be physically tested in a fully representative environment. This summary describes the results of the first portion of the code inter-comparison between PFLOTRAN and RepoTREND, which compares the radionuclide source term used in a typical performance assessment.

Validation of the analytical methods in the LWR code BOXER for gadolinium-loaded fuel pins

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

Paratte, J.M.; Arkuszewski, J.J.; Kamboj, B.K.

1990-01-01

Due to the very high absorption occurring in gadolinium-loaded fuel pins, calculations of lattices with such pins present are a demanding test of the analysis methods in light water reactor (LWR) cell and assembly codes. Considerable effort has, therefore, been devoted to the validation of code methods for gadolinia fuel. The goal of the work reported in this paper is to check the analysis methods in the LWR cell/assembly code BOXER and its associated cross-section processing code ETOBOX, by comparison of BOXER results with those from a very accurate Monte Carlo calculation for a gadolinium benchmark problem. Initial results ofmore » such a comparison have been previously reported. However, the Monte Carlo calculations, done with the MCNP code, were performed at Los Alamos National Laboratory using ENDF/B-V data, while the BOXER calculations were performed at the Paul Scherrer Institute using JEF-1 nuclear data. This difference in the basic nuclear data used for the two calculations, caused by the restricted nature of these evaluated data files, led to associated uncertainties in a comparison of the results for methods validation. In the joint investigations at the Georgia Institute of Technology and PSI, such uncertainty in this comparison was eliminated by using ENDF/B-V data for BOXER calculations at Georgia Tech.« less

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

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.

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.

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

Elementary Kaluza-Klein towers revisited

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

Grard, Fernand; Nuyts, Jean

2006-12-15

Considering that the momentum squared in the extra dimensions is the physically relevant quantity for the generation of the Kaluza-Klein mass states, we have reanalyzed mathematically the procedure for five dimensional scalar fields within the Arkhani-Ahmed, Dimopoulos and Dvali scenario. We find new sets of physically allowed boundary conditions. Beside the usual results, they lead to new towers with non regular mass spacing, to lonely mass states and to tachyons.

Biological Response to the Dynamic Spectral-Polarized Underwater Light Field

DTIC Science & Technology

2013-09-30

Z39-18 2 optical suite including underwater video- polarimetry (full Stokes vector video-imaging camera custom-built Cummings; and “SALSA” (Bossa...operations, we couple polarimetry measurements of live, free-swimming animals in their environments with a full suite of optical measurements...Ahmed). We also restrain live, awake animals to take polarimetry measurements (in the field and laboratory) under a complete set of viewing angles and

Qatar: Background and U.S. Relations

DTIC Science & Technology

2014-11-04

Ahmed bin Abdullah bin Ziad Al Mahmoud Foreign Minister Khalid Bin Mohammed Al Attiyah Minister of Energy and Industry Mohammed bin Saleh al Sada...about voter franchise extension were resolved.5 The Advisory Council would have oversight authority over the Council of Ministers and would be able...Sunni armed groups in Syria has the potential to have a more lasting impact on the region, but has challenged the traditional Qatari preference for

Functional Digital Literacy Calls for SOS by a Smuggled Afghan Boy: Teaching Phonics and Pragmatics for Survival Language

ERIC Educational Resources Information Center

Lu, Lucia Y.

2016-01-01

On April 8, 2016 when the class was discussing "digital literacy," a shocking news story from London AP intrigued us. The news was about a brief text message delivered by Ahmed, a refugee Afghan boy of 6-year old. His text message flashed on the cellphone of Liz Clegg, a volunteer at a migrant camp in France. Clegg and other volunteers…

Critical Thinking and Army Religious Leadership: Challenges and Opportunities

DTIC Science & Technology

2011-06-10

rational standards of judgment, some chaplains find in CT a secular humanistic or even ―liberal‖ agenda against religious expressions and beliefs. This...Akbar Ahmed situates the debate between CT and religious beliefs and values within the context of postmodernism and raises some existential questions...truly thought critically. Yet matters of faith do not always lend themselves to rationalistic or humanistic inquiry and resist easily agreeing to

The MIT Alewife Machine: A Large-Scale Distributed-Memory Multiprocessor

DTIC Science & Technology

1991-06-01

Symposium on Compiler Construction, June 1986. [14] Daniel Gajski , David Kuck, Duncan Lawrie, and Ahmed Saleh. Cedar - A Large Scale Multiprocessor. In...Directory Methods. In Proceedings 17th Annual International Symposium on Computer Architecture, June 1990. [31] G . M. Papadopoulos and D.E. Culler...Monsoon: An Explicit Token-Store Ar- chitecture. In Proceedings 17th Annual International Symposium on Computer Architecture, June 1990. [32] G . F

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.

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 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.

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.

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.

Colour cyclic code for Brillouin distributed sensors

NASA Astrophysics Data System (ADS)

Le Floch, Sébastien; Sauser, Florian; Llera, Miguel; Rochat, Etienne

2015-09-01

For the first time, a colour cyclic coding (CCC) is theoretically and experimentally demonstrated for Brillouin optical time-domain analysis (BOTDA) distributed sensors. Compared to traditional intensity-modulated cyclic codes, the code presents an additional gain of √2 while keeping the same number of sequences as for a colour coding. A comparison with a standard BOTDA sensor is realized and validates the theoretical coding gain.

Two dimension MDW OCDMA code cross-correlation for reduction of phase induced intensity noise

NASA Astrophysics Data System (ADS)

Ahmed, Israa Sh.; Aljunid, Syed A.; Nordin, Junita M.; Dulaimi, Layth A. Khalil Al; Matem, Rima

2017-11-01

In this paper, we first review 2-D MDW code cross correlation equations and table to be improved significantly by using code correlation properties. These codes can be used in the synchronous optical CDMA systems for multi access interference cancellation and maximum suppress the phase induced intensity noise. Low Psr is due to the reduction of interference noise that is induced by the 2-D MDW code PIIN suppression. High data rate causes increases in BER, requires high effective power and severely deteriorates the system performance. The 2-D W/T MDW code has an excellent system performance where the value of PIIN is suppressed as low as possible at the optimum Psr with high data bit rate. The 2-D MDW code shows better tolerance to PIIN in comparison to others with enhanced system performance. We prove by numerical analysis that the PIIN maximally suppressed by MDW code through the minimizing property of cross correlation in comparison to 2-D PDC and 2-D MQC OCDMA code.scheme systems.

Comparison of ORSAT and SCARAB Reentry Analysis Tools for a Generic Satellite Test Case

NASA Technical Reports Server (NTRS)

Kelley, Robert L.; Hill, Nicole M.; Rochelle, W. C.; Johnson, Nicholas L.; Lips, T.

2010-01-01

Reentry analysis is essential to understanding the consequences of the full life cycle of a spacecraft. Since reentry is a key factor in spacecraft development, NASA and ESA have separately developed tools to assess the survivability of objects during reentry. Criteria such as debris casualty area and impact energy are particularly important to understanding the risks posed to people on Earth. Therefore, NASA and ESA have undertaken a series of comparison studies of their respective reentry codes for verification and improvements in accuracy. The NASA Object Reentry Survival Analysis Tool (ORSAT) and the ESA Spacecraft Atmospheric Reentry and Aerothermal Breakup (SCARAB) reentry analysis tools serve as standard codes for reentry survivability assessment of satellites. These programs predict whether an object will demise during reentry and calculate the debris casualty area of objects determined to survive, establishing the reentry risk posed to the Earth's population by surviving debris. A series of test cases have been studied for comparison and the most recent uses "Testsat," a conceptual satellite composed of generic parts, defined to use numerous simple shapes and various materials for a better comparison of the predictions of these two codes. This study is an improvement on the others in this series because of increased consistency in modeling techniques and variables. The overall comparison demonstrated that the two codes arrive at similar results. Either most objects modeled resulted in close agreement between the two codes, or if the difference was significant, the variance could be explained as a case of semantics in the model definitions. This paper presents the main results of ORSAT and SCARAB for the Testsat case and discusses the sources of any discovered differences. Discussion of the results of previous comparisons is made for a summary of differences between the codes and lessons learned from this series of tests.

Validating the BISON fuel performance code to integral LWR experiments

DOE PAGES

Williamson, R. L.; Gamble, K. A.; Perez, D. M.; ...

2016-03-24

BISON is a modern finite element-based nuclear fuel performance code that has been under development at the Idaho National Laboratory (INL) since 2009. The code is applicable to both steady and transient fuel behavior and has been used to analyze a variety of fuel forms in 1D spherical, 2D axisymmetric, or 3D geometries. Code validation is underway and is the subject of this study. A brief overview of BISON’s computational framework, governing equations, and general material and behavioral models is provided. BISON code and solution verification procedures are described, followed by a summary of the experimental data used to datemore » for validation of Light Water Reactor (LWR) fuel. Validation comparisons focus on fuel centerline temperature, fission gas release, and rod diameter both before and following fuel-clad mechanical contact. Comparisons for 35 LWR rods are consolidated to provide an overall view of how the code is predicting physical behavior, with a few select validation cases discussed in greater detail. Our results demonstrate that 1) fuel centerline temperature comparisons through all phases of fuel life are very reasonable with deviations between predictions and experimental data within ±10% for early life through high burnup fuel and only slightly out of these bounds for power ramp experiments, 2) accuracy in predicting fission gas release appears to be consistent with state-of-the-art modeling and with the involved uncertainties and 3) comparison of rod diameter results indicates a tendency to overpredict clad diameter reduction early in life, when clad creepdown dominates, and more significantly overpredict the diameter increase late in life, when fuel expansion controls the mechanical response. In the initial rod diameter comparisons they were unsatisfactory and have lead to consideration of additional separate effects experiments to better understand and predict clad and fuel mechanical behavior. Results from this study are being used to define priorities for ongoing code development and validation activities.« less

Comparison of space radiation calculations for deterministic and Monte Carlo transport codes

NASA Astrophysics Data System (ADS)

Lin, Zi-Wei; Adams, James; Barghouty, Abdulnasser; Randeniya, Sharmalee; Tripathi, Ram; Watts, John; Yepes, Pablo

For space radiation protection of astronauts or electronic equipments, it is necessary to develop and use accurate radiation transport codes. Radiation transport codes include deterministic codes, such as HZETRN from NASA and UPROP from the Naval Research Laboratory, and Monte Carlo codes such as FLUKA, the Geant4 toolkit and HETC-HEDS. The deterministic codes and Monte Carlo codes complement each other in that deterministic codes are very fast while Monte Carlo codes are more elaborate. Therefore it is important to investigate how well the results of deterministic codes compare with those of Monte Carlo transport codes and where they differ. In this study we evaluate these different codes in their space radiation applications by comparing their output results in the same given space radiation environments, shielding geometry and material. Typical space radiation environments such as the 1977 solar minimum galactic cosmic ray environment are used as the well-defined input, and simple geometries made of aluminum, water and/or polyethylene are used to represent the shielding material. We then compare various outputs of these codes, such as the dose-depth curves and the flux spectra of different fragments and other secondary particles. These comparisons enable us to learn more about the main differences between these space radiation transport codes. At the same time, they help us to learn the qualitative and quantitative features that these transport codes have in common.

How the Geothermal Community Upped the Game for Computer Codes

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

None

The Geothermal Technologies Office Code Comparison Study brought 11 research institutions together to collaborate on coupled thermal, hydrologic, geomechanical, and geochemical numerical simulators. These codes have the potential to help facilitate widespread geothermal energy development.

Numerical algorithm comparison for the accurate and efficient computation of high-incidence vortical flow

NASA Technical Reports Server (NTRS)

Chaderjian, Neal M.

1991-01-01

Computations from two Navier-Stokes codes, NSS and F3D, are presented for a tangent-ogive-cylinder body at high angle of attack. Features of this steady flow include a pair of primary vortices on the leeward side of the body as well as secondary vortices. The topological and physical plausibility of this vortical structure is discussed. The accuracy of these codes are assessed by comparison of the numerical solutions with experimental data. The effects of turbulence model, numerical dissipation, and grid refinement are presented. The overall efficiency of these codes are also assessed by examining their convergence rates, computational time per time step, and maximum allowable time step for time-accurate computations. Overall, the numerical results from both codes compared equally well with experimental data, however, the NSS code was found to be significantly more efficient than the F3D code.

Toward a CFD nose-to-tail capability - Hypersonic unsteady Navier-Stokes code validation

NASA Technical Reports Server (NTRS)

Edwards, Thomas A.; Flores, Jolen

1989-01-01

Computational fluid dynamics (CFD) research for hypersonic flows presents new problems in code validation because of the added complexity of the physical models. This paper surveys code validation procedures applicable to hypersonic flow models that include real gas effects. The current status of hypersonic CFD flow analysis is assessed with the Compressible Navier-Stokes (CNS) code as a case study. The methods of code validation discussed to beyond comparison with experimental data to include comparisons with other codes and formulations, component analyses, and estimation of numerical errors. Current results indicate that predicting hypersonic flows of perfect gases and equilibrium air are well in hand. Pressure, shock location, and integrated quantities are relatively easy to predict accurately, while surface quantities such as heat transfer are more sensitive to the solution procedure. Modeling transition to turbulence needs refinement, though preliminary results are promising.

WEC3: Wave Energy Converter Code Comparison Project: Preprint

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

Combourieu, Adrien; Lawson, Michael; Babarit, Aurelien

This paper describes the recently launched Wave Energy Converter Code Comparison (WEC3) project and present preliminary results from this effort. The objectives of WEC3 are to verify and validate numerical modelling tools that have been developed specifically to simulate wave energy conversion devices and to inform the upcoming IEA OES Annex VI Ocean Energy Modelling Verification and Validation project. WEC3 is divided into two phases. Phase 1 consists of a code-to-code verification and Phase II entails code-to-experiment validation. WEC3 focuses on mid-fidelity codes that simulate WECs using time-domain multibody dynamics methods to model device motions and hydrodynamic coefficients to modelmore » hydrodynamic forces. Consequently, high-fidelity numerical modelling tools, such as Navier-Stokes computational fluid dynamics simulation, and simple frequency domain modelling tools were not included in the WEC3 project.« less

Convolutional coding combined with continuous phase modulation

NASA Technical Reports Server (NTRS)

Pizzi, S. V.; Wilson, S. G.

1985-01-01

Background theory and specific coding designs for combined coding/modulation schemes utilizing convolutional codes and continuous-phase modulation (CPM) are presented. In this paper the case of r = 1/2 coding onto a 4-ary CPM is emphasized, with short-constraint length codes presented for continuous-phase FSK, double-raised-cosine, and triple-raised-cosine modulation. Coding buys several decibels of coding gain over the Gaussian channel, with an attendant increase of bandwidth. Performance comparisons in the power-bandwidth tradeoff with other approaches are made.

Multi-dimensional free-electron laser simulation codes : a comparison study.

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

Biedron, S. G.; Chae, Y. C.; Dejus, R. J.

A self-amplified spontaneous emission (SASE) free-electron laser (FEL) is under construction at the Advanced Photon Source (APS). Five FEL simulation codes were used in the design phase: GENESIS, GINGER, MEDUSA, RON, and TDA3D. Initial comparisons between each of these independent formulations show good agreement for the parameters of the APS SASE FEL.

Multi-Dimensional Free-Electron Laser Simulation Codes: A Comparison Study

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

Nuhn, Heinz-Dieter

A self-amplified spontaneous emission (SASE) free-electron laser (FEL) is under construction at the Advanced Photon Source (APS). Five FEL simulation codes were used in the design phase: GENESIS, GINGER, MEDUSA, RON, and TDA3D. Initial comparisons between each of these independent formulations show good agreement for the parameters of the APS SASE FEL.

The APS SASE FEL : modeling and code comparison.

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

Biedron, S. G.

A self-amplified spontaneous emission (SASE) free-electron laser (FEL) is under construction at the Advanced Photon Source (APS). Five FEL simulation codes were used in the design phase: GENESIS, GINGER, MEDUSA, RON, and TDA3D. Initial comparisons between each of these independent formulations show good agreement for the parameters of the APS SASE FEL.

Comparison of reversible methods for data compression

NASA Astrophysics Data System (ADS)

Heer, Volker K.; Reinfelder, Hans-Erich

1990-07-01

Widely differing methods for data compression described in the ACR-NEMA draft are used in medical imaging. In our contribution we will review various methods briefly and discuss the relevant advantages and disadvantages. In detail we evaluate 1st order DPCM pyramid transformation and S transformation. We compare as coding algorithms both fixed and adaptive Huffman coding and Lempel-Ziv coding. Our comparison is performed on typical medical images from CT MR DSA and DLR (Digital Luminescence Radiography). Apart from the achieved compression factors we take into account CPU time required and main memory requirement both for compression and for decompression. For a realistic comparison we have implemented the mentioned algorithms in the C program language on a MicroVAX II and a SPARC station 1. 2.

Comparison of Evolutionary (Genetic) Algorithm and Adjoint Methods for Multi-Objective Viscous Airfoil Optimizations

NASA Technical Reports Server (NTRS)

Pulliam, T. H.; Nemec, M.; Holst, T.; Zingg, D. W.; Kwak, Dochan (Technical Monitor)

2002-01-01

A comparison between an Evolutionary Algorithm (EA) and an Adjoint-Gradient (AG) Method applied to a two-dimensional Navier-Stokes code for airfoil design is presented. Both approaches use a common function evaluation code, the steady-state explicit part of the code,ARC2D. The parameterization of the design space is a common B-spline approach for an airfoil surface, which together with a common griding approach, restricts the AG and EA to the same design space. Results are presented for a class of viscous transonic airfoils in which the optimization tradeoff between drag minimization as one objective and lift maximization as another, produces the multi-objective design space. Comparisons are made for efficiency, accuracy and design consistency.

Radiant Energy Measurements from a Scaled Jet Engine Axisymmetric Exhaust Nozzle for a Baseline Code Validation Case

NASA Technical Reports Server (NTRS)

Baumeister, Joseph F.

1994-01-01

A non-flowing, electrically heated test rig was developed to verify computer codes that calculate radiant energy propagation from nozzle geometries that represent aircraft propulsion nozzle systems. Since there are a variety of analysis tools used to evaluate thermal radiation propagation from partially enclosed nozzle surfaces, an experimental benchmark test case was developed for code comparison. This paper briefly describes the nozzle test rig and the developed analytical nozzle geometry used to compare the experimental and predicted thermal radiation results. A major objective of this effort was to make available the experimental results and the analytical model in a format to facilitate conversion to existing computer code formats. For code validation purposes this nozzle geometry represents one validation case for one set of analysis conditions. Since each computer code has advantages and disadvantages based on scope, requirements, and desired accuracy, the usefulness of this single nozzle baseline validation case can be limited for some code comparisons.

Impact of dynamic rate coding aspects of mobile phone networks on forensic voice comparison.

PubMed

Alzqhoul, Esam A S; Nair, Balamurali B T; Guillemin, Bernard J

2015-09-01

Previous studies have shown that landline and mobile phone networks are different in their ways of handling the speech signal, and therefore in their impact on it. But the same is also true of the different networks within the mobile phone arena. There are two major mobile phone technologies currently in use today, namely the global system for mobile communications (GSM) and code division multiple access (CDMA) and these are fundamentally different in their design. For example, the quality of the coded speech in the GSM network is a function of channel quality, whereas in the CDMA network it is determined by channel capacity (i.e., the number of users sharing a cell site). This paper examines the impact on the speech signal of a key feature of these networks, namely dynamic rate coding, and its subsequent impact on the task of likelihood-ratio-based forensic voice comparison (FVC). Surprisingly, both FVC accuracy and precision are found to be better for both GSM- and CDMA-coded speech than for uncoded. Intuitively one expects FVC accuracy to increase with increasing coded speech quality. This trend is shown to occur for the CDMA network, but, surprisingly, not for the GSM network. Further, in respect to comparisons between these two networks, FVC accuracy for CDMA-coded speech is shown to be slightly better than for GSM-coded speech, particularly when the coded-speech quality is high, but in terms of FVC precision the two networks are shown to be very similar. Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

Verification of Three Dimensional Triangular Prismatic Discrete Ordinates Transport Code ENSEMBLE-TRIZ by Comparison with Monte Carlo Code GMVP

NASA Astrophysics Data System (ADS)

Homma, Yuto; Moriwaki, Hiroyuki; Ohki, Shigeo; Ikeda, Kazumi

2014-06-01

This paper deals with verification of three dimensional triangular prismatic discrete ordinates transport calculation code ENSEMBLE-TRIZ by comparison with multi-group Monte Carlo calculation code GMVP in a large fast breeder reactor. The reactor is a 750 MWe electric power sodium cooled reactor. Nuclear characteristics are calculated at beginning of cycle of an initial core and at beginning and end of cycle of equilibrium core. According to the calculations, the differences between the two methodologies are smaller than 0.0002 Δk in the multi-plication factor, relatively about 1% in the control rod reactivity, and 1% in the sodium void reactivity.

Improving the coding and classification of ambulance data through the application of International Classification of Disease 10th revision.

PubMed

Cantwell, Kate; Morgans, Amee; Smith, Karen; Livingston, Michael; Dietze, Paul

2014-02-01

This paper aims to examine whether an adaptation of the International Classification of Disease (ICD) coding system can be applied retrospectively to final paramedic assessment data in an ambulance dataset with a view to developing more fine-grained, clinically relevant case definitions than are available through point-of-call data. Over 1.2 million case records were extracted from the Ambulance Victoria data warehouse. Data fields included dispatch code, cause (CN) and final primary assessment (FPA). Each FPA was converted to an ICD-10-AM code using word matching or best fit. ICD-10-AM codes were then converted into Major Diagnostic Categories (MDC). CN was aligned with the ICD-10-AM codes for external cause of morbidity and mortality. The most accurate results were obtained when ICD-10-AM codes were assigned using information from both FPA and CN. Comparison of cases coded as unconscious at point-of-call with the associated paramedic assessment highlighted the extra clinical detail obtained when paramedic assessment data are used. Ambulance paramedic assessment data can be aligned with ICD-10-AM and MDC with relative ease, allowing retrospective coding of large datasets. Coding of ambulance data using ICD-10-AM allows for comparison of not only ambulance service users but also with other population groups. WHAT IS KNOWN ABOUT THE TOPIC? There is no reliable and standard coding and categorising system for paramedic assessment data contained in ambulance service databases. WHAT DOES THIS PAPER ADD? This study demonstrates that ambulance paramedic assessment data can be aligned with ICD-10-AM and MDC with relative ease, allowing retrospective coding of large datasets. Representation of ambulance case types using ICD-10-AM-coded information obtained after paramedic assessment is more fine grained and clinically relevant than point-of-call data, which uses caller information before ambulance attendance. WHAT ARE THE IMPLICATIONS FOR PRACTITIONERS? This paper describes a model of coding using an internationally recognised standard coding and categorising system to support analysis of paramedic assessment. Ambulance data coded using ICD-10-AM allows for reliable reporting and comparison within the prehospital setting and across the healthcare industry.

Selective Optimization

DTIC Science & Technology

2015-07-06

NUMBER 5b. GRANT NUMBER AFOSR FA9550-12-1-0154 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Shabbir Ahmed and Santanu S. Dey 5d. PROJECT NUMBER 5e. TASK...standard mixed-integer programming (MIP) formulations of selective optimization problems. While such formulations can be attacked by commercial...F33615-86-C-5169. 5b. GRANT NUMBER. Enter all grant numbers as they appear in the report, e.g. AFOSR-82-1234. 5c. PROGRAM ELEMENT NUMBER. Enter

2005 Tri-Service Infrastructure Systems Conference and Exhibition. Volume 9, Tracks 9-11

DTIC Science & Technology

2005-08-04

Walls ETL 1110-2-563, by John D. Clarkson and Robert C. Patev Belleville Locks & Dam Barge Accident on 6 Jan 05, by John Clarkson Portugues Dam Project...Update, by Alberto Gonzalez, Jim Mangold and Dave Dollar Portugues Dam: RCC Materials Investigation, by Jim Hinds Nonlinear Incremental Thermal Stress...Strain Analysis Portugues Dam, by David Dollar, Ahmed Nisar, Paul Jacob and Charles Logie Seismic Isolation of Mission-Critical Infrastructure to

Lumley and Miller Student Scholarships Awarded to Ramos-Garcés and Ahmed

NASA Astrophysics Data System (ADS)

McCarthy, Lauren

2013-03-01

As part of the strategic plan, AGU works to enhance engagement and involvement of students and early-career scientists with the scientific community and uses its position as a diverse and inclusive organization to build the global talent pool in Earth and space science. Student travel grants, awards, and scholarships are a few of the essential ways students and early-career scientists get involved in AGU every year.

