The potential for reintroduction of tumor cells during intraoperative blood salvage: reduction of risk with use of the RC-400 leukocyte depletion filter.

PubMed

Edelman, M J; Potter, P; Mahaffey, K G; Frink, R; Leidich, R B

1996-02-01

Intraoperative autotransfusion of shed blood is widely utilized in surgery. However, several studies have raised concern about the transmission of tumor cells during oncologic procedures. We compared the ability of a leukocyte depletion filter (RC-400; LDF) to a standard red blood cell filter (SBF) to remove tumor cells derived from urologic malignancies. Cells were suspended in media and passed through a SBF or a LDF. The filtrate was evaluated for the presence of viable cells utilizing the trypan blue exclusion method as well as cell culture. In a second experiment, cells were suspended in fresh bovine blood and processed through a cell saver apparatus followed by filtration with either a SBF or a LDF. Aliquots were cultured after admixture with blood, after processing, and after filtration. The LDF was able to remove tumor cells completely, as demonstrated by both counting with the trypan blue exclusion test and by cell culture. In contrast, admixture with blood processing through the cell saver apparatus nor a standard red blood cell filter removed these cells. Tumor cells derived from urologic malignancies are easily removed with a LDF but not with a SBF. Filtration of blood salvaged at the time of uro-oncologic surgery with a LDF but not with a SBF reduces the potential for reinfusion of viable tumor cells.

[Nailfold capillaroscopy and blood flow laser-doppler analysis of the microvascular damage in systemic sclerosis: preliminary results].

PubMed

Secchi, M E; Sulli, A; Pizzorni, C; Cutolo, M

2009-01-01

Systemic sclerosis (SSc) is characterized by altered microvascular structure and function. Nailfold videocapillaroscopy (NVC) is the tool to evaluate capillary morphological structure and laser-Doppler Blood flowmetry (LDF) can be used to estimate cutaneous blood flow of microvessels. The aim of this study was to investigate possible relationships between capillary morphology and blood flow in SSc. Twenty-seven SSc patients and 12 healthy subjects were enrolled. SSc microvascular involvement, as evaluated by NVC, was classified in three different patterns ("Early", "Active", "Late"). LDF analysis was performed at the II, III, IV, V hand fingers in both hands and both at cutaneous temperature and at 36 degrees C. Statistical evaluation was carried out by non-parametric procedures. Blood flow was found significantly lower in SSc patients when compared with healthy subjects (p<0.05). The heating of the probe to 36 degrees C induced a significant increase in peripheral blood flow in all subjects compared to baseline (p <0.05), however, the amount of variation was significantly lower in patients with SSc, compared with healthy controls (p <0.05). The SSc patients with NVC "Late" pattern, showed lower values of peripheral blood flow than patients with NVC "Active" or "Early" patterns (p<0.05). Moreover, a negative correlation between the tissue perfusion score and the progression of the SSc microangiopathy was observed, as well as between the tissue perfusion and the duration of the Raynaud's phenomenon (p <0.03). LDF can be employed to evaluate blood perfusion in the microvascular circulation in SSc patients. The blood flow changes observed with the LDF seem to correlate with the severity of microvascular damage in SSc as detected by NVC.

Application of advanced material systems to composite frame elements

NASA Technical Reports Server (NTRS)

Llorente, Steven; Minguet, Pierre; Fay, Russell; Medwin, Steven

1992-01-01

A three phase program has been conducted to investigate DuPont's Long Discontinuous Fiber (LDF) composites. Additional tests were conducted to compare LDF composites against toughened thermosets and a baseline thermoset system. Results have shown that the LDF AS4/PEKK offers improved interlaminar (flange bending) strength with little reduction in mechanical properties due to the discontinuous nature of the fibers. In the third phase, a series of AS4/PEKK LDF C-section curved frames (representing a typical rotorcraft light frame) were designed, manufactured and tested. Specimen reconsolidation after 'stretch forming' and frame thickness were found to be key factors in this light frame's performance. A finite element model was constructed to correlate frame test results with expected strain levels determined from material property tests. Adequately reconsolidated frames performed well and failed at strain levels at or above baseline thermoset material test strains. Finally a cost study was conducted which has shown that the use of LDF for this frame would result in a significant cost savings, for moderate to large lot sizes compared with the hand lay-up of a thermoset frame.

Evaluation of laser Doppler flowmetry for measurement of capillary blood flow in the stomach wall of dogs during gastric dilatation-volvulus.

PubMed

Monnet, Eric; Pelsue, Davyd; MacPhail, Catriona

2006-02-01

To validate laser doppler flowmetry (LDF) for measurement of blood flow in the stomach wall of dogs with gastric dilatation-volvulus (GDV). Six purpose-bred dogs and 24 dogs with naturally occurring GDV. Experimental and clinical. Capillary blood flow in the body of the stomach and pyloric antrum was measured with LDF (tissue perfusion unit (TPU) before and after induction of portal hypertension (PH) and after PH plus gastric ischemia (GI; PH + GI) and compared with flow measured by colored microsphere technique. Capillary flow was measured by LDF in the stomach wall of dogs with GDV. PH and PH+GI induced a significant reduction in blood flow in the body of the stomach (P = .019). A significant positive correlation was present between percent changes in capillary blood flow measured by LDF and colored microspheres after induction of PH + GI in the body of the stomach (r = 0.94, P = .014) and in the pyloric antrum (r = 0.95, P = .049). Capillary blood flow measured in the body of the stomach of 6 dogs that required partial gastrectomy (5.00+/-3.30 TPU) was significantly lower than in dogs that did not (28.00+/-14.40 TPU, P = .013). LDF can detect variations in blood flow in the stomach wall of dogs. LDF may have application for evaluation of stomach wall viability during surgery in dogs with GDV.

Characteristics in the beat-to-beat laser-Doppler waveform indices in subjects with diabetes.

PubMed

Hsiu, Hsin; Hu, Hsiao-Feng; Wu, Guan-Shian; Hsiao, Fone-Ching

2014-01-01

The present study performed laser-Doppler flowmetry (LDF) measurements on the skin surface around the ankle with the aim of verifying if beat-to-beat analysis of the LDF waveform can help to discriminate the microcirculatory-blood-flow (MBF) characteristics between diabetic, prediabetic, and healthy subjects. 84 subjects were assigned to three groups (diabetic, prediabetic, and normal) according to the results of oral glucose tolerance tests. Beat-to-beat analysis was performed on the pulsatile LDF waveform to obtain foot delay time (FDT), flow rise time (FRT), and the corresponding MBF-variability parameters (FDTCV and FRTCV). Relative to the control group, FDT and FRT were significantly shorter in prediabetic subjects, FDT was significantly shorter in diabetic subjects, and FRTCV and FDTCV were significantly larger in prediabetic and diabetic subjects. There were no significant associations for FRT after adjustment for age and gender. The present results indicate that FRT may help to discriminate differences in the elastic properties of local vascular beds during diabetes or even during prediabetic stages. The proposed blood-filling-volume model can help to explain the underlying mechanism. The present findings may aid the noninvasive early detection of diabetes-associated vascular damage, and could be used in the development of home-care and telemedicine applications.

Evaluation of gingival vascularisation using laser Doppler flowmetry

NASA Astrophysics Data System (ADS)

Vitez, B.; Todea, C.; Velescu, A.; Şipoş, C.

2016-03-01

Aim: The present study aims to assess the level of vascularisation of the lower frontal gingiva of smoker patients, in comparison with non-smokers by using Laser Doppler Flowmetry (LDF), in order to determine the changes in gingival microcirculation. Material & methods: 16 volunteers were included in this study and separated into 2 equal groups: non-smoker subjects in Group I and smoker subjects in Group II. All patients were submitted to a visual examination and professional cleaning The gingival bloodflow of each patient was recorded in 5 zones using LDF, resulting in a total of 80 recordings. LDF was done with the Moor Instruments Ltd. "moorLAB" Laser Doppler. All data were collected as graphs, raw values and statistically analyzed. Results: After strict analysis results show that Group II presents a steady level of gingival microcirculation with even patterns in the graph, while Group I shows many signs of damage to it`s microvascular system through many irregularities in the microcirculation level and graph patterns. Conclusion: The results suggest that prolonged smoking has a definitive effect on the gingival vascularisation making it a key factor in periodontal pathology.

The calculations of small molecular conformation energy differences by density functional method

NASA Astrophysics Data System (ADS)

Topol, I. A.; Burt, S. K.

1993-03-01

The differences in the conformational energies for the gauche (G) and trans(T) conformers of 1,2-difluoroethane and for myo-and scyllo-conformer of inositol have been calculated by local density functional method (LDF approximation) with geometry optimization using different sets of calculation parameters. It is shown that in the contrast to Hartree—Fock methods, density functional calculations reproduce the correct sign and value of the gauche effect for 1,2-difluoroethane and energy difference for both conformers of inositol. The results of normal vibrational analysis for1,2-difluoroethane showed that harmonic frequencies calculated in LDF approximation agree with experimental data with the accuracy typical for scaled large basis set Hartree—Fock calculations.

Analysis of skin blood microflow oscillations in patients with rheumatic diseases

NASA Astrophysics Data System (ADS)

Mizeva, Irina; Makovik, Irina; Dunaev, Andrey; Krupatkin, Alexander; Meglinski, Igor

2017-07-01

Laser Doppler flowmetry (LDF) has been applied for the assessment of variation in blood microflows in patients with rheumatic diseases and healthy volunteers. Oscillations of peripheral blood microcirculation observed by LDF have been analyzed utilizing a wavelet transform. A higher amplitude of blood microflow oscillations has been observed in a high frequency band (over 0.1 Hz) in patients with rheumatic diseases. Oscillations in the high frequency band decreased in healthy volunteers in response to the cold pressor test, whereas lower frequency pulsations prevailed in patients with rheumatic diseases. A higher perfusion rate at normal conditions was observed in patients, and a weaker response to cold stimulation was observed in healthy volunteers. Analysis of blood microflow oscillations has a high potential for evaluation of mechanisms of blood flow regulation and diagnosis of vascular abnormalities associated with rheumatic diseases.

Relationship between skin blood flow and sweating rate, and age related regional differences.

PubMed

Inoue, Y; Shibasaki, M; Hirata, K; Araki, T

1998-12-01

To examine the mechanisms and regional differences in the age-related decrement of skin blood flow, 11 young (age 20-25 years) and 10 older (age 64-76 years) men were exposed to a mild heat stress by immersing their feet and lower legs in water at 42 degrees C for 60 min, while they were sitting in near thermoneutral conditions [25 degrees C and 45% relative humidity (rh)]. During the equilibrium period (25 degrees C and 45% rh) before the heat test, no group differences were observed in rectal (Tre) and mean skin (Tsk) temperatures or mean arterial pressure (MAP). During passive heating, Tsk was significantly lower in the older men 20 min after commencing exposure (P<0.001), although there were similar increases in Tre in both groups. Exposure time and age did not affect MAP. The local sweating rate (m(sw)) and the percentage change in skin blood flow by laser Doppler flowmetry (%LDF) relative to baseline values on the chest, back, forearm and thigh were significantly lower in the older men (P<0.001), especially on the thigh. After starting the heat exposure, three temporal phases were observed in the relationship between %LDF and m(sw) at most sites in each subject. In phase A, %LDF increased but with no increase in m(sw). In phase B, m(sw) increased but with no secondary increase in %LDF. Finally, in phase C, there were proportional increases in %LDF and m(sw). The increase in %LDF in phase A was significantly lower on the forearm and thigh (P<0.05) for the older men, but not on the chest and back. In phase C, the slopes of the regression lines between %LDF and m(sw) were lower for the older men on the back (P<0.03), forearm (P = 0.08) and thigh (P<0.03), but not on the chest. These results would suggest that the age-related decrement in skin blood flow in response to passive heating may be due in part to a smaller release of vasoconstrictor tone and to less active vasodilatation once sweating begins. Regional differences exist in the impaired vasoconstriction and active vasodilatation systems.

The effect of nerve blockade on forearm and finger skin blood flow during body heating and cooling.

PubMed

Saumet, J L; Degoute, C S; Saumet, M; Abraham, P

1992-08-01

To determine the role of the active cutaneous vasodilatator response in forearm and finger skin, direct assessment of only skin blood flow was performed before and after musculocutaneous and median nerve blockade during whole body heating and cooling. Forearm laser Doppler flow (LDF forearm), forearm heat thermal clearance (HTC forearm), and finger laser Doppler flow (LDF finger) were monitored in the nerve blocked skin and contralateral untreated skin (control). In the pre-blockade period, no significant differences were found between experimental and control arm skin. After nerve block a significant increase occurred only in LDF finger, which rose from 4.3 +/- 0.6 to 6.0 +/- 0.5 volts (p less than 0.05). During whole body heating LDF forearm and HTC forearm increased significantly on both arms. The increase in LDF forearm was greater (p less than 0.05) in control (18.3 +/- 1.2 volts) than in nerve blocked skin (14.6 +/- 1.8 volts) and occurred earlier. The same tendency was observed in HTC forearm between nerve blocked skin (0.522 +/- 0.06 W.m-1.degrees C-1) and control 0.671 +/- 0.037 W.m-1.degrees C-1) (NS). LDF raise up to 6.6 +/- 0.5 and 6.8 +/- 0.5 volts in the blocked finger and in the control respectively. During cooling LDF finger in the control decreased to 1.3 +/- 0.1 volt and was significantly (p less than 0.05) lower than in the resting period, and lower than that in the nerve blocked finger (3.4 +/- 0.8 volts) (p less than 0.05). We conclude that the active vasodilatator system plays an important role as far as the timing and the amplitude of the cutaneous vasodilatator response to whole body heating in the forearm but not in the finger. At thermal neutrality, the vascular vasoconstrictor tone is high to the finger but not to the forearm. The vasoconstrictor response to cooling occurred only in the finger.

Differences in time-domain and spectral indexes of skin-surface laser-Doppler signals between controls and breast-cancer subjects.

PubMed

Hsiu, Hsin; Chen, Chao-Tsung; Hung, Shuo-Hui; Chen, Guan-Zhang; Huang, Yu-Ling

2018-04-13

There is an urgent need to improve the early diagnosis of breast cancer. The present study applied spectral and beat-to-beat analyses to laser-Doppler (LDF) data sequences measured on the skin surface on the back of the right hands, with the aim of comparing the different peripheral microcirculatory-blood-flow (MBF) perfusion condition between breast-cancer and control subjects. ECG and LDF signals were obtained simultaneously and noninvasively from 23 breast-cancer patients and 23 age-matched control subjects. Time-domain beat-to-beat indexes and their variability parameters were calculated. Spectral indexes were calculated using the Morlet wavelet transform. The beat-to-beat LDF pulse width and its variability were significantly smaller in cancer patients than in the controls. The energy contributions of endothelial-, neural-, and myogenic-related frequency bands were also significantly smaller in cancer patients. The present study has revealed significant differences in the beat-to-beat and spectral indexes of skin-surface-acquired LDF signals between control subjects and breast-cancer patients. This illustrates that LDF indexes may be useful for monitoring the changes in the MBF perfusion condition induced by breast cancer. Since the breast-cancer patients were at TNM stages 0- 2, the present findings may aid the development of indexes for detecting breast cancer.

Effects of endothelium-derived nitric oxide on skin and digital blood flow in humans.

PubMed

Coffman, J D

1994-12-01

The effects of NG-monomethyl-L-arginine (L-NMMA) on total finger and forearm, and dorsal finger and forearm skin, blood flows were studied in the basal state and during reflex sympathetic vasoconstriction in normal subjects. Total flows were measured by venous occlusion plethysmography and skin flows by laser-Doppler flowmetry (LDF). L-NMMA in doses of 2, 4, and 8 microM/min given by constant infusion via a brachial artery catheter significantly decreased finger blood flow, forearm blood flow, and vascular conductances. At 8 microM/min, total finger blood flow decreased 38.4% and forearm blood flow decreased 24.8%. Dorsal finger and forearm skin LDF were also significantly decreased (25 and 37% at 8 microM/min). Body cooling significantly decreased finger blood flow (73.6%), vascular conductance, and finger LDF (59.7%). L-NMMA had no effect on total finger blood flow or dorsal finger LDF during body cooling. Nitric oxide or related compounds contribute to the basal dilator tone of the dorsal finger and forearm skin but not during reflex sympathetic vasoconstriction.

Development of a 32 Inch Diameter Levitated Ducted Fan Conceptual Design

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J.; Gallo, Christopher a.; Solano, Paul A.; Thompson, William K.; Vrnak, Daniel R.

2006-01-01

The NASA John H. Glenn Research Center has developed a revolutionary 32 in. diameter Levitated Ducted Fan (LDF) conceptual design. The objective of this work is to develop a viable non-contact propulsion system utilizing Halbach arrays for all-electric flight, and many other applications. This concept will help to reduce harmful emissions, reduce the Nation s dependence on fossil fuels, and mitigate many of the concerns and limitations encountered in conventional aircraft propulsors. The physical layout consists of a ducted fan drum rotor with blades attached at the outer diameter and supported by a stress tuner ring at the inner diameter. The rotor is contained within a stator. This concept exploits the unique physical dimensions and large available surface area to optimize a custom, integrated, electromagnetic system that provides both the levitation and propulsion functions. The rotor is driven by modulated electromagnetic fields between the rotor and the stator. When set in motion, the time varying magnetic fields interact with passive coils in the stator assembly to produce repulsive forces between the stator and the rotor providing magnetic suspension. LDF can provide significant improvements in aviation efficiency, reliability, and safety, and has potential application in ultra-efficient motors, computers, and space power systems.

A novel, microscope based, non invasive Laser Doppler flowmeter for choroidal blood flow assessment

PubMed Central

Strohmaier, C; Werkmeister, RM; Bogner, B; Runge, C; Schroedl, F; Brandtner, H; Radner, W; Schmetterer, L; Kiel, JW; Grabnerand, G; Reitsamer, HA

2015-01-01

Impaired ocular blood flow is involved in the pathogenesis of numerous ocular diseases like glaucoma or AMD. The purpose of the present study was to introduce and validate a novel, microscope based, non invasive laser Doppler flowmeter (NILDF) for measurement of blood flow in the choroid. The custom made NI-LDF was compared with a commercial fiber optic based laser Doppler flowmeter (Perimed PF4000). Linearity and stability of the NI-LDF were assessed in a silastic tubing model (i.d. 0.3 mm) at different flow rates (range 0.4 – 3 ml/h). In a rabbit model continuous choroidal blood flow measurements were performed with both instruments simultaneously. During blood flow measurements ocular perfusion pressure was changed by manipulations of intraocular pressure via intravitreal saline infusions. The NILDF measurement correlated linearly to intraluminal flow rates in the perfused tubing model (r = 0.99, p<0.05) and remained stable during a 1 hour measurement at a constant flow rate. Rabbit choroidal blood flow measured by the PF4000 and the NI-LDF linearly correlated with each other over the entire measurement range (r = 0.99, y = x* 1,01 – 12,35 P.U., p < 0,001). In conclusion, the NI-LDF provides valid, semi quantitative measurements of capillary blood flow in comparison to an established LDF instrument and is suitable for measurements at the posterior pole of the eye. PMID:21443871

Digital obstructive arterial disease can be detected by laser Doppler measurements with high sensitivity and specificity.

PubMed

Mahe, Guillaume; Liedl, David A; McCarter, Charlene; Shepherd, Roger; Gloviczki, Peter; McPhail, Ian R; Rooke, Thom W; Wennberg, Paul W

2014-04-01

This study was conducted to determine the sensitivity and specificity of laser Doppler flowmetry (LDF) measurements for digital obstructive arterial disease (DOAD) using angiography as the reference standard and to compare the accuracy of different classical tests used to assess DOAD. Diagnosis of vascular abnormalities at the digital level is challenging. Angiography is the gold standard for assessment of DOAD but is invasive and expensive to perform. We performed a retrospective analysis of consecutive patients referred at Mayo Clinic (Rochester, Minn) for upper extremity arterial assessment during a 27-month period. Finger-brachial index, skin blood flow (in arbitrary units [a.u.]), and skin temperature (in degrees Celsius) were recorded in each digit on the pulp at baseline and after a thermal challenge test (hand placed in a thermal box at 47.0°C for 15 minutes). Angiogram analysis was blinded and performed by a radiologist using a vascularization scale ranging from 0 (no vessel) to 4 (normal). The receiver operating characteristic curve was used to define a specific cutoff point to detect DOAD. Twenty-two patients had LDF measurements and complete angiograms. A total of 185 digits were analyzed because some patients had only analysis of one hand. The best area under the curve (AUC) was 0.98 (range, 0.94-0.99) for postwarming skin blood flow, with a cutoff point of ≤206 a.u. This AUC was statistically different from AUCs of all the other tests (P < .01). Sensitivity and specificity were 93% (95% confidence interval, 85%-97%) and 96% (95% confidence interval, 90%-99%), respectively. LDF combined with a thermal challenge is highly accurate, safe, and noninvasive means to detect DOAD. Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Application of wavelet analysis to detect dysfunction in cerebral blood flow autoregulation during experimental hyperhomocysteinaemia.

PubMed

Aleksandrin, Valery V; Ivanov, Alexander V; Virus, Edward D; Bulgakova, Polina O; Kubatiev, Aslan A

2018-04-03

The purpose of the present study was to investigate the use of laser Doppler flowmetry (LDF) signals coupled with spectral wavelet analysis to detect endothelial link dysfunction in the autoregulation of cerebral blood flow in the setting of hyperhomocysteinaemia (HHcy). Fifty-one rats were assigned to three groups (intact, control, and HHcy) according to the results of biochemical assays of homocysteine level in blood plasma. LDF signals on the rat brain were recorded by LAKK-02 device to measure the microcirculatory blood flow. The laser operating wavelength and output power density were1064 nm and 0.051 W/mm 2 , respectively. A Morlet mother wavelet transform was applied to the measured 8-min LDF signals, and periodic oscillations with five frequency intervals were identified (0.01-0.04 Hz, 0.04-0.15 Hz, 0.15-0.4 Hz, 0.4-2 Hz, and 2-5 Hz) corresponding to endothelial, neurogenic, myogenic, respiratory, and cardiac origins, respectively. In initial state, the amplitude of the oscillations decreased by 38% (P < 0.05) in the endothelial range in HHcy rats than in control rats. Cerebral autoregulation was challenged by hemorrhagic hypotension. The lower limit of autoregulation raised in a rat model of chronic HHcy (71.5 ± 0.7 mmHg in HHcy vs. 62.3 ± 0.5 mmHg in control). The data obtained indicate that the laser Doppler method and wavelet analysis may be successfully applied to detect the dysfunction of the endothelial link in cerebral vessel tone and to reveal the pathological shift of lower limit of autoregulation.

Fluorometric assessments of viability and mitochondrial status of boar spermatozoa following liquid storage.

PubMed

Fraser, L; Lecewicz, M; Strzezek, J

2002-01-01

A study was conducted to assess viability and mitochondrial status of boar spermatozoa stored at 5 degrees C and 16 degrees C. Gel-free ejaculates, collected from 3 mature boars, were extended in a standard diluent (K3) supplemented with a low-density lipoprotein fraction (LDF) isolated from egg yolk, and stored for 96 h at 5 degrees C and 16 degrees C. Motility analysis was conducted after semen dilution (D0) and on D1-D4 of storage. A double staining method, rhodamine 123 (R123) and propidium iodide (PI), was used to assess sperm viability and mitochondrial status. Sperm viability was also assessed using Hoechst 33,258 (H33258) stain. In fresh semen samples, the percentage of motility was significantly correlated with the percentage of viable spermatozoa with functional mitochondria (R123-PI), viable spermatozoa determined by H33258 staining and ATP content (r = 0.88, p < or = 0.01; r = 0.69, p < or = 0.05; r = 0.77, p < or = 0.01, respectively). The ATP content was also positively correlated with the percentage of viable spermatozoa with functional mitochondria (r = 0.76, p < or = 0.01). Sperm cells progressively lost motility, viability and mitochondrial capacity when stored in the supportive media at 5 degrees C and 16 degrees C. Motility estimates were lower (p < or = 0.05) than the percentage of viable spermatozoa with functional mitochondria during storage in K3 and LDF-based diluents on D4 and D3-D4, respectively. Deterioration in motility and membrane integrity was less marked in spermatozoa stored in LDF-based diluents. Spermatozoa doubly-stained with R123-PI appeared to possess some functional mitochondria, particularly in LDF-based diluent semen. Estimates of sperm viability, as determined by R123-PI staining, were equivalent (p > or = 0.05) to estimates made using H33258 staining. A decrease in mitochondrial activity, as measured by R123 uptake, was accompanied by lower ATP content in spermatozoa stored in K3 and LDF-based diluents after 48 h and 72 h of storage, respectively. Fluorometric measurements of viability and mitochondrial status of boar spermatozoa during liquid storage seem to provide reliable information about the sperm functional membranes.

Electronic structure Fermi liquid theory of high Tc superconductors: Comparison of predictions with experiments

NASA Technical Reports Server (NTRS)

Yu, Jaejun; Freeman, A. J.

1991-01-01

Predictions of local density functional (LDF) calculations of the electronic structure and transport properties of high T(sub c) superconductors are presented. As evidenced by the excellent agreement with both photoemission and positron annihilation experiments, a Fermi liquid nature of the 'normal' state of the high T(sub c) superconductors become clear for the metallic phase of these oxides. In addition, LDF predictions on the normal state transport properties are qualitatively in agreement with experiments on single crystals. It is emphasized that the signs of the Hall coefficients for the high T(sub c) superconductors are not consistent with the types of dopants (e.g., electron-doped or hole-doped) but are determined by the topology of the Fermi surfaces obtained from the LDF calculations.

Learnable despeckling framework for optical coherence tomography images

NASA Astrophysics Data System (ADS)

Adabi, Saba; Rashedi, Elaheh; Clayton, Anne; Mohebbi-Kalkhoran, Hamed; Chen, Xue-wen; Conforto, Silvia; Nasiriavanaki, Mohammadreza

2018-01-01

Optical coherence tomography (OCT) is a prevalent, interferometric, high-resolution imaging method with broad biomedical applications. Nonetheless, OCT images suffer from an artifact called speckle, which degrades the image quality. Digital filters offer an opportunity for image improvement in clinical OCT devices, where hardware modification to enhance images is expensive. To reduce speckle, a wide variety of digital filters have been proposed; selecting the most appropriate filter for an OCT image/image set is a challenging decision, especially in dermatology applications of OCT where a different variety of tissues are imaged. To tackle this challenge, we propose an expandable learnable despeckling framework, we call LDF. LDF decides which speckle reduction algorithm is most effective on a given image by learning a figure of merit (FOM) as a single quantitative image assessment measure. LDF is learnable, which means when implemented on an OCT machine, each given image/image set is retrained and its performance is improved. Also, LDF is expandable, meaning that any despeckling algorithm can easily be added to it. The architecture of LDF includes two main parts: (i) an autoencoder neural network and (ii) filter classifier. The autoencoder learns the FOM based on several quality assessment measures obtained from the OCT image including signal-to-noise ratio, contrast-to-noise ratio, equivalent number of looks, edge preservation index, and mean structural similarity index. Subsequently, the filter classifier identifies the most efficient filter from the following categories: (a) sliding window filters including median, mean, and symmetric nearest neighborhood, (b) adaptive statistical-based filters including Wiener, homomorphic Lee, and Kuwahara, and (c) edge preserved patch or pixel correlation-based filters including nonlocal mean, total variation, and block matching three-dimensional filtering.

Comparison of NIRS, laser Doppler flowmetry, photoplethysmography, and pulse oximetry during vascular occlusion challenges.

PubMed

Abay, T Y; Kyriacou, P A

2016-04-01

Monitoring changes in blood volume, blood flow, and oxygenation in tissues is of vital importance in fields such as reconstructive surgery and trauma medicine. Near infrared spectroscopy (NIRS), laser Doppler (LDF) flowmetry, photoplethysmography (PPG), and pulse oximetry (PO) contribute to such fields due to their safe and noninvasive nature. However, the techniques have been rarely investigated simultaneously or altogether. The aim of this study was to investigate all the techniques simultaneously on healthy subjects during vascular occlusion challenges. Sensors were attached on the forearm (NIRS and LDF) and fingers (PPG and PO) of 19 healthy volunteers. Different degrees of vascular occlusion were induced by inflating a pressure cuff on the upper arm. The responses of tissue oxygenation index (NIRS), tissue haemoglobin index (NIRS), flux (LDF), perfusion index (PPG), and arterial oxygen saturation (PO) have been recorded and analyzed. Moreover, the optical densities were calculated from slow varying dc PPG, in order to distinguish changes in venous blood volumes. The indexes showed significant changes (p  <  0.05) in almost all occlusions, either venous or over-systolic occlusions. However, differentiation between venous and arterial occlusion by LDF may be challenging and the perfusion index (PI) may not be adequate to indicate venous occlusions. Optical densities may be an additional tool to detect venous occlusions by PPG.

Thermoplastic composite parts manufacture at Du Pont

NASA Astrophysics Data System (ADS)

Medwin, Steven J.; Coyle, Edward J.

1993-01-01

Low-cost routes to the manufacture of complex shaped composite parts have been defined using metal forming techniques and Du Pont's long discontinuous fiber (LDF) Technology. These manufacturing techniques include roll forming, stretch forming, and press forming. Near equivalence between the static, dynamic, and damage tolerance properties of LDF and continuous fiber composites have been demonstrated. Several examples are cited which demonstrate the potential for this technology to significantly reduce the cost of aerospace components.

The lateral distribution of extensive air showers produced by cosmic rays above 10 19 eV as measured by water-Čerenkov detectors

NASA Astrophysics Data System (ADS)

Coy, R. N.; Cunningham, G.; Pryke, C. L.; Watson, A. A.

1997-03-01

Measurements of the lateral distribution function (ldf) of Extensive Air Showers (EAS) as recorded by the array of water-Čerenkov detectors at Haverah Park are described, and accurate experimental parameterizations expressing the mean ldf for 2 × 10 17 < E < 4 × 10 18 eV, 50 < r < 700 m, and θ < 45° are given. An extrapolation of these relations to the regime E ≥ 10 19 eV and r > 700 m is described: extrapolation in this energy domain appears valid, and an approximate correction term is given for the larger core distances. The results of recent Monte Carlo simulations of shower development and detector behavior are compared to the parameterized ldf. The agreement is good increasing confidence that these simulations may be trusted as design tools for the Auger project, a proposed 'next generation' detector system.