Capturing the Range of Learning: Implications for Disaster Health in a Resource Constrained Future

DTIC Science & Technology

2012-12-01

article suggests the value of Coombs and Ahmed’s three interrelated “modes of education” (formal, nonformal, and informal) in considering disaster health...learning by health professionals, amidst an environment of resource constraint, is challenging. This article suggests the value of Coombs and...TABLES Table 1. Coombs and Ahmed’s three interelated "modes of education" (formal, nonformal, and informal)a,b with disaster health examples

Beleaguered Muslim Fortresses and Ethiopian Imperial Expansion from the 13th to the 16th Century

DTIC Science & Technology

2008-06-01

year later Emperor Zara Yakob (r. 1433-1468) took the throne of the Ethiopian Empire.84 Sultan Badlay’s area of control roughly covered the Afar plain...101 Ahmed, 2000: 12; Henze, 79-81; Pankhurst, 1982: 62; Iliffe, 59 (Emperor Zara Yakob as part of...the Christian Empire. On the other hand, throughout that time period, the Christian Emperors, particularly Amda Seyon and Zara Yakob, expanded

Background characterization techniques for target detection using scene metrics and pattern recognition

NASA Astrophysics Data System (ADS)

Noah, Paul V.; Noah, Meg A.; Schroeder, John W.; Chernick, Julian A.

1990-09-01

The U.S. Army has a requirement to develop systems for the detection and identification of ground targets in a clutter environment. Autonomous Homing Munitions (AHM) using infrared, visible, millimeter wave and other sensors are being investigated for this application. Advanced signal processing and computational approaches using pattern recognition and artificial intelligence techniques combined with multisensor data fusion have the potential to meet the Army's requirements for next generation ARM.

Evaluation and optimization of the performance of frame geometries for lithium-ion battery application by computer simulation

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

Miranda, D.; Instituto Politécnico de Viana do Castelo, Viana do Castelo; Miranda, F.

2016-06-08

Tailoring battery geometries is essential for many applications, as geometry influences the delivered capacity value. Two geometries, frame and conventional, have been studied and, for a given scan rate of 330C, the square frame shows a capacity value of 305,52 Ahm{sup −2}, which is 527 times higher than the one for the conventional geometry for a constant the area of all components.

Time Transfer With the Galileo Precise Timing Facility

DTIC Science & Technology

2007-11-01

being designed on the basis of three techniques: TWSTFT , CV, and use of OSPF products. The last technique implies interfacing an external facility...hydrogen masers (AHM) manufactured by T4S (Switzerland) and the 4 cesiums by Symmetricom. • Time Transfer Subsystem This includes the TWSTFT Station...PTF GACF MUCF TSP GMS UTC(k) BIPM OSPF GSS GalileoSat TWSTFT links Slave PTF CV links 442 39th Annual Precise Time and Time Interval

Honoring Navy SEALs Petty Officer 2nd Class Matthew McCabe, Petty Officer 2nd Class Jonathan Keefe, and Petty Officer 1st Class Julio Huertas for their heroic actions in the capture of Ahmed Hashim Abed, the mastermind behind of one of the most notorious crimes against Americans in Iraq.

THOMAS, 111th Congress

Rep. Poe, Ted [R-TX-2

2009-12-16

House - 01/21/2010 Referred to the Subcommittee on Terrorism, Unconventional Threats and Capabilities. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Sir Sayyid Ahmed Kahn's History of the Bijnor Rebellion, Translated with Notes and Introduction. South Asia Series, Occasional Paper No. 17.

ERIC Educational Resources Information Center

Michigan State Univ., East Lansing. Asian Studies Center.

The Bijnor Rebellion of 1857 was a revolt of the Muslim minority in the Bijnor district of India against the British East India Company and Hindu loyalists. Sir Sayyid Ahmad Khan was an Indian Muslim serving the British Company. His account of the events of 1857 is the only one produced by an Indian who both participated in and analyzed the…

Translations on Environmental Quality, Number 175.

DTIC Science & Technology

1978-08-11

9 Jul 78) 17 NEAR EAST AND NORTH AFRICA MAURITANIA Palm Groves’ Deterioration in Adrar, Especially in Atar (Brahim 0. Sid’Ahmed; CHAAB, 5...detrimental to the people." He said: "if the people of all countries are to protect human environment, they must wage a resolute struggle against the...manifestation of all other human values be developed. "Important successes have been achieved in reforestation, the improvement of river basins, the

Alkylation Induced DNA Repair and Mutagenesis in Escherichia coli.

DTIC Science & Technology

1987-11-23

III (Gates and inn, 1977), Micrococcus luteus UV endo- nuclease (Grossman et al, 1978) and bacteriophage T UV endonuclease (Warner et al, 1980) have DNA...34, Garland Publishing, Inc. New York & London USA. Ather, A., Z. Ahmed and S. Riazxxddin, 1984. Adaptive response of Micrococcus luteus to alkylating...Laval, J., 3. Pierre and F. Laval. 1981. Release of 7-nmthylguanine residues frain alkylated ENA by extracts of Micrococcus luteus and Escherichia

A verification of the gyrokinetic microstability codes GEM, GYRO, and GS2

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

Bravenec, R. V.; Chen, Y.; Wan, W.

2013-10-15

A previous publication [R. V. Bravenec et al., Phys. Plasmas 18, 122505 (2011)] presented favorable comparisons of linear frequencies and nonlinear fluxes from the Eulerian gyrokinetic codes gyro[J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] and gs2[W. Dorland et al., Phys. Rev. Lett. 85, 5579 (2000)]. The motivation was to verify the codes, i.e., demonstrate that they correctly solve the gyrokinetic-Maxwell equations. The premise was that it is highly unlikely for both codes to yield the same incorrect results. In this work, we add the Lagrangian particle-in-cell code gem[Y. Chen and S. Parker, J. Comput. Phys.more » 220, 839 (2007)] to the comparisons, not simply to add another code, but also to demonstrate that the codes' algorithms do not matter. We find good agreement of gem with gyro and gs2 for the plasma conditions considered earlier, thus establishing confidence that the codes are verified and that ongoing validation efforts for these plasma parameters are warranted.« less

Error control techniques for satellite and space communications

NASA Technical Reports Server (NTRS)

Costello, Daniel J., Jr.

1989-01-01

The performance of bandwidth efficient trellis codes on channels with phase jitter, or those disturbed by jamming and impulse noise is analyzed. An heuristic algorithm for construction of bandwidth efficient trellis codes with any constraint length up to about 30, any signal constellation, and any code rate was developed. Construction of good distance profile trellis codes for sequential decoding and comparison of random coding bounds of trellis coded modulation schemes are also discussed.

International comparison of sudden unexpected death in infancy rates using a newly proposed set of cause-of-death codes.

PubMed

Taylor, Barry J; Garstang, Joanna; Engelberts, Adele; Obonai, Toshimasa; Cote, Aurore; Freemantle, Jane; Vennemann, Mechtild; Healey, Matt; Sidebotham, Peter; Mitchell, Edwin A; Moon, Rachel Y

2015-11-01

Comparing rates of sudden unexpected death in infancy (SUDI) in different countries and over time is difficult, as these deaths are certified differently in different countries, and, even within the same jurisdiction, changes in this death certification process have occurred over time. To identify if International Classification of Diseases-10 (ICD-10) codes are being applied differently in different countries, and to develop a more robust tool for international comparison of these types of deaths. Usage of six ICD-10 codes, which code for the majority of SUDI, was compared for the years 2002-2010 in eight high-income countries. There was a great variability in how each country codes SUDI. For example, the proportion of SUDI coded as sudden infant death syndrome (R95) ranged from 32.6% in Japan to 72.5% in Germany. The proportion of deaths coded as accidental suffocation and strangulation in bed (W75) ranged from 1.1% in Germany to 31.7% in New Zealand. Japan was the only country to consistently use the R96 code, with 44.8% of SUDI attributed to that code. The lowest, overall, SUDI rate was seen in the Netherlands (0.19/1000 live births (LB)), and the highest in New Zealand (1.00/1000 LB). SUDI accounted for one-third to half of postneonatal mortality in 2002-2010 for all of the countries except for the Netherlands. The proposed set of ICD-10 codes encompasses the codes used in different countries for most SUDI cases. Use of these codes will allow for better international comparisons and tracking of trends over time. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

GPS receiver CODE bias estimation: A comparison of two methods

NASA Astrophysics Data System (ADS)

McCaffrey, Anthony M.; Jayachandran, P. T.; Themens, D. R.; Langley, R. B.

2017-04-01

The Global Positioning System (GPS) is a valuable tool in the measurement and monitoring of ionospheric total electron content (TEC). To obtain accurate GPS-derived TEC, satellite and receiver hardware biases, known as differential code biases (DCBs), must be estimated and removed. The Center for Orbit Determination in Europe (CODE) provides monthly averages of receiver DCBs for a significant number of stations in the International Global Navigation Satellite Systems Service (IGS) network. A comparison of the monthly receiver DCBs provided by CODE with DCBs estimated using the minimization of standard deviations (MSD) method on both daily and monthly time intervals, is presented. Calibrated TEC obtained using CODE-derived DCBs, is accurate to within 0.74 TEC units (TECU) in differenced slant TEC (sTEC), while calibrated sTEC using MSD-derived DCBs results in an accuracy of 1.48 TECU.

Comparing the coding of complications in Queensland and Victorian admitted patient data.

PubMed

Michel, Jude L; Cheng, Diana; Jackson, Terri J

2011-08-01

To examine differences between Queensland and Victorian coding of hospital-acquired conditions and suggest ways to improve the usefulness of these data in the monitoring of patient safety events. Secondary analysis of admitted patient episode data collected in Queensland and Victoria. Comparison of depth of coding, and patterns in the coding of ten commonly coded complications of five elective procedures. Comparison of the mean complication codes assigned per episode revealed Victoria assigns more valid codes than Queensland for all procedures, with the difference between the states being significantly different in all cases. The proportion of the codes flagged as complications was consistently lower for Queensland when comparing 10 common complications for each of the five selected elective procedures. The estimated complication rates for the five procedures showed Victoria to have an apparently higher complication rate than Queensland for 35 of the 50 complications examined. Our findings demonstrate that the coding of complications is more comprehensive in Victoria than in Queensland. It is known that inconsistencies exist between states in routine hospital data quality. Comparative use of patient safety indicators should be viewed with caution until standards are improved across Australia. More exploration of data quality issues is needed to identify areas for improvement.

Watershed Scale Stable Isotope Distribution and Implications on Soil Organic Carbon Loss Monitoring under Hydrologic Uncertainty

NASA Astrophysics Data System (ADS)

Ahmed, I.; Karim, A.; Boutton, T. W.; Strom, K.; Fox, J.

2013-12-01

The thematic focus of this 3-year period multidisciplinary USDA-CBG collaborative applied research is integrated monitoring of soil organic carbon (SOC) loss from multi-use lands using state-of-the-art stable isotope science under uncertain hydrologic influences. In this study, SOC loss and water runoff are being monitored on a 150 square kilometer watershed in Houston, Texas, using natural rainfall events, and total organic carbon/nitrogen concentration (TOC/TN) and stable isotope ratio (δ13C, δ15N) measurements with different land-use types. The work presents the interdisciplinary research results to uncover statistically valid and scientifically sound ways to monitor SOC loss by (i) application of Bayesian Markov Chain Monte Carlo statistical models to assess the relationship between rainfall-runoff and SOC release during soil erosion in space and time, (ii) capturing the episodic nature of rainfall events and its role in the spatial distribution of SOC loss from water erosion, (iii) stable isotope composition guided fingerprinting (source and quantity) of SOC by considering various types of erosion processes common in a heterogeneous watershed, to be able to tell what percentage of SOC is lost from various land-use types (Fox and Papanicolaou, 2008), (iv) creating an integrated watershed scale statistical soil loss monitoring model driven by spatial and temporal correlation of flow and stable isotope composition (Ahmed et. al., 2013a,b), and (v) creation of an integrated decision support system (DSS) for sustainable management of SOC under hydrologic uncertainty to assist the end users. References: Ahmed, I., Karim, A., Boutton, T.W., and Strom, K.B. (2013a). 'Monitoring Soil Organic Carbon Loss from Erosion Using Stable Isotopes.' Proc., Soil Carbon Sequestration, International Conference, May 26-29, Reykjavik, Iceland. Ahmed, I, Bouttom, T.W., Strom, K. B., Karim, A., and Irvin-Smith, N. (2013b). 'Soil carbon distribution and loss monitoring in the urbanized Buffalo Bayou watershed, Houston, Texas.' Proc., 4th Annual All Investigators Meeting of the North American Carbon Program, February 4-7, Albuquerque, NM. Fox, J.F. and Papanicolaou, A.N. (2008). An un-mixing model to study watershed erosion processes. Advances in Water Resources, 31, 96-108. ______________________________ * Corresponding author';s e-mail: ifahmed@pvamu.edu

Light transport feature for SCINFUL.

PubMed

Etaati, G R; Ghal-Eh, N

2008-03-01

An extended version of the scintillator response function prediction code SCINFUL has been developed by incorporating PHOTRACK, a Monte Carlo light transport code. Comparisons of calculated and experimental results for organic scintillators exposed to neutrons show that the extended code improves the predictive capability of SCINFUL.

Importance of the nature of comparison conditions for testing theory-based interventions: comment on Michie and Prestwich (2010).

PubMed

Williams, David M

2010-09-01

Comments on the original article 'Are interventions theory-based? Development of a theory coding scheme' by Susan Michie and Andrew Prestwich (see record 2010-00152-001). In their admirable effort to develop a coding scheme for the theoretical contribution of intervention research, Michie and Prestwich rightly point out the importance of the presence of a comparison condition when examining the effect of an intervention on targeted theoretical variables and behavioral outcomes (Table 2, item 15). However, they fail to discuss the critical importance of the nature of the comparison condition. Weaker comparison conditions will yield stronger intervention effects; stronger comparison conditions will yield a stronger science of behavior change. (c) 2010 APA, all rights reserved).

Application of thin-layer Navier-Stokes equations near maximum lift

NASA Technical Reports Server (NTRS)

Anderson, W. K.; Thomas, J. L.; Rumsey, C. L.

1984-01-01

The flowfield about a NACA 0012 airfoil at a Mach number of 0.3 and Reynolds number of 1 million is computed through an angle of attack range, up to 18 deg, corresponding to conditions up to and beyond the maximum lift coefficient. Results obtained using the compressible thin-layer Navier-Stokes equations are presented as well as results from the compressible Euler equations with and without a viscous coupling procedure. The applicability of each code is assessed and many thin-layer Navier-Stokes benchmark solutions are obtained which can be used for comparison with other codes intended for use at high angles of attack. Reasonable agreement of the Navier-Stokes code with experiment and the viscous-inviscid interaction code is obtained at moderate angles of attack. An unsteady solution is obtained with the thin-layer Navier-Stokes code at the highest angle of attack considered. The maximum lift coefficient is overpredicted, however, in comparison to experimental data, which is attributed to the presence of a laminar separation bubble near the leading edge not modeled in the computations. Two comparisons with experimental data are also presented at a higher Mach number.

A Comparison of Three Navier-Stokes Solvers for Exhaust Nozzle Flowfields

NASA Technical Reports Server (NTRS)

Georgiadis, Nicholas J.; Yoder, Dennis A.; Debonis, James R.

1999-01-01

A comparison of the NPARC, PAB, and WIND (previously known as NASTD) Navier-Stokes solvers is made for two flow cases with turbulent mixing as the dominant flow characteristic, a two-dimensional ejector nozzle and a Mach 1.5 elliptic jet. The objective of the work is to determine if comparable predictions of nozzle flows can be obtained from different Navier-Stokes codes employed in a multiple site research program. A single computational grid was constructed for each of the two flows and used for all of the Navier-Stokes solvers. In addition, similar k-e based turbulence models were employed in each code, and boundary conditions were specified as similarly as possible across the codes. Comparisons of mass flow rates, velocity profiles, and turbulence model quantities are made between the computations and experimental data. The computational cost of obtaining converged solutions with each of the codes is also documented. Results indicate that all of the codes provided similar predictions for the two nozzle flows. Agreement of the Navier-Stokes calculations with experimental data was good for the ejector nozzle. However, for the Mach 1.5 elliptic jet, the calculations were unable to accurately capture the development of the three dimensional elliptic mixing layer.

Flood Control Structures Research Program. Annotated Bibliography on Grade Control Structures

DTIC Science & Technology

1991-09-01

evaluating the effects of geology, geomorphology, soils, land use, and climate on runoff and sediment production from major source areas; (4...Otto, and ,t:iji, Ahmed. 1987. "Theoret- ical Flow Model for Drop Structures," -’. aulic ’ngineering, Proceed- ings of the 1987 National Confere’,ce on...Facilities for Unique Flood Problems," Journal of the-Waterways and Harbors Division, ASCE, Vol 97, No. WWI, pp 185-203. The unusual climatic

Analysis of Novel Prostate Cancer Biomarkers and Their Predictive Utility in an Active Surveillance Protocol

DTIC Science & Technology

2016-05-01

Pathways for CHF, DVT, and Normal Vaginal Delivery with 24 hour LOS . Brigham and Women’s Hospital, Boston, MA. 1994-1995 Research Assistant Adverse...Lecturer 25 Residents 1 hour 5 hours 2008-present Ambulatory Teaching Rounds - Department of Medicine – Uro -oncology for the primary care...Radiofrequency Ablation. In: Ahmed HU, et al. Eds. Interventional Techniques in Uro -Oncology. Oxford, UK: Wiley; 2011. p. 68-85. 5. Feldman AS, Hsu C

2005 Tri-Service Infrastructure Systems Conference and Exhibition. Volume 11, Tracks 13 and 14

DTIC Science & Technology

2005-08-04

Walls ETL 1110-2-563, by John D. Clarkson and Robert C. Patev Belleville Locks & Dam Barge Accident on 6 Jan 05, by John Clarkson Portugues Dam Project...Update, by Alberto Gonzalez, Jim Mangold and Dave Dollar Portugues Dam: RCC Materials Investigation, by Jim Hinds Nonlinear Incremental Thermal Stress...Strain Analysis Portugues Dam, by David Dollar, Ahmed Nisar, Paul Jacob and Charles Logie Seismic Isolation of Mission-Critical Infrastructure to

Translations on Near East and North Africa, Number 1865, ’ABD-Al-Nasir’s Secret Papers’

DTIC Science & Technology

1978-11-14

Shuqayri (PLO), Abdelaziz Bouteflika (Algerian minister of foreign affairs on behalf of President Houari Boumediene), Ahmed Benhima (Moroccan prime...Naturally, we are continuing the political dialog with them through Ashraf Ghurbal (publisher’s note: Ashraf Ghurbal was head of the Egyptian Affairs...himself with. He said: The American position of partiality to Israel has not changed. Today, the Americans presented a new proposal to Ashraf

A U.S. Strategy for Achieving Stability in Pakistan: Expanding Educational Opportunities

DTIC Science & Technology

2002-09-02

5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES...SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM( S ) 11. SPONSOR/MONITOR’S REPORT NUMBER( S ) 12. DISTRIBUTION...Pakistan Reform Party, Education for Life: First Priority Shamim Ahmed Rizvi, New Education Policy: Universalization of Primary Education has the Pivotal

EG and G and NASA face seal codes comparison

NASA Technical Reports Server (NTRS)

Basu, Prit

1994-01-01

This viewgraph presentation presents the following results for the example comparison: EG&G code with face deformations suppressed and SPIRALG agree well with each other as well as with the experimental data; 0 rpm stiffness data calculated by EG&G code are about 70-100 percent lower than that by SPIRALG; there is no appreciable difference between 0 rpm and 16,000 rpm stiffness and damping coefficients calculated by SPIRALG; and the film damping above 500 psig calculated by SPIRALG is much higher than the O-Ring secondary seal damping (e.g. 50 lbf.s/in).

Experimental research and comparison of LDPC and RS channel coding in ultraviolet communication systems.

PubMed

Wu, Menglong; Han, Dahai; Zhang, Xiang; Zhang, Feng; Zhang, Min; Yue, Guangxin

2014-03-10

We have implemented a modified Low-Density Parity-Check (LDPC) codec algorithm in ultraviolet (UV) communication system. Simulations are conducted with measured parameters to evaluate the LDPC-based UV system performance. Moreover, LDPC (960, 480) and RS (18, 10) are implemented and experimented via a non-line-of-sight (NLOS) UV test bed. The experimental results are in agreement with the simulation and suggest that based on the given power and 10(-3)bit error rate (BER), in comparison with an uncoded system, average communication distance increases 32% with RS code, while 78% with LDPC code.

Advanced Health Management System for the Space Shuttle Main Engine

NASA Technical Reports Server (NTRS)

Davidson, Matt; Stephens, John; Rodela, Chris

2006-01-01

Pratt & Whitney Rocketdyne, Inc., in cooperation with NASA-Marshall Space Flight Center (MSFC), has developed a new Advanced Health Management System (AHMS) controller for the Space Shuttle Main Engine (SSME) that will increase the probability of successfully placing the shuttle into the intended orbit and increase the safety of the Space Transportation System (STS) launches. The AHMS is an upgrade o the current Block II engine controller whose primary component is an improved vibration monitoring system called the Real-Time Vibration Monitoring System (RTVMS) that can effectively and reliably monitor the state of the high pressure turbomachinery and provide engine protection through a new synchronous vibration redline which enables engine shutdown if the vibration exceeds predetermined thresholds. The introduction of this system required improvements and modification to the Block II controller such as redesigning the Digital Computer Unit (DCU) memory and the Flight Accelerometer Safety Cut-Off System (FASCOS) circuitry, eliminating the existing memory retention batteries, installation of the Digital Signal Processor (DSP) technology, and installation of a High Speed Serial Interface (HSSI) with accompanying outside world connectors. Test stand hot-fire testing along with lab testing have verified successful implementation and is expected to reduce the probability of catastrophic engine failures during the shuttle ascent phase and improve safely by about 23% according to the Quantitative Risk Assessment System (QRAS), leading to a safer and more reliable SSME.

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

The efficacy of Ahmed glaucoma valve drainage devices in cases of adult refractory glaucoma in Indian eyes

PubMed Central

Parihar, Jitendra K S; Vats, Devendra P; Maggon, Rakesh; Mathur, Vijay; Singh, Anirudh; Mishra, Sanjay K

2009-01-01

Aim: To evaluate the efficacy of Ahmed glaucoma valve (AGV) drainage devices in cases of adult refractory glaucoma in Indian eyes. Settings and Design: Retrospective interventional case series study. Materials and Methods: Fifty two eyes of 32 patients of refractory glaucoma in the age group of 35 to 60 years who underwent AGV implantation with or without concomitant procedures from January 2003 to Jan 2007 were studied. Of these, 46 eyes (88%) had undergone filtering surgery earlier whereas remaining eyes underwent primary AGV implantation following failure of maximal medical therapy. The follow up ranged between 12 months to 48 months Results: Eighteen eyes (35%) had undergone phacoemulsification with AGV implantation, penetrating keratoplasty (PK) with AGV and intraocular lens (IOL) implantation in 13 eyes (25%), AGV over preexisting IOL in eight eyes (15%). AGV implantation alone was done in six (11%) eyes. Anterior chamber (AC) reconstruction with secondary IOL and AGV was performed in the remaining eyes. The mean intra ocular pressure (IOP) decreased from 36.3 ± 15.7 mm Hg to 19.6 ± 9.2 mm Hg. Complete success as per criteria was achieved in 46 eyes (88%). None of the eyes had failure to maintain IOP control following AGV. Conclusion: The AGV resulted in effective and sustained control of IOP in cases of adult refractory glaucoma in intermediate follow up. PMID:19700871

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.

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.