Evaluation of blood microcirculation parameters by combined use of laser Doppler flowmetry and videocapillaroscopy methods

NASA Astrophysics Data System (ADS)

Volkov, M. V.; Kostrova, D. A.; Margaryants, N. B.; Gurov, I. P.; Erofeev, N. P.; Dremin, V. V.; Zharkikh, E. V.; Zherebtsov, E. A.; Kozlov, I. O.; Dunaev, A. V.

2017-03-01

Laser Doppler flowmetry (LDF) is widely used for diagnosing blood microcirculation diseases. It is well known that the Doppler shift of laser radiation scattered by moving red blood cells (RBC) can be assessed through analyzing photocurrent produced by a photodetector. LDF signal contains information about regulating blood flow rhythms: myogenic, cardiac, nervous and endothelial. The method of videocapillaroscopy (VCS) allows local capillary blood flow velocity evaluation and, using video data processing algorithms, is able to assess RBC velocity changes into capillary. We present the results of simultaneous investigations of changes in tissue perfusion of the distal phalanx of human finger by the LDF as well as changes in capillary blood flow velocity in the nail bed evaluated by the VCS method during arterial occlusion test. The experimental results confirmed the correspondence between blood perfusion and blood flow velocity.

Three-Dimensional Characterization of Microstructure by Electron Back-Scatter Diffraction

DTIC Science & Technology

2007-03-28

Costa LDF, Cesar RM, Cesar J. 2000. Shape Analysis and Classification: Theory and Practice. Boca Raton, FL: CRC Press. 660 pp. 7. Williams RE. 1968...The distribution of grain boundaries in magnesia as a function of five macroscopic parameters. Acta Mater. 51:3663–74 27. Schaeben H, Apel M, Frank T

Wavelet-analysis of gastric microcirculation in rats with ulcer bleedings

NASA Astrophysics Data System (ADS)

Pavlov, A. N.; Semyachkina-Glushkovskaya, O. V.; Pavlova, O. N.; Bibikova, O. A.; Kurths, J.

2013-10-01

Nitric oxide (NO) plays an important role in regulation of central and peripheral circulation in normal state and during hemorrhagic stress. Because the impaired gastric mucosal blood flow is the major cause of gastroduodenal lesions including ulcer bleeding (UB), we study in this work the NO-ergic mechanism responsible for regulation of this blood flow. Our study is performed in rats with a model of stress-induced UB using laser Doppler flowmetry (LDF) that characterizes the rate of blood flow by measuring a Doppler shift of the laser beam scattered by the moving red blood cells. Numerical analysis of LDF-data is based on the discrete wavelet-transform (DWT) using Daubechies wavelets aiming to quantify influences of NO on the gastric microcirculation. We show that the stress-induced UB is associated with an increased level of NO in the gastric tissue and a stronger vascular sensitivity to pharmacological modulation of NO-production by L-NAME. We demonstrate that wavelet-based analyses of NO-dependent regulation of gastric microcirculation can provide an effective endoscopic diagnostics of a risk of UB.

Cardiac frequency and cutaneous microcirculation during and after exercising in the view of physical condition.

PubMed

Saemann, Lars; Lachner, Karin; Wenzel, Folker

2017-01-01

In the field of cardiovascular diseases an ergometer test is a common diagnostical method in which a change in microcirculation can be reached. In this paper cardiac frequency and cutaneous microcirculation during and after exercising will be compared with each other. The cutaneous microcirculation of  6 healthy volunteers (2 females, 4 males) is measured. As an instrument the PeriFlux 5000 combined with a Laser-Doppler-Flow(LDF)-Probe (Perimed Instruments) is used. The cardiac frequency (CF) is measured by the POLAR T31 sensor and as an ergometer the ERGO-FIT ® 457 is used. The mean initial LDF (97,7±57,3 PU) decreases at the beginning (64,5±21,7 PU), increases during theexercise, reaches its maximum (247,8±82,1 PU) after the end of the exercise and drops to lower values (256,4±69,5 PU)after a few minutes. Contrasting to the LDF the mean initial CF (86±22/min) increases at the beginning (97±9/min),furthermore during the whole exercise (103±9/min) and then falls after having finished the exercise (96±3/min).Furthermore, during regeneration, one can see the CF decreasing towards its initial value, while LDF reaches its maximum. In further studies, realized with volunteers with well-known levels of physical condition, a directconnection between cutaneous microcirculation and physical condition might be found.

Low-pressure sequential compression of lower limbs enhances forearm skin blood flow.

PubMed

Amah, Guy; Voicu, Sebastian; Bonnin, Philippe; Kubis, Nathalie

2016-12-01

We investigated whether forearm skin blood flow could be improved when a multilayer pulsatile inflatable suit was applied at a low pressure to the lower limbs and abdomen. We hypothesized that a non-invasive purely mechanical stimulation of the lower limbs could induce remote forearm blood flow modifications. The pulsatile suit induced a sequential compartmentalized low compression (65 mmHg), which was synchronized with each diastole of the cardiac cycle with each phase evolving centripetally (lower limbs to abdomen). Modifications of the forearm skin blood flow were continuously recorded by laser Doppler flowmetry (LDF) at baseline and during the pulsatile suit application. Endothelium-dependent and endothelium-independent vasodilations of the forearm skin microcirculation were measured by LDF in response to a local transdermal iontophoretic application of acetylcholine (ACh-test) and to hyperthermia (hyperT- test). Twenty-four healthy volunteers, 12 men and 12 women (43±14 years) were included in the study. LDF responses increased 1) under pulsatile suit (97±106%, p.

Increased lucid dreaming frequency in narcolepsy.

PubMed

Rak, Michael; Beitinger, Pierre; Steiger, Axel; Schredl, Michael; Dresler, Martin

2015-05-01

Nightmares are a frequent symptom in narcolepsy. Lucid dreaming, i.e., the phenomenon of becoming aware of the dreaming state during dreaming, has been demonstrated to be of therapeutic value for recurrent nightmares. Data on lucid dreaming in narcolepsy patients, however, is sparse. The aim of this study was to evaluate the frequency of recalled dreams (DF), nightmares (NF), and lucid dreams (LDF) in narcolepsy patients compared to healthy controls. In addition, we explored if dream lucidity provides relief during nightmares in narcolepsy patients. We interviewed patients with narcolepsy and healthy controls. Telephone interview. 60 patients diagnosed with narcolepsy (23-82 years, 35 females) and 919 control subjects (14-93 years, 497 females). N/A. Logistic regression revealed significant (P < 0.001) differences in DF, NF, and LDF between narcolepsy patients and controls after controlling for age and gender, with effect sizes lying in the large range (Cohen's d > 0.8). The differences in NF and LDF between patients and controls stayed significant after controlling for DF. Comparison of 35 narcolepsy patients currently under medication with their former drug-free period revealed significant differences in DF and NF (z < 0.05, signed-rank test) but not LDF (z = 0.8). Irrespective of medication, 70% of narcolepsy patients with experience in lucid dreaming indicated that dream lucidity provides relief during nightmares. Narcolepsy patients experience a markedly higher lucid dreaming frequency compared to controls, and many patients report a positive impact of dream lucidity on the distress experienced from nightmares. © 2015 Associated Professional Sleep Societies, LLC.

Limited daily feeding and intermittent feeding have different effects on regional brain energy homeostasis during aging.

PubMed

Smiljanic, Kosara; Todorovic, Smilja; Mladenovic Djordjevic, Aleksandra; Vanmierlo, Tim; Lütjohann, Dieter; Ivkovic, Sanja; Kanazir, Selma

2018-04-01

Albeit aging is an inevitable process, the rate of aging is susceptible to modifications. Dietary restriction (DR) is a vigorous nongenetic and nonpharmacological intervention that is known to delay aging and increase healthspan in diverse species. This study aimed to compare the impact of different restricting feeding regimes such as limited daily feeding (LDF, 60% AL) and intermittent feeding (IF) on brain energy homeostasis during aging. The analysis was focused on the key molecules in glucose and cholesterol metabolism in the cortex and hippocampus of middle-aged (12-month-old) and aged (24-month-old) male Wistar rats. We measured the impact of different DRs on the expression levels of AMPK, glucose transporters (GLUT1, GLUT3, GLUT4), and the rate-limiting enzyme in the cholesterol synthesis pathway (HMGCR). Additionally, we assessed the changes in the amounts of cholesterol, its metabolite, and precursors following LDF and IF. IF decreased the levels of AMPK and pAMPK in the cortex while the increased levels were detected in the hippocampus. Glucose metabolism was more affected in the cortex, while cholesterol metabolism was more influenced in the hippocampus. Overall, the hippocampus was more resilient to the DRs, with fewer changes compared to the cortex. We showed that LDF and IF differently affected the brain energy homeostasis during aging and that specific brain regions exhibited distinct vulnerabilities towards DRs. Consequently, special attention should be paid to the DR application among elderly as different phases of aging do not respond equally to altered nutritional regimes.

Measurements in the peripheral retina using LDF and laser interferometry are mainly influenced by the choroidal circulation.

PubMed

Polska, Elzbieta; Luksch, Alexandra; Ehrlich, Paulina; Sieder, Anna; Schmetterer, Leopold

2002-04-01

Two laser based methods for the assessment of ocular hemodynamics in humans have been investigated: laser Doppler flowmetry (LDF) and laser interferometric measurement of fundus pulsation amplitude (FPA). When the laser with either of the two methods is focused onto the fovea it is obvious that only choroidal blood flow contributes to the signals. When the laser is, however, directed to other parts of the retina the situation is more complex. Whereas the retina shows a pronounced vasoconstrictor response to systemic hyperoxia the effect in the choroid is small. We therefore investigated the effect of 100% O2 breathing on results as obtained with the above mentioned techniques at different fundus locations. Twelve healthy subjects were included. Four 15-minutes 100% O2 breathing periods were scheduled for each subject. During two of these breathing periods LDF was performed at the fovea (ChBFf) and at a fundus location approximately 7.5 degrees nasally to the fovea (ChBFp), respectively. During the other two periods FPA was assessed at the same fundus locations (FPAf, FPAp). ChBFf tended to decrease during 100% oxygen breathing (6 +/- 4%), but this effect was not significant. The decrease in ChBFp (10 +/- 4%), was comparable. FPAf (10 +/- 2%; P < 0.001) and FPAp (13 +/- 2%; P < 0.001) decreased significantly during systemic hyperoxia, but again there was no difference in the response obtained at the two fundus locations. When LDF and FPA are applied at the peripheral retina the obtained signal is mainly influenced by the choroidal circulation.

Evaluation of the microcirculation in a sheep island pedicle flap with laser Doppler flowmeter and 99m-Tc-labelled red blood cells

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

Banic, A.; Kouris, K.; Lewis, D.H.

1990-10-01

The aim of the study was experimentally to evaluate the capability and reliability of laser Doppler flowmetry (LDF) in conditions of circulatory deficiency, by correlating it to flow-related parameters measured by a radionuclide-imaging technique and using 99m-Tc red blood cells (RBCs). For this purpose, a pedicle island flap in the sheep was used, with well-perfused proximal parts and with evident stasis in the distal third of the flap. No correlation was found between results obtained with the two techniques. In regions with evident stasis, falsely high LDF readings were recorded. This may be due to a back-and-forth motion of themore » RBCs under the probe, rather than to true flow. It was concluded that, while LDF seems reliable in detecting complete arterial occlusion, it is unreliable in predicting either complete venous occlusion or partial obstruction of the flow to and from the flap. Clinical use for this purpose cannot be recommended.« less

Laser Doppler Flowmetry and Transcutaneous Oximetry in Chronic Skin Ulcers: A Comparative Evaluation.

PubMed

Raposio, Edoardo; Bertozzi, Nicolò; Moretti, Rebecca; Grignaffini, Eugenio; Grieco, Michele P

2017-07-01

Laser Doppler Flowmetry (LDF) and transcutaneous oximetry (TcpO2) are established methods for investigating cutaneous perfusion. To date, no study previously performed has compared data obtained from these 2 methodologies in cases of chronic cutaneous ulcers. Laser Doppler Flowmetry and TcpO2 were performed in 25 consecutive outpatients with chronic lower limb ulcers (group A, experimental; 9 women and 16 men; mean age 67 years [range, 52-81 years]) and 25 age- and sex-matched healthy control subjects (group B, control) enrolled for the study. Ulcer aetiologies included 12 peripheral arterial occlusive disease, 9 chronic venous insufficiencies, and 4 pressure ulcers. Data were analyzed with Shapiro-Wilk and Wilcoxon-Mann-Whitney tests. A statistically significant difference (P < .05) was found between LDF values of the 2 groups. No statistically significant differences were found between the 2 groups regarding the TcpO2 measurements. The data confirmed the soundness of LDF while investigating local perfusion in patients with chronic cutaneous ulcers. The same diagnostic accuracy was not obtained by means of TcpO2.

A new laser Doppler flowmeter prototype for depth dependent monitoring of skin microcirculation

NASA Astrophysics Data System (ADS)

Figueiras, E.; Campos, R.; Semedo, S.; Oliveira, R.; Requicha Ferreira, L. F.; Humeau-Heurtier, A.

2012-03-01

Laser Doppler flowmetry (LDF) is now commonly used in clinical research to monitor microvascular blood flow. However, the dependence of the LDF signal on the microvascular architecture is still unknown. That is why we propose a new laser Doppler flowmeter for depth dependent monitoring of skin microvascular perfusion. This new laser Doppler flowmeter combines for the first time, in a device, several wavelengths and different spaced detection optical fibres. The calibration of the new apparatus is herein presented together with in vivo validation. Two in vivo validation tests are performed. In the first test, signals collected in the ventral side of the forearm are analyzed; in the second test, signals collected in the ventral side of the forearm are compared with signals collected in the hand palm. There are good indicators that show that different wavelengths and fibre distances probe different skin perfusion layers. However, multiple scattering may affect the results, namely the ones obtained with the larger fibre distance. To clearly understand the wavelength effect in LDF measurements, other tests have to be performed.

Analysis of La Dehesa paleo-landslide. Central Pre-Andes of Argentina

NASA Astrophysics Data System (ADS)

Tapia Baldis, Carla; Rothis, Luis Martín; Perucca, Laura; Esper Angillieri, María; Vargas, Horacio; Ponce, David; Allis, Carlos

2018-04-01

The main objective of this paper is to consider the influence of Quaternary faults as likely triggering factor for rockslides occurrence in the Central Pre-Andes, a region with intense shallow seismic activity. A rockslide deposit was selected as study case, placed in the western flank of La Dehesa and Talacasto (DT) range (31°3‧37″ S and 68°46‧ 8″ W). Applied methodology includes the characterization of main discontinuities, reconstruction of the topography using a high-resolution digital elevation model, safety factor calculation along the sliding surface and, Newmark displacements estimation for three different hypothetical seismic scenarios, recreated from existing neotectonic local information. Equilibrium-limit method's results confirm that study case, La Dehesa rockslide (LDR), had a stable and safe slope's configuration under static conditions. However, a seismic horizontal coefficient between 0.2 and 0.3 decreases safety factor below the safety threshold. Newmark's displacements for different seismic reconstructed scenarios varies between 4.1 and 15.9 cm, values that agreed with a coherent failure process, likely triggered by Pleistocene to Holocene seismogenic sources in Central Pre-Andes. LDR trigger could be assigned mainly to an earthquake related to La Dehesa Quaternary fault (LDF) activity; however, similar movements produced by neighboring faults should not be discarded. LDR triggering related to climatic conditions is despised. Finally, the methodology presented in this work is easy to reproduce and may be applied to other rockslides located in the mountainous areas of the Central Pre-Andes of Argentina.

Increased Lucid Dreaming Frequency in Narcolepsy

PubMed Central

Rak, Michael; Beitinger, Pierre; Steiger, Axel; Schredl, Michael; Dresler, Martin

2015-01-01

Study Objective: Nightmares are a frequent symptom in narcolepsy. Lucid dreaming, i.e., the phenomenon of becoming aware of the dreaming state during dreaming, has been demonstrated to be of therapeutic value for recurrent nightmares. Data on lucid dreaming in narcolepsy patients, however, is sparse. The aim of this study was to evaluate the frequency of recalled dreams (DF), nightmares (NF), and lucid dreams (LDF) in narcolepsy patients compared to healthy controls. In addition, we explored if dream lucidity provides relief during nightmares in narcolepsy patients. Design: We interviewed patients with narcolepsy and healthy controls. Setting: Telephone interview. Patients: 60 patients diagnosed with narcolepsy (23–82 years, 35 females) and 919 control subjects (14–93 years, 497 females) Interventions: N/A. Measurements and Results: Logistic regression revealed significant (P < 0.001) differences in DF, NF, and LDF between narcolepsy patients and controls after controlling for age and gender, with effect sizes lying in the large range (Cohen's d > 0.8). The differences in NF and LDF between patients and controls stayed significant after controlling for DF. Comparison of 35 narcolepsy patients currently under medication with their former drug-free period revealed significant differences in DF and NF (z < 0.05, signed-rank test) but not LDF (z = 0.8). Irrespective of medication, 70% of narcolepsy patients with experience in lucid dreaming indicated that dream lucidity provides relief during nightmares. Conclusion: Narcolepsy patients experience a markedly higher lucid dreaming frequency compared to controls, and many patients report a positive impact of dream lucidity on the distress experienced from nightmares. Citation: Rak M, Beitinger P, Steiger A, Schredl M, Dresler M. Increased lucid dreaming frequency in narcolepsy. SLEEP 2015;38(5):787–792. PMID:25325481

Habitual dietary fibre intake influences gut microbiota response to an inulin-type fructan prebiotic: a randomised, double-blind, placebo-controlled, cross-over, human intervention study.

PubMed

Healey, Genelle; Murphy, Rinki; Butts, Christine; Brough, Louise; Whelan, Kevin; Coad, Jane

2018-01-01

Dysbiotic gut microbiota have been implicated in human disease. Diet-based therapeutic strategies have been used to manipulate the gut microbiota towards a more favourable profile. However, it has been demonstrated that large inter-individual variability exists in gut microbiota response to a dietary intervention. The primary objective of this study was to investigate whether habitually low dietary fibre (LDF) v. high dietary fibre (HDF) intakes influence gut microbiota response to an inulin-type fructan prebiotic. In this randomised, double-blind, placebo-controlled, cross-over study, thirty-four healthy participants were classified as LDF or HDF consumers. Gut microbiota composition (16S rRNA bacterial gene sequencing) and SCFA concentrations were assessed following 3 weeks of daily prebiotic supplementation (Orafti® Synergy 1; 16 g/d) or placebo (Glucidex® 29 Premium; 16 g/d), as well as after 3 weeks of the alternative intervention, following a 3-week washout period. In the LDF group, the prebiotic intervention led to an increase in Bifidobacterium (P=0·001). In the HDF group, the prebiotic intervention led to an increase in Bifidobacterium (P<0·001) and Faecalibacterium (P=0·010) and decreases in Coprococcus (P=0·010), Dorea (P=0·043) and Ruminococcus (Lachnospiraceae family) (P=0·032). This study demonstrates that those with HDF intakes have a greater gut microbiota response and are therefore more likely to benefit from an inulin-type fructan prebiotic than those with LDF intakes. Future studies aiming to modulate the gut microbiota and improve host health, using an inulin-type fructan prebiotic, should take habitual dietary fibre intake into account.

Beyond residential mobility: A broader conceptualization of instability and its impact on victimization risk among children.

PubMed

Merrick, Melissa T; Henly, Megan; Turner, Heather A; David-Ferdon, Corinne; Hamby, Sherry; Kacha-Ochana, Akadia; Simon, Thomas R; Finkelhor, David

2018-05-01

Predictability in a child's environment is a critical quality of safe, stable, nurturing relationships and environments, which promote wellbeing and protect against maltreatment. Research has focused on residential mobility's effect on this predictability. This study augments such research by analyzing the impact of an instability index-including the lifetime destabilization factors (LDFs) of natural disasters, homelessness, child home removal, multiple moves, parental incarceration, unemployment, deployment, and multiple marriages--on childhood victimizations. The cross-sectional, nationally representative sample of 12,935 cases (mean age = 8.6 years) was pooled from 2008, 2011, and 2014 National Surveys of Children's Exposure to Violence (NatSCEV). Logistic regression models controlling for demographics, socio-economic status, and family structure tested the association between excessive residential mobility, alone, and with LDFs, and past year childhood victimizations (sexual victimization, witnessing community or family violence, maltreatment, physical assault, property crime, and polyvictimization). Nearly 40% of the sample reported at least one LDF. Excessive residential mobility was significantly predictive of increased odds of all but two victimizations; almost all associations were no longer significant after other destabilizing factors were included. The LDF index without residential mobility was significantly predictive of increased odds of all victimizations (AOR's ranged from 1.36 to 1.69), and the adjusted odds ratio indicated a 69% increased odds of polyvictimization for each additional LDF a child experienced. The LDF index thus provides a useful alternative to using residential moves as the sole indicator of instability. These findings underscore the need for comprehensive supports and services to support stability for children and families. Copyright © 2018. Published by Elsevier Ltd.

Beyond residential mobility: A broader conceptualization of instability and its impact on victimization risk among children☆

PubMed Central

Merrick, Melissa T.; Henly, Megan; Turner, Heather A.; David-Ferdon, Corinne; Hamby, Sherry; Kacha-Ochana, Akadia; Simon, Thomas R.; Finkelhor, David

2018-01-01

Predictability in a child’s environment is a critical quality of safe, stable, nurturing relationships and environments, which promote wellbeing and protect against maltreatment. Research has focused on residential mobility’s effect on this predictability. This study augments such research by analyzing the impact of an instability index—including the lifetime destabilization factors (LDFs) of natural disasters, homelessness, child home removal, multiple moves, parental incarceration, unemployment, deployment, and multiple marriages–on childhood victimizations. The cross-sectional, nationally representative sample of 12,935 cases (mean age = 8.6 years) was pooled from 2008, 2011, and 2014 National Surveys of Children’s Exposure to Violence (NatSCEV). Logistic regression models controlling for demographics, socio-economic status, and family structure tested the association between excessive residential mobility, alone, and with LDFs, and past year childhood victimizations (sexual victimization, witnessing community or family violence, maltreatment, physical assault, property crime, and polyvictimization). Nearly 40% of the sample reported at least one LDF. Excessive residential mobility was significantly predictive of increased odds of all but two victimizations; almost all associations were no longer significant after other destabilizing factors were included. The LDF index without residential mobility was significantly predictive of increased odds of all victimizations (AOR’s ranged from 1.36 to 1.69), and the adjusted odds ratio indicated a 69% increased odds of polyvictimization for each additional LDF a child experienced. The LDF index thus provides a useful alternative to using residential moves as the sole indicator of instability. These findings underscore the need for comprehensive supports and services to support stability for children and families. PMID:29558715

Long-term repetitive sodium lauryl sulfate-induced irritation of the skin: an in vivo study.

PubMed

Branco, Nara; Lee, Ivy; Zhai, Hongbo; Maibach, Howard I

2005-11-01

Skin may adapt to topical irritants through accommodation. This study focuses on long-term exposure to irritants and attempts to demonstrate accommodation. Sodium lauryl sulfate (SLS) induced irritant contact dermatitis at 3 concentrations (0.025% to 0.075%). Distilled water, acetone and an empty chamber served as controls. Experimental compounds were applied to forearms of 7 healthy volunteers for 24 hr before replacing by a fresh chamber for 6 non-consecutive weeks over 103 days. Possible accommodation was quantified by visual scoring (erythema and dryness) and by bioengineering parameters: transepidermal water loss (TEWL), capacitance, chromametry and laser Doppler flowmetry (LDF). Significant erythema, dryness, elevated TEWL, skin colour reflectance and LDF values occurred during the exposure periods. Upon repeat exposure, an immediate and augmented response in erythema, TEWL, skin colour reflectance and LDF developed. However, irritant skin changes were not sustained. Irritation parameters return to baseline after cessation of exposure. There was no evidence of sustained irritation or accommodation after the last exposure. Study findings do not document sustained accommodation or adaptive hyposensitivity after long-term repetitive irritant exposure under these test conditions. Alternative models should be developed to prove or disprove the accommodation hypothesis.

Quantitative in vivo studies of hyperemia in the course of the tissue response to biomaterial implantation

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

Bouet, T.; Schmitt, M.; Desuzinges, C.

1990-11-01

Hyperemia associated with an inflammatory response has been investigated in rats, by using four different experimental models, i.e., positive and negative polymer implants from the pharmacopea, operative control, and abscess induced by turpentine oil. 133Xenon clearance, infrared thermography and Laser Doppler Flowmetry (LDF) were used to monitor the subcutaneous local hemodynamic changes from 1 to 40 postoperative days. LDF proved to be a sensitive, reproducible method, able to discriminate positive from negative implants already at the 3rd postoperative day and up to 40 days. This increased local blood flow was also visualized at the site of positive implants at themore » 14th and 21st postoperative days by means of 133Xe Clearance. Additional information obtained by infrared thermography allowed discrimination between positive implants and control sites but only at the very early stage (1 to 3 days). The significance of the different data collected by the three techniques was correlated with histological events occurring at the different implant sites. LDF may therefore represent a useful technique for noninvasive semiquantitative assessment of tissue response to biomaterials.« less

Vessel packaging effect in laser speckle contrast imaging and laser Doppler imaging.

PubMed

Fredriksson, Ingemar; Larsson, Marcus

2017-10-01

Laser speckle-based techniques are frequently used to assess microcirculatory blood flow. Perfusion estimates are calculated either by analyzing the speckle fluctuations over time as in laser Doppler flowmetry (LDF), or by analyzing the speckle contrast as in laser speckle contrast imaging (LSCI). The perfusion estimates depend on the amount of blood and its speed distribution. However, the perfusion estimates are commonly given in arbitrary units as they are nonlinear and depend on the magnitude and the spatial distribution of the optical properties in the tissue under investigation. We describe how the spatial confinement of blood to vessels, called the vessel packaging effect, can be modeled in LDF and LSCI, which affect the Doppler power spectra and speckle contrast, and the underlying bio-optical mechanisms for these effects. As an example, the perfusion estimate is reduced by 25% for LDF and often more than 50% for LSCI when blood is located in vessels with an average diameter of 40  μm, instead of being homogeneously distributed within the tissue. This significant effect can be compensated for only with knowledge of the average diameter of the vessels in the tissue. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Optical techniques for perfusion monitoring of the gastric tube after esophagectomy: a review of technologies and thresholds.

PubMed

Jansen, S M; de Bruin, D M; van Berge Henegouwen, M I; Strackee, S D; Veelo, D P; van Leeuwen, T G; Gisbertz, S S

2018-06-01

Anastomotic leakage is one of the most severe complications after esophageal resection with gastric tube reconstruction. Impaired perfusion of the gastric fundus is seen as the main contributing factor for this complication. Optical modalities show potential in recognizing compromised perfusion in real time, when ischemia is still reversible. This review provides an overview of optical techniques with the aim to evaluate the (1) quantitative measurement of change in perfusion in gastric tube reconstruction and (2) to test which parameters are the most predictive for anastomotic leakage.A Pubmed, MEDLINE, and Embase search was performed and articles on laser Doppler flowmetry (LDF), near-infrared spectroscopy (NIRS), laser speckle contrast imaging (LSCI), fluorescence imaging (FI), sidestream darkfield microscopy (SDF), and optical coherence tomography (OCT) regarding blood flow in gastric tube surgery were reviewed. Two independent reviewers critically appraised articles and extracted the data: Primary outcome was quantitative measure of perfusion change; secondary outcome was successful prediction of necrosis or anastomotic leakage by measured perfusion parameters.Thirty-three articles (including 973 patients and 73 animals) were selected for data extraction, quality assessment, and risk of bias (QUADAS-2). LDF, NIRS, LSCI, and FI were investigated in gastric tube surgery; all had a medium level of evidence. IDEAL stage ranges from 1 to 3. Most articles were found on LDF (n = 12), which is able to measure perfusion in arbitrary perfusion units with a significant lower amount in tissue with necrosis development and on FI (n = 12). With FI blood flow routes could be observed and flow was qualitative evaluated in rapid, slow, or low flow. NIRS uses mucosal oxygen saturation and hemoglobin concentration as perfusion parameters. With LSCI, a decrease of perfusion units is observed toward the gastric fundus intraoperatively. The perfusion units (LDF, LSCI), although arbitrary and not absolute values, and low flow or length of demarcation to the anastomosis (FI) both seem predictive values for necrosis intraoperatively. SDF and OCT are able to measure microvascular flow, intraoperative prediction of necrosis is not yet described.Optical techniques aim to improve perfusion monitoring by real-time, high-resolution, and high-contrast measurements and could therefore be valuable in intraoperative perfusion mapping. LDF and LSCI use perfusion units, and are therefore subjective in interpretation. FI visualizes influx directly, but needs a quantitative parameter for interpretation during surgery.

Extreme-value statistics of work done in stretching a polymer in a gradient flow.

PubMed

Vucelja, M; Turitsyn, K S; Chertkov, M

2015-02-01

We analyze the statistics of work generated by a gradient flow to stretch a nonlinear polymer. We obtain the large deviation function (LDF) of the work in the full range of appropriate parameters by combining analytical and numerical tools. The LDF shows two distinct asymptotes: "near tails" are linear in work and dominated by coiled polymer configurations, while "far tails" are quadratic in work and correspond to preferentially fully stretched polymers. We find the extreme value statistics of work for several singular elastic potentials, as well as the mean and the dispersion of work near the coil-stretch transition. The dispersion shows a maximum at the transition.

Physiological effects of indomethacin and celecobix: an S-transform laser Doppler flowmetry signal analysis

NASA Astrophysics Data System (ADS)

Assous, S.; Humeau, A.; Tartas, M.; Abraham, P.; L'Huillier, J. P.

2005-05-01

Conventional signal processing typically involves frequency selective techniques which are highly inadequate for nonstationary signals. In this paper, we present an approach to perform time-frequency selective processing of laser Doppler flowmetry (LDF) signals using the S-transform. The approach is motivated by the excellent localization, in both time and frequency, afforded by the wavelet basis functions. Suitably chosen Gaussian wavelet functions are used to characterize the subspace of signals that have a given localized time-frequency support, thus enabling a time-frequency partitioning of signals. In this paper, the goal is to study the influence of various pharmacological substances taken by the oral way (celecobix (Celebrex®), indomethacin (Indocid®) and placebo) on the physiological activity behaviour. The results show that no statistical differences are observed in the energy computed from the time-frequency representation of LDF signals, for the myogenic, neurogenic and endothelial related metabolic activities between Celebrex and placebo, and Indocid and placebo. The work therefore proves that these drugs do not affect these physiological activities. For future physiological studies, there will therefore be no need to exclude patients having taken cyclo-oxygenase 1 inhibitions.