Assessment of intrinsic small signal parameters of submicron SiC MESFETs

NASA Astrophysics Data System (ADS)

Riaz, Mohammad; Ahmed, Muhammad Mansoor; Rafique, Umair; Ahmed, Umer Farooq

2018-01-01

In this paper, a technique has been developed to estimate intrinsic small signal parameters of submicron SiC MESFETs, designed for high power microwave applications. In the developed technique, small signal parameters are extracted by involving drain-to-source current, Ids instead of Schottky barrier depletion layer expression. It has been demonstrated that in SiC MESFETs, the depletion layer gets modified due to intense transverse electric field and/or self-heating effects, which are conventionally not taken into account. Thus, assessment of AC small signal parameters by employing depletion layer expression loses its accuracy for devices meant for high power applications. A set of expressions for AC small signal elements has been developed using Ids and its dependence on device biasing has been discussed. The validity of the proposed technique has been demonstrated using experimental data. Dr. Ahmed research interests are in Microelectronics, Microwave and RF Engineering and he has supervised numerous MS and PhD research projects. He authored over 100 research papers in the field of microelectronics. Dr. Ahmed is a fellow of the Institution of Engineering and Technology (IET), UK.; a Chartered Engineer (CEng) from the UK Engineering Council and holds the title of European Engineer (Eur Ing) from the European Federation of National Engineering Association (FEANI), Brussels. He is a life member of PEC (Pak); EDS & MTTS (USA).

Comparison of Space Radiation Calculations from Deterministic and Monte Carlo Transport Codes

NASA Technical Reports Server (NTRS)

Adams, J. H.; Lin, Z. W.; Nasser, A. F.; Randeniya, S.; Tripathi, r. K.; Watts, J. W.; Yepes, P.

2010-01-01

The presentation outline includes motivation, radiation transport codes being considered, space radiation cases being considered, results for slab geometry, results from spherical geometry, and summary. ///////// main physics in radiation transport codes hzetrn uprop fluka geant4, slab geometry, spe, gcr,

TOPLHA and ALOHA: comparison between Lower Hybrid wave coupling codes

NASA Astrophysics Data System (ADS)

Meneghini, Orso; Hillairet, J.; Goniche, M.; Bilato, R.; Voyer, D.; Parker, R.

2008-11-01

TOPLHA and ALOHA are wave coupling simulation tools for LH antennas. Both codes are able to account for realistic 3D antenna geometries and use a 1D plasma model. In the framework of a collaboration between MIT and CEA laboratories, the two codes have been extensively compared. In TOPLHA the EM problem is self consistently formulated by means of a set of multiple coupled integral equations having as domain the triangles of the meshed antenna surface. TOPLHA currently uses the FELHS code for modeling the plasma response. ALOHA instead uses a mode matching approach and its own plasma model. Comparisons have been done for several plasma scenarios on different antenna designs: an array of independent waveguides, a multi-junction antenna and a passive/active multi-junction antenna. When simulating the same geometry and plasma conditions the two codes compare remarkably well both for the reflection coefficients and for the launched spectra. The different approach of the two codes to solve the same problem strengthens the confidence in the final results.

Comparison of codes assessing galactic cosmic radiation exposure of aircraft crew.

PubMed

Bottollier-Depois, J F; Beck, P; Bennett, B; Bennett, L; Bütikofer, R; Clairand, I; Desorgher, L; Dyer, C; Felsberger, E; Flückiger, E; Hands, A; Kindl, P; Latocha, M; Lewis, B; Leuthold, G; Maczka, T; Mares, V; McCall, M J; O'Brien, K; Rollet, S; Rühm, W; Wissmann, F

2009-10-01

The assessment of the exposure to cosmic radiation onboard aircraft is one of the preoccupations of bodies responsible for radiation protection. Cosmic particle flux is significantly higher onboard aircraft than at ground level and its intensity depends on the solar activity. The dose is usually estimated using codes validated by the experimental data. In this paper, a comparison of various codes is presented, some of them are used routinely, to assess the dose received by the aircraft crew caused by the galactic cosmic radiation. Results are provided for periods close to solar maximum and minimum and for selected flights covering major commercial routes in the world. The overall agreement between the codes, particularly for those routinely used for aircraft crew dosimetry, was better than +/-20 % from the median in all but two cases. The agreement within the codes is considered to be fully satisfactory for radiation protection purposes.

Secure ADS-B authentication system and method

NASA Technical Reports Server (NTRS)

Viggiano, Marc J (Inventor); Valovage, Edward M (Inventor); Samuelson, Kenneth B (Inventor); Hall, Dana L (Inventor)

2010-01-01

A secure system for authenticating the identity of ADS-B systems, including: an authenticator, including a unique id generator and a transmitter transmitting the unique id to one or more ADS-B transmitters; one or more ADS-B transmitters, including a receiver receiving the unique id, one or more secure processing stages merging the unique id with the ADS-B transmitter's identification, data and secret key and generating a secure code identification and a transmitter transmitting a response containing the secure code and ADSB transmitter's data to the authenticator; the authenticator including means for independently determining each ADS-B transmitter's secret key, a receiver receiving each ADS-B transmitter's response, one or more secure processing stages merging the unique id, ADS-B transmitter's identification and data and generating a secure code, and comparison processing comparing the authenticator-generated secure code and the ADS-B transmitter-generated secure code and providing an authentication signal based on the comparison result.

User's manual for Axisymmetric Diffuser Duct (ADD) code. Volume 1: General ADD code description

NASA Technical Reports Server (NTRS)

Anderson, O. L.; Hankins, G. B., Jr.; Edwards, D. E.

1982-01-01

This User's Manual contains a complete description of the computer codes known as the AXISYMMETRIC DIFFUSER DUCT code or ADD code. It includes a list of references which describe the formulation of the ADD code and comparisons of calculation with experimental flows. The input/output and general use of the code is described in the first volume. The second volume contains a detailed description of the code including the global structure of the code, list of FORTRAN variables, and descriptions of the subroutines. The third volume contains a detailed description of the CODUCT code which generates coordinate systems for arbitrary axisymmetric ducts.

The Bauschinger Effect in Autofrettaged Tubes- A Comparison of Models Including the ASME Code

DTIC Science & Technology

1998-06-01

possible error in Division 3 of Section Vm of the ASME Boiler and Pressure Vessel Code . They show that the empirical method used in the code to...Discussion presented by DP Kendall We appreciate the acknowledgement in the Kendall discussion that Division 3 of Section VIII of the ASME Boiler and Pressure Vessel Code may

Space Radiation Transport Codes: A Comparative Study for Galactic Cosmic Rays Environment

NASA Astrophysics Data System (ADS)

Tripathi, Ram; Wilson, John W.; Townsend, Lawrence W.; Gabriel, Tony; Pinsky, Lawrence S.; Slaba, Tony

For long duration and/or deep space human missions, protection from severe space radiation exposure is a challenging design constraint and may be a potential limiting factor. The space radiation environment consists of galactic cosmic rays (GCR), solar particle events (SPE), trapped radiation, and includes ions of all the known elements over a very broad energy range. These ions penetrate spacecraft materials producing nuclear fragments and secondary particles that damage biological tissues, microelectronic devices, and materials. In deep space missions, where the Earth's magnetic field does not provide protection from space radiation, the GCR environment is significantly enhanced due to the absence of geomagnetic cut-off and is a major component of radiation exposure. Accurate risk assessments critically depend on the accuracy of the input information as well as radiation transport codes used, and so systematic verification of codes is necessary. In this study, comparisons are made between the deterministic code HZETRN2006 and the Monte Carlo codes HETC-HEDS and FLUKA for an aluminum shield followed by a water target exposed to the 1977 solar minimum GCR spectrum. Interaction and transport of high charge ions present in GCR radiation environment provide a more stringent constraint in the comparison of the codes. Dose, dose equivalent and flux spectra are compared; details of the comparisons will be discussed, and conclusions will be drawn for future directions.

Compression performance comparison in low delay real-time video for mobile applications

NASA Astrophysics Data System (ADS)

Bivolarski, Lazar

2012-10-01

This article compares the performance of several current video coding standards in the conditions of low-delay real-time in a resource constrained environment. The comparison is performed using the same content and the metrics and mix of objective and perceptual quality metrics. The metrics results in different coding schemes are analyzed from a point of view of user perception and quality of service. Multiple standards are compared MPEG-2, MPEG4 and MPEG-AVC and well and H.263. The metrics used in the comparison include SSIM, VQM and DVQ. Subjective evaluation and quality of service are discussed from a point of view of perceptual metrics and their incorporation in the coding scheme development process. The performance and the correlation of results are presented as a predictor of the performance of video compression schemes.

Comparisons of survival predictions using survival risk ratios based on International Classification of Diseases, Ninth Revision and Abbreviated Injury Scale trauma diagnosis codes.

PubMed

Clarke, John R; Ragone, Andrew V; Greenwald, Lloyd

2005-09-01

We conducted a comparison of methods for predicting survival using survival risk ratios (SRRs), including new comparisons based on International Classification of Diseases, Ninth Revision (ICD-9) versus Abbreviated Injury Scale (AIS) six-digit codes. From the Pennsylvania trauma center's registry, all direct trauma admissions were collected through June 22, 1999. Patients with no comorbid medical diagnoses and both ICD-9 and AIS injury codes were used for comparisons based on a single set of data. SRRs for ICD-9 and then for AIS diagnostic codes were each calculated two ways: from the survival rate of patients with each diagnosis and when each diagnosis was an isolated diagnosis. Probabilities of survival for the cohort were calculated using each set of SRRs by the multiplicative ICISS method and, where appropriate, the minimum SRR method. These prediction sets were then internally validated against actual survival by the Hosmer-Lemeshow goodness-of-fit statistic. The 41,364 patients had 1,224 different ICD-9 injury diagnoses in 32,261 combinations and 1,263 corresponding AIS injury diagnoses in 31,755 combinations, ranging from 1 to 27 injuries per patient. All conventional ICD-9-based combinations of SRRs and methods had better Hosmer-Lemeshow goodness-of-fit statistic fits than their AIS-based counterparts. The minimum SRR method produced better calibration than the multiplicative methods, presumably because it did not magnify inaccuracies in the SRRs that might occur with multiplication. Predictions of survival based on anatomic injury alone can be performed using ICD-9 codes, with no advantage from extra coding of AIS diagnoses. Predictions based on the single worst SRR were closer to actual outcomes than those based on multiplying SRRs.

Concatenated coding for low date rate space communications.

NASA Technical Reports Server (NTRS)

Chen, C. H.

1972-01-01

In deep space communications with distant planets, the data rate as well as the operating SNR may be very low. To maintain the error rate also at a very low level, it is necessary to use a sophisticated coding system (longer code) without excessive decoding complexity. The concatenated coding has been shown to meet such requirements in that the error rate decreases exponentially with the overall length of the code while the decoder complexity increases only algebraically. Three methods of concatenating an inner code with an outer code are considered. Performance comparison of the three concatenated codes is made.

Application of MCT Failure Criterion using EFM

DTIC Science & Technology

2010-03-26

because HELIUS:MCT™ does not facilitate this. Attempts have been made to use ABAQUS native thermal expansion model combined in addition to Helius-MCT... ABAQUS using a user defined element subroutine EFM. Comparisons have been made between the analysis results using EFM-MCT code and HELIUS:MCT™ code...using the Element-Failure Method (EFM) in ABAQUS . The EFM-MCT has been implemented in ABAQUS using a user defined element subroutine EFM. Comparisons

Comment on ‘egs_brachy: a versatile and fast Monte Carlo code for brachytherapy’

NASA Astrophysics Data System (ADS)

Yegin, Gultekin

2018-02-01

In a recent paper (Chamberland et al 2016 Phys. Med. Biol. 61 8214) develop a new Monte Carlo code called egs_brachy for brachytherapy treatments. It is based on EGSnrc, and written in the C++ programming language. In order to benchmark the egs_brachy code, the authors use it in various test case scenarios in which complex geometry conditions exist. Another EGSnrc based brachytherapy dose calculation engine, BrachyDose, is used for dose comparisons. The authors fail to prove that egs_brachy can produce reasonable dose values for brachytherapy sources in a given medium. The dose comparisons in the paper are erroneous and misleading. egs_brachy should not be used in any further research studies unless and until all the potential bugs are fixed in the code.

An improved algorithm for evaluating trellis phase codes

NASA Technical Reports Server (NTRS)

Mulligan, M. G.; Wilson, S. G.

1982-01-01

A method is described for evaluating the minimum distance parameters of trellis phase codes, including CPFSK, partial response FM, and more importantly, coded CPM (continuous phase modulation) schemes. The algorithm provides dramatically faster execution times and lesser memory requirements than previous algorithms. Results of sample calculations and timing comparisons are included.

An improved algorithm for evaluating trellis phase codes

NASA Technical Reports Server (NTRS)

Mulligan, M. G.; Wilson, S. G.

1984-01-01

A method is described for evaluating the minimum distance parameters of trellis phase codes, including CPFSK, partial response FM, and more importantly, coded CPM (continuous phase modulation) schemes. The algorithm provides dramatically faster execution times and lesser memory requirements than previous algorithms. Results of sample calculations and timing comparisons are included.

Overlooking the obvious: a meta-analytic comparison of digit symbol coding tasks and other cognitive measures in schizophrenia.

PubMed

Dickinson, Dwight; Ramsey, Mary E; Gold, James M

2007-05-01

In focusing on potentially localizable cognitive impairments, the schizophrenia meta-analytic literature has overlooked the largest single impairment: on digit symbol coding tasks. To compare the magnitude of the schizophrenia impairment on coding tasks with impairments on other traditional neuropsychological instruments. MEDLINE and PsycINFO electronic databases and reference lists from identified articles. English-language studies from 1990 to present, comparing performance of patients with schizophrenia and healthy controls on coding tasks and cognitive measures representing at least 2 other cognitive domains. Of 182 studies identified, 40 met all criteria for inclusion in the meta-analysis. Means, standard deviations, and sample sizes were extracted for digit symbol coding and 36 other cognitive variables. In addition, we recorded potential clinical moderator variables, including chronicity/severity, medication status, age, and education, and potential study design moderators, including coding task variant, matching, and study publication date. Main analyses synthesized data from 37 studies comprising 1961 patients with schizophrenia and 1444 comparison subjects. Combination of mean effect sizes across studies by means of a random effects model yielded a weighted mean effect for digit symbol coding of g = -1.57 (95% confidence interval, -1.66 to -1.48). This effect compared with a grand mean effect of g = -0.98 and was significantly larger than effects for widely used measures of episodic memory, executive functioning, and working memory. Moderator variable analyses indicated that clinical and study design differences between studies had little effect on the coding task effect. Comparison with previous meta-analyses suggested that current results were representative of the broader literature. Subsidiary analysis of data from relatives of patients with schizophrenia also suggested prominent coding task impairments in this group. The 5-minute digit symbol coding task, reliable and easy to administer, taps an information processing inefficiency that is a central feature of the cognitive deficit in schizophrenia and deserves systematic investigation.

Systematic Comparison of Photoionized Plasma Codes with Application to Spectroscopic Studies of AGN in X-Rays

NASA Technical Reports Server (NTRS)

Mehdipour, M.; Kaastra, J. S.; Kallman, T.

2016-01-01

Atomic data and plasma models play a crucial role in the diagnosis and interpretation of astrophysical spectra, thus influencing our understanding of the Universe. In this investigation we present a systematic comparison of the leading photoionization codes to determine how much their intrinsic differences impact X-ray spectroscopic studies of hot plasmas in photoionization equilibrium. We carry out our computations using the Cloudy, SPEX, and XSTAR photoionization codes, and compare their derived thermal and ionization states for various ionizing spectral energy distributions. We examine the resulting absorption-line spectra from these codes for the case of ionized outflows in active galactic nuclei. By comparing the ionic abundances as a function of ionization parameter, we find that on average there is about 30 deviation between the codes in where ionic abundances peak. For H-like to B-like sequence ions alone, this deviation in is smaller at about 10 on average. The comparison of the absorption-line spectra in the X-ray band shows that there is on average about 30 deviation between the codes in the optical depth of the lines produced at log 1 to 2, reducing to about 20 deviation at log 3. We also simulate spectra of the ionized outflows with the current and upcoming high-resolution X-ray spectrometers, on board XMM-Newton, Chandra, Hitomi, and Athena. From these simulations we obtain the deviation on the best-fit model parameters, arising from the use of different photoionization codes, which is about 10 to40. We compare the modeling uncertainties with the observational uncertainties from the simulations. The results highlight the importance of continuous development and enhancement of photoionization codes for the upcoming era of X-ray astronomy with Athena.

Linear and nonlinear verification of gyrokinetic microstability codes

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

Bravenec, R. V.; Candy, J.; Barnes, M.

2011-12-15

Verification of nonlinear microstability codes is a necessary step before comparisons or predictions of turbulent transport in toroidal devices can be justified. By verification we mean demonstrating that a code correctly solves the mathematical model upon which it is based. Some degree of verification can be accomplished indirectly from analytical instability threshold conditions, nonlinear saturation estimates, etc., for relatively simple plasmas. However, verification for experimentally relevant plasma conditions and physics is beyond the realm of analytical treatment and must rely on code-to-code comparisons, i.e., benchmarking. The premise is that the codes are verified for a given problem or set ofmore » parameters if they all agree within a specified tolerance. True verification requires comparisons for a number of plasma conditions, e.g., different devices, discharges, times, and radii. Running the codes and keeping track of linear and nonlinear inputs and results for all conditions could be prohibitive unless there was some degree of automation. We have written software to do just this and have formulated a metric for assessing agreement of nonlinear simulations. We present comparisons, both linear and nonlinear, between the gyrokinetic codes GYRO[J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] and GS2[W. Dorland, F. Jenko, M. Kotschenreuther, and B. N. Rogers, Phys. Rev. Lett. 85, 5579 (2000)]. We do so at the mid-radius for the same discharge as in earlier work [C. Holland, A. E. White, G. R. McKee, M. W. Shafer, J. Candy, R. E. Waltz, L. Schmitz, and G. R. Tynan, Phys. Plasmas 16, 052301 (2009)]. The comparisons include electromagnetic fluctuations, passing and trapped electrons, plasma shaping, one kinetic impurity, and finite Debye-length effects. Results neglecting and including electron collisions (Lorentz model) are presented. We find that the linear frequencies with or without collisions agree well between codes, as do the time averages of the nonlinear fluxes without collisions. With collisions, the differences between the time-averaged fluxes are larger than the uncertainties defined as the oscillations of the fluxes, with the GS2 fluxes consistently larger (or more positive) than those from GYRO. However, the electrostatic fluxes are much smaller than those without collisions (the electromagnetic energy flux is negligible in both cases). In fact, except for the electron energy fluxes, the absolute magnitudes of the differences in fluxes with collisions are the same or smaller than those without. None of the fluxes exhibit large absolute differences between codes. Beyond these results, the specific linear and nonlinear benchmarks proposed here, as well as the underlying methodology, provide the basis for a wide variety of future verification efforts.« less

Review of the 9th NLTE code comparison workshop

DOE PAGES

Piron, Robin; Gilleron, Franck; Aglitskiy, Yefim; ...

2017-02-24

Here, we review the 9th NLTE code comparison workshop, which was held in the Jussieu campus, Paris, from November 30th to December 4th, 2015. This time, the workshop was mainly focused on a systematic investigation of iron NLTE steady-state kinetics and emissivity, over a broad range of temperature and density. Through these comparisons, topics such as modeling of the dielectronic processes, density effects or the effect of an external radiation field were addressed. The K-shell spectroscopy of iron plasmas was also addressed, notably through the interpretation of tokamak and laser experimental spectra.

Transport methods and interactions for space radiations

NASA Technical Reports Server (NTRS)

Wilson, John W.; Townsend, Lawrence W.; Schimmerling, Walter S.; Khandelwal, Govind S.; Khan, Ferdous S.; Nealy, John E.; Cucinotta, Francis A.; Simonsen, Lisa C.; Shinn, Judy L.; Norbury, John W.

1991-01-01

A review of the program in space radiation protection at the Langley Research Center is given. The relevant Boltzmann equations are given with a discussion of approximation procedures for space applications. The interaction coefficients are related to solution of the many-body Schroedinger equation with nuclear and electromagnetic forces. Various solution techniques are discussed to obtain relevant interaction cross sections with extensive comparison with experiments. Solution techniques for the Boltzmann equations are discussed in detail. Transport computer code validation is discussed through analytical benchmarking, comparison with other codes, comparison with laboratory experiments and measurements in space. Applications to lunar and Mars missions are discussed.

Review of the 9th NLTE code comparison workshop

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

Piron, Robin; Gilleron, Franck; Aglitskiy, Yefim

Here, we review the 9th NLTE code comparison workshop, which was held in the Jussieu campus, Paris, from November 30th to December 4th, 2015. This time, the workshop was mainly focused on a systematic investigation of iron NLTE steady-state kinetics and emissivity, over a broad range of temperature and density. Through these comparisons, topics such as modeling of the dielectronic processes, density effects or the effect of an external radiation field were addressed. The K-shell spectroscopy of iron plasmas was also addressed, notably through the interpretation of tokamak and laser experimental spectra.

Review of the 9th NLTE code comparison workshop

NASA Astrophysics Data System (ADS)

Piron, R.; Gilleron, F.; Aglitskiy, Y.; Chung, H.-K.; Fontes, C. J.; Hansen, S. B.; Marchuk, O.; Scott, H. A.; Stambulchik, E.; Ralchenko, Yu.

2017-06-01

We review the 9th NLTE code comparison workshop, which was held in the Jussieu campus, Paris, from November 30th to December 4th, 2015. This time, the workshop was mainly focused on a systematic investigation of iron NLTE steady-state kinetics and emissivity, over a broad range of temperature and density. Through these comparisons, topics such as modeling of the dielectronic processes, density effects or the effect of an external radiation field were addressed. The K-shell spectroscopy of iron plasmas was also addressed, notably through the interpretation of tokamak and laser experimental spectra.

A Country Divided: The Impacts of Fragmented Communities on Iraq’s Government

DTIC Science & Technology

2007-09-01

trash collection, and even conducts weddings. The Sadr Bureau also provides cooking fuel at a reduced price to the poor—at 4,000 dinars ($3.15) per...canister instead of the market price of 24,000 dinars .29 When I patrolled Sadr City in early 2005, my unit frequented sewage sub-stations (which...before they entered the city. Sadr City residents regard the Mahdi Militia as heroes; Shihab Ahmed , a 24 year-old salesmen wounded in the attack

WHK Interns Sweep Entire Category at Frederick County Science Fair | Poster

Cancer.gov

By Nancy Parrish, Staff Writer The competitors in the cellular and molecular biology category of the Frederick County Science and Engineering Fair on March 22–23 didn’t stand a chance against the Werner H. Kirsten student interns at the National Cancer Institute at Frederick. These interns swept the entire category, with Madelyne Xiao, a rising intern, winning first place; Maria Hamscher, second place; Ashley Babyak and Dahlia Kronfli tying for third place; and Maham Ahmed receiving an honorable mention.

The 21st Century FBI: A Domestic National Security Mission Under the Rule of Law

DTIC Science & Technology

2011-03-08

intelligence, and further created a special comt for the approval of warrants. 18 Since its inception, FISA Court judges have demonstrated particular...embassies in Kenya and Tanzania in August of 1998. In December 1999, one of al Qaeda’s soldiers, Ahmed Ressam, entered the U.S. to bomb Los Angeles...the East Africa embassy attacks on August 7, 1998. Together, they were able to indict bin Laden prior to August 7 for a plot to murder U.S. soldiers

Molecular Biological Studies on the Biogenesis of Human Cholinesterases in vivo and as Directed by Cloned Cholinesterase DNA Sequences

DTIC Science & Technology

1990-10-24

amplifications. A considerable body of information, accumulated over the years, demonstrates cytotoxic and mutogenic effects for OP poisons. Pesticide -induced...occupational exposure to pesticides (306). However, the damage may not be limited to these high-risk groups of humans, since pesticide residues were found in...with amplification of the HER-2/neu oncogene. Science 235: 177-182 (1987). 296 Ahmed, F.; Hart, R.; Lewis, N. Pesticide induced DNA damage and its

Sequential Analysis of Automatic Target Detection with Classification Algorithms and Optimality of Dynamic Decision Making Under Uncertainty

DTIC Science & Technology

2013-02-01

Pavlovian   drug  cues  to  produce   excessive  “wanting”  to...motivation:  Incentive   salience  boosts  of   drug  or  appetite  states.  Behavioral  Brain  Science  31:440-­‐441...learning   into  motivation.  In  Gutkin,  B.  and  Ahmed,  S.H.  (Eds.)  Computational  Neuroscience  of   Drug

Review and Assessment of United States Strategy to Combat Terrorism

DTIC Science & Technology

2002-01-01

LTC Antulio J . Echevarria II Project Advisor The views expressed in this academic research paper are those of the author and do not necessarily...IFedera mre"I J F LFETC• S&Human •emces • ~ na’eenrl geni~ _. .. Jd USc Agenc Di.-,--a o7 S ;=eo Jt It ~~en offC;-’ Airecto of CentralcDefens I W...Fadhil, Sheikh Ahmed Salim Swedan, Fahid Mohammed Ally Msalam, Anas al- Liby, Abdul Rahman Yasin, Khalid Shaikh Mohammed, Abdelkarim Hussein Mohamed al

Recognizing the exemplarily service, devotion to country, and selfless sacrifice of Special Warfare Operators 2nd Class Matthew McCabe and Jonathan Keefe and Special Warfare Operator 1st Class Julio Huertas in capturing Ahmed Hashim Abed, one of the most-wanted terrorists in Iraq, and pledging to continue to support members of the United States Armed Forces serving in harm's way.