Infrared Thermography-based Biophotonics: Integrated Diagnostic Technique for Systemic Reaction Monitoring

NASA Astrophysics Data System (ADS)

Vainer, Boris G.; Morozov, Vitaly V.

A peculiar branch of biophotonics is a measurement, visualisation and quantitative analysis of infrared (IR) radiation emitted from living object surfaces. Focal plane array (FPA)-based IR cameras make it possible to realize in medicine the so called interventional infrared thermal diagnostics. An integrated technique aimed at the advancement of this new approach in biomedical science and practice is described in the paper. The assembled system includes a high-performance short-wave (2.45-3.05 μm) or long-wave (8-14 μm) IR camera, two laser Doppler flowmeters (LDF) and additional equipment and complementary facilities implementing the monitoring of human cardiovascular status. All these means operate synchronously. It is first ascertained the relationship between infrared thermography (IRT) and LDF data in humans in regard to their systemic cardiovascular reactivity. Blood supply real-time dynamics in a narcotized patient is first visualized and quantitatively represented during surgery in order to observe how the general hyperoxia influences thermoregulatory mechanisms; an abrupt increase in temperature of the upper limb is observed using IRT. It is outlined that the IRT-based integrated technique may act as a take-off runway leading to elaboration of informative new methods directly applicable to medicine and biomedical sciences.

Relationship of oscillating and average components of laser Doppler flowmetry signal

NASA Astrophysics Data System (ADS)

Mizeva, Irina; Frick, Peter; Podtaev, Sergey

2016-08-01

Signals from laser Doppler flowmeters widely used in intravital studies of skin blood flow include, along with a slowly varying average component, an oscillating part. However, in most clinical studies, pulsations are usually smoothed by data preprocessing and only the mean blood flow is analyzed. To reveal the relationship between average and oscillating perfusion components measured by a laser Doppler flowmeter, we examined the microvascular response to the contralateral cold pressor test recorded at two different sites of the hand: dorsal part of the arm and finger pad. Such a protocol makes it possible to provide a wide range of perfusion. The average perfusion always decreases during cooling, while the oscillating component demonstrates a differently directed response. The wavelet analysis of laser Doppler flowmetry (LDF) signals shows that the pulsatile component is nonlinearly related to the average perfusion. Under low perfusion, the amplitude of pulsations is proportional to its mean value, but, as perfusion increases, the amplitude of pulsations becomes lower. The type of response is defined by the basal perfusion and the degree of vasoconstriction caused by cooling. Interpretation of the results is complicated by the nonlinear transfer function of the LDF device, the contribution of which is studied using artificial examples.

Evaluation of a high framerate multi-exposure laser speckle contrast imaging setup

NASA Astrophysics Data System (ADS)

Hultman, Martin; Fredriksson, Ingemar; Strömberg, Tomas; Larsson, Marcus

2018-02-01

We present a first evaluation of a new multi-exposure laser speckle contrast imaging (MELSCI) system for assessing spatial variations in the microcirculatory perfusion. The MELSCI system is based on a 1000 frames per second 1-megapixel camera connected to a field programmable gate arrays (FPGA) capable of producing MELSCI data in realtime. The imaging system is evaluated against a single point laser Doppler flowmetry (LDF) system during occlusionrelease provocations of the arm in five subjects. Perfusion is calculated from MELSCI data using current state-of-the-art inverse models. The analysis displayed a good agreement between measured and modeled data, with an average error below 6%. This strongly indicates that the applied model is capable of accurately describing the MELSCI data and that the acquired data is of high quality. Comparing readings from the occlusion-release provocation showed that the MELSCI perfusion was significantly correlated (R=0.83) to the single point LDF perfusion, clearly outperforming perfusion estimations based on a single exposure time. We conclude that the MELSCI system provides blood flow images of enhanced quality, taking us one step closer to a system that accurately can monitor dynamic changes in skin perfusion over a large area in real-time.

Microcirculation assessment using an individualized model for diffuse reflectance spectroscopy and conventional laser Doppler flowmetry

NASA Astrophysics Data System (ADS)

Strömberg, Tomas; Karlsson, Hanna; Fredriksson, Ingemar; Nyström, Fredrik H.; Larsson, Marcus

2014-05-01

Microvascular assessment would benefit from co-registration of blood flow and hemoglobin oxygenation dynamics during stimulus response tests. We used a fiber-optic probe for simultaneous recording of white light diffuse reflectance (DRS; 475-850 nm) and laser Doppler flowmetry (LDF; 780 nm) spectra at two source-detector distances (0.4 and 1.2 mm). An inverse Monte Carlo algorithm, based on a multiparameter three-layer adaptive skin model, was used for analyzing DRS data. LDF spectra were conventionally processed for perfusion. The system was evaluated on volar forearm recordings of 33 healthy subjects during a 5-min systolic occlusion protocol. The calibration scheme and the optimal adaptive skin model fitted DRS spectra at both distances within 10%. During occlusion, perfusion decreased within 5 s while oxygenation decreased slowly (mean time constant 61 s dissociation of oxygen from hemoglobin). After occlusion release, perfusion and oxygenation increased within 3 s (inflow of oxygenized blood). The increased perfusion was due to increased blood tissue fraction and speed. The supranormal hemoglobin oxygenation indicates a blood flow in excess of metabolic demands. In conclusion, by integrating DRS and LDF in a fiber-optic probe, a powerful tool for assessment of blood flow and oxygenation in the same microvascular bed has been presented.

Microcirculation assessment using an individualized model for diffuse reflectance spectroscopy and conventional laser Doppler flowmetry.

PubMed

Strömberg, Tomas; Karlsson, Hanna; Fredriksson, Ingemar; Nyström, Fredrik H; Larsson, Marcus

2014-05-01

Microvascular assessment would benefit from co-registration of blood flow and hemoglobin oxygenation dynamics during stimulus response tests. We used a fiber-optic probe for simultaneous recording of white light diffuse reflectance (DRS; 475-850 nm) and laser Doppler flowmetry (LDF; 780 nm) spectra at two source-detector distances (0.4 and 1.2 mm). An inverse Monte Carlo algorithm, based on a multiparameter three-layer adaptive skin model, was used for analyzing DRS data. LDF spectra were conventionally processed for perfusion. The system was evaluated on volar forearm recordings of 33 healthy subjects during a 5-min systolic occlusion protocol. The calibration scheme and the optimal adaptive skin model fitted DRS spectra at both distances within 10%. During occlusion, perfusion decreased within 5 s while oxygenation decreased slowly (mean time constant 61 s; dissociation of oxygen from hemoglobin). After occlusion release, perfusion and oxygenation increased within 3 s (inflow of oxygenized blood). The increased perfusion was due to increased blood tissue fraction and speed. The supranormal hemoglobin oxygenation indicates a blood flow in excess of metabolic demands. In conclusion, by integrating DRS and LDF in a fiber-optic probe, a powerful tool for assessment of blood flow and oxygenation in the same microvascular bed has been presented.

Optical monitoring of cerebral microcirculation in neurointensive care.

PubMed

Rejmstad, Peter; Haj-Hosseini, Neda; Åneman, Oscar; Wårdell, Karin

2017-12-08

Continuous optical monitoring of local cerebral microcirculation could benefit neurointensive care patients treated for subarachnoid hemorrhage (SAH). The aim of the study was to evaluate laser Doppler flowmetry (LDF) and diffuse reflectance spectroscopy (DRS) for long-term monitoring of brain microcirculation and oxygen saturation (SO 2 ) in the neurointensive care unit (NICU). A fiber optic probe was designed for intraparenchymal use and connected to LDF and DRS for assessment of the local blood flow (perfusion and tissue reflectance (TLI)) and SO 2 in the brain. The optically monitored parameters were compared with conventional NICU monitors and Xe-CT. The LDF signals were low with median and 25 to 75% interquartiles of perfusion = 70 (59 to 83) a.u. and TLI = 2.0 (1.0 to 2.4) a.u. and showed correlation with the NICU monitors in terms of heart rate. Median and interquartiles of SO 2 were 17.4 (15.7 to 19.8) %. The lack of correlation between local perfusion and cerebral perfusion pressure indicated intact cerebral autoregulation. The systems were capable of monitoring both local perfusion and SO 2 with stable signals in the NICU over 4 days. Further clinical studies are required to evaluate the optical systems' potential for assessing the onset of secondary brain injury.

[Microcirculatory blood and lymph flow examination in eyelid skin by laser Doppler flowmetry].

PubMed

Safonova, T N; Kintyukhina, N P; Sidorov, V V; Gladkova, O V; Reyn, E S

to study normal blood and lymph microcirculation of the upper and lower eyelids in different age groups. The study included 108 volunteers (216 eyes) aged from 20 to 80 years with no signs of changes in anterior segment structures, who were grouped by age ranges (20-30 years, 31-40 years, 41-50 years, 51-60 years, 61-70 years, and 71-80 years) into 6 groups equal in gender and quantitative composition. In all volunteers, microcirculation of the upper and lower eyelids was examined by laser Doppler flowmetry (LDF) ('LASMA MC-1' peripheral blood and lymph flow analyzer and 'LASMA MC' laser diagnostic complex, LASMA LLC). The average perfusion changes in blood and lymph flow as well as blood and lymph flow oscillations were analyzed. Blood and lymph flow in the microvasculature of the upper and lower eyelids is variable and depends on neither the age, nor gender of the test subject. On LDF-gram, every increase in amplitude of blood flow corresponds to a decrease in that of lymph flow. The non-invasive method of LDF expands our diagnostic capabilities as it enables assessment of not only blood, but also lymph flow. The data obtained can serve as a starting point for exploring microcirculation in different age groups in the presence of different pathological processes.

Effects of hypoxia on cochlear blood flow in mice evaluated using Doppler optical microangiography.

PubMed

Dziennis, Suzan; Reif, Roberto; Zhi, Zhongwei; Nuttall, Alfred L; Wang, Ruikang K

2012-10-01

Reduced cochlear blood flow (CoBF) is a main contributor to hearing loss. Studying CoBF has remained a challenge due to the lack of available tools. Doppler optical microangiography (DOMAG), a method to quantify single-vessel absolute blood flow, and laser Doppler flowmetry (LDF), a method for measuring the relative blood flow within a large volume of tissue, were used for determining the changes in CoBF due to systemic hypoxia in mice. DOMAG determined the change in blood flow in the apical turn (AT) with single-vessel resolution, while LDF averaged the change in the blood flow within a large volume of the cochlea (hemisphere with ∼1 to 1.5 mm radius). Hypoxia was induced by decreasing the concentration of oxygen-inspired gas, so that the oxygen saturation was reduced from >95% to ∼80%. DOMAG determined that during hypoxia the blood flow in two areas of the AT near and far from the helicotrema were increased and decreased, respectively. The LDF detected a decrease in blood flow within a larger volume of the cochlea (several turns averaged together). Therefore, the use of DOMAG as a tool for studying cochlear blood flow due to its ability to determine absolute flow values with single-vessel resolution was proposed.

Effects of hypoxia on cochlear blood flow in mice evaluated using Doppler optical microangiography

NASA Astrophysics Data System (ADS)

Dziennis, Suzan; Reif, Roberto; Zhi, Zhongwei; Nuttall, Alfred L.; Wang, Ruikang K.

2012-10-01

Reduced cochlear blood flow (CoBF) is a main contributor to hearing loss. Studying CoBF has remained a challenge due to the lack of available tools. Doppler optical microangiography (DOMAG), a method to quantify single-vessel absolute blood flow, and laser Doppler flowmetry (LDF), a method for measuring the relative blood flow within a large volume of tissue, were used for determining the changes in CoBF due to systemic hypoxia in mice. DOMAG determined the change in blood flow in the apical turn (AT) with single-vessel resolution, while LDF averaged the change in the blood flow within a large volume of the cochlea (hemisphere with ˜1 to 1.5 mm radius). Hypoxia was induced by decreasing the concentration of oxygen-inspired gas, so that the oxygen saturation was reduced from >95% to ˜80%. DOMAG determined that during hypoxia the blood flow in two areas of the AT near and far from the helicotrema were increased and decreased, respectively. The LDF detected a decrease in blood flow within a larger volume of the cochlea (several turns averaged together). Therefore, the use of DOMAG as a tool for studying cochlear blood flow due to its ability to determine absolute flow values with single-vessel resolution was proposed.

Dynamic characteristics of laser Doppler flowmetry signals obtained in response to a local and progressive pressure applied on diabetic and healthy subjects

NASA Astrophysics Data System (ADS)

Humeau, Anne; Koitka, Audrey; Abraham, Pierre; Saumet, Jean-Louis; L'Huillier, Jean-Pierre

2004-09-01

In the biomedical field, the laser Doppler flowmetry (LDF) technique is a non-invasive method to monitor skin perfusion. On the skin of healthy humans, LDF signals present a significant transient increase in response to a local and progressive pressure application. This vasodilatory reflex response may have important implications for cutaneous pathologies involved in various neurological diseases and in the pathophysiology of decubitus ulcers. The present work analyses the dynamic characteristics of these signals on young type 1 diabetic patients, and on healthy age-matched subjects. To obtain accurate dynamic characteristic values, a de-noising wavelet-based algorithm is first applied to LDF signals. All the de-noised signals are then normalised to the same value. The blood flow peak and the time to reach this peak are then calculated on each computed signal. The results show that a large vasodilation is present on signals of healthy subjects. The mean peak occurs at a pressure of 3.2 kPa approximately. However, a vasodilation of limited amplitude appears on type 1 diabetic patients. The maximum value is visualised, on the average, when the pressure is 1.1 kPa. The inability for diabetic patients to increase largely their cutaneous blood flow may bring explanations to foot ulcers.

Novel technique for laparoscopic harvesting of latissimus dorsi flap with prosthesis implantation for breast reconstruction

PubMed Central

Xu, Shuman; Tang, Peng; Chen, Xianchun; Yang, Xi; Pan, Qinwen; Gui, Yu; Chen, Li

2016-01-01

Abstract Backgroud: An important drawback of the traditional technique for harvesting latissimus dorsi (LD) myocutaneous flap is a long, posterior donor-site incision. Current techniques involve endoscopic or robotic harvesting via a combined approach of open and closed surgery, which necessitates an open axillary incision and the use of special retractors. In this paper, we introduce a fully enclosed laparoscopic technique for harvesting LD flap (LDF) using only 3 small trocar ports. This technique eliminates the need for axillary and donor-site incisions and specialized retractors and considerably reduces the incision size. Methods: We performed laparoscopic harvesting of LDF with prosthesis implantation for immediate breast reconstruction (IBR) after nipple-sparing mastectomy in 2 patients with malignant breast neoplasm who wished to avoid a long scar on the back. Results: IBR using this technique was uneventful in both cases, without any donor-site complications or flap failure. Both patients were satisfied with the esthetic results of the procedure, especially the absence of a visible scar on the back. Conclusion: Enclosed laparoscopic harvesting of LDF is simpler and less invasive than the traditional methods. These preliminary results warrant further evaluation in a larger population to validate the benefits of this technique. PMID:27861385

Laser Doppler flowmetry, transcutaneous oxygen tension measurements and Doppler pressure compared in patients undergoing amputation.

PubMed

Lantsberg, L; Goldman, M

1991-04-01

The level of amputation continues to present a challenge for surgeons. In view of this, 24 patients who required an amputation of their ischaemic leg were studied prospectively using Laser Doppler flowmetry (LDF), TcpO2 measurements and Doppler ultrasound to assess the best level for amputation. In all patients gangrene of the leg and rest pain were the indication for an amputation. Skin oxygen tension (TcpO2) and skin blood flow (LDF) measurements were obtained the day before surgery on the proposed anterior and posterior skin flaps for below knee amputation and the maximum Doppler systolic pressure was measured. The level of amputation was chosen at surgery by clinical judgement without reference to the measurements mentioned above. A below knee amputation was performed in 17 patients and an above knee in seven. All amputations healed by primary intention. Doppler pressures showed poor discrimination with a median value of 10 mmHg (0-25) in AK patients and 35 mmHg (0-85) in the BK group (p greater than 0.05). In contrast TcpO2 showed a trend. In the BK group the median value was 20 mmHg (4-50) on the anterior and 22 mmHg (2-60) on the posterior flap compared to above knee amputees with median values of 6 mmHg (2-11) and 8 mmHg (3-38), respectively (p greater than 0.05). Laser Doppler seemed more useful. In BK patients the median LDF values were 36 mV (20-85) on the anterior and 34 mV (20-80) on the posterior flap with median LDF values of 10 mV (10-18) on the anterior and 11 mV (8-38) on the posterior flap in the above knee group (p less than 0.01). Laser Doppler flowmetry is a simple objective test, which is a better discriminator of skin flap perfusion than either TcpO2 or Doppler ankle pressures.

Regional relation between skin blood flow and sweating to passive heating and local administration of acetylcholine in young, healthy humans.

PubMed

Smith, Caroline J; Kenney, W Larry; Alexander, Lacy M

2013-04-01

Regional variation in sweating over the human body is widely recognized yet variation in vasomotor responses and mechanisms causing this variation remain unclear. This study aimed to explore the relation between regional sweating rates (RSR) and skin blood flow (SkBF) responses to thermal and pharmacological stimuli in young, healthy subjects. In nine subjects (23 ± 3 yr), intradermal microdialysis (MD) probes were inserted into the ventral forearm, abdomen, thigh, and lower back and perfused with lactated Ringer solution. RSR over each MD membrane were measured using ventilated capsules with a laser Doppler probe housed in each capsule for measurement of red cell flux (laser Doppler flux, LDF) as an index of SkBF. Subjects completed a whole body heating protocol to 1°C rise in oral temperature and an acetylcholine dose response (ACh 1 × 10(-7)-0.1 M; mean skin temperature 34°C). Maximal LDF were obtained at the end of both protocols (50 mM sodium nitroprusside).During heating RSR varied among sites (P < 0.0001) and was greater on the back versus other sites (P < 0.05), but LDF was similar between sites (P = 0.343). RSR and SkBF showed a strong relation during initial (arm: r = 0.77 ± 0.09, thigh: r = 0.81 ± 0.08, abdomen: r = 0.89 ± 0.04, back: r = 0.86 ± 0.04) but not latter stages of heating. No differences in RSR (P = 0.160) or SkBF (LDF, P = 0.841) were observed between sites during ACh perfusion. Taken together, these data suggest that increases in SkBF are necessary to initiate and increase sweating, but further rises in RSR are not fully dependent on SkBF in a dose-response manner. Furthermore, RSR cannot be explained by cholinergic sensitivity or variation in SkBF.

On the modified grain-size-distribution method to evaluate the dynamic recrystallisation fraction in AISI 304 stainless steel

NASA Astrophysics Data System (ADS)

Hong, D. H.; Park, J. K.

2018-04-01

The purpose of the present work was to verify the grain size distribution (GSD) method, which was recently proposed by one of the present authors as a method for evaluating the fraction of dynamic recrystallisation (DRX) in a microalloyed medium carbon steel. To verify the GSD-method, we have selected a 304 stainless steel as a model system and have measured the evolution of the overall grain size distribution (including both the recrystallised and unrecrystallised grains) during hot compression at 1,000 °C in a Gleeble machine; the DRX fraction estimated using the GSD method is compared with the experimentally measured value via EBSD. The results show that the previous GSD method tends to overestimate the DRX fraction due to the utilisation of a plain lognormal distribution function (LDF). To overcome this shortcoming, we propose a modified GSD-method wherein an area-weighted LDF, in place of a plain LDF, is employed to model the evolution of GSD during hot deformation. Direct measurement of the DRX fraction using EBSD confirms that the modified GSD-method provides a reliable method for evaluating the DRX fraction from the experimentally measured GSDs. Reasonable agreement between the DRX fraction and softening fraction suggests that the Kocks-Mecking method utilising the Voce equation can be satisfactorily used to model the work hardening and dynamic recovery behaviour of steels during hot deformation.

Absorption and scattering coefficient dependence of laser-Doppler flowmetry models for large tissue volumes.

PubMed

Binzoni, T; Leung, T S; Rüfenacht, D; Delpy, D T

2006-01-21

Based on quasi-elastic scattering theory (and random walk on a lattice approach), a model of laser-Doppler flowmetry (LDF) has been derived which can be applied to measurements in large tissue volumes (e.g. when the interoptode distance is >30 mm). The model holds for a semi-infinite medium and takes into account the transport-corrected scattering coefficient and the absorption coefficient of the tissue, and the scattering coefficient of the red blood cells. The model holds for anisotropic scattering and for multiple scattering of the photons by the moving scatterers of finite size. In particular, it has also been possible to take into account the simultaneous presence of both Brownian and pure translational movements. An analytical and simplified version of the model has also been derived and its validity investigated, for the case of measurements in human skeletal muscle tissue. It is shown that at large optode spacing it is possible to use the simplified model, taking into account only a 'mean' light pathlength, to predict the blood flow related parameters. It is also demonstrated that the 'classical' blood volume parameter, derived from LDF instruments, may not represent the actual blood volume variations when the investigated tissue volume is large. The simplified model does not need knowledge of the tissue optical parameters and thus should allow the development of very simple and cost-effective LDF hardware.

Doppler ultrasonography and single-fiber laser Doppler flowmetry for measurement of hind limb blood flow in anesthetized horses.

PubMed

Raisis, A L; Young, L E; Taylor, P M; Walsh, K P; Lekeux, P

2000-03-01

To use Doppler ultrasonography and single-fiber laser Doppler flowmetry (LDF) to evaluate blood flow in the dependent and nondependent hind limbs of anesthetized horses and to evaluate changes in femoral arterial blood flow and microvascular skeletal muscle perfusion in response to administration of phenylephrine hydrochloride or dobutamine hydrochloride. 6 healthy adult horses. Horses were anesthetized and positioned in left lateral recumbency. Doppler ultrasonography was used to measure velocity and volumetric flow in the femoral vessels. Single-fiber LDF was used to measure relative microvascular perfusion at a single site in the semimembranosus muscles. Phenylephrine or dobutamine was then administered to decrease or increase femoral arterial blood flow, and changes in blood flow and microvascular perfusion were recorded. Administration of phenylephrine resulted in significant decreases in femoral arterial and venous blood flows and cardiac output and significant increases in mean aortic blood pressure, systemic vascular resistance, and PCV. Administration of dobutamine resulted in significant increases in femoral arterial blood flow, mean aortic blood pressure, and PCV. Significant changes in microvascular perfusion were not detected. Results suggest that Doppler ultrasonography and single-fiber LDF can be used to study blood flows in the hind limbs of anesthetized horses. However, further studies are required to determine why changes in femoral arterial blood flows were not associated with changes in microvascular perfusion.

Comparison Of Eigenvector-Based Statistical Pattern Recognition Algorithms For Hybrid Processing

NASA Astrophysics Data System (ADS)

Tian, Q.; Fainman, Y.; Lee, Sing H.

1989-02-01

The pattern recognition algorithms based on eigenvector analysis (group 2) are theoretically and experimentally compared in this part of the paper. Group 2 consists of Foley-Sammon (F-S) transform, Hotelling trace criterion (HTC), Fukunaga-Koontz (F-K) transform, linear discriminant function (LDF) and generalized matched filter (GMF). It is shown that all eigenvector-based algorithms can be represented in a generalized eigenvector form. However, the calculations of the discriminant vectors are different for different algorithms. Summaries on how to calculate the discriminant functions for the F-S, HTC and F-K transforms are provided. Especially for the more practical, underdetermined case, where the number of training images is less than the number of pixels in each image, the calculations usually require the inversion of a large, singular, pixel correlation (or covariance) matrix. We suggest solving this problem by finding its pseudo-inverse, which requires inverting only the smaller, non-singular image correlation (or covariance) matrix plus multiplying several non-singular matrices. We also compare theoretically the effectiveness for classification with the discriminant functions from F-S, HTC and F-K with LDF and GMF, and between the linear-mapping-based algorithms and the eigenvector-based algorithms. Experimentally, we compare the eigenvector-based algorithms using a set of image data bases each image consisting of 64 x 64 pixels.

Optical characteristics of modified fiber tips in single fiber, laser Doppler flowmetry

NASA Astrophysics Data System (ADS)

Oberg, P. Ake; Cai, Hongming; Rohman, Hakan; Larsson, Sven-Erik

1994-02-01

Percutaneous laser Doppler flowmetry (LDF) and bipolar surface electromyography (EMG) were used simultaneously for measurement of skeletal muscle (trapezius) perfusion in relation to static load and fatigue. On-line computer (386 SX) processing of the LDF- and EMG- signals made possible interpretation of the relationship between the perfusion and the activity of the muscle. The single fiber laser Doppler technique was used in order to minimize the trauma. A ray-tracing program was developed in the C language by which the optical properties of the fiber and fiber ends could be simulated. Isoirradiance graphs were calculated for three fiber end types and the radiance characteristics were measured for each fiber end. The three types of fiber-tips were evaluated and compared in flow model measurements.

On the determination of the depth of EAS development maximum using the lateral distribution of Cerenkov light at distances 150 m from EAS axis

NASA Technical Reports Server (NTRS)

Aliev, N.; Alimov, T.; Kakhkharov, M.; Makhmudov, B. M.; Rakhimova, N.; Tashpulatov, R.; Kalmykov, N. N.; Khristiansen, G. B.; Prosin, V. V.

1985-01-01

The Samarkand extensive air showers (EAS) array was used to measure the mean and individual lateral distribution functions (LDF) of EAS Cerenkov light. The analysis of the individual parameters b showed that the mean depth of EAS maximum and the variance of the depth distribution of maxima of EAS with energies of approx. 2x10 to the 15th power eV can properly be described in terms of Kaidalov-Martirosyan quark-gluon string model (QGSM).

The study of synchronization of rhythms of microvascular blood flow and oxygen saturation during adaptive changes

NASA Astrophysics Data System (ADS)

Dunaev, Andrey V.; Sidorov, Victor V.; Krupatkin, Alexander I.; Rafailov, Ilya E.; Palmer, Scott G.; Sokolovski, Sergei G.; Stewart, Neil A.; Rafailov, Edik U.

2014-02-01

Multi-functional laser non-invasive diagnostic systems, such as "LAKK-M", allow the study of a number of microcirculatory parameters, including blood microcirculatory index (Im) (by laser Doppler flowmetry, LDF) and oxygen saturation (StO2) of skin tissue (by tissue reflectance oximetry, TRO). Such systems may provide significant information relevant to physiology and clinical medicine. The aim of this research was to use such a system to study the synchronization of microvascular blood flow and oxygen saturation rhythms under normal and adaptive change conditions. Studies were conducted with 8 healthy volunteers - 3 females and 5 males of 21-49 years. Each volunteer was subjected to basic 3 minute tests. The volunteers were observed for between 1-4 months each, totalling 422 basic tests. Measurements were performed on the palmar surface of the right middle finger and the forearm medial surface. Wavelet analysis was used to study rhythmic oscillations in LDF- and TRO-data. Tissue oxygen consumption (from arterial and venal blood oxygen saturation and nutritive flux volume) was calculated for all volunteers during "adaptive changes" as (617+/-123 AU) and (102+/-38 AU) with and without arteriovenous anastomoses (AVAs) respectively. This demonstrates increased consumption compared to normal (495+/-170 AU) and (69+/-40 AU) with and without AVAs respectively. Data analysis demonstrated the emergence of resonance and synchronization of rhythms of microvascular blood flow and oxygen saturation as an adaptive change in myogenic oscillation (vasomotion) resulting from exercise and potentially from psychoemotional stress. Synchronization of myogenic rhythms during adaptive changes suggest increased oxygen consumption resulting from increased microvascular blood flow velocity.

PULPAL BLOOD FLOW CHANGES IN ABUTMENT TEETH OF REMOVABLE PARTIAL DENTURES

PubMed Central

Kunt, Göknil Ergün; Kökçü, Deniz; Ceylan, Gözlem; Yılmaz, Nergiz; Güler, Ahmet Umut

2009-01-01

The purpose of this study was to investigate the effect of tooth supported (TSD) and toothtissue supported (TTSD) removable partial denture wearing on pulpal blood flow (PBF) of the abutment teeth by using Laser Doppler Flowmeter (LDF). Measurements were carried out on 60 teeth of 28 patients (28 teeth and 12 patients of TTSD group, 32 teeth and 16 patients of TSD group) who had not worn any type of removable partial dentures before, had no systemic problems and were non smokers. PBF values were recorded by LDF before insertion (day 0) and after insertion of dentures at day 1, day 7 and day 30. Statistical analysis was performed by student t test and covariance analyses of repeated measurements. In the group TTSD, the mean values of PBF decreased statistically significantly at day 1 after insertion when compared with PBF values before insertion (p<0,01). There was no statistically significant difference among PBF mean values on 1st, 7th and 30th day. However, in the group TSD, there was no statistically significant difference among PBF mean values before insertion and on 1st, 7th and 30th day. In other words, PBF mean values in group TSD continued without changing statistically significant on 1st, 7th and 30th day. TTSD wearing may show negative effect on the abutment teeth due to decreasing basal PBF. PMID:20001995

Non-invasive diagnostic methods in dentistry

NASA Astrophysics Data System (ADS)

Todea, Carmen

2016-03-01

The paper, will present the most important non-invasive methods for diagnostic, in different fields of dentistry. Moreover, the laser-based methods will be emphasis. In orthodontics, 3D laser scanners are increasingly being used to establish database for normative population and cross-sectional growth changes but also to asses clinical outcomes in orthognatic surgical and non-surgical treatments. In prevention the main methods for diagnostic of demineralization and caries detection in early stages are represented by laser fluorescence - Quantitative Light Florescence (QLF); DiagnoDent-system-655nm; FOTI-Fiberoptic transillumination; DIFOTI-Digital Imaging Fiberoptic transillumination; and Optical Coherence Tomography (OCT). In odontology, Laser Doppler Flowmetry (LDF) is a noninvasive real time method used for determining the tooth vitality by monitoring the pulp microcirculation in traumatized teeth, fractured teeth, and teeth undergoing different conservative treatments. In periodontology, recently study shows the ability of LDF to evaluate the health of gingival tissue in periodontal tissue diseases but also after different periodontal treatments.

Parametric analysis of cherenkov light LDF from EAS for high energy gamma rays and nuclei: Ways of practical application

NASA Astrophysics Data System (ADS)

Elshoukrofy, A. Sh. M.; Postnikov, E. B.; Korosteleva, E. E.; Sveshnikova, L. G.; Motaweh, H. A.

2017-06-01

In this paper we propose a `knee-like' approximation of the lateral distribution of the Cherenkov light from extensive air showers in the energy range 30-3000 TeV and study a possibility of its practical application in high energy ground-based gamma-ray astronomy experiments (in particular, in TAIGA-HiSCORE). The approximation has a very good accuracy for individual showers and can be easily simplified for practical application in the HiSCORE wide angle timing array in the condition of a limited number of triggered stations.