THOMAS, 111th Congress

Rep. Hunter, Duncan D. [R-CA-52

2009-12-16

House - 01/21/2010 Referred to the Subcommittee on Terrorism, Unconventional Threats and Capabilities. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Update to the NASA Lewis Ice Accretion Code LEWICE

NASA Technical Reports Server (NTRS)

Wright, William B.

1994-01-01

This report is intended as an update to NASA CR-185129 'User's Manual for the NASA Lewis Ice Accretion Prediction Code (LEWICE).' It describes modifications and improvements made to this code as well as changes to the input and output files, interactive input, and graphics output. The comparison of this code to experimental data is shown to have improved as a result of these modifications.

Evaluation of COBRA III-C and SABRE-I (wire wrap version) computational results by comparison with steady-state data from a 19-pin internally guard heated sodium cooled bundle with a six-channel central blockage (THORS bundle 3C). [LMFBR

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

Dearing, J F; Rose, S D; Nelson, W R

The predicted computational results of two well-known sub-channel analysis codes, COBRA-III-C and SABRE-I (wire wrap version), have been evaluated by comparison with steady state temperature data from the THORS Facility at ORNL. Both codes give good predictions of transverse and axial temperatures when compared with wire wrap thermocouple data. The crossflow velocity profiles predicted by these codes are similar which is encouraging since the wire wrap models are based on different assumptions.

Analysis of thermo-chemical nonequilibrium models for carbon dioxide flows

NASA Technical Reports Server (NTRS)

Rock, Stacey G.; Candler, Graham V.; Hornung, Hans G.

1992-01-01

The aerothermodynamics of thermochemical nonequilibrium carbon dioxide flows is studied. The chemical kinetics models of McKenzie and Park are implemented in separate three-dimensional computational fluid dynamics codes. The codes incorporate a five-species gas model characterized by a translational-rotational and a vibrational temperature. Solutions are obtained for flow over finite length elliptical and circular cylinders. The computed flowfields are then employed to calculate Mach-Zehnder interferograms for comparison with experimental data. The accuracy of the chemical kinetics models is determined through this comparison. Also, the methodology of the three-dimensional thermochemical nonequilibrium code is verified by the reproduction of the experiments.

Comparison of the LLNL ALE3D and AKTS Thermal Safety Computer Codes for Calculating Times to Explosion in ODTX and STEX Thermal Cookoff Experiments

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

Wemhoff, A P; Burnham, A K

2006-04-05

Cross-comparison of the results of two computer codes for the same problem provides a mutual validation of their computational methods. This cross-validation exercise was performed for LLNL's ALE3D code and AKTS's Thermal Safety code, using the thermal ignition of HMX in two standard LLNL cookoff experiments: the One-Dimensional Time to Explosion (ODTX) test and the Scaled Thermal Explosion (STEX) test. The chemical kinetics model used in both codes was the extended Prout-Tompkins model, a relatively new addition to ALE3D. This model was applied using ALE3D's new pseudospecies feature. In addition, an advanced isoconversional kinetic approach was used in the AKTSmore » code. The mathematical constants in the Prout-Tompkins code were calibrated using DSC data from hermetically sealed vessels and the LLNL optimization code Kinetics05. The isoconversional kinetic parameters were optimized using the AKTS Thermokinetics code. We found that the Prout-Tompkins model calculations agree fairly well between the two codes, and the isoconversional kinetic model gives very similar results as the Prout-Tompkins model. We also found that an autocatalytic approach in the beta-delta phase transition model does affect the times to explosion for some conditions, especially STEX-like simulations at ramp rates above 100 C/hr, and further exploration of that effect is warranted.« less

Analytical ice shape predictions for flight in natural icing conditions

NASA Technical Reports Server (NTRS)

Berkowitz, Brian M.; Riley, James T.

1988-01-01

LEWICE is an analytical ice prediction code that has been evaluated against icing tunnel data, but on a more limited basis against flight data. Ice shapes predicted by LEWICE is compared with experimental ice shapes accreted on the NASA Lewis Icing Research Aircraft. The flight data selected for comparison includes liquid water content recorded using a hot wire device and droplet distribution data from a laser spectrometer; the ice shape is recorded using stereo photography. The main findings are as follows: (1) An equivalent sand grain roughness correlation different from that used for LEWICE tunnel comparisons must be employed to obtain satisfactory results for flight; (2) Using this correlation and making no other changes in the code, the comparisons to ice shapes accreted in flight are in general as good as the comparisons to ice shapes accreted in the tunnel (as in the case of tunnel ice shapes, agreement is least reliable for large glaze ice shapes at high angles of attack); (3) In some cases comparisons can be somewhat improved by utilizing the code so as to take account of the variation of parameters such as liquid water content, which may vary significantly in flight.

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

VLBI2010 Feed Comparison

NASA Technical Reports Server (NTRS)

Petrachenko, Bill

2013-01-01

VLBI2010 requires a feed that simultaneously has high efficiency over the full 2.2-14 GHz frequency range. The simultaneity requirement implies that the feed must operate at high efficiency over the full frequency range without the need to adjust its focal position to account for frequency dependent phase centre variations. Two feeds meet this specification: The Eleven Feed developed at Chalmers University. (For more information, contact Miroslav Pantaleev, miroslav.pantaleev@chalmers.se. The Eleven Feed, integrated with LNA's in a cryogenic receiver, is available as a product from Omnisys Instruments, info@omnisys.se). The Quadruple Ridged Flared Horn (QRFH) developed at the California Institute of Technology. (For more information please contact Ahmed Akgiray, aakgiray@ieee.org or Sander Weinreb, sweinreb@caltech.edu) Although not VLBI2010 compliant, two triband S/X/Ka feeds are also being developed for the commissioning of VLBI2010 antennas, for S/X observations during the VLBI2010 transition period, and to support X/Ka CRF observations. The two feeds are: The Twin Telescopes Wettzell (TTW) triband feed developed by Mirad Microwave. (For more information please contact Gerhard Kronschnabl, Gerhard.Kronschnabl@bkg.bund.de) The RAEGE (Spain) triband feed developed at Yebes Observatory. (For more information please contact Jose Antonio Lopez Perez, ja.lopezperez@oan.es)

Validation of the SINDA/FLUINT code using several analytical solutions

NASA Technical Reports Server (NTRS)

Keller, John R.

1995-01-01

The Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA/FLUINT) code has often been used to determine the transient and steady-state response of various thermal and fluid flow networks. While this code is an often used design and analysis tool, the validation of this program has been limited to a few simple studies. For the current study, the SINDA/FLUINT code was compared to four different analytical solutions. The thermal analyzer portion of the code (conduction and radiative heat transfer, SINDA portion) was first compared to two separate solutions. The first comparison examined a semi-infinite slab with a periodic surface temperature boundary condition. Next, a small, uniform temperature object (lumped capacitance) was allowed to radiate to a fixed temperature sink. The fluid portion of the code (FLUINT) was also compared to two different analytical solutions. The first study examined a tank filling process by an ideal gas in which there is both control volume work and heat transfer. The final comparison considered the flow in a pipe joining two infinite reservoirs of pressure. The results of all these studies showed that for the situations examined here, the SINDA/FLUINT code was able to match the results of the analytical solutions.

10Gbps 2D MGC OCDMA Code over FSO Communication System

NASA Astrophysics Data System (ADS)

Professor Urmila Bhanja, Associate, Dr.; Khuntia, Arpita; Alamasety Swati, (Student

2017-08-01

Currently, wide bandwidth signal dissemination along with low latency is a leading requisite in various applications. Free space optical wireless communication has introduced as a realistic technology for bridging the gap in present high data transmission fiber connectivity and as a provisional backbone for rapidly deployable wireless communication infrastructure. The manuscript highlights on the implementation of 10Gbps SAC-OCDMA FSO communications using modified two dimensional Golomb code (2D MGC) that possesses better auto correlation, minimum cross correlation and high cardinality. A comparison based on pseudo orthogonal (PSO) matrix code and modified two dimensional Golomb code (2D MGC) is developed in the proposed SAC OCDMA-FSO communication module taking different parameters into account. The simulative outcome signifies that the communication radius is bounded by the multiple access interference (MAI). In this work, a comparison is made in terms of bit error rate (BER), and quality factor (Q) based on modified two dimensional Golomb code (2D MGC) and PSO matrix code. It is observed that the 2D MGC yields better results compared to the PSO matrix code. The simulation results are validated using optisystem version 14.

Support for Debugging Automatically Parallelized Programs

NASA Technical Reports Server (NTRS)

Hood, Robert; Jost, Gabriele

2001-01-01

This viewgraph presentation provides information on support sources available for the automatic parallelization of computer program. CAPTools, a support tool developed at the University of Greenwich, transforms, with user guidance, existing sequential Fortran code into parallel message passing code. Comparison routines are then run for debugging purposes, in essence, ensuring that the code transformation was accurate.

Comparison of LEWICE 1.6 and LEWICE/NS with IRT experimental data from modern air foil tests

DOT National Transportation Integrated Search

1998-01-01

A research project is underway at NASA Lewis to produce a computer code which can accurately predict ice growth under any meteorological conditions for any aircraft surface. The most recent release of this code is LEWICE 1.6. This code is modular in ...

A Comparison of Fatigue Design Methods

DTIC Science & Technology

2001-04-05

Boiler and Pressure Vessel Code does not...Engineers, "ASME Boiler and Pressure Vessel Code ," ASME, 3 Park Ave., New York, NY 10016-5990. [4] Langer, B. F., "Design of Pressure Vessels Involving... and Pressure Vessel Code [3] presents these methods and has expanded the procedures to other pressure vessels besides nuclear pressure vessels. B.

Monitoring Cosmic Radiation Risk: Comparisons between Observations and Predictive Codes for Naval Aviation

DTIC Science & Technology

2009-01-01

proton PARMA PHITS -based Analytical Radiation Model in the Atmosphere PCAIRE Predictive Code for Aircrew Radiation Exposure PHITS Particle and...radiation transport code utilized is called PARMA ( PHITS based Analytical Radiation Model in the Atmosphere) [36]. The particle fluxes calculated from the...same dose equivalent coefficient regulations from the ICRP-60 regulations. As a result, the transport codes utilized by EXPACS ( PHITS ) and CARI-6

Monitoring Cosmic Radiation Risk: Comparisons Between Observations and Predictive Codes for Naval Aviation

DTIC Science & Technology

2009-07-05

proton PARMA PHITS -based Analytical Radiation Model in the Atmosphere PCAIRE Predictive Code for Aircrew Radiation Exposure PHITS Particle and Heavy...transport code utilized is called PARMA ( PHITS based Analytical Radiation Model in the Atmosphere) [36]. The particle fluxes calculated from the input...dose equivalent coefficient regulations from the ICRP-60 regulations. As a result, the transport codes utilized by EXPACS ( PHITS ) and CARI-6 (PARMA

Comparison of deterministic and stochastic approaches for isotopic concentration and decay heat uncertainty quantification on elementary fission pulse

NASA Astrophysics Data System (ADS)

Lahaye, S.; Huynh, T. D.; Tsilanizara, A.

2016-03-01

Uncertainty quantification of interest outputs in nuclear fuel cycle is an important issue for nuclear safety, from nuclear facilities to long term deposits. Most of those outputs are functions of the isotopic vector density which is estimated by fuel cycle codes, such as DARWIN/PEPIN2, MENDEL, ORIGEN or FISPACT. CEA code systems DARWIN/PEPIN2 and MENDEL propagate by two different methods the uncertainty from nuclear data inputs to isotopic concentrations and decay heat. This paper shows comparisons between those two codes on a Uranium-235 thermal fission pulse. Effects of nuclear data evaluation's choice (ENDF/B-VII.1, JEFF-3.1.1 and JENDL-2011) is inspected in this paper. All results show good agreement between both codes and methods, ensuring the reliability of both approaches for a given evaluation.

A comparison of cosmological hydrodynamic codes

NASA Technical Reports Server (NTRS)

Kang, Hyesung; Ostriker, Jeremiah P.; Cen, Renyue; Ryu, Dongsu; Hernquist, Lars; Evrard, August E.; Bryan, Greg L.; Norman, Michael L.

1994-01-01

We present a detailed comparison of the simulation results of various hydrodynamic codes. Starting with identical initial conditions based on the cold dark matter scenario for the growth of structure, with parameters h = 0.5 Omega = Omega(sub b) = 1, and sigma(sub 8) = 1, we integrate from redshift z = 20 to z = O to determine the physical state within a representative volume of size L(exp 3) where L = 64 h(exp -1) Mpc. Five indenpendent codes are compared: three of them Eulerian mesh-based and two variants of the smooth particle hydrodynamics 'SPH' Lagrangian approach. The Eulerian codes were run at N(exp 3) = (32(exp 3), 64(exp 3), 128(exp 3), and 256(exp 3)) cells, the SPH codes at N(exp 3) = 32(exp 3) and 64(exp 3) particles. Results were then rebinned to a 16(exp 3) grid with the exception that the rebinned data should converge, by all techniques, to a common and correct result as N approaches infinity. We find that global averages of various physical quantities do, as expected, tend to converge in the rebinned model, but that uncertainites in even primitive quantities such as (T), (rho(exp 2))(exp 1/2) persists at the 3%-17% level achieve comparable and satisfactory accuracy for comparable computer time in their treatment of the high-density, high-temeprature regions as measured in the rebinned data; the variance among the five codes (at highest resolution) for the mean temperature (as weighted by rho(exp 2) is only 4.5%. Examined at high resolution we suspect that the density resolution is better in the SPH codes and the thermal accuracy in low-density regions better in the Eulerian codes. In the low-density, low-temperature regions the SPH codes have poor accuracy due to statiscal effects, and the Jameson code gives the temperatures which are too high, due to overuse of artificial viscosity in these high Mach number regions. Overall the comparison allows us to better estimate errors; it points to ways of improving this current generation ofhydrodynamic codes and of suiting their use to problems which exploit their best individual features.

Revisiting Fenton Hill Phase I reservoir creation and stimulation mechanisms through the GTO code comparison effort

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

Fu, Pengcheng; Mcclure, Mark; Shiozawa, Sogo

A series of experiments performed at the Fenton Hill hot dry rock site after stage 2 drilling of Phase I reservoir provided intriguing field observations on the reservoir’s responses to injection and venting under various conditions. Two teams participating in the US DOE Geothermal Technologies Office (GTO)’s Code Comparison Study (CCS) used different numerical codes to model these five experiments with the objective of inferring the hydraulic stimulation mechanism involved. The codes used by the two teams are based on different numerical principles, and the assumptions made were also different, due to intrinsic limitations in the codes and the modelers’more » personal interpretations of the field observations. Both sets of models were able to produce the most important field observations and both found that it was the combination of the vertical gradient of the fracture opening pressure, injection volume, and the use/absence of proppant that yielded the different outcomes of the five experiments.« less

Stream chemistry modeling of two watersheds in the Front Range, Colorado

USGS Publications Warehouse

Meixner, Thomas; Bales, Roger C.; Williams, Mark W.; Campbell, Donald H.; Baron, Jill S.

2000-01-01

We investigated the hydrologic, geochemical, and biogeochemical controls on stream chemical composition on the Green Lakes Valley and Andrews Creek watersheds using the alpine hydrochemical model (AHM). Both sites had comparable data sets from 1994 and 1996, including high‐resolution spatial data and high‐frequency time series of hydrology, geochemistry, and meteorology. The model of each watershed consisted of three terrestrial subunits (soil, talus, and rock), with the routing between the subunits determined by spatial land cover data. Using 1994 data for model calibration and 1996 data for evaluation, AHM captured the dominant processes and successfully simulated daily stream chemical composition on both watersheds. These results confirm our procedure of using spatial and site‐specific field and laboratory data to generate an initial catchment model and then calibrating the model to calculate effective parameters for unmeasured processes. A net source of nitrogen was identified in the Andrews Creek watershed during the spring snowmelt period, whereas nitrogen was immobilized in the Green Lakes Valley. This difference was most likely due to the larger and more dominant area of talus in the Andrews Creek watershed. Our results also indicate that routing of snowmelt through either soil or talus material is sufficient for retention of H+ and release of base cations but that N retention is more important on areas mapped as soil. Owing to the larger ionic pulse and larger fraction of surface runoff the Green Lakes Valley was more sensitive to a doubling of wet deposition chemistry than the Andrews Creek watershed.

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.

Multi-level Simulation of a Real Time Vibration Monitoring System Component

NASA Technical Reports Server (NTRS)

Robertson, Bryan A.; Wilkerson, Delisa

2005-01-01

This paper describes the development of a custom built Digital Signal Processing (DSP) printed circuit board designed to implement the Advanced Real Time Vibration Monitoring Subsystem proposed by Marshall Space Flight Center (MSFC) Transportation Directorate in 2000 for the Space Shuttle Main Engine Advanced Health Management System (AHMS). This Real Time Vibration Monitoring System (RTVMS) is being developed for ground use as part of the AHMS Health Management Computer-Integrated Rack Assembly (HMC-IRA). The HMC-IRA RTVMS design contains five DSPs which are highly interconnected through individual communication ports, shared memory, and a unique communication router that allows all the DSPs to receive digitized data fiom two multi-channel analog boards simultaneously. This paper will briefly cover the overall board design but will focus primarily on the state-of-the-art simulation environment within which this board was developed. This 16-layer board with over 1800 components and an additional mezzanine card has been an extremely challenging design. Utilization of a Mentor Graphics simulation environment provided the unique board and system level simulation capability to ascertain any timing or functional concerns before production. By combining VHDL, Synopsys Software and Hardware Models, and the Mentor Design Capture Environment, multiple simulations were developed to verify the RTVMS design. This multi-level simulation allowed the designers to achieve complete operability without error the first time the RTVMS printed circuit board was powered. The HMC-IRA design has completed all engineering and deliverable unit testing. P

Multi-level Simulation of a Real Time Vibration Monitoring System Component

NASA Technical Reports Server (NTRS)

Roberston, Bryan; Wilkerson, DeLisa

2004-01-01

This paper describes the development of a custom built Digital Signal Processing (DSP) printed circuit board designed to implement the Advanced Real Time Vibration Monitoring Subsystem proposed by MSFC Transportation Directorate in 2000 for the Space Shuttle Main Engine Advanced Health Management System (AHMS). This Real Time Vibration Monitoring System (RTVMS) is being developed for ground use as part of the AHMS Health Management Computer-Integrated Rack Assembly (HMC-IRA). The HMC-IRA RTVMS design contains five DSPs which are highly interconnected through individual communication ports, shared memory, and a unique communication router that allows all the DSPs to receive digitized data from two multi-channel analog boards simultaneously. This paper will briefly cover the overall board design but will focus primarily on the state-of-the-art simulation environment within which this board was developed. This 16-layer board with over 1800 components and an additional mezzanine card has been an extremely challenging design. Utilization of a Mentor Graphics simulation environment provided the unique board and system level simulation capability to ascertain any timing or functional concerns before production. By combining VHDL, Synopsys Software and Hardware Models, and the Mentor Design Capture Environment, multiple simulations were developed to verify the RTVMS design. This multi-level simulation allowed the designers to achieve complete operability without error the first time the RTVMS printed circuit board was powered. The HMCIRA design has completed all engineering unit testing and the deliverable unit is currently under development.

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.

Comparison of GLIMPS and HFAST Stirling engine code predictions with experimental data

NASA Technical Reports Server (NTRS)

Geng, Steven M.; Tew, Roy C.

1992-01-01

Predictions from GLIMPS and HFAST design codes are compared with experimental data for the RE-1000 and SPRE free piston Stirling engines. Engine performance and available power loss predictions are compared. Differences exist between GLIMPS and HFAST loss predictions. Both codes require engine specific calibration to bring predictions and experimental data into agreement.

Validation of the Electromagnetic Code FACETS for Numerical Simulation of Radar Target Images

DTIC Science & Technology

2009-12-01

Validation of the electromagnetic code FACETS for numerical simulation of radar target images S. Wong...Validation of the electromagnetic code FACETS for numerical simulation of radar target images S. Wong DRDC Ottawa...for simulating radar images of a target is obtained, through direct simulation-to-measurement comparisons. A 3-dimensional computer-aided design

Comparative study of the safety and efficacy of the Ahmed glaucoma valve model M4 (high density porous polyethylene) and the model S2 (polypropylene) in patients with neovascular glaucoma.

PubMed

Gil-Carrasco, F; Jiménez-Román, J; Turati-Acosta, M; Bello-López Portillo, H; Isida-Llerandi, C G

2016-09-01

To prospectively evaluate the safety and efficacy of the Ahmed glaucoma valve model M4 (High density porous polyethylene plate; Medpor) compared with the model S2 (polypropylene plate). Mexican patients with neovascular glaucoma were randomly included for each group (M4 and S2). They were operated on using conventional techniques and creating a sub-episcleral tunnel to place the valve tube in the anterior chamber. After one year of follow-up, the results were evaluated with respect to a post-operative reduction in pressure, changes in visual acuity, the need for drugs, and complications, as well as the demographic characteristics of each group. Each operation using the M4 valve was performed by a single surgeon (FGC). Those operated on using the S2 model had their surgery performed by the staff surgeons at the Glaucoma Department of the Mexican Association to Prevent Blindness (APEC). Each group (M4 and S2) contained 21 eyes of 21 Mexican patients with a diagnosis of neovascular glaucoma, leading to a total of 42 patients undergoing surgery. The mean preoperative intraocular pressure (IOP) was 43.5 (±11.8), and 42.24 (±12.84) mmHg for the M4 and S2 groups, respectively. After one year of follow-up, the IOP reported was 18.9 (±9.7) mmHg for the final 18 patients in the M4 group, and 16.38 (±9.76) mmHg for the 21 patients in the S2 group. The design of a drainage valve device such as that of Ahmed has characteristics such as moderate control of IOP, thanks to the valve component in the immediate post-operative period, which makes them safer than other non-valve devices. This avoids an excess of flat chambers and the presence of low IOPs, which can lead to bleeding in the early post-operative period due to the weak desmosomal junctions of the newly formed vessels, with the advantage of maintaining suitable control of IOP from the first day after surgery. Further studies with longer follow-up with a larger number of patients are needed to evaluate the effectiveness of this porous coating in the control of neovascular glaucoma. Copyright © 2016 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

Grid-Adapted FUN3D Computations for the Second High Lift Prediction Workshop

NASA Technical Reports Server (NTRS)

Lee-Rausch, E. M.; Rumsey, C. L.; Park, M. A.

2014-01-01

Contributions of the unstructured Reynolds-averaged Navier-Stokes code FUN3D to the 2nd AIAA CFD High Lift Prediction Workshop are described, and detailed comparisons are made with experimental data. Using workshop-supplied grids, results for the clean wing configuration are compared with results from the structured code CFL3D Using the same turbulence model, both codes compare reasonably well in terms of total forces and moments, and the maximum lift is similarly over-predicted for both codes compared to experiment. By including more representative geometry features such as slat and flap brackets and slat pressure tube bundles, FUN3D captures the general effects of the Reynolds number variation, but under-predicts maximum lift on workshop-supplied grids in comparison with the experimental data, due to excessive separation. However, when output-based, off-body grid adaptation in FUN3D is employed, results improve considerably. In particular, when the geometry includes both brackets and the pressure tube bundles, grid adaptation results in a more accurate prediction of lift near stall in comparison with the wind-tunnel data. Furthermore, a rotation-corrected turbulence model shows improved pressure predictions on the outboard span when using adapted grids.

Predictions of Supersonic Jet Mixing and Shock-Associated Noise Compared With Measured Far-Field Data

NASA Technical Reports Server (NTRS)

Dahl, Milo D.