Compression therapy in mixed ulcers increases venous output and arterial perfusion.

PubMed

Mosti, Giovanni; Iabichella, Maria Letizia; Partsch, Hugo

2012-01-01

This study was conducted to define bandage pressures that are safe and effective in treating leg ulcers of mixed arterial-venous etiology. In 25 patients with mixed-etiology leg ulcers who received inelastic bandages applied with pressures from 20 to 30, 31 to 40, and 41 to 50 mm Hg, the following measurements were performed before and after bandage application to ensure patient safety throughout the investigation: laser Doppler fluxmetry (LDF) close to the ulcer under the bandage and at the great toe, transcutaneous oxygen pressure (TcPo(2)) on the dorsum of the foot, and toe pressure. Ejection fraction (EF) of the venous pump was performed to assess efficacy on venous hemodynamics. LDF values under the bandages increased by 33% (95% confidence interval [CI], 17-48; P < .01), 28% (95% CI, 12-45; P < .05), and 10% (95% CI, -7 to 28), respectively, under the three pressure ranges applied. At toe level, a significant decrease in flux of -20% (95% CI, -48 to 9; P < .05) was seen when bandage pressure >41 mm Hg. Toe pressure values and TcPo(2) showed a moderate increase, excluding a restriction to arterial perfusion induced by the bandages. Inelastic bandages were highly efficient in improving venous pumping function, increasing the reduced ejection fraction by 72% (95% CI, 50%-95%; P < .001) under pressure of 21 to 30 mm Hg and by 103% (95% CI, 70%-128%; P < .001) at 31 to 40 mm Hg. In patients with mixed ulceration, an ankle-brachial pressure index >0.5 and an absolute ankle pressure of >60 mm Hg, inelastic compression of up to 40 mm Hg does not impede arterial perfusion but may lead to a normalization of the highly reduced venous pumping function. Such bandages are therefore recommended in combination with walking exercises as the basic conservative management for patients with mixed leg ulcers. Copyright © 2012 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Assessing the Effects of Acupuncture by Comparing Needling the Hegu Acupoint and Needling Nearby Nonacupoints by Spectral Analysis of Microcirculatory Laser Doppler Signals

PubMed Central

Hsiu, Hsin; Hsu, Wei-Chen; Hsu, Chia-Liang; Huang, Shih-Min

2011-01-01

We aimed to assess the effects of acupuncture by analyzing the frequency content of skin blood-flow signals simultaneously recorded at the Hegu acupoint and two nearby nonacupoints following acupuncture stimulation (AS). Laser Doppler flowmetry (LDF) signals were measured in male healthy volunteers in two groups of experiments: needling the Hegu acupoint (n = 13) and needling a nearby nonacupoint (control experiment; n = 10). Each experiment involved recording a 20 min baseline-data sequence and two sets of effects data recorded 0–20 and 50–70 min after stopping AS. Wavelet transform with Morlet mother wavelet was applied to the measured LDF signals. Needling the Hegu acupoint significantly increased the blood flow, significantly decreased the relative energy contribution at 0.02–0.06 Hz and significantly increased the relative energy contribution at 0.4–1.6 Hz at Hegu, but induced no significant changes at the nonacupoints. Also, needling a nearby nonacupoint had no effect in any band at any site. This is the first time that spectral analysis has been used to investigate the microcirculatory blood-flow responses induced by AS, and has revealed possible differences in sympathetic nerve activities between needling the Hegu acupoint and its nearby nonacupoint. One possible weakness of the present design is that different De-Qi feelings following AS could lead to nonblind experimental setup, which may bias the comparison between needling Hegu and its nearby nonacupoint. Our results suggest that the described noninvasive method can be used to evaluate sympathetic control of peripheral vascular activity, which might be useful for studying the therapeutic effects of AS. PMID:21804856

Neuronal nitric oxide synthase control mechanisms in the cutaneous vasculature of humans in vivo

PubMed Central

Kellogg, Dean L; Zhao, Joan L; Wu, Yubo

2008-01-01

The physiological roles of constituitively expressed nitric oxide synthase (NOS) isoforms in humans, in vivo, are unknown. Cutaneous vasodilatation during both central nervous system-mediated, thermoregulatory reflex responses to whole-body heat stress and during peripheral axon reflex-mediated, local responses to skin warming in humans depend on nitric oxide (NO) generation by constituitively expressed NOS of uncertain isoform. We hypothesized that neuronal NOS (nNOS, NOS I) effects cutaneous vasodilatation during whole-body heat stress, but not during local skin warming. We examined the effects of the nNOS inhibitor 7-nitroindazole (7-NI) administered by intradermal microdialysis on vasodilatation induced by whole-body heat stress or local skin warming. Skin blood flow (SkBF) was monitored by laser–Doppler flowmetry (LDF). Blood pressure (MAP) was monitored and cutaneous vascular conductance calculated (CVC = LDF/MAP). In protocol 1, whole-body heat stress was induced with water-perfused suits. In protocol 2, local skin warming was induced through local warming units at LDF sites. At the end of each protocol, 56 mm sodium nitroprusside was perfused at microdialysis sites to raise SkBF to maximal levels for data normalization. 7-NI significantly attenuated CVC increases during whole-body heat stress (P < 0.05), but had no effect on CVC increases induced by local skin warming (P > 0.05). These diametrically opposite effects of 7-NI on two NO-dependent processes verify selective nNOS antagonism, thus proving that the nNOS isoform affects NO increases and hence vasodilatation during centrally mediated, reflex responses to whole-body heat stress, but not during locally mediated, axon reflex responses to local skin warming. We conclude that the constituitively expressed nNOS isoform has distinct physiological roles in cardiovascular control mechanisms in humans, in vivo. PMID:18048451

Reduced Arteriovenous Shunting Capacity After Local Heating and Redistribution of Baseline Skin Blood Flow in Type 2 Diabetes Assessed With Velocity-Resolved Quantitative Laser Doppler Flowmetry

PubMed Central

Fredriksson, Ingemar; Larsson, Marcus; Nyström, Fredrik H.; Länne, Toste; Östgren, Carl J.; Strömberg, Tomas

2010-01-01

OBJECTIVE To compare the microcirculatory velocity distribution in type 2 diabetic patients and nondiabetic control subjects at baseline and after local heating. RESEARCH DESIGN AND METHODS The skin blood flow response to local heating (44°C for 20 min) was assessed in 28 diabetic patients and 29 control subjects using a new velocity-resolved quantitative laser Doppler flowmetry technique (qLDF). The qLDF estimates erythrocyte (RBC) perfusion (velocity × concentration), in a physiologically relevant unit (grams RBC per 100 g tissue × millimeters per second) in a fixed output volume, separated into three velocity regions: v <1 mm/s, v 1–10 mm/s, and v >10 mm/s. RESULTS The increased blood flow occurs in vessels with a velocity >1 mm/s. A significantly lower response in qLDF total perfusion was found in diabetic patients than in control subjects after heat provocation because of less high-velocity blood flow (v >10 mm/s). The RBC concentration in diabetic patients increased sevenfold for v between 1 and 10 mm/s, and 15-fold for v >10 mm/s, whereas no significant increase was found for v <1 mm/s. The mean velocity increased from 0.94 to 7.3 mm/s in diabetic patients and from 0.83 to 9.7 mm/s in control subjects. CONCLUSIONS The perfusion increase occurs in larger shunting vessels and not as an increase in capillary flow. Baseline diabetic patient data indicated a redistribution of flow to higher velocity regions, associated with longer duration of diabetes. A lower perfusion was associated with a higher BMI and a lower toe-to-brachial systolic blood pressure ratio. PMID:20393143

[The application of impulse magnetic therapy for the treatment of the patients presenting with lymphedema of the lower extremities].

PubMed

Kulchitskaya, D B; Gerasimenko, M Yu; Aphanova, T V; Konchugova, T V

The principal objective of the present work was to evaluate the influence of impulse magnetic therapy on the state of the microcirculatory system in the patients presenting with lymphedema of the lower extremities. The study included 59 patients with stage of 1 and 2 lymphedema who were divided into two groups. Those comprising the first group had impulse magnetic therapy applied to their lower extremities while the patients making up the second group served as controls. All the patients were examined with the use of the laser Doppler flowmetry (LDF) that revealed the initially present pathological changes in the microcirculatory system of their lower extremities. The study has demonstrated that the application of impulse magnetic therapy produced a positive effect on all the constituent components of the microcirculatory blood stream of the patients suffering from lymphedema of the lower extremities. Specifically, the initially increased arteriolar tonus was decreased, the blood flow in the capillary vessels was improved, and congestive phenomena in the venular segments of the microcirculation blood stream were markedly reduced. The results of the LDF examination in the control group gave no evidence of significant changes in the patients' microcirculatory system. The results of the LDF examination of the patients of the control group suggested the absence of any appreciable changes in the microcirculatory system. The present study has demonstrated the advisability of the application of impulse magnetic therapy for the treatment of the patients presenting with lymphedema of the lower extremities as a minimally invasive technique for the evaluation of the condition of the microcirculatory system and the objective assessment of the effectiveness of the outcomes of physiotherapy in the patients with vascular pathology.

Laser Doppler flowmetry evaluation of gingival recovery response after laser treatment

NASA Astrophysics Data System (ADS)

Todea, Carmen; Cânjǎu, Silvana; Dodenciu, Dorin; Miron, Mariana I.; Tudor, Anca; Bǎlǎbuc, Cosmin

2013-06-01

This study was performed in order to evaluate in vivo the applicability of Laser Doppler Flowmetry (LDF) in recording the gingival blood flow and to assess the changes of gingival blood flow following gingival reshaping performed with Er:YAG and 980 nm diode lasers. The LDF evaluation was performed on 20 anterior teeth, which underwent reshaping of gingiva, corresponding to 5 female patients (4 anterior teeth/patient), aged between 20 and 35. One part of the mouth was treated with Er:YAG laser (LP, VLP modes, 140 - 250 mJ, 10 - 20 Hz, using cylindrical sapphire tips) and other part with 980 nm diode laser (CW, 4 W, contact mode and saline solution cooling). The gingival blood flow was monitored using a MoorLab laser Doppler equipment (Moor Instruments Ltd., Axminster, UK) with a straight optical probe, MP3b, 10 mm. The data were processed using statistical analysis software SPSS v16.0.1. The investigation showed an evident decrease in perfusion for both areas in comparison with the baseline values 24 hours after treatment. The microvascular blood flow increased significantly after 7 days in both areas but mostly in diode area (p<0.001). After 14 days for the Er:YAG area the blood perfusion returned to the initial value. The results in diode area remained at a high level after 14 days. Both lasers proved efficiency in the surgical treatment of gingival tissue. Moreover, Laser Doppler Flowmetry is adequate for recording changes in gingival blood flow following periodontal surgery.

A Complex Approach to Noninvasive Estimation of Microcirculatory Tissue Impairments in Feet of Patients with Diabetes Mellitus using Spectroscopy

NASA Astrophysics Data System (ADS)

Potapova, E. V.; Dremin, V. V.; Zherebtsov, E. A.; Makovik, I. N.; Zharkikh, E. V.; Dunaev, A. V.; Pilipenko, O. V.; Sidorov, V. V.; Krupatkin, A. I.

2017-12-01

The possibility of a complex approach for studying changes in the system of blood microcirculation and metabolic processes in the biotissue of lower extremities using optical noninvasive methods of laser doppler flowmetry (LDF), fluorescence spectroscopy, and diffuse reflectance spectroscopy in combination with different modes of heating tests has been assessed. Seventy-six patients with type 2 diabetes mellitus, with 14 patients having visible trophic foot impairments, and 48 healthy volunteers have been examined. The parameters of LDF signals and spectra of fluorescence intensity and diffuse reflectance for foot skin have been analyzed. Statistically significant differences in the recorded parameters between the groups under study have been found. It has been concluded that combined application of noninvasive methods of spectroscopy could be used for diagnostics of complications both upon the occurrence of preliminary symptoms of diabetes, when pathological changes are still reversible, and in the presence of impairments to prevent aggravation of the disease and select an adequate correction of the treatment.

Local heat stress and skin blood flowmotion in subjects with familial predisposition or newly diagnosed hypertension.

PubMed

Gryglewska, Barbara; Nęcki, Mirosław; Cwynar, Marcin; Baron, Tomasz; Grodzicki, Tomasz

2010-12-01

The aim of the study was to investigate the skin microcirculation blood flow and flowmotion response to heat stress in normotensive subjects with familial predisposition to hypertension and in hypertensive patients. Normotensives without [NT(-)] or with [NT(+)] familial predisposition and subjects with newly diagnosed hypertension (HT) were studied. Clinic blood pressure (BP) measurements and ambulatory BP monitoring as well as laboratory assessments were performed. Resting (RF), heat (HF) and maximal heat (MHF) blood flows were measured using PeriFlux laser Doppler flowmetry (LDF) and expressed as absolute units (AU) and as index of cutaneous vascular conductance (CVC). Spectral analysis of the skin LDF signal was performed by means of the Perisoft dedicated software. Kruskall-Wallis analysis of variance, χ(2) statistic and multivariate reverse regression analysis were used for calculation. The studied population consisted of 70 persons (mean age 36.1 ± 10.3 years, 44.3% women): 17 NT(-), 22 NT(+) and 31 HT, age and gender matched. Higher values of body mass index (BMI), and insulin, glucose and triglyceride levels were observed in HT than in NT groups. RF, HF and MHF were similar in all study groups, but CVC of maximal heat flow differed (p=0.02); in particular, lower values were observed in the HT than in NT(-) group (p=0.01). The study groups differed with regard to total power (p=0.01) and myogenic (p=0.03) origin flowmotion with the lowest values in the NT(+) group. BMI and night BP characteristics were strong predictors of reduction of CVC, MHF and myogenic origin flowmotion. Skin microcirculation response to local heat stress is altered in hypertensive patients with decrease in maximal heat CVC values. Moreover, normotensive subjects with familial predisposition to hypertension are characterized by diminished myogenic origin of skin blood flowmotion.

The Nature of Dynamic Arteriolar Vasoreactivity: A Mini-Review and A classification Scheme

DTIC Science & Technology

1993-06-08

small veins. In this videomicroscopy study we always examined a junction of a true transverse (TR) and a true terminal (TE) arteriole within the muscle...by LDF), comparisons of vascular wall behavior were made from intravital videomicroscopy records. Vasoreactive behavior of the microvessels was

Spectral analysis of blood perfusion in the free latissimus dorsi myocutaneous flap and in normal skin

NASA Astrophysics Data System (ADS)

Liu, Xudong; Zeng, Bingfang; Fan, Cunyi; Jiang, Peizhu; Hu, Xiao

2006-01-01

To find the properties in the oscillatory components of the cutaneous blood flow on the successful free flap, a wavelet transform was applied to the laser Doppler flowmetry (LDF) signals which were measured simultaneously on the surfaces of the free latissimus dorsi myocutaneous flap and on the adjacent intact skin of the healthy limb, of 18 patients. The frequency interval from 0.0095 to 1.6 Hz was examined and was divided into five subintervals (I: 0.0095-0.021 Hz; II: 0.021-0.052 Hz; III: 0.052-0.145 Hz; IV: 0.145-0.6 Hz and V: 0.6-1.6 Hz) corresponding to endothelial metabolic, neurogenic, myogenic, respiratory and cardiac origins. The average amplitude and total power in the frequency range 0.0095-1.6 Hz as well as within subintervals I, II, IV and V were significantly lower for signals measured on the free flap than those obtained in the healthy limb. However in interval III, they were significantly higher. The normalized spectral amplitude and power in the free flap were significantly lower in only two intervals, I and II, yet in interval III they were significantly higher; no statistical significance was observed in intervals IV and V. The distinctive finding made in this study, aside from the decrease of endothelial metabolic processes and sympathetic control, was the significant increase of myogenic activity in the free flap. It is hoped that this work will contribute towards knowledge on blood circulation in free flaps and make the monitoring by LDF more reliable.