2010-01-01

Codes for predicting supersonic jet mixing and broadband shock-associated noise were assessed using a database containing noise measurements of a jet issuing from a convergent nozzle. Two types of codes were used to make predictions. Fast running codes containing empirical models were used to compute both the mixing noise component and the shock-associated noise component of the jet noise spectrum. One Reynolds-averaged, Navier-Stokes-based code was used to compute only the shock-associated noise. To enable the comparisons of the predicted component spectra with data, the measured total jet noise spectra were separated into mixing noise and shock-associated noise components. Comparisons were made for 1/3-octave spectra and some power spectral densities using data from jets operating at 24 conditions covering essentially 6 fully expanded Mach numbers with 4 total temperature ratios.

Digital data for quick response (QR) codes of alkalophilic Bacillus pumilus to identify and to compare bacilli isolated from Lonar Crator Lake, India.

PubMed

Rekadwad, Bhagwan N; Khobragade, Chandrahasya N

2016-06-01

Microbiologists are routinely engaged isolation, identification and comparison of isolated bacteria for their novelty. 16S rRNA sequences of Bacillus pumilus were retrieved from NCBI repository and generated QR codes for sequences (FASTA format and full Gene Bank information). 16SrRNA were used to generate quick response (QR) codes of Bacillus pumilus isolated from Lonar Crator Lake (19° 58' N; 76° 31' E), India. Bacillus pumilus 16S rRNA gene sequences were used to generate CGR, FCGR and PCA. These can be used for visual comparison and evaluation respectively. The hyperlinked QR codes, CGR, FCGR and PCA of all the isolates are made available to the users on a portal https://sites.google.com/site/bhagwanrekadwad/. This generated digital data helps to evaluate and compare any Bacillus pumilus strain, minimizes laboratory efforts and avoid misinterpretation of the species.

Potential end-to-end imaging information rate advantages of various alternative communication systems

NASA Technical Reports Server (NTRS)

Rice, R. F.

1978-01-01

Various communication systems were considered which are required to transmit both imaging and a typically error sensitive, class of data called general science/engineering (gse) over a Gaussian channel. The approach jointly treats the imaging and gse transmission problems, allowing comparisons of systems which include various channel coding and data compression alternatives. Actual system comparisons include an Advanced Imaging Communication System (AICS) which exhibits the rather significant potential advantages of sophisticated data compression coupled with powerful yet practical channel coding.

Product code optimization for determinate state LDPC decoding in robust image transmission.

PubMed

Thomos, Nikolaos; Boulgouris, Nikolaos V; Strintzis, Michael G

2006-08-01

We propose a novel scheme for error-resilient image transmission. The proposed scheme employs a product coder consisting of low-density parity check (LDPC) codes and Reed-Solomon codes in order to deal effectively with bit errors. The efficiency of the proposed scheme is based on the exploitation of determinate symbols in Tanner graph decoding of LDPC codes and a novel product code optimization technique based on error estimation. Experimental evaluation demonstrates the superiority of the proposed system in comparison to recent state-of-the-art techniques for image transmission.

Extremely accurate sequential verification of RELAP5-3D

DOE PAGES

Mesina, George L.; Aumiller, David L.; Buschman, Francis X.

2015-11-19

Large computer programs like RELAP5-3D solve complex systems of governing, closure and special process equations to model the underlying physics of nuclear power plants. Further, these programs incorporate many other features for physics, input, output, data management, user-interaction, and post-processing. For software quality assurance, the code must be verified and validated before being released to users. For RELAP5-3D, verification and validation are restricted to nuclear power plant applications. Verification means ensuring that the program is built right by checking that it meets its design specifications, comparing coding to algorithms and equations and comparing calculations against analytical solutions and method ofmore » manufactured solutions. Sequential verification performs these comparisons initially, but thereafter only compares code calculations between consecutive code versions to demonstrate that no unintended changes have been introduced. Recently, an automated, highly accurate sequential verification method has been developed for RELAP5-3D. The method also provides to test that no unintended consequences result from code development in the following code capabilities: repeating a timestep advancement, continuing a run from a restart file, multiple cases in a single code execution, and modes of coupled/uncoupled operation. In conclusion, mathematical analyses of the adequacy of the checks used in the comparisons are provided.« less

Monte Carlo calculation of dose rate conversion factors for external exposure to photon emitters in soil

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

Clovas, A.; Zanthos, S.; Antonopoulos-Domis, M.

2000-03-01

The dose rate conversion factors {dot D}{sub CF} (absorbed dose rate in air per unit activity per unit of soil mass, nGy h{sup {minus}1} per Bq kg{sup {minus}1}) are calculated 1 m above ground for photon emitters of natural radionuclides uniformly distributed in the soil. Three Monte Carlo codes are used: (1) The MCNP code of Los Alamos; (2) The GEANT code of CERN; and (3) a Monte Carlo code developed in the Nuclear Technology Laboratory of the Aristotle University of Thessaloniki. The accuracy of the Monte Carlo results is tested by the comparison of the unscattered flux obtained bymore » the three Monte Carlo codes with an independent straightforward calculation. All codes and particularly the MCNP calculate accurately the absorbed dose rate in air due to the unscattered radiation. For the total radiation (unscattered plus scattered) the {dot D}{sub CF} values calculated from the three codes are in very good agreement between them. The comparison between these results and the results deduced previously by other authors indicates a good agreement (less than 15% of difference) for photon energies above 1,500 keV. Antithetically, the agreement is not as good (difference of 20--30%) for the low energy photons.« less

Validation of OpenFoam for heavy gas dispersion applications.

PubMed

Mack, A; Spruijt, M P N

2013-11-15

In the present paper heavy gas dispersion calculations were performed with OpenFoam. For a wind tunnel test case, numerical data was validated with experiments. For a full scale numerical experiment, a code to code comparison was performed with numerical results obtained from Fluent. The validation was performed in a gravity driven environment (slope), where the heavy gas induced the turbulence. For the code to code comparison, a hypothetical heavy gas release into a strongly turbulent atmospheric boundary layer including terrain effects was selected. The investigations were performed for SF6 and CO2 as heavy gases applying the standard k-ɛ turbulence model. A strong interaction of the heavy gas with the turbulence is present which results in a strong damping of the turbulence and therefore reduced heavy gas mixing. Especially this interaction, based on the buoyancy effects, was studied in order to ensure that the turbulence-buoyancy coupling is the main driver for the reduced mixing and not the global behaviour of the turbulence modelling. For both test cases, comparisons were performed between OpenFoam and Fluent solutions which were mainly in good agreement with each other. Beside steady state solutions, the time accuracy was investigated. In the low turbulence environment (wind tunnel test) which for both codes (laminar solutions) was in good agreement, also with the experimental data. The turbulent solutions of OpenFoam were in much better agreement with the experimental results than the Fluent solutions. Within the strong turbulence environment, both codes showed an excellent comparability. Copyright © 2013 Elsevier B.V. All rights reserved.

"SEN's Completely Different Now": Critical Discourse Analysis of Three "Codes of Practice for Special Educational Needs" (1994, 2001, 2015)

ERIC Educational Resources Information Center

Lehane, Teresa

2017-01-01

Regardless of the differing shades of neo-liberalism, successive governments have claimed to champion the cause of "special educational needs and/or disability" (SEND) through official Codes of Practice in 1994, 2001 and 2015. This analysis and comparison of the three Codes of Practice aims to contribute to the debate by exploring…

The Role of IL-17 in the Angiogenesis of Rheumatoid Arthritis

DTIC Science & Technology

2013-07-01

model of contact dermatitis . Am. J. Pathol. 144: 244–259. 34. Shahrara, S., A. E. Proudfoot, J. M. Woods, J. H. Ruth, M. A. Amin, C. C. Park, C. S. Haas...vascular endothelium: up- regulation in an in vivo model of contact dermatitis . Am J Pathol 1994;144:244–59. 27. Haas CS, Amin MA, Ruth JH, Allen BL, Ahmed...recognizing a novel antigen expressed on aberrant vascular endothelium. Upregulation in an in vivo model of contact dermatitis . Am J Pathol 144:244

Visual Sensitivities and Discriminations and Their Role in Aviation

DTIC Science & Technology

1987-10-30

both x and y, Aimn can be found by using one quarter of the plane. Hence 2P0r far.eco(-keosy) Ahm = i coa nv (coa x + kcoa y)cos mx dx dy since f(z,y...198-201. 142. Neima D, LeBlanc R & Regan D (1984) Visual field defects in ocular hypertension and glaucoma . Arch Ophthalmol 102, 1042-5. 143. Regan D...Neima D (1984) Visual fatigue and VEPs in multiple sclerosis, glaucoma , ocular hypertension and Parkinson’s disease. J Neurol Neurosurg Psychiat 47

Application of Rapid Solidification Techniques to Aluminum Alloys

DTIC Science & Technology

1980-10-01

relatkonship h e 4r eoTs/(T5 TG) (3.7) 32 where e is the surface emissivity, a is the Stefan Boltzmann constant, Ts and TG are the droplet and cooling...their fully implicit form and solved by a Gauss Seidel iteration routine. The results are I I 40I compared with the equivalent Newtonian case and...temperature respectively, Fo is the Fourier number or dimensionless time, Fo = aLt/r2 (5.2) and Ste is the Stefan number, Ste = CL (TM - TG)/AHM (5.3) which

Stratigraphy and Glacial-Marine Sediments of the Amerasian Basin, Central Arctic Ocean.

DTIC Science & Technology

1981-02-01

to light sello~ish-hrown silt v l: t te (unit I. ahme. Scale bar% art- I cn). /19 FL 216- 18 L-i prohaih1 ilects the thickncss pattern of unitI I...so~ 100011 I3 M, 560 2 Figure I S. Thick ness (of unit t in centimetres. All1 fractional % aluesl are Figure 18 . IDistrihoution oif the comhined...estimated date ofl occurrence (hased] on Age of Stratigraphic Units magnetic signature) for (fhe unconforntitv in core H. 2 18 is, (0.29 m. ’ %o

Comparison of Code Predictions to Test Measurements for Two Orifice Compensated Hydrostatic Bearings at High Reynolds Numbers

NASA Technical Reports Server (NTRS)

Keba, John E.

1996-01-01

Rotordynamic coefficients obtained from testing two different hydrostatic bearings are compared to values predicted by two different computer programs. The first set of test data is from a relatively long (L/D=1) orifice compensated hydrostatic bearing tested in water by Texas A&M University (TAMU Bearing No.9). The second bearing is a shorter (L/D=.37) bearing and was tested in a lower viscosity fluid by Rocketdyne Division of Rockwell (Rocketdyne 'Generic' Bearing) at similar rotating speeds and pressures. Computed predictions of bearing rotordynamic coefficients were obtained from the cylindrical seal code 'ICYL', one of the industrial seal codes developed for NASA-LeRC by Mechanical Technology Inc., and from the hydrodynamic bearing code 'HYDROPAD'. The comparison highlights the difference the bearing has on the accuracy of the predictions. The TAMU Bearing No. 9 test data is closely matched by the predictions obtained for the HYDROPAD code (except for added mass terms) whereas significant differences exist between the data from the Rocketdyne 'Generic' bearing the code predictions. The results suggest that some aspects of the fluid behavior in the shorter, higher Reynolds Number 'Generic' bearing may not be modeled accurately in the codes. The ICYL code predictions for flowrate and direct stiffness approximately equal those of HYDROPAD. Significant differences in cross-coupled stiffness and the damping terms were obtained relative to HYDROPAD and both sets of test data. Several observations are included concerning application of the ICYL code.

Parametric study of potential early commercial power plants Task 3-A MHD cost analysis

NASA Technical Reports Server (NTRS)

1983-01-01

The development of costs for an MHD Power Plant and the comparison of these costs to a conventional coal fired power plant are reported. The program is divided into three activities: (1) code of accounts review; (2) MHD pulverized coal power plant cost comparison; (3) operating and maintenance cost estimates. The scope of each NASA code of account item was defined to assure that the recently completed Task 3 capital cost estimates are consistent with the code of account scope. Improvement confidence in MHD plant capital cost estimates by identifying comparability with conventional pulverized coal fired (PCF) power plant systems is undertaken. The basis for estimating the MHD plant operating and maintenance costs of electricity is verified.

Code comparison for accelerator design and analysis

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

Parsa, Z.

1988-01-01

We present a comparison between results obtained from standard accelerator physics codes used for the design and analysis of synchrotrons and storage rings, with programs SYNCH, MAD, HARMON, PATRICIA, PATPET, BETA, DIMAD, MARYLIE and RACE-TRACK. In our analysis we have considered 5 (various size) lattices with large and small angles including AGS Booster (10/degree/ bend), RHIC (2.24/degree/), SXLS, XLS (XUV ring with 45/degree/ bend) and X-RAY rings. The differences in the integration methods used and the treatment of the fringe fields in these codes could lead to different results. The inclusion of nonlinear (e.g., dipole) terms may be necessary inmore » these calculations specially for a small ring. 12 refs., 6 figs., 10 tabs.« less

Comparison of FDNS liquid rocket engine plume computations with SPF/2

NASA Technical Reports Server (NTRS)

Kumar, G. N.; Griffith, D. O., II; Warsi, S. A.; Seaford, C. M.

1993-01-01

Prediction of a plume's shape and structure is essential to the evaluation of base region environments. The JANNAF standard plume flowfield analysis code SPF/2 predicts plumes well, but cannot analyze base regions. Full Navier-Stokes CFD codes can calculate both zones; however, before they can be used, they must be validated. The CFD code FDNS3D (Finite Difference Navier-Stokes Solver) was used to analyze the single plume of a Space Transportation Main Engine (STME) and comparisons were made with SPF/2 computations. Both frozen and finite rate chemistry models were employed as well as two turbulence models in SPF/2. The results indicate that FDNS3D plume computations agree well with SPF/2 predictions for liquid rocket engine plumes.

Development and Verification of Enclosure Radiation Capabilities in the CHarring Ablator Response (CHAR) Code

NASA Technical Reports Server (NTRS)

Salazar, Giovanni; Droba, Justin C.; Oliver, Brandon; Amar, Adam J.

2016-01-01

With the recent development of multi-dimensional thermal protection system (TPS) material response codes, the capability to account for surface-to-surface radiation exchange in complex geometries is critical. This paper presents recent efforts to implement such capabilities in the CHarring Ablator Response (CHAR) code developed at NASA's Johnson Space Center. This work also describes the different numerical methods implemented in the code to compute geometric view factors for radiation problems involving multiple surfaces. Verification of the code's radiation capabilities and results of a code-to-code comparison are presented. Finally, a demonstration case of a two-dimensional ablating cavity with enclosure radiation accounting for a changing geometry is shown.

POPCORN: A comparison of binary population synthesis codes

NASA Astrophysics Data System (ADS)

Claeys, J. S. W.; Toonen, S.; Mennekens, N.

2013-01-01

We compare the results of three binary population synthesis codes to understand the differences in their results. As a first result we find that when equalizing the assumptions the results are similar. The main differences arise from deviating physical input.

Implementation of a Blowing Boundary Condition in the LAURA Code

NASA Technical Reports Server (NTRS)

Thompson, Richard a.; Gnoffo, Peter A.

2008-01-01

Preliminary steps toward modeling a coupled ablation problem using a finite-volume Navier-Stokes code (LAURA) are presented in this paper. Implementation of a surface boundary condition with mass transfer (blowing) is described followed by verification and validation through comparisons with analytic results and experimental data. Application of the code to a carbon-nosetip ablation problem is demonstrated and the results are compared with previously published data. It is concluded that the code and coupled procedure are suitable to support further ablation analyses and studies.

Viewpoint: a comparison of cause-of-injury coding in U.S. military and civilian hospitals.

PubMed

Amoroso, P J; Bell, N S; Smith, G S; Senier, L; Pickett, D

2000-04-01

Complete and accurate coding of injury causes is essential to the understanding of injury etiology and to the development and evaluation of injury-prevention strategies. While civilian hospitals use ICD-9-CM external cause-of-injury codes, military hospitals use codes derived from the NATO Standardization Agreement (STANAG) 2050. The STANAG uses two separate variables to code injury cause. The Trauma code uses a single digit with 10 possible values to identify the general class of injury as battle injury, intentionally inflicted nonbattle injury, or unintentional injury. The Injury code is used to identify cause or activity at the time of the injury. For a subset of the Injury codes, the last digit is modified to indicate place of occurrence. This simple system contains fewer than 300 basic codes, including many that are specific to battle- and sports-related injuries not coded well by either the ICD-9-CM or the draft ICD-10-CM. However, while falls, poisonings, and injuries due to machinery and tools are common causes of injury hospitalizations in the military, few STANAG codes correspond to these events. Intentional injuries in general and sexual assaults in particular are also not well represented in the STANAG. Because the STANAG does not map directly to the ICD-9-CM system, quantitative comparisons between military and civilian data are difficult. The ICD-10-CM, which will be implemented in the United States sometime after 2001, expands considerably on its predecessor, ICD-9-CM, and provides more specificity and detail than the STANAG. With slight modification, it might become a suitable replacement for the STANAG.

EVALUATION OF AN INDIVIDUALLY PACED COURSE FOR AIRBORNE RADIO CODE OPERATORS. FINAL REPORT.

ERIC Educational Resources Information Center

BALDWIN, ROBERT O.; JOHNSON, KIRK A.

IN THIS STUDY COMPARISONS WERE MADE BETWEEN AN INDIVIDUALLY PACED VERSION OF THE AIRBORNE RADIO CODE OPERATOR (ARCO) COURSE AND TWO VERSIONS OF THE COURSE IN WHICH THE STUDENTS PROGRESSED AT A FIXED PACE. THE ARCO COURSE IS A CLASS C SCHOOL IN WHICH THE STUDENT LEARNS TO SEND AND RECEIVE MILITARY MESSAGES USING THE INTERNATIONAL MORSE CODE. THE…

The Contract Management Body of Knowledge: A Comparison of Contracting Competencies

DTIC Science & Technology

2013-12-01

SME subject matter expert SOW statement of work TINA Truth in Negotiations Act UCC uniform commercial code WBS work breakdown structure xv...documents whose terms and condition are legally enforceable. Sources of law and guidance covered include the uniform commercial code ( UCC ), Federal...contracting including the uniform commercial code ( UCC ), Federal Acquisition Regulation (FAR), as well as various other laws pertaining to both

Integrated Modeling of the Battlespace Environment

DTIC Science & Technology

2010-10-01

Office of Counsel.Code 1008.3 ADOR/Director NCST E. R. Franchi , 7000 Public Affairs (Unclassified/ Unlimited Only). Code 7030 4 Division, Code...ESMF: the Hakamada- Akasofu-Fry version 2 (HAFv2) solar wind model and the global assimilation of ionospheric mea- surements (GAIM1) forecast...ground-truth measurements for comparison with the solar wind predictions. Global Assimilation of Ionospheric Measurements The GAIMv2.3 effort

Comparison of a 3-D GPU-Assisted Maxwell Code and Ray Tracing for Reflectometry on ITER

NASA Astrophysics Data System (ADS)

Gady, Sarah; Kubota, Shigeyuki; Johnson, Irena

2015-11-01

Electromagnetic wave propagation and scattering in magnetized plasmas are important diagnostics for high temperature plasmas. 1-D and 2-D full-wave codes are standard tools for measurements of the electron density profile and fluctuations; however, ray tracing results have shown that beam propagation in tokamak plasmas is inherently a 3-D problem. The GPU-Assisted Maxwell Code utilizes the FDTD (Finite-Difference Time-Domain) method for solving the Maxwell equations with the cold plasma approximation in a 3-D geometry. Parallel processing with GPGPU (General-Purpose computing on Graphics Processing Units) is used to accelerate the computation. Previously, we reported on initial comparisons of the code results to 1-D numerical and analytical solutions, where the size of the computational grid was limited by the on-board memory of the GPU. In the current study, this limitation is overcome by using domain decomposition and an additional GPU. As a practical application, this code is used to study the current design of the ITER Low Field Side Reflectometer (LSFR) for the Equatorial Port Plug 11 (EPP11). A detailed examination of Gaussian beam propagation in the ITER edge plasma will be presented, as well as comparisons with ray tracing. This work was made possible by funding from the Department of Energy for the Summer Undergraduate Laboratory Internship (SULI) program. This work is supported by the US DOE Contract No.DE-AC02-09CH11466 and DE-FG02-99-ER54527.

A comparison of IBC with 1997 UBC for modal response spectrum analysis in standard-occupancy buildings

NASA Astrophysics Data System (ADS)

Nahhas, Tariq M.

2011-03-01

This paper presents a comparison of the seismic forces generated from a Modal Response Spectrum Analysis (MRSA) by applying the provisions of two building codes, the 1997 Uniform Building Code (UBC) and the 2000-2009 International Building Code (IBC), to the most common ordinary residential buildings of standard occupancy. Considering IBC as the state of the art benchmark code, the primary concern is the safety of buildings designed using the UBC as compared to those designed using the IBC. A sample of four buildings with different layouts and heights was used for this comparison. Each of these buildings was assumed to be located at four different geographical sample locations arbitrarily selected to represent various earthquake zones on a seismic map of the USA, and was subjected to code-compliant response spectrum analyses for all sample locations and for five different soil types at each location. Response spectrum analysis was performed using the ETABS software package. For all the cases investigated, the UBC was found to be significantly more conservative than the IBC. The UBC design response spectra have higher spectral accelerations, and as a result, the response spectrum analysis provided a much higher base shear and moment in the structural members as compared to the IBC. The conclusion is that ordinary office and residential buildings designed using UBC 1997 are considered to be overdesigned, and therefore they are quite safe even according to the IBC provisions.

A Deterministic Transport Code for Space Environment Electrons

NASA Technical Reports Server (NTRS)

Nealy, John E.; Chang, C. K.; Norman, Ryan B.; Blattnig, Steve R.; Badavi, Francis F.; Adamczyk, Anne M.

2010-01-01

A deterministic computational procedure has been developed to describe transport of space environment electrons in various shield media. This code is an upgrade and extension of an earlier electron code. Whereas the former code was formulated on the basis of parametric functions derived from limited laboratory data, the present code utilizes well established theoretical representations to describe the relevant interactions and transport processes. The shield material specification has been made more general, as have the pertinent cross sections. A combined mean free path and average trajectory approach has been used in the transport formalism. Comparisons with Monte Carlo calculations are presented.

Overview of the H.264/AVC video coding standard

NASA Astrophysics Data System (ADS)

Luthra, Ajay; Topiwala, Pankaj N.

2003-11-01

H.264/MPEG-4 AVC is the latest coding standard jointly developed by the Video Coding Experts Group (VCEG) of ITU-T and Moving Picture Experts Group (MPEG) of ISO/IEC. It uses state of the art coding tools and provides enhanced coding efficiency for a wide range of applications including video telephony, video conferencing, TV, storage (DVD and/or hard disk based), streaming video, digital video creation, digital cinema and others. In this paper an overview of this standard is provided. Some comparisons with the existing standards, MPEG-2 and MPEG-4 Part 2, are also provided.

TRAC posttest calculations of Semiscale Test S-06-3. [PWR

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

Ireland, J.R.; Bleiweis, P.B.

A comparison of Transient Reactor Analysis Code (TRAC) steady-state and transient results with Semiscale Test S-06-3 (US Standard Problem 8) experimental data is discussed. The TRAC model used employs fewer mesh cells than normal data comparison models so that TRAC's ability to obtain reasonable results with less computer time can be assessed. In general, the TRAC results are in good agreement with the data and the major phenomena found in the experiment are reproduced by the code with a substantial reduction in computing times.

Comparisons for ESTA-Task3: ASTEC, CESAM and CLÉS

NASA Astrophysics Data System (ADS)

Christensen-Dalsgaard, J.

The ESTA activity under the CoRoT project aims at testing the tools for computing stellar models and oscillation frequencies that will be used in the analysis of asteroseismic data from CoRoT and other large-scale upcoming asteroseismic projects. Here I report results of comparisons between calculations using the Aarhus code (ASTEC) and two other codes, for models that include diffusion and settling. It is found that there are likely deficiencies, requiring further study, in the ASTEC computation of models including convective cores.

Thermodynamic equilibrium-air correlations for flowfield applications

NASA Technical Reports Server (NTRS)

Zoby, E. V.; Moss, J. N.

1981-01-01

Equilibrium-air thermodynamic correlations have been developed for flowfield calculation procedures. A comparison between the postshock results computed by the correlation equations and detailed chemistry calculations is very good. The thermodynamic correlations are incorporated in an approximate inviscid flowfield code with a convective heating capability for the purpose of defining the thermodynamic environment through the shock layer. Comparisons of heating rates computed by the approximate code and a viscous-shock-layer method are good. In addition to presenting the thermodynamic correlations, the impact of several viscosity models on the convective heat transfer is demonstrated.

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.

The use of irradiated corneal patch grafts in pediatric Ahmed drainage implant surgery.

PubMed

Nolan, Kaitlyn Wallace; Lucas, Jordyn; Abbasian, Javaneh

2015-10-01

To describe the use of irradiated cornea for scleral reinforcement in Ahmed glaucoma valve drainage implant (AGV) devices in children. The medical records of patients <18 years of age who underwent AGV surgery with irradiated cornea as scleral reinforcement were reviewed retrospectively. The primary outcome measure was erosion of the drainage tube through the corneal patch graft. Secondary outcome measures included other major complications: persistent inflammation, wound dehiscence, transmission of infectious disease, endophthalmitis, and tube/plate self-explantation. A total of 25 procedures (20 patients) met inclusion criteria. Average patient age was 70 months (range, 2 months to 17 years). Mean follow-up was 24.8 months (range, 6 months to 6.2 years). One tube experienced conjunctival exposure through two separate corneal grafts (2/25 cases [8%]), sequentially in the same eye. The first event occurred at month 3.5 after primary implantation of the tube shunt; the second erosion occurred following revision of the existing implant at month 1.5 postoperatively. There were 2 cases of auto-explantation, 2 cases of wound dehiscence, and 1 case of persistent inflammation. There were no cases of endophthalmitis or other infections. To our knowledge, this is the first report describing the use of corneal patch grafts in children. Irradiated cornea improves cosmesis and enhances visualization of the tube. The risk of tube exposure was found to be low and comparable to other materials used as a patch graft. Copyright © 2015 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

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.

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.

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.

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.

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.

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.

CFD investigations of the aerodynamics of vehicle overtaking maneuvers

NASA Astrophysics Data System (ADS)

Uddin, Mesbah; Chellaram, Arune Dhiren; Robinson, Austin Clay

2017-06-01

When two vehicle bodies are involved in a passing maneuver, interesting and intricate aerodynamic interactions occur between them. Such passing maneuvers are very important in racing and have been an area of active interest in motorsports for quite some time. The existing literature shows only a few studies in this area, and, as such, very little is known about the complex aerodynamics of racing in proximity. This paper presents a Computational Fluid Dynamics (CFD) methodology capable of describing the transient effects that occur in this scenario. This is achieved by simulating two tandem simplified vehicle bodies, the Ahmed body, which were placed in a virtual wind tunnel. One Ahmed body was kept stationary, while the other was allowed to move in the longitudinal direction with a relatively low velocity. In order to achieve reliable CFD results when one of the solid objects is moving, a new meshing methodology, called the overset mesh model, was implemented in the CFD process. The simulations were run using Star CCM+, a commercial finite-volume CFD program, in which the unsteady Reynolds Averaged Navier-Stokes (URANS) solver was applied. The CFD results are compared against fully transient and quasi-steady-state experimental results where encouraging correlations between the CFD and experiments are observed. The veracity of the CFD work presented in this paper provides significant insight into the complex aerodynamics of a passing maneuver, and lays the foundation for further analysis in this area using more complex vehicle shapes and more complex tandem racing or passing maneuvers at a yaw angle.

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.

Tailored Codes for Small Quantum Memories

NASA Astrophysics Data System (ADS)

Robertson, Alan; Granade, Christopher; Bartlett, Stephen D.; Flammia, Steven T.

2017-12-01

We demonstrate that small quantum memories, realized via quantum error correction in multiqubit devices, can benefit substantially by choosing a quantum code that is tailored to the relevant error model of the system. For a biased noise model, with independent bit and phase flips occurring at different rates, we show that a single code greatly outperforms the well-studied Steane code across the full range of parameters of the noise model, including for unbiased noise. In fact, this tailored code performs almost optimally when compared with 10 000 randomly selected stabilizer codes of comparable experimental complexity. Tailored codes can even outperform the Steane code with realistic experimental noise, and without any increase in the experimental complexity, as we demonstrate by comparison in the observed error model in a recent seven-qubit trapped ion experiment.

Ex-Vessel Core Melt Modeling Comparison between MELTSPREAD-CORQUENCH and MELCOR 2.1

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

Robb, Kevin R.; Farmer, Mitchell; Francis, Matthew W.

System-level code analyses by both United States and international researchers predict major core melting, bottom head failure, and corium-concrete interaction for Fukushima Daiichi Unit 1 (1F1). Although system codes such as MELCOR and MAAP are capable of capturing a wide range of accident phenomena, they currently do not contain detailed models for evaluating some ex-vessel core melt behavior. However, specialized codes containing more detailed modeling are available for melt spreading such as MELTSPREAD as well as long-term molten corium-concrete interaction (MCCI) and debris coolability such as CORQUENCH. In a preceding study, Enhanced Ex-Vessel Analysis for Fukushima Daiichi Unit 1: Meltmore » Spreading and Core-Concrete Interaction Analyses with MELTSPREAD and CORQUENCH, the MELTSPREAD-CORQUENCH codes predicted the 1F1 core melt readily cooled in contrast to predictions by MELCOR. The user community has taken notice and is in the process of updating their systems codes; specifically MAAP and MELCOR, to improve and reduce conservatism in their ex-vessel core melt models. This report investigates why the MELCOR v2.1 code, compared to the MELTSPREAD and CORQUENCH 3.03 codes, yield differing predictions of ex-vessel melt progression. To accomplish this, the differences in the treatment of the ex-vessel melt with respect to melt spreading and long-term coolability are examined. The differences in modeling approaches are summarized, and a comparison of example code predictions is provided.« less

[Coding Causes of Death with IRIS Software. Impact in Navarre Mortality Statistic].

PubMed

Floristán Floristán, Yugo; Delfrade Osinaga, Josu; Carrillo Prieto, Jesus; Aguirre Perez, Jesus; Moreno-Iribas, Conchi

2016-08-02

There are few studies that analyze changes in mortality statistics derived from the use of IRIS software, an automatic system for coding multiple causes of death and for the selection of the underlying cause of death, compared to manual coding. This study evaluated the impact of the use of IRIS in the Navarre mortality statistic. We proceeded to double coding 5,060 death certificates corresponding to residents in Navarra in 2014. We calculated coincidence between the two encodings for ICD10 chapters and for the list of causes of the Spanish National Statistics Institute (INE-102) and we estimated the change on mortality rates. IRIS automatically coded 90% of death certificates. The coincidence to 4 characters and in the same chapter of the CIE10 was 79.1% and 92.0%, respectively. Furthermore, coincidence with the short INE-102 list was 88.3%. Higher matches were found in death certificate of people under 65 years. In comparison with manual coding there was an increase in deaths from endocrine diseases (31%), mental disorders (19%) and disease of nervous system (9%), while a decrease of genitourinary system diseases was observed (21%). The coincidence at level of ICD10 chapters coding by IRIS in comparison to manual coding was 9 out of 10 deaths, similar to what is observed in other studies. The implementation of IRIS has led to increased of endocrine diseases, especially diabetes and hyperlipidaemia, and mental disorders, especially dementias.

Evaluation of Spanwise Variable Impedance Liners with Three-Dimensional Aeroacoustics Propagation Codes

NASA Technical Reports Server (NTRS)

Jones, M. G.; Watson, W. R.; Nark, D. M.; Schiller, N. H.

2017-01-01

Three perforate-over-honeycomb liner configurations, one uniform and two with spanwise variable impedance, are evaluated based on tests conducted in the NASA Grazing Flow Impedance Tube (GFIT) with a plane-wave source. Although the GFIT is only 2" wide, spanwise impedance variability clearly affects the measured acoustic pressure field, such that three-dimensional (3D) propagation codes are required to properly predict this acoustic pressure field. Three 3D propagation codes (CHE3D, COMSOL, and CDL) are used to predict the sound pressure level and phase at eighty-seven microphones flush-mounted in the GFIT (distributed along all four walls). The CHE3D and COMSOL codes compare favorably with the measured data, regardless of whether an exit acoustic pressure or anechoic boundary condition is employed. Except for those frequencies where the attenuation is large, the CDL code also provides acceptable estimates of the measured acoustic pressure profile. The CHE3D and COMSOL predictions diverge slightly from the measured data for frequencies away from resonance, where the attenuation is noticeably reduced, particularly when an exit acoustic pressure boundary condition is used. For these conditions, the CDL code actually provides slightly more favorable comparison with the measured data. Overall, the comparisons of predicted and measured data suggest that any of these codes can be used to understand data trends associated with spanwise variable-impedance liners.

Comparison of Space Shuttle Hot Gas Manifold analysis to air flow data

NASA Technical Reports Server (NTRS)

Mcconnaughey, P. K.

1988-01-01

This paper summarizes several recent analyses of the Space Shuttle Main Engine Hot Gas Manifold and compares predicted flow environments to air flow data. Codes used in these analyses include INS3D, PAGE, PHOENICS, and VAST. Both laminar (Re = 250, M = 0.30) and turbulent (Re = 1.9 million, M = 0.30) results are discussed, with the latter being compared to data for system losses, outer wall static pressures, and manifold exit Mach number profiles. Comparison of predicted results for the turbulent case to air flow data shows that the analysis using INS3D predicted system losses within 1 percent error, while the PHOENICS, PAGE, and VAST codes erred by 31, 35, and 47 percent, respectively. The INS3D, PHOENICS, and PAGE codes did a reasonable job of predicting outer wall static pressure, while the PHOENICS code predicted exit Mach number profiles with acceptable accuracy. INS3D was approximately an order of magnitude more efficient than the other codes in terms of code speed and memory requirements. In general, it is seen that complex internal flows in manifold-like geometries can be predicted with a limited degree of confidence, and further development is necessary to improve both efficiency and accuracy of codes if they are to be used as design tools for complex three-dimensional geometries.

Comparisons of anomalous and collisional radial transport with a continuum kinetic edge code

NASA Astrophysics Data System (ADS)

Bodi, K.; Krasheninnikov, S.; Cohen, R.; Rognlien, T.

2009-05-01

Modeling of anomalous (turbulence-driven) radial transport in controlled-fusion plasmas is necessary for long-time transport simulations. Here the focus is continuum kinetic edge codes such as the (2-D, 2-V) transport version of TEMPEST, NEO, and the code being developed by the Edge Simulation Laboratory, but the model also has wider application. Our previously developed anomalous diagonal transport matrix model with velocity-dependent convection and diffusion coefficients allows contact with typical fluid transport models (e.g., UEDGE). Results are presented that combine the anomalous transport model and collisional transport owing to ion drift orbits utilizing a Krook collision operator that conserves density and energy. Comparison is made of the relative magnitudes and possible synergistic effects of the two processes for typical tokamak device parameters.

Development of new two-dimensional spectral/spatial code based on dynamic cyclic shift code for OCDMA system

NASA Astrophysics Data System (ADS)

Jellali, Nabiha; Najjar, Monia; Ferchichi, Moez; Rezig, Houria

2017-07-01

In this paper, a new two-dimensional spectral/spatial codes family, named two dimensional dynamic cyclic shift codes (2D-DCS) is introduced. The 2D-DCS codes are derived from the dynamic cyclic shift code for the spectral and spatial coding. The proposed system can fully eliminate the multiple access interference (MAI) by using the MAI cancellation property. The effect of shot noise, phase-induced intensity noise and thermal noise are used to analyze the code performance. In comparison with existing two dimensional (2D) codes, such as 2D perfect difference (2D-PD), 2D Extended Enhanced Double Weight (2D-Extended-EDW) and 2D hybrid (2D-FCC/MDW) codes, the numerical results show that our proposed codes have the best performance. By keeping the same code length and increasing the spatial code, the performance of our 2D-DCS system is enhanced: it provides higher data rates while using lower transmitted power and a smaller spectral width.

A Comprehensive High Performance Predictive Tool for Fusion Liquid Metal Hydromagnetics

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

Huang, Peter; Chhabra, Rupanshi; Munipalli, Ramakanth

In Phase I SBIR project, HyPerComp and Texcel initiated the development of two induction-based MHD codes as a predictive tool for fusion hydro-magnetics. The newly-developed codes overcome the deficiency of other MHD codes based on the quasi static approximation by defining a more general mathematical model that utilizes the induced magnetic field rather than the electric potential as the main electromagnetic variable. The UCLA code is a finite-difference staggered-mesh code that serves as a supplementary tool to the massively-parallel finite-volume code developed by HyPerComp. As there is no suitable experimental data under blanket-relevant conditions for code validation, code-to-code comparisons andmore » comparisons against analytical solutions were successfully performed for three selected test cases: (1) lid-driven MHD flow, (2) flow in a rectangular duct in a transverse magnetic field, and (3) unsteady finite magnetic Reynolds number flow in a rectangular enclosure. The performed tests suggest that the developed codes are accurate and robust. Further work will focus on enhancing the code capabilities towards higher flow parameters and faster computations. At the conclusion of the current Phase-II Project we have completed the preliminary validation efforts in performing unsteady mixed-convection MHD flows (against limited data that is currently available in literature), and demonstrated flow behavior in large 3D channels including important geometrical features. Code enhancements such as periodic boundary conditions, unmatched mesh structures are also ready. As proposed, we have built upon these strengths and explored a much increased range of Grashof numbers and Hartmann numbers under various flow conditions, ranging from flows in a rectangular duct to prototypic blanket modules and liquid metal PFC. Parametric studies, numerical and physical model improvements to expand the scope of simulations, code demonstration, and continued validation activities have also been completed.« less

Dual Coding and Bilingual Memory.

ERIC Educational Resources Information Center

Paivio, Allan; Lambert, Wallace

1981-01-01

Describes study which tested a dual coding approach to bilingual memory using tasks that permit comparison of the effects of bilingual encoding with verbal-nonverbal dual encoding items. Results provide strong support for a version of the independent or separate stories view of bilingual memory. (Author/BK)

Capabilities of LEWICE 1.6 and Comparison With Experimental Data

DOT National Transportation Integrated Search

1996-01-01

A research project is underway at NASA Lewis to produce a computer code which can accurately predict ice growth under any meteorological conditions for any aircraft surface. The most recent release of this code is LEWICE 1.6. This paper will demonstr...

Further Validation of a CFD Code for Calculating the Performance of Two-Stage Light Gas Guns

NASA Technical Reports Server (NTRS)

Bogdanoff, David W.

2017-01-01

Earlier validations of a higher-order Godunov code for modeling the performance of two-stage light gas guns are reviewed. These validation comparisons were made between code predictions and experimental data from the NASA Ames 1.5" and 0.28" guns and covered muzzle velocities of 6.5 to 7.2 km/s. In the present report, five more series of code validation comparisons involving experimental data from the Ames 0.22" (1.28" pump tube diameter), 0.28", 0.50", 1.00" and 1.50" guns are presented. The total muzzle velocity range of the validation data presented herein is 3 to 11.3 km/s. The agreement between the experimental data and CFD results is judged to be very good. Muzzle velocities were predicted within 0.35 km/s for 74% of the cases studied with maximum differences being 0.5 km/s and for 4 out of 50 cases, 0.5 - 0.7 km/s.

Digital data for quick response (QR) codes of alkalophilic Bacillus pumilus to identify and to compare bacilli isolated from Lonar Crator Lake, India

PubMed Central

Rekadwad, Bhagwan N.; Khobragade, Chandrahasya N.

2016-01-01

Microbiologists are routinely engaged isolation, identification and comparison of isolated bacteria for their novelty. 16S rRNA sequences of Bacillus pumilus were retrieved from NCBI repository and generated QR codes for sequences (FASTA format and full Gene Bank information). 16SrRNA were used to generate quick response (QR) codes of Bacillus pumilus isolated from Lonar Crator Lake (19° 58′ N; 76° 31′ E), India. Bacillus pumilus 16S rRNA gene sequences were used to generate CGR, FCGR and PCA. These can be used for visual comparison and evaluation respectively. The hyperlinked QR codes, CGR, FCGR and PCA of all the isolates are made available to the users on a portal https://sites.google.com/site/bhagwanrekadwad/. This generated digital data helps to evaluate and compare any Bacillus pumilus strain, minimizes laboratory efforts and avoid misinterpretation of the species. PMID:27141529

Decoding a Decision Process in the Neuronal Population of Dorsal Premotor Cortex.

PubMed

Rossi-Pool, Román; Zainos, Antonio; Alvarez, Manuel; Zizumbo, Jerónimo; Vergara, José; Romo, Ranulfo

2017-12-20

When trained monkeys discriminate the temporal structure of two sequential vibrotactile stimuli, dorsal premotor cortex (DPC) showed high heterogeneity among its neuronal responses. Notably, DPC neurons coded stimulus patterns as broader categories and signaled them during working memory, comparison, and postponed decision periods. Here, we show that such population activity can be condensed into two major coding components: one that persistently represented in working memory both the first stimulus identity and the postponed informed choice and another that transiently coded the initial sensory information and the result of the comparison between the two stimuli. Additionally, we identified relevant signals that coded the timing of task events. These temporal and task-parameter readouts were shown to be strongly linked to the monkeys' behavior when contrasted to those obtained in a non-demanding cognitive control task and during error trials. These signals, hidden in the heterogeneity, were prominently represented by the DPC population response. Copyright © 2017 Elsevier Inc. All rights reserved.

A dynamic wall model for Large-Eddy simulations of wind turbine dedicated airfoils

NASA Astrophysics Data System (ADS)

J, Calafell; O, Lehmkuhl; A, Carmona; D, Pérez-Segarra C.; A, Oliva

2014-06-01

This work aims at modelling the flow behavior past a wind turbine dedicated airfoil at high Reynolds number and large angle of attack (AoA). The DU-93-W-210 airfoil has been selected. To do this, Large Eddy Simulations (LES) have been performed. Momentum equations have been solved with a parallel unstructured symmetry preserving formulation while the wall-adapting local-eddy viscosity model within a variational multi-scale framework (VMS- WALE) is used as the subgrid-scales model. Since LES calculations are still very expensive at high Reynolds Number, specially at the near-wall region, a dynamic wall model has been implemented in order to overcome this limitation. The model has been validated with a very unresolved Channel Flow case at Reτ = 2000. Afterwards, the model is also tested with the Ahmed Car case, that from the flow physics point of view is more similar to an stalled airfoil than the Channel Flow is, including flow features as boundary layer detachment and recirculations. This case has been selected because experimental results of mean velocity profiles are available. Finally, a flow around a DU-93-W-210 airfoil is computed at Re = 3 x 106 and with an AoA of 15°. Numerical results are presented in comparison with Direct Numerical Simulation (DNS) or experimental data for all cases.

Accuracy of the new ICD-9-CM code for "drip-and-ship" thrombolytic treatment in patients with ischemic stroke.

PubMed

Tonarelli, Silvina B; Tibbs, Michael; Vazquez, Gabriela; Lakshminarayan, Kamakshi; Rodriguez, Gustavo J; Qureshi, Adnan I

2012-02-01

A new International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis code, V45.88, was approved by the Centers for Medicare and Medicaid Services (CMS) on October 1, 2008. This code identifies patients in whom intravenous (IV) recombinant tissue plasminogen activator (rt-PA) is initiated in one hospital's emergency department, followed by transfer within 24 hours to a comprehensive stroke center, a paradigm commonly referred to as "drip-and-ship." This study assessed the use and accuracy of the new V45.88 code for identifying ischemic stroke patients who meet the criteria for drip-and-ship at 2 advanced certified primary stroke centers. Consecutive patients over a 12-month period were identified by primary ICD-9-CM diagnosis codes related to ischemic stroke. The accuracy of V45.88 code utilization using administrative data provided by Health Information Management Services was assessed through a comparison with data collected in prospective stroke registries maintained at each hospital by a trained abstractor. Out of a total of 428 patients discharged from both hospitals with a diagnosis of ischemic stroke, 37 patients were given ICD-9-CM code V45.88. The internally validated data from the prospective stroke database demonstrated that a total of 40 patients met the criteria for drip-and-ship. A concurrent comparison found that 92% (sensitivity) of the patients treated with drip-and-ship were coded with V45.88. None of the non-drip-and-ship stroke cases received the V45.88 code (100% specificity). The new ICD-9-CM code for drip-and-ship appears to have high specificity and sensitivity, allowing effective data collection by the CMS. Copyright © 2012 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Performance Comparison of Orthogonal and Quasi-orthogonal Codes in Quasi-Synchronous Cellular CDMA Communication

NASA Astrophysics Data System (ADS)

Jos, Sujit; Kumar, Preetam; Chakrabarti, Saswat

Orthogonal and quasi-orthogonal codes are integral part of any DS-CDMA based cellular systems. Orthogonal codes are ideal for use in perfectly synchronous scenario like downlink cellular communication. Quasi-orthogonal codes are preferred over orthogonal codes in the uplink communication where perfect synchronization cannot be achieved. In this paper, we attempt to compare orthogonal and quasi-orthogonal codes in presence of timing synchronization error. This will give insight into the synchronization demands in DS-CDMA systems employing the two classes of sequences. The synchronization error considered is smaller than chip duration. Monte-Carlo simulations have been carried out to verify the analytical and numerical results.

Revisiting Yasinsky and Henry`s benchmark using modern nodal codes

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

Feltus, M.A.; Becker, M.W.

1995-12-31

The numerical experiments analyzed by Yasinsky and Henry are quite trivial by comparison with today`s standards because they used the finite difference code WIGLE for their benchmark. Also, this problem is a simple slab (one-dimensional) case with no feedback mechanisms. This research attempts to obtain STAR (Ref. 2) and NEM (Ref. 3) code results in order to produce a more modern kinetics benchmark with results comparable WIGLE.

EMPIRE: A code for nuclear astrophysics

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

Palumbo, A.

The nuclear reaction code EMPIRE is presented as a useful tool for nuclear astrophysics. EMPIRE combines a variety of the reaction models with a comprehensive library of input parameters providing a diversity of options for the user. With exclusion of the directsemidirect capture all reaction mechanisms relevant to the nuclear astrophysics energy range of interest are implemented in the code. Comparison to experimental data show consistent agreement for all relevant channels.

COCOA code for creating mock observations of star cluster models

NASA Astrophysics Data System (ADS)

Askar, Abbas; Giersz, Mirek; Pych, Wojciech; Dalessandro, Emanuele

2018-04-01

We introduce and present results from the COCOA (Cluster simulatiOn Comparison with ObservAtions) code that has been developed to create idealized mock photometric observations using results from numerical simulations of star cluster evolution. COCOA is able to present the output of realistic numerical simulations of star clusters carried out using Monte Carlo or N-body codes in a way that is useful for direct comparison with photometric observations. In this paper, we describe the COCOA code and demonstrate its different applications by utilizing globular cluster (GC) models simulated with the MOCCA (MOnte Carlo Cluster simulAtor) code. COCOA is used to synthetically observe these different GC models with optical telescopes, perform point spread function photometry, and subsequently produce observed colour-magnitude diagrams. We also use COCOA to compare the results from synthetic observations of a cluster model that has the same age and metallicity as the Galactic GC NGC 2808 with observations of the same cluster carried out with a 2.2 m optical telescope. We find that COCOA can effectively simulate realistic observations and recover photometric data. COCOA has numerous scientific applications that maybe be helpful for both theoreticians and observers that work on star clusters. Plans for further improving and developing the code are also discussed in this paper.

SU-F-BRD-02: Application of ARCHERRT-- A GPU-Based Monte Carlo Dose Engine for Radiation Therapy -- to Tomotherapy and Patient-Independent IMRT

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

Su, L; Du, X; Liu, T

Purpose: As a module of ARCHER -- Accelerated Radiation-transport Computations in Heterogeneous EnviRonments, ARCHER{sub RT} is designed for RadioTherapy (RT) dose calculation. This paper describes the application of ARCHERRT on patient-dependent TomoTherapy and patient-independent IMRT. It also conducts a 'fair' comparison of different GPUs and multicore CPU. Methods: The source input used for patient-dependent TomoTherapy is phase space file (PSF) generated from optimized plan. For patient-independent IMRT, the open filed PSF is used for different cases. The intensity modulation is simulated by fluence map. The GEANT4 code is used as benchmark. DVH and gamma index test are employed to evaluatemore » the accuracy of ARCHER{sub RT} code. Some previous studies reported misleading speedups by comparing GPU code with serial CPU code. To perform a fairer comparison, we write multi-thread code with OpenMP to fully exploit computing potential of CPU. The hardware involved in this study are a 6-core Intel E5-2620 CPU and 6 NVIDIA M2090 GPUs, a K20 GPU and a K40 GPU. Results: Dosimetric results from ARCHER{sub RT} and GEANT4 show good agreement. The 2%/2mm gamma test pass rates for different clinical cases are 97.2% to 99.7%. A single M2090 GPU needs 50~79 seconds for the simulation to achieve a statistical error of 1% in the PTV. The K40 card is about 1.7∼1.8 times faster than M2090 card. Using 6 M2090 card, the simulation can be finished in about 10 seconds. For comparison, Intel E5-2620 needs 507∼879 seconds for the same simulation. Conclusion: We successfully applied ARCHER{sub RT} to Tomotherapy and patient-independent IMRT, and conducted a fair comparison between GPU and CPU performance. The ARCHER{sub RT} code is both accurate and efficient and may be used towards clinical applications.« less

Validation and Performance Comparison of Numerical Codes for Tsunami Inundation

NASA Astrophysics Data System (ADS)

Velioglu, D.; Kian, R.; Yalciner, A. C.; Zaytsev, A.

2015-12-01

In inundation zones, tsunami motion turns from wave motion to flow of water. Modelling of this phenomenon is a complex problem since there are many parameters affecting the tsunami flow. In this respect, the performance of numerical codes that analyze tsunami inundation patterns becomes important. The computation of water surface elevation is not sufficient for proper analysis of tsunami behaviour in shallow water zones and on land and hence for the development of mitigation strategies. Velocity and velocity patterns are also crucial parameters and have to be computed at the highest accuracy. There are numerous numerical codes to be used for simulating tsunami inundation. In this study, FLOW 3D and NAMI DANCE codes are selected for validation and performance comparison. Flow 3D simulates linear and nonlinear propagating surface waves as well as long waves by solving three-dimensional Navier-Stokes (3D-NS) equations. FLOW 3D is used specificaly for flood problems. NAMI DANCE uses finite difference computational method to solve linear and nonlinear forms of shallow water equations (NSWE) in long wave problems, specifically tsunamis. In this study, these codes are validated and their performances are compared using two benchmark problems which are discussed in 2015 National Tsunami Hazard Mitigation Program (NTHMP) Annual meeting in Portland, USA. One of the problems is an experiment of a single long-period wave propagating up a piecewise linear slope and onto a small-scale model of the town of Seaside, Oregon. Other benchmark problem is an experiment of a single solitary wave propagating up a triangular shaped shelf with an island feature located at the offshore point of the shelf. The computed water surface elevation and velocity data are compared with the measured data. The comparisons showed that both codes are in fairly good agreement with each other and benchmark data. All results are presented with discussions and comparisons. The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement No 603839 (Project ASTARTE - Assessment, Strategy and Risk Reduction for Tsunamis in Europe)

Posttest calculation of the PBF LOC-11B and LOC-11C experiments using RELAP4/MOD6. [PWR

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

Hendrix, C.E.

Comparisons between RELAP4/MOD6, Update 4 code-calculated and measured experimental data are presented for the PBF LOC-11C and LOC-11B experiments. Independent code verification techniques are now being developed and this study represents a preliminary effort applying structured criteria for developing computer models, selecting code input, and performing base-run analyses. Where deficiencies are indicated in the base-case representation of the experiment, methods of code and criteria improvement are developed and appropriate recommendations are made.

Magnetohydrodynamic modelling of exploding foil initiators

NASA Astrophysics Data System (ADS)

Neal, William

2015-06-01

Magnetohydrodynamic (MHD) codes are currently being developed, and used, to predict the behaviour of electrically-driven flyer-plates. These codes are of particular interest to the design of exploding foil initiator (EFI) detonators but there is a distinct lack of comparison with high-fidelity experimental data. This study aims to compare a MHD code with a collection of temporally and spatially resolved diagnostics including PDV, dual-axis imaging and streak imaging. The results show the code's excellent representation of the flyer-plate launch and highlight features within the experiment that the model fails to capture.

Multi-D Full Boltzmann Neutrino Hydrodynamic Simulations in Core Collapse Supernovae and their detailed comparison with Monte Carlo method

NASA Astrophysics Data System (ADS)

Nagakura, Hiroki; Richers, Sherwood; Ott, Christian; Iwakami, Wakana; Furusawa, Shun; Sumiyoshi, Kohsuke; Yamada, Shoichi

2017-01-01

We have developed a multi-d radiation-hydrodynamic code which solves first-principles Boltzmann equation for neutrino transport. It is currently applicable specifically for core-collapse supernovae (CCSNe), but we will extend their applicability to further extreme phenomena such as black hole formation and coalescence of double neutron stars. In this meeting, I will discuss about two things; (1) detailed comparison with a Monte-Carlo neutrino transport (2) axisymmetric CCSNe simulations. The project (1) gives us confidence of our code. The Monte-Carlo code has been developed by Caltech group and it is specialized to obtain a steady state. Among CCSNe community, this is the first attempt to compare two different methods for multi-d neutrino transport. I will show the result of these comparison. For the project (2), I particularly focus on the property of neutrino distribution function in the semi-transparent region where only first-principle Boltzmann solver can appropriately handle the neutrino transport. In addition to these analyses, I will also discuss the ``explodability'' by neutrino heating mechanism.

A Comparative Study on Seismic Analysis of Bangladesh National Building Code (BNBC) with Other Building Codes

NASA Astrophysics Data System (ADS)

Bari, Md. S.; Das, T.

2013-09-01

Tectonic framework of Bangladesh and adjoining areas indicate that Bangladesh lies well within an active seismic zone. The after effect of earthquake is more severe in an underdeveloped and a densely populated country like ours than any other developed countries. Bangladesh National Building Code (BNBC) was first established in 1993 to provide guidelines for design and construction of new structure subject to earthquake ground motions in order to minimize the risk to life for all structures. A revision of BNBC 1993 is undergoing to make this up to date with other international building codes. This paper aims at the comparison of various provisions of seismic analysis as given in building codes of different countries. This comparison will give an idea regarding where our country stands when it comes to safety against earth quake. Primarily, various seismic parameters in BNBC 2010 (draft) have been studied and compared with that of BNBC 1993. Later, both 1993 and 2010 edition of BNBC codes have been compared graphically with building codes of other countries such as National Building Code of India 2005 (NBC-India 2005), American Society of Civil Engineering 7-05 (ASCE 7-05). The base shear/weight ratios have been plotted against the height of the building. The investigation in this paper reveals that BNBC 1993 has the least base shear among all the codes. Factored Base shear values of BNBC 2010 are found to have increased significantly than that of BNBC 1993 for low rise buildings (≤20 m) around the country than its predecessor. Despite revision of the code, BNBC 2010 (draft) still suggests less base shear values when compared to the Indian and American code. Therefore, this increase in factor of safety against the earthquake imposed by the proposed BNBC 2010 code by suggesting higher values of base shear is appreciable.

Relative efficiency and accuracy of two Navier-Stokes codes for simulating attached transonic flow over wings

NASA Technical Reports Server (NTRS)

Bonhaus, Daryl L.; Wornom, Stephen F.

1991-01-01

Two codes which solve the 3-D Thin Layer Navier-Stokes (TLNS) equations are used to compute the steady state flow for two test cases representing typical finite wings at transonic conditions. Several grids of C-O topology and varying point densities are used to determine the effects of grid refinement. After a description of each code and test case, standards for determining code efficiency and accuracy are defined and applied to determine the relative performance of the two codes in predicting turbulent transonic wing flows. Comparisons of computed surface pressure distributions with experimental data are made.

P-Code-Enhanced Encryption-Mode Processing of GPS Signals

NASA Technical Reports Server (NTRS)

Young, Lawrence; Meehan, Thomas; Thomas, Jess B.

2003-01-01

A method of processing signals in a Global Positioning System (GPS) receiver has been invented to enable the receiver to recover some of the information that is otherwise lost when GPS signals are encrypted at the transmitters. The need for this method arises because, at the option of the military, precision GPS code (P-code) is sometimes encrypted by a secret binary code, denoted the A code. Authorized users can recover the full signal with knowledge of the A-code. However, even in the absence of knowledge of the A-code, one can track the encrypted signal by use of an estimate of the A-code. The present invention is a method of making and using such an estimate. In comparison with prior such methods, this method makes it possible to recover more of the lost information and obtain greater accuracy.

Comparison of theoretical and flight-measured local flow aerodynamics for a low-aspect-ratio fin

NASA Technical Reports Server (NTRS)

Johnson, J. B.; Sandlin, D. R.

1984-01-01

Flight test and theoretical aerodynamic data were obtained for a flight test fixture mounted on the underside of an F-104G aircraft. The theoretical data were generated using two codes, a two dimensional transonic code called Code H, and a three dimensional subsonic and supersonic code call wing-body. Pressure distributions generated by the codes for the flight test fixture as well as boundary layer displacement thickness generated by the two dimensional code were compared to the flight test data. The two dimensional code pressure distributions compared well except at the minimum pressure point and trailing edge. Shock locations compared well except at high transonic speeds. The three dimensional code pressure distributions compared well except at the trailing edge of the flight test fixture. The two dimensional code does not predict displacement thickness of the flight test fixture well.

Performance Analysis of New Binary User Codes for DS-CDMA Communication

NASA Astrophysics Data System (ADS)

Usha, Kamle; Jaya Sankar, Kottareddygari

2016-03-01

This paper analyzes new binary spreading codes through correlation properties and also presents their performance over additive white Gaussian noise (AWGN) channel. The proposed codes are constructed using gray and inverse gray codes. In this paper, a n-bit gray code appended by its n-bit inverse gray code to construct the 2n-length binary user codes are discussed. Like Walsh codes, these binary user codes are available in sizes of power of two and additionally code sets of length 6 and their even multiples are also available. The simple construction technique and generation of code sets of different sizes are the salient features of the proposed codes. Walsh codes and gold codes are considered for comparison in this paper as these are popularly used for synchronous and asynchronous multi user communications respectively. In the current work the auto and cross correlation properties of the proposed codes are compared with those of Walsh codes and gold codes. Performance of the proposed binary user codes for both synchronous and asynchronous direct sequence CDMA communication over AWGN channel is also discussed in this paper. The proposed binary user codes are found to be suitable for both synchronous and asynchronous DS-CDMA communication.

A comparative study of space radiation organ doses and associated cancer risks using PHITS and HZETRN.

PubMed

Bahadori, Amir A; Sato, Tatsuhiko; Slaba, Tony C; Shavers, Mark R; Semones, Edward J; Van Baalen, Mary; Bolch, Wesley E

2013-10-21

NASA currently uses one-dimensional deterministic transport to generate values of the organ dose equivalent needed to calculate stochastic radiation risk following crew space exposures. In this study, organ absorbed doses and dose equivalents are calculated for 50th percentile male and female astronaut phantoms using both the NASA High Charge and Energy Transport Code to perform one-dimensional deterministic transport and the Particle and Heavy Ion Transport Code System to perform three-dimensional Monte Carlo transport. Two measures of radiation risk, effective dose and risk of exposure-induced death (REID) are calculated using the organ dose equivalents resulting from the two methods of radiation transport. For the space radiation environments and simplified shielding configurations considered, small differences (<8%) in the effective dose and REID are found. However, for the galactic cosmic ray (GCR) boundary condition, compensating errors are observed, indicating that comparisons between the integral measurements of complex radiation environments and code calculations can be misleading. Code-to-code benchmarks allow for the comparison of differential quantities, such as secondary particle differential fluence, to provide insight into differences observed in integral quantities for particular components of the GCR spectrum.

A comparative study of space radiation organ doses and associated cancer risks using PHITS and HZETRN

NASA Astrophysics Data System (ADS)

Bahadori, Amir A.; Sato, Tatsuhiko; Slaba, Tony C.; Shavers, Mark R.; Semones, Edward J.; Van Baalen, Mary; Bolch, Wesley E.

2013-10-01

NASA currently uses one-dimensional deterministic transport to generate values of the organ dose equivalent needed to calculate stochastic radiation risk following crew space exposures. In this study, organ absorbed doses and dose equivalents are calculated for 50th percentile male and female astronaut phantoms using both the NASA High Charge and Energy Transport Code to perform one-dimensional deterministic transport and the Particle and Heavy Ion Transport Code System to perform three-dimensional Monte Carlo transport. Two measures of radiation risk, effective dose and risk of exposure-induced death (REID) are calculated using the organ dose equivalents resulting from the two methods of radiation transport. For the space radiation environments and simplified shielding configurations considered, small differences (<8%) in the effective dose and REID are found. However, for the galactic cosmic ray (GCR) boundary condition, compensating errors are observed, indicating that comparisons between the integral measurements of complex radiation environments and code calculations can be misleading. Code-to-code benchmarks allow for the comparison of differential quantities, such as secondary particle differential fluence, to provide insight into differences observed in integral quantities for particular components of the GCR spectrum.

The Scylla Multi-Code Comparison Project

NASA Astrophysics Data System (ADS)

Maller, Ariyeh; Stewart, Kyle; Bullock, James; Oñorbe, Jose; Scylla Team

2016-01-01

Cosmological hydrodynamical simulations are one of the main techniques used to understand galaxy formation and evolution. However, it is far from clear to what extent different numerical techniques and different implementations of feedback yield different results. The Scylla Multi-Code Comparison Project seeks to address this issue by running idenitical initial condition simulations with different popular hydrodynamic galaxy formation codes. Here we compare simulations of a Milky Way mass halo using the codes enzo, ramses, art, arepo and gizmo-psph. The different runs produce galaxies with a variety of properties. There are many differences, but also many similarities. For example we find that in all runs cold flow disks exist; extended gas structures, far beyond the galactic disk, that show signs of rotation. Also, the angular momentum of warm gas in the halo is much larger than the angular momentum of the dark matter. We also find notable differences between runs. The temperature and density distribution of hot gas can differ by over an order of magnitude between codes and the stellar mass to halo mass relation also varies widely. These results suggest that observations of galaxy gas halos and the stellar mass to halo mass relation can be used to constarin the correct model of feedback.

A project based on multi-configuration Dirac-Fock calculations for plasma spectroscopy

NASA Astrophysics Data System (ADS)

Comet, M.; Pain, J.-C.; Gilleron, F.; Piron, R.

2017-09-01

We present a project dedicated to hot plasma spectroscopy based on a Multi-Configuration Dirac-Fock (MCDF) code, initially developed by J. Bruneau. The code is briefly described and the use of the transition state method for plasma spectroscopy is detailed. Then an opacity code for local-thermodynamic-equilibrium plasmas using MCDF data, named OPAMCDF, is presented. Transition arrays for which the number of lines is too large to be handled in a Detailed Line Accounting (DLA) calculation can be modeled within the Partially Resolved Transition Array method or using the Unresolved Transition Arrays formalism in jj-coupling. An improvement of the original Partially Resolved Transition Array method is presented which gives a better agreement with DLA computations. Comparisons with some absorption and emission experimental spectra are shown. Finally, the capability of the MCDF code to compute atomic data required for collisional-radiative modeling of plasma at non local thermodynamic equilibrium is illustrated. In addition to photoexcitation, this code can be used to calculate photoionization, electron impact excitation and ionization cross-sections as well as autoionization rates in the Distorted-Wave or Close Coupling approximations. Comparisons with cross-sections and rates available in the literature are discussed.

Actuated Hybrid Mirrors for Space Telescopes

NASA Technical Reports Server (NTRS)

Hickey, Gregory; Ealey, Mark; Redding, David

2010-01-01

This paper describes new, large, ultra-lightweight, replicated, actively controlled mirrors, for use in space telescopes. These mirrors utilize SiC substrates, with embedded solid-state actuators, bonded to Nanolaminate metal foil reflective surfaces. Called Actuated Hybrid Mirrors (AHMs), they use replication techniques for high optical quality as well as rapid, low cost manufacturing. They enable an Active Optics space telescope architecture that uses periodic image-based wavefront sensing and control to assure diffraction-limited performance, while relaxing optical system fabrication, integration and test requirements. The proposed International Space Station Observatory seeks to demonstrate this architecture in space.

Role of Cyclin E as an Early Event in Ovarian Carcinogenesis

DTIC Science & Technology

2012-04-01

degradation . P27 is a powerful negative regulator of the cell cycle, preventing activation of cyclin E- cdk2 or cyclin D-cdk4 complexes and cell cycle...Ahmed M, Bavi P, et al. Bortezomib (Velcade) induces p27Kip1 expression through S-phase kinase protein 2 degradation in colorectal cancer. Cancer Res...CA1251CA72·4 CA 125 CA72-4 M-CSF CA 125/CA 72-4/M-CSFICA 15-3 CA125 CA 125/mesothelin CA 125/IL·6JIL·8NEGF;EGF CA 125/IL-6,G-CSFNEGF/EGF Leptin

Modelling of charged satellite motion in Earth's gravitational and magnetic fields

NASA Astrophysics Data System (ADS)

Abd El-Bar, S. E.; Abd El-Salam, F. A.

2018-05-01

In this work Lagrange's planetary equations for a charged satellite subjected to the Earth's gravitational and magnetic force fields are solved. The Earth's gravity, and magnetic and electric force components are obtained and expressed in terms of orbital elements. The variational equations of orbit with the considered model in Keplerian elements are derived. The solution of the problem in a fully analytical way is obtained. The temporal rate of changes of the orbital elements of the spacecraft are integrated via Lagrange's planetary equations and integrals of the normalized Keplerian motion obtained by Ahmed (Astron. J. 107(5):1900, 1994).

Initial clinical experience of tube-shunt surgery in Ethiopian patients with refractory glaucoma.

PubMed

T/Giorgis, Abeba

2012-04-01

In Ethiopia, it is not uncommon to encounter refractory glaucoma cases that could be managed with tube-shunt surgery. Tube-shunt implant surgery has been a standard procedure option and widely used for various forms of refractory glaucoma. To described the initial experience and outcome of Ahmed Tube shunt implant for refractory adult Ethiopian glaucoma cases. Retrospective review of consecutive adult patients with refractory glaucoma who underwent Ahmed glaucoma valve implant at the Department of ophthalmology, Menelik II Hospital, Addis Ababa between April 2009 and December 2010. intraocular pressure (IOP), visual acuity, use of supplemental medical therapy and surgical complications. Success was defined as IOP greater than 5 and less than 22 mmHg with at least 30% reduction in IOP from preoperative levels with and without supplemental glaucoma medications, no additional surgeries to lower the IOP and without visual loss of light perception from devastating postoperative complications. Thirteen eyes of 12 patients (10 men, 2 women; mean age 52.4 +/- 15. 7) who underwent glaucoma tube-shunt drainage surgery with Ahmed-tube valve were included in this analysis. The mean preoperative IOP was 31.38 +/- 8.67 mmHg with 2.23 +/- 0.44 antiglaucoma medications. Postoperatively, the mean IOP reduced to 15.52 +/- 8.80 mmHg at 1 week, 14.77 +/- 6.39 mmHg at 1 month, 16.62 +/- 4.48 mmHg at 3 months, and 17.15 +/- 3.87 mmHg at 6 months. The reduction from the preoperative mean IOP at last follow up was 45.3% with 1.08 +/- 0.44 supplemental glaucoma medications. The success rate of IOP controlling according to the definition was 76.9%. The pressure remained below 18 mmHg with and without medication in 9/13 (69.2%) eyes, while three eyes required no medication at all till the last follow-up with sustained IOP < 15 mmHg. At the last follow-up the visual acuity reduced by > or = 2 lines in two eyes while one patient's vision worsened from counting finger of one meter to hand movement. Visual improvement of one and two lines documented in two eyes. Hypotony, Tube-corneal touch, acceleration of cataract, choroidal effusion, flat anterior chamber, visual reduction and tube exposure were the types of complications encountered in 6 eyes, while 3 eyes had more than one complication. The study has shown that tube-shunt implant to be effective in lowering intraocular pressure in refractory glaucoma cases. The few cases reported are indicators of the importance of the procedure in salvaging vision of patients with refractory glaucoma and the need of large scale prospective study in the country.

Sharp Interface Algorithm for Large Density Ratio Incompressible Multiphase Magnetohydrodynamic Flows

DTIC Science & Technology

2013-01-01

experiments on liquid metal jets . The FronTier-MHD code has been used for simulations of liquid mercury targets for the proposed muon collider...validated through the comparison with experiments on liquid metal jets . The FronTier-MHD code has been used for simulations of liquid mercury targets...FronTier-MHD code have been performed using experimental and theoretical studies of liquid mercury jets in magnetic fields. Experimental studies of a

A Comparison of Grid-based and SPH Binary Mass-transfer and Merger Simulations

DOE PAGES

Motl, Patrick M.; Frank, Juhan; Staff, Jan; ...

2017-03-29

There is currently a great amount of interest in the outcomes and astrophysical implications of mergers of double degenerate binaries. In a commonly adopted approximation, the components of such binaries are represented by polytropes with an index of n = 3/2. We present detailed comparisons of stellar mass-transfer and merger simulations of polytropic binaries that have been carried out using two very different numerical algorithms—a finite-volume "grid" code and a smoothed-particle hydrodynamics (SPH) code. We find that there is agreement in both the ultimate outcomes of the evolutions and the intermediate stages if the initial conditions for each code aremore » chosen to match as closely as possible. We find that even with closely matching initial setups, the time it takes to reach a concordant evolution differs between the two codes because the initial depth of contact cannot be matched exactly. There is a general tendency for SPH to yield higher mass transfer rates and faster evolution to the final outcome. Here, we also present comparisons of simulations calculated from two different energy equations: in one series, we assume a polytropic equation of state and in the other series an ideal gas equation of state. In the latter series of simulations, an atmosphere forms around the accretor, which can exchange angular momentum and cause a more rapid loss of orbital angular momentum. In the simulations presented here, the effect of the ideal equation of state is to de-stabilize the binary in both SPH and grid simulations, but the effect is more pronounced in the grid code.« less

Hypersonic CFD applications at NASA Langley using CFL3D and CFL3DE

NASA Technical Reports Server (NTRS)

Richardson, Pamela F.

1989-01-01

The CFL3D/CFL3DE CFD codes and the industrial use status of the codes are outlined. Comparison of grid density, pressure, heat transfer, and aerodynamic coefficience are presented. Future plans related to the National Aerospace Plane Program are briefly outlined.

CoRoT/ESTA TASK 1 and TASK 3 comparison of the internal structure and seismic properties of representative stellar models. Comparisons between the ASTEC, CESAM, CLES, GARSTEC and STAROX codes

NASA Astrophysics Data System (ADS)

Lebreton, Yveline; Montalbán, Josefina; Christensen-Dalsgaard, Jørgen; Roxburgh, Ian W.; Weiss, Achim

2008-08-01

We compare stellar models produced by different stellar evolution codes for the CoRoT/ESTA project, comparing their global quantities, their physical structure, and their oscillation properties. We discuss the differences between models and identify the underlying reasons for these differences. The stellar models are representative of potential CoRoT targets. Overall we find very good agreement between the five different codes, but with some significant deviations. We find noticeable discrepancies (though still at the per cent level) that result from the handling of the equation of state, of the opacities and of the convective boundaries. The results of our work will be helpful in interpreting future asteroseismology results from CoRoT.

Jet-A reaction mechanism study for combustion application

NASA Technical Reports Server (NTRS)

Lee, Chi-Ming; Kundu, Krishna; Acosta, Waldo

1991-01-01

Simplified chemical kinetic reaction mechanisms for the combustion of Jet A fuel was studied. Initially, 40 reacting species and 118 elementary chemical reactions were chosen based on a literature review. Through a sensitivity analysis with the use of LSENS General Kinetics and Sensitivity Analysis Code, 16 species and 21 elementary chemical reactions were determined from this study. This mechanism is first justified by comparison of calculated ignition delay time with the available shock tube data, then it is validated by comparison of calculated emissions from the plug flow reactor code with in-house flame tube data.

A Study of Flow Separation in Transonic Flow Using Inviscid and Viscous Computational Fluid Dynamics (CFD) Schemes

NASA Technical Reports Server (NTRS)

Rhodes, J. A.; Tiwari, S. N.; Vonlavante, E.

1988-01-01

A comparison of flow separation in transonic flows is made using various computational schemes which solve the Euler and the Navier-Stokes equations of fluid mechanics. The flows examined are computed using several simple two-dimensional configurations including a backward facing step and a bump in a channel. Comparison of the results obtained using shock fitting and flux vector splitting methods are presented and the results obtained using the Euler codes are compared to results on the same configurations using a code which solves the Navier-Stokes equations.

Intercode comparison of gyrokinetic global electromagnetic modes

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

Görler, T., E-mail: tobias.goerler@ipp.mpg.de; Tronko, N.; Hornsby, W. A.

Aiming to fill a corresponding lack of sophisticated test cases for global electromagnetic gyrokinetic codes, a new hierarchical benchmark is proposed. Starting from established test sets with adiabatic electrons, fully gyrokinetic electrons, and electrostatic fluctuations are taken into account before finally studying the global electromagnetic micro-instabilities. Results from up to five codes involving representatives from different numerical approaches as particle-in-cell methods, Eulerian and Semi-Lagrangian are shown. By means of spectrally resolved growth rates and frequencies and mode structure comparisons, agreement can be confirmed on ion-gyro-radius scales, thus providing confidence in the correct implementation of the underlying equations.

Reconciliation of international administrative coding systems for comparison of colorectal surgery outcome.

PubMed

Munasinghe, A; Chang, D; Mamidanna, R; Middleton, S; Joy, M; Penninckx, F; Darzi, A; Livingston, E; Faiz, O

2014-07-01

Significant variation in colorectal surgery outcomes exists between different countries. Better understanding of the sources of variable outcomes using administrative data requires alignment of differing clinical coding systems. We aimed to map similar diagnoses and procedures across administrative coding systems used in different countries. Administrative data were collected in a central database as part of the Global Comparators (GC) Project. In order to unify these data, a systematic translation of diagnostic and procedural codes was undertaken. Codes for colorectal diagnoses, resections, operative complications and reoperative interventions were mapped across the respective national healthcare administrative coding systems. Discharge data from January 2006 to June 2011 for patients who had undergone colorectal surgical resections were analysed to generate risk-adjusted models for mortality, length of stay, readmissions and reoperations. In all, 52 544 case records were collated from 31 institutions in five countries. Mapping of all the coding systems was achieved so that diagnosis and procedures from the participant countries could be compared. Using the aligned coding systems to develop risk-adjusted models, the 30-day mortality rate for colorectal surgery was 3.95% (95% CI 0.86-7.54), the 30-day readmission rate was 11.05% (5.67-17.61), the 28-day reoperation rate was 6.13% (3.68-9.66) and the mean length of stay was 14 (7.65-46.76) days. The linkage of international hospital administrative data that we developed enabled comparison of documented surgical outcomes between countries. This methodology may facilitate international benchmarking. Colorectal Disease © 2014 The Association of Coloproctology of Great Britain and Ireland.

Validation of US3D for Capsule Aerodynamics using 05-CA Wind Tunnel Test Data

NASA Technical Reports Server (NTRS)

Schwing, Alan

2012-01-01

Several comparisons of computational fluid dynamics to wind tunnel test data are shown for the purpose of code validation. The wind tunnel test, 05-CA, uses a 7.66% model of NASA's Multi-Purpose Crew Vehicle in the 11-foot test section of the Ames Unitary Plan Wind tunnel. A variety of freestream conditions over four Mach numbers and three angles of attack are considered. Test data comparisons include time-averaged integrated forces and moments, time-averaged static pressure ports on the surface, and Strouhal Number. The applicability of the US3D code to subsonic and transonic flow over a bluff body is assessed on a comprehensive data set. With close comparison, this work validates US3D for highly separated flows similar to those examined here.

Cavitation Modeling in Euler and Navier-Stokes Codes

NASA Technical Reports Server (NTRS)

Deshpande, Manish; Feng, Jinzhang; Merkle, Charles L.

1993-01-01

Many previous researchers have modeled sheet cavitation by means of a constant pressure solution in the cavity region coupled with a velocity potential formulation for the outer flow. The present paper discusses the issues involved in extending these cavitation models to Euler or Navier-Stokes codes. The approach taken is to start from a velocity potential model to ensure our results are compatible with those of previous researchers and available experimental data, and then to implement this model in both Euler and Navier-Stokes codes. The model is then augmented in the Navier-Stokes code by the inclusion of the energy equation which allows the effect of subcooling in the vicinity of the cavity interface to be modeled to take into account the experimentally observed reduction in cavity pressures that occurs in cryogenic fluids such as liquid hydrogen. Although our goal is to assess the practicality of implementing these cavitation models in existing three-dimensional, turbomachinery codes, the emphasis in the present paper will center on two-dimensional computations, most specifically isolated airfoils and cascades. Comparisons between velocity potential, Euler and Navier-Stokes implementations indicate they all produce consistent predictions. Comparisons with experimental results also indicate that the predictions are qualitatively correct and give a reasonable first estimate of sheet cavitation effects in both cryogenic and non-cryogenic fluids. The impact on CPU time and the code modifications required suggests that these models are appropriate for incorporation in current generation turbomachinery codes.

High performance and cost effective CO-OFDM system aided by polar code.

PubMed

Liu, Ling; Xiao, Shilin; Fang, Jiafei; Zhang, Lu; Zhang, Yunhao; Bi, Meihua; Hu, Weisheng

2017-02-06

A novel polar coded coherent optical orthogonal frequency division multiplexing (CO-OFDM) system is proposed and demonstrated through experiment for the first time. The principle of a polar coded CO-OFDM signal is illustrated theoretically and the suitable polar decoding method is discussed. Results show that the polar coded CO-OFDM signal achieves a net coding gain (NCG) of more than 10 dB at bit error rate (BER) of 10^-3 over 25-Gb/s 480-km transmission in comparison with conventional CO-OFDM. Also, compared to the 25-Gb/s low-density parity-check (LDPC) coded CO-OFDM 160-km system, the polar code provides a NCG of 0.88 dB @BER = 10^-3. Moreover, the polar code can relieve the laser linewidth requirement massively to get a more cost-effective CO-OFDM system.

Los Alamos radiation transport code system on desktop computing platforms

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

Briesmeister, J.F.; Brinkley, F.W.; Clark, B.A.

The Los Alamos Radiation Transport Code System (LARTCS) consists of state-of-the-art Monte Carlo and discrete ordinates transport codes and data libraries. These codes were originally developed many years ago and have undergone continual improvement. With a large initial effort and continued vigilance, the codes are easily portable from one type of hardware to another. The performance of scientific work-stations (SWS) has evolved to the point that such platforms can be used routinely to perform sophisticated radiation transport calculations. As the personal computer (PC) performance approaches that of the SWS, the hardware options for desk-top radiation transport calculations expands considerably. Themore » current status of the radiation transport codes within the LARTCS is described: MCNP, SABRINA, LAHET, ONEDANT, TWODANT, TWOHEX, and ONELD. Specifically, the authors discuss hardware systems on which the codes run and present code performance comparisons for various machines.« less

Development of code evaluation criteria for assessing predictive capability and performance

NASA Technical Reports Server (NTRS)

Lin, Shyi-Jang; Barson, S. L.; Sindir, M. M.; Prueger, G. H.

1993-01-01

Computational Fluid Dynamics (CFD), because of its unique ability to predict complex three-dimensional flows, is being applied with increasing frequency in the aerospace industry. Currently, no consistent code validation procedure is applied within the industry. Such a procedure is needed to increase confidence in CFD and reduce risk in the use of these codes as a design and analysis tool. This final contract report defines classifications for three levels of code validation, directly relating the use of CFD codes to the engineering design cycle. Evaluation criteria by which codes are measured and classified are recommended and discussed. Criteria for selecting experimental data against which CFD results can be compared are outlined. A four phase CFD code validation procedure is described in detail. Finally, the code validation procedure is demonstrated through application of the REACT CFD code to a series of cases culminating in a code to data comparison on the Space Shuttle Main Engine High Pressure Fuel Turbopump Impeller.

VizieR Online Data Catalog: Comparison of evolutionary tracks (Martins+, 2013)

NASA Astrophysics Data System (ADS)

Martins, F.; Palacios, A.

2013-11-01

Tables of evolutionary models for massive stars. The files m*_stol.dat correspond to models computed with the code STAREVOL. The files m*_mesa.dat correspond to models computed with the code MESA. For each code, models with initial masses equal to 7, 9, 15, 20, 25, 40 and 60M⊙ are provided. No rotation is included. The overshooting parameter f is equal to 0.01. The metallicity is solar. (14 data files).

Energy balance in TM-1-MH Tokamak (ohmical heating)

NASA Astrophysics Data System (ADS)

Stoeckel, J.; Koerbel, S.; Kryska, L.; Kopecky, V.; Dadalec, V.; Datlov, J.; Jakubka, K.; Magula, P.; Zacek, F.; Pereverzev, G. V.

1981-10-01

Plasma in the TM-1-MH Tokamak was experimentally studied in the parameter range: tor. mg. field B = 1,3 T, plasma current I sub p = 14 kA, electron density N sub E 3.10 to the 19th power cubic meters. The two numerical codes are available for the comparison with experimental data. TOKATA-code solves simplified energy balance equations for electron and ion components. TOKSAS-code solves the detailed energy balance of the ion component.

Nonperturbative methods in HZE ion transport

NASA Technical Reports Server (NTRS)

Wilson, John W.; Badavi, Francis F.; Costen, Robert C.; Shinn, Judy L.

1993-01-01

A nonperturbative analytic solution of the high charge and energy (HZE) Green's function is used to implement a computer code for laboratory ion beam transport. The code is established to operate on the Langley Research Center nuclear fragmentation model used in engineering applications. Computational procedures are established to generate linear energy transfer (LET) distributions for a specified ion beam and target for comparison with experimental measurements. The code is highly efficient and compares well with the perturbation approximations.

A Unified View of Global Instability of Compressible Flow over Open Cavities

DTIC Science & Technology

2006-03-28

in terms of number of steps realized by the DNS code per second (S/sec) as the number of processors ( np ) increases. For this comparison the “new...computations). It may clearly be seen that both solutions performed comparably well at low number of processors; however, as np increased, the Myrinet...has subsequently been designed, hard -coded and validated at nu modelling. Design characteristics of the code have been a) high-accuracy, b

Application of the RNS3D Code to a Circular-Rectangular Transition Duct With and Without Inlet Swirl and Comparison with Experiments

NASA Technical Reports Server (NTRS)

Cavicchi, Richard H.

1999-01-01

Circular-rectangular transition ducts are used between engine exhausts and nozzles with rectangular cross sections that are designed for high performance aircraft. NASA Glenn Research Center has made experimental investigations of a series of circular-rectangular transition ducts to provide benchmark flow data for comparison with numerical calculations. These ducts are all designed with superellipse cross sections to facilitate grid generation. In response to this challenge, the three-dimensional RNS3D code has been applied to one of these transition ducts. This particular duct has a length-to-inlet diameter ratio of 1.5 and an exit-plane aspect ratio of 3.0. The inlet Mach number is 0.35. Two GRC experiments and the code were run for this duct without inlet swirl. One GRC experiment and the code were also run with inlet swirl. With no inlet swirl the code was successful in predicting pressures and secondary flow conditions, including a pair of counter-rotating vortices at both sidewalls of the exit plane. All these phenomena have been reported from the two GRC experiments. However, these vortices were suppressed in the one experiment when inlet swirl was used; whereas the RNS3D code still predicted them. The experiment was unable to provide data near the sidewalls, the very region where the vortices were predicted.

A comparison of five benchmarks

NASA Technical Reports Server (NTRS)

Huss, Janice E.; Pennline, James A.

1987-01-01

Five benchmark programs were obtained and run on the NASA Lewis CRAY X-MP/24. A comparison was made between the programs codes and between the methods for calculating performance figures. Several multitasking jobs were run to gain experience in how parallel performance is measured.

Test code for the assessment and improvement of Reynolds stress models

NASA Technical Reports Server (NTRS)

Rubesin, M. W.; Viegas, J. R.; Vandromme, D.; Minh, H. HA

1987-01-01

An existing two-dimensional, compressible flow, Navier-Stokes computer code, containing a full Reynolds stress turbulence model, was adapted for use as a test bed for assessing and improving turbulence models based on turbulence simulation experiments. To date, the results of using the code in comparison with simulated channel flow and over an oscillating flat plate have shown that the turbulence model used in the code needs improvement for these flows. It is also shown that direct simulation of turbulent flows over a range of Reynolds numbers are needed to guide subsequent improvement of turbulence models.

Comparison of two methods of MMPI-2 profile classification.

PubMed

Munley, P H; Germain, J M

2000-10-01

The present study investigated the extent of agreement of the highest scale method and the best-fit method in matching MMPI-2 profiles to database code-type profiles and considered profile characteristics that may relate to agreement or disagreement of code-type matches by these two methods. A sample of 519 MMPI-2 profiles that had been classified into database profile code types by these two methods was studied. Resulting code-type matches were classified into three groups: identical (30%), similar (39%), and different (31%), and the profile characteristics of profile elevation, dispersion, and profile code-type definition were studied. Profile code-type definition was significantly different across the three groups with identical and similar match profile groups showing greater profile code-type definition and the different group consisting of profiles that were less well-defined.

HZETRN: A heavy ion/nucleon transport code for space radiations

NASA Technical Reports Server (NTRS)

Wilson, John W.; Chun, Sang Y.; Badavi, Forooz F.; Townsend, Lawrence W.; Lamkin, Stanley L.

1991-01-01

The galactic heavy ion transport code (GCRTRN) and the nucleon transport code (BRYNTRN) are integrated into a code package (HZETRN). The code package is computer efficient and capable of operating in an engineering design environment for manned deep space mission studies. The nuclear data set used by the code is discussed including current limitations. Although the heavy ion nuclear cross sections are assumed constant, the nucleon-nuclear cross sections of BRYNTRN with full energy dependence are used. The relation of the final code to the Boltzmann equation is discussed in the context of simplifying assumptions. Error generation and propagation is discussed, and comparison is made with simplified analytic solutions to test numerical accuracy of the final results. A brief discussion of biological issues and their impact on fundamental developments in shielding technology is given.

Comparison of procedure coding systems for level 1 and 2 hospitals in South Africa.

PubMed

Montewa, Lebogang; Hanmer, Lyn; Reagon, Gavin

2013-01-01

The ability of three procedure coding systems to reflect the procedure concepts extracted from patient records from six hospitals was compared, in order to inform decision making about a procedure coding standard for South Africa. A convenience sample of 126 procedure concepts was extracted from patient records at three level 1 hospitals and three level 2 hospitals. Each procedure concept was coded using ICPC-2, ICD-9-CM, and CCSA-2001. The extent to which each code assigned actually reflected the procedure concept was evaluated (between 'no match' and 'complete match'). For the study sample, CCSA-2001 was found to reflect the procedure concepts most completely, followed by ICD-9-CM and then ICPC-2. In practice, decision making about procedure coding standards would depend on multiple factors in addition to coding accuracy.

The analysis of a nonsimilar laminar boundary layer

NASA Technical Reports Server (NTRS)

Stalmach, D. D.; Bertin, J. J.

1978-01-01

A computer code is described which yields accurate solutions for a broad range of laminar, nonsimilar boundary layers, providing the inviscid flow field is known. The boundary layer may be subject to mass injection for perfect-gas, nonreacting flows. If no mass injection is present, the code can be used with either perfect-gas or real-gas thermodynamic models. Solutions, ranging from two-dimensional similarity solutions to solutions for the boundary layer on the Space Shuttle Orbiter during reentry conditions, have been obtained with the code. Comparisons of these solutions, and others, with solutions presented in the literature; and with solutions obtained from other codes, demonstrate the accuracy of the present code.

Workshop report - A validation study of Navier-Stokes codes for transverse injection into a Mach 2 flow

NASA Technical Reports Server (NTRS)

Eklund, Dean R.; Northam, G. B.; Mcdaniel, J. C.; Smith, Cliff

1992-01-01

A CFD (Computational Fluid Dynamics) competition was held at the Third Scramjet Combustor Modeling Workshop to assess the current state-of-the-art in CFD codes for the analysis of scramjet combustors. Solutions from six three-dimensional Navier-Stokes codes were compared for the case of staged injection of air behind a step into a Mach 2 flow. This case was investigated experimentally at the University of Virginia and extensive in-stream data was obtained. Code-to-code comparisons have been made with regard to both accuracy and efficiency. The turbulence models employed in the solutions are believed to be a major source of discrepancy between the six solutions.

Radiative transfer codes for atmospheric correction and aerosol retrieval: intercomparison study.

PubMed

Kotchenova, Svetlana Y; Vermote, Eric F; Levy, Robert; Lyapustin, Alexei

2008-05-01

Results are summarized for a scientific project devoted to the comparison of four atmospheric radiative transfer codes incorporated into different satellite data processing algorithms, namely, 6SV1.1 (second simulation of a satellite signal in the solar spectrum, vector, version 1.1), RT3 (radiative transfer), MODTRAN (moderate resolution atmospheric transmittance and radiance code), and SHARM (spherical harmonics). The performance of the codes is tested against well-known benchmarks, such as Coulson's tabulated values and a Monte Carlo code. The influence of revealed differences on aerosol optical thickness and surface reflectance retrieval is estimated theoretically by using a simple mathematical approach. All information about the project can be found at http://rtcodes.ltdri.org.

Radiative transfer codes for atmospheric correction and aerosol retrieval: intercomparison study

NASA Astrophysics Data System (ADS)

Kotchenova, Svetlana Y.; Vermote, Eric F.; Levy, Robert; Lyapustin, Alexei

2008-05-01

Results are summarized for a scientific project devoted to the comparison of four atmospheric radiative transfer codes incorporated into different satellite data processing algorithms, namely, 6SV1.1 (second simulation of a satellite signal in the solar spectrum, vector, version 1.1), RT3 (radiative transfer), MODTRAN (moderate resolution atmospheric transmittance and radiance code), and SHARM (spherical harmonics). The performance of the codes is tested against well-known benchmarks, such as Coulson's tabulated values and a Monte Carlo code. The influence of revealed differences on aerosol optical thickness and surface reflectance retrieval is estimated theoretically by using a simple mathematical approach. All information about the project can be found at http://rtcodes.ltdri.org.

Adaptive harvest management for the Svalbard population of pink-footed geese: briefing summary

USGS Publications Warehouse

Johnson, Fred A.

2013-01-01

The African-Eurasian Waterbird Agreement (AEWA; http://www.unep-aewa.org/) calls for means to manage populations which cause conflicts with certain human economic activities. The Svalbard population of the pink-footed goose has been selected as the first test case for such an international species management plan to be developed. This document describes progress to date on the development of an adaptive harvest management (AHM) strategy for maintaining pink-footed goose abundance near their target level by providing for sustainable harvasts in Norway and Denmark. This briefing supplements material provided in the Progress Summary distributed to the International Working Group on February 1, 2013. We emphasize that peer review is an essential aspect of the process of developing and implementing an AHM program for pink-footed geese, and we will continue to solicit reviews by the International Working Group and their staff, as well as scientists not engaged in this effort. We wish to make the Working Group aware the the following two manuscripts have been submitted recently to refereed journals and are available upon request from the senior authors: Jensen, G.H., J. Madsen, F.A. Johnson, and M. Tamstorf. Snow conditions as an estimator of the breeding output in high-Arctic pink-footed geese Anser brachyrhynchus. Polar Biology: In review. Johnson, F.A., G.H. Jensen, J. Madsen, and B.K. Williams. Uncertainity, robustness, and the value of information in managing an expanding Arctic goose population. Ecological Modeling: In review. In addition to these manuscripts, the Progress Summary (February 1, 2013), and this Briefing Summary (April 23, 2013) an annual report will be produced in August 2013 and every summer thereafter. Additional manuscripts for journal publication are also anticipated.

Advanced Health Management System for the Space Shuttle Main Engine

NASA Technical Reports Server (NTRS)

Davidson, Matt; Stephens, John

2004-01-01

Boeing-Canoga Park (BCP) and NASA-Marshall Space Flight Center (NASA-MSFC) are developing an Advanced Health Management System (AHMS) for use on the Space Shuttle Main Engine (SSME) that will improve Shuttle safety by reducing the probability of catastrophic engine failures during the powered ascent phase of a Shuttle mission. This is a phased approach that consists of an upgrade to the current Space Shuttle Main Engine Controller (SSMEC) to add turbomachinery synchronous vibration protection and addition of a separate Health Management Computer (HMC) that will utilize advanced algorithms to detect and mitigate predefined engine anomalies. The purpose of the Shuttle AHMS is twofold; one is to increase the probability of successfully placing the Orbiter into the intended orbit, and the other is to increase the probability of being able to safely execute an abort of a Space Transportation System (STS) launch. Both objectives are achieved by increasing the useful work envelope of a Space Shuttle Main Engine after it has developed anomalous performance during launch and the ascent phase of the mission. This increase in work envelope will be the result of two new anomaly mitigation options, in addition to existing engine shutdown, that were previously unavailable. The added anomaly mitigation options include engine throttle-down and performance correction (adjustment of engine oxidizer to fuel ratio), as well as enhanced sensor disqualification capability. The HMC is intended to provide the computing power necessary to diagnose selected anomalous engine behaviors and for making recommendations to the engine controller for anomaly mitigation. Independent auditors have assessed the reduction in Shuttle ascent risk to be on the order of 40% with the combined system and a three times improvement in mission success.

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

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

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

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.

A mixed-methods study identifying key intervention targets to improve participation in daily living activities in primary Sjögren's syndrome patients.

PubMed

Hackett, Katie L; Deane, Katherine H O; Newton, Julia L; Deary, Vincent; Bowman, Simon; Rapley, Tim; Ng, Wan-Fai

2018-02-06

Functional ability and participation in life situations are compromised in many primary Sjögren's syndrome (PSS) patients. This study aims to identify the key barriers and priorities to participation in daily living activities, in order to develop potential future interventions. Group concept mapping (GCM), a semi-quantitative, mixed-methods, approach was used to identify and structure ideas from UK PSS patients, adults living with a PSS patient (AHMs) and health care professionals (HCPs). Brainstorming generated ideas, which were summarised into a final set of statements. Participants individually arranged these statements into themes and rated each statement for importance. Multidimensional scaling and hierarchical cluster analysis were applied to sorted and rated data to produce visual representations of the ideas (concept maps), enabling identification of agreed priority areas for interventions. 121 patients, 43 AHMs and 67 HCPs took part. 463 ideas were distilled down to 94 statements. These statements were grouped into seven clusters; 'Patient empowerment', 'Symptoms', 'Wellbeing', 'Access and coordination of healthcare', 'Knowledge and support', 'Public awareness and support' and 'Family and friends'. Patient empowerment and Symptoms were rated as priority conceptual themes. Important statements within priority clusters indicate patients should be taken seriously and supported to self-manage symptoms of oral and ocular dryness, fatigue, pain and poor sleep. Our data highlighted that in addition to managing PSS symptoms; interventions aiming to improve patient empowerment, general wellbeing, access to healthcare, patient education and social support are important to facilitate improved participation in daily living activities. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Modeling movement and fidelity of American black ducks

USGS Publications Warehouse

Zimpfer, N.L.; Conroy, M.J.

2006-01-01

Spatial relationships among stocks of breeding waterfowl can be an important component of harvest management. Prediction and optimal harvest management under adaptive harvest management (AHM) requires information on the spatial relationships among breeding populations (fidelity and inter-year exchange), as well as rates of movements from breeding to harvest regions. We used band-recovery data to develop a model to estimate probabilities of movement for American black ducks (Anas rubripes) among 3 Canadian breeding strata and 6 harvest regions (3 in Canada, and 3 in the United States) over the period 1965-1998. Model selection criteria suggested that models containing area-, year-, and age-specific recovery rates with area- and sex-specific movement rates were the best for modeling movement. Movement by males to southern harvest areas was variable depending on the originating area. Males from the western breeding area predominantly moved to the Mississippi Flyway or southern Atlantic Flyway (??ij = 0.353, SE = 0.0187 and ??ij = 0.473, SE = 0.037, respectively), whereas males that originated in the eastern and central breeding strata moved to the northern Atlantic flyway (??ij = 0.842, SE = 0.010 and ??ij = 0.578, SE = 0.0222, respectively). We used combined recoveries and recaptures in Program MARK to estimate fidelity to the 3 Canadian breeding strata. Information criteria identified a model containing sex- and age-specific fidelity for black ducks. Estimates of fidelity were 0.9695 (SE = 0.0249) and 0.9554 (SE = 0.0434) for adult males and females, respectively. Estimates of fidelity for juveniles were slightly lower at 0.9210 (SE = 0.0931) and 0.8870 (SE = 0.0475) for males and females, respectively. These models have application to the development of spatially stratified black duck harvest management models for use in AHM.

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

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).

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.