Towards a cosmic-ray mass-composition study at Tunka Radio Extension

NASA Astrophysics Data System (ADS)

Kostunin, D.; Bezyazeekov, P. A.; Budnev, N. M.; Fedorov, O.; Gress, O. A.; Haungs, A.; Hiller, R.; Huege, T.; Kazarina, Y.; Kleifges, M.; Korosteleva, E. E.; Krömer, O.; Kungel, V.; Kuzmichev, L. A.; Lubsandorzhiev, N.; Mirgazov, R. R.; Monkhoev, R.; Osipova, E. A.; Pakhorukov, A.; Pankov, L.; Prosin, V. V.; Rubtsov, G. I.; Schröder, F. G.; Wischnewski, R.; Zagorodnikov, A.

2017-03-01

The Tunka Radio Extension (Tunka-Rex) is a radio detector at the TAIGA facility located in Siberia nearby the southern tip of Lake Baikal. Tunka-Rex measures air-showers induced by high-energy cosmic rays, in particular, the lateral distribution of the radio pulses. The depth of the air-shower maximum, statistically depends on the mass of the primary particle, is determined from the slope of the lateral distribution function (LDF). Using a model-independent approach, we have studied possible features of the one-dimensional slope method and tried to find improvements for the reconstruction of primary mass. To study the systematic uncertainties given by different primary particles, we have performed simulations using the CONEX and CoREAS software packages of the recently released CORSIKA v7.5 including the modern high-energy hadronic models QGSJet-II.04 and EPOS-LHC. The simulations have shown that the largest systematic uncertainty in the energy deposit is due to the unknown primary particle. Finally, we studied the relation between the polarization and the asymmetry of the LDF.

Statistical classification approach to discrimination between weak earthquakes and quarry blasts recorded by the Israel Seismic Network

NASA Astrophysics Data System (ADS)

Kushnir, A. F.; Troitsky, E. V.; Haikin, L. M.; Dainty, A.

1999-06-01

A semi-automatic procedure has been developed to achieve statistically optimum discrimination between earthquakes and explosions at local or regional distances based on a learning set specific to a given region. The method is used for step-by-step testing of candidate discrimination features to find the optimum (combination) subset of features, with the decision taken on a rigorous statistical basis. Linear (LDF) and Quadratic (QDF) Discriminant Functions based on Gaussian distributions of the discrimination features are implemented and statistically grounded; the features may be transformed by the Box-Cox transformation z=(1/ α)( yα-1) to make them more Gaussian. Tests of the method were successfully conducted on seismograms from the Israel Seismic Network using features consisting of spectral ratios between and within phases. Results showed that the QDF was more effective than the LDF and required five features out of 18 candidates for the optimum set. It was found that discrimination improved with increasing distance within the local range, and that eliminating transformation of the features and failing to correct for noise led to degradation of discrimination.

Protective effect of estrogen in endothelin-induced middle cerebral artery occlusion in female rats.

PubMed

Glendenning, Michele L; Lovekamp-Swan, Tara; Schreihofer, Derek A

2008-11-14

Estrogen is a powerful endogenous and exogenous neuroprotective agent in animal models of brain injury, including focal cerebral ischemia. Although this protection has been demonstrated in several different treatment and injury paradigms, it has not been demonstrated in focal cerebral ischemia induced by intraparenchymal endothelin-1 injection, a model with many advantages over other models of experimental focal ischemia. Reproductively mature female Sprague-Dawley rats were ovariectomized and divided into placebo and estradiol-treated groups. Two weeks later, halothane-anesthetized rats underwent middle cerebral artery (MCA) occlusion by interparenchymal stereotactic injection of the potent vasoconstrictor endothelin 1 (180pmoles/2microl) near the middle cerebral artery. Laser-Doppler flowmetry (LDF) revealed similar reductions in cerebral blood flow in both groups. Animals were behaviorally evaluated before, and 2 days after, stroke induction, and infarct size was evaluated. In agreement with other models, estrogen treatment significantly reduced infarct size evaluated by both TTC and Fluoro-Jade staining and behavioral deficits associated with stroke. Stroke size was significantly correlated with LDF in both groups, suggesting that cranial perfusion measures can enhance success in this model.

Improvement of microcirculation and wound healing in vertical ridge augmentation after pre-treatment with self-inflating soft tissue expanders - a randomized study in dogs.

PubMed

Kaner, Dogan; Zhao, Han; Terheyden, Hendrik; Friedmann, Anton

2015-06-01

We investigated the effect of soft tissue expansion (STE) on vertical ridge augmentation with regard to the incidence of wound dehiscences and the impairment of microcirculation in dogs, and the applicability of laser Doppler flowmetry (LDF) to explore the relation between microcirculation and wound healing. Bone defects were created on both mandibular sides in ten beagle dogs by extraction of premolars and removal of bone. Six weeks later, self-filling tissue expanders were implanted in randomly assigned test sites. After 5 weeks of expansion, vertical augmentation was carried out in test and control sites using calvarial onlay grafts side by side with granular biphasic calcium phosphate covered with a resorbable polyethylene glycol membrane. Microcirculation was evaluated with laser Doppler flowmetry (LDF). The incidence of wound dehiscences was evaluated after 2 weeks. The validity of LDF to predict dehiscences was evaluated by construction of receiver operating characteristic (ROC) curves. After augmentation, test sites showed significantly better perfusion than control sites without preceding STE (P = 0.012). Three days after surgery, perfusion was still significantly decreased in control sites (P = 0.005), while microcirculation in test sites had returned to pre-surgical levels. After 2 weeks, healing in test sites was good, whereas eight dehiscences were found in control sites (P = 0.002). ROC curves showed that microcirculation levels immediately after augmentation surgery significantly predicted subsequent wound dehiscences (AUC = 0.799, CI 0.642-0.955, P = 0.006). Laser Doppler flowmetry is suitable for evaluation of soft tissue microcirculation after ridge augmentation. STE reduced the impairment of microcirculation caused by vertical ridge augmentation and decreased the incidence of wound dehiscences in the investigated animal model. © 2014 The Authors. Clinical Oral Implants Research Published by John Wiley & Sons Ltd.

Contributions of endothelial nitric oxide synthase, noradrenaline, and neuropeptide Y to local warming-induced cutaneous vasodilatation in men.

PubMed

Hodges, Gary J; Sparks, Paul A

2013-11-01

We performed a two-part study to determine the roles of endothelial nitric oxide synthase (eNOS) and the vasoconstrictor nerves neurotransmitters noradrenaline (NA) and neuropeptide Y (NPY) in the cutaneous vasodilator response to local skin warming. Forearm skin sites were instrumented with intradermal microdialysis fibres, local heaters, and laser-Doppler flow (LDF) probes. Sites were locally heated from 34 to 42°C. LDF was expressed as cutaneous vascular conductance (CVC; LDF/mean arterial pressure). In Part I, we tested whether sympathetic noradrenergic nerves acted via eNOS. In 8 male participants, treatments were as follows: 1) untreated; 2) bretylium tosylate (BT), preventing sympathetic neurotransmitter release; 3) l-NAA to inhibit eNOS; and 4) combined BT+l-NAA. At treated sites, the initial peak response was markedly reduced, and the plateau phase response to 35min of local warming was also reduced (P<0.05), which was not different among those sites (P>0.05). In Part II, we tested whether NA and NPY were involved in the vasodilator response to local warming. In Part IIa, treatments were: 1) untreated; 2) propranolol and yohimbine to antagonize α- and β-receptors; 3) l-NAA; and 4) combined propranolol, yohimbine, and l-NAA. In Part IIb, conditions were: 1) untreated; 2) BIBP to antagonize Y1-receptors; 3) l-NAA; and 4) combined BIBP and l-NAA. All treatments caused a reduction in the initial peak and plateau responses to local skin warming (P<0.05). The results of Part II indicate that both NA and NPY play roles in the cutaneous vasodilator response and their actions are achieved via eNOS. These data indicate that NA and NPY are involved in the initial, rapid rise in skin blood flow at the onset of local skin warming. However, their vasodilator actions in response to local skin warming appears to be manifested through eNOS. © 2013.

Skin reaction and regeneration after single sodium lauryl sulfate exposure stratified by filaggrin genotype and atopic dermatitis phenotype.

PubMed

Bandier, J; Carlsen, B C; Rasmussen, M A; Petersen, L J; Johansen, J D

2015-06-01

Filaggrin is key for the integrity of the stratum corneum. Mutations in the filaggrin gene (FLGnull) play a prominent role in atopic dermatitis (AD) pathogenesis. People with AD have increased susceptibility to irritants. However, little is known about the effect of filaggrin genotype and AD phenotype on irritant response and skin regeneration. To investigate the role of FLGnull and AD groups for skin reaction and recovery after sodium lauryl sulfate (SLS) irritation. This is a case-control study comprising 67 subjects, including healthy controls and patients with and without FLGnull and AD. Reactivity to different doses of SLS at 24, 48, 72 and 145 h after SLS application was measured by transepidermal water loss (TEWL) and laser Doppler flowmetry (LDF). Reactivity was assessed univariately and by pattern analysis. All patient groups showed a higher degree of skin-barrier disruption and inflammation than did controls in response to SLS. Assessing reactivity by the delta value of the area under the curve for both TEWL and LDF showed significant differences between healthy controls and those with the AD phenotype, irrespective of filaggrin mutation. The poorest regeneration was among those with the AD phenotype. The two AD phenotype groups were separated by multivariate technique, due to earlier inflammatory reactivity among subjects with FLGnullplus AD compared with the AD phenotype alone. Both skin reaction and regeneration were significantly different between the patient population and the healthy controls. Additionally, response severity and regeneration depended more on AD phenotype than on filaggrin genotype, whereas the response was more rapid among the FLGnullplus AD individuals. © 2015 British Association of Dermatologists.

An endoscopic laser Doppler flowmetry of a gastroduodenal mucosa at bleeding ulcer

NASA Astrophysics Data System (ADS)

Shapkin, U. G.; Kapralov, C. V.; Gogolev, A. A.; Lychagov, V. V.; Tuchin, V. V.

2006-08-01

One of the important problems of a bleeding gastroduodenal ulcer surgery is a prognosis of the recurrent hemorrhage and appraisal of endoscopic hemostasis quality. Endoscopic Laser Doppler Flowmetry of a mucous coat of stomach and a duodenum was made on 34 patients for the purpose of investigation of features of microcirculation. Analogous researches are made on 30 patients with a peptic ulcer and on 28 practically healthy people. Analysis of LDF-grams has shown certain differences in regional microcirculations in stomach and duodenal at normal and at a pathology. Increase of regional perfusion in periulcerose zone with its pathology disbalance can serve as a criterion for activities of an alteration processes in gastroduodenal ulcer defining the risk of possible hemorrhage.

Mapping the Limitations of Breakthrough Analysis in Fixed-Bed Adsorption

NASA Technical Reports Server (NTRS)

Knox, James Clinton

2017-01-01

The separation of gases through adsorption plays an important role in the chemical processing industry, where the separation step is often the costliest part of a chemical process and thus worthy of careful study and optimization. This work developed a number of new, archival aspects on the computer simulations used for the refinement and design of these gas adsorption processes: 1. Presented a new approach to fit the undetermined heat and mass transfer coefficients in the axially dispersed plug flow equation and associated balance equations 2. Examined and described the conditions where non-physical simulation results can arise 3. Presented an approach to determine the limits of the axial dispersion and LDF mass transfer terms above which non-physical simulation results occur.

Effects of Dose Frequency of Early Communication Intervention in Young Children with and without Down Syndrome

ERIC Educational Resources Information Center

Yoder, Paul; Woynaroski, Tiffany; Fey, Marc; Warren, Steven

2014-01-01

Children with intellectual disability were randomly assigned to receive Milieu Communication Teaching (MCT) at one 1-hr session per week (low dose frequency, LDF) or five 1-hr sessions per week (high dose frequency, HDF) over 9 months (Fey, Yoder, Warren, & Bredin-Oja, 2013. Non-Down syndrome (NDS) and Down syndrome (DS) subgroups were matched…

Torque Production in a Halbach Machine

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.; Vrnak, Daniel R.

2006-01-01

The NASA John H. Glenn Research Center initiated the investigation of torque production in a Halbach machine for the Levitated Ducted Fan (LDF) Project to obtain empirical data in determining the feasibility of using a Halbach motor for the project. LDF is a breakthrough technology for "Electric Flight" with the development of a clean, quiet, electric propulsor system. Benefits include zero emissions, decreased dependence on fossil fuels, increased efficiency, increased reliability, reduced maintenance, and decreased operating noise levels. A commercial permanent magnet brushless motor rotor was tested with a custom stator. An innovative rotor utilizing a Halbach array was designed and developed to fit directly into the same stator. The magnets are oriented at 90deg to the adjacent magnet, which cancels the magnetic field on the inside of the rotor and strengthens the field on the outside of the rotor. A direct comparison of the commercial rotor and the Halbach rotor was made. In addition, various test models were designed and developed to validate the basic principles described, and the theoretical work that was performed. The report concludes that a Halbach array based motor can provide significant improvements in electric motor performance and reliability.

Rate dependency and role of nitric oxide in the vascular response to direct cooling in human skin.

PubMed

Yamazaki, Fumio; Sone, Ryoko; Zhao, Kun; Alvarez, Guy E; Kosiba, Wojciech A; Johnson, John M

2006-01-01

Local cooling of nonglabrous skin without functional sympathetic nerves causes an initial vasodilation followed by vasoconstriction. To further characterize these responses to local cooling, we examined the importance of the rate of local cooling and the effect of nitric oxide synthase (NOS) inhibition in intact skin and in skin with vasoconstrictor function inhibited. Release of norepinephrine was blocked locally (iontophoresis) with bretylium tosylate (BT). Skin blood flow was monitored from the forearm by laser-Doppler flowmetry (LDF). Cutaneous vascular conductance (CVC) was calculated as the ratio of LDF to blood pressure. Local temperature was controlled over 6.3 cm2 around the sites of LDF measurement. Local cooling was applied at -0.33 or -4 degrees C/min. At -4 degrees C/min, CVC increased (P < 0.05) at BT sites in the early phase. At -0.33 degrees C/min, there was no early vasodilator response, but there was a delay in the onset of vasoconstriction relative to intact skin. The NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) (intradermal microdialysis) decreased (P < 0.05) CVC by 28.3 +/- 3.8% at untreated sites and by 46.9 +/- 6.3% at BT-treated sites from the value before infusion. Rapid local cooling (-4 degrees C/min) to 24 degrees C decreased (P < 0.05) CVC at both untreated (saline) sites and L-NAME only sites from the precooling levels, but it transiently increased (P < 0.05) CVC at both BT + saline sites and BT + L-NAME sites in the early phase. After 35-45 min of local cooling, CVC decreased at BT + saline sites relative to the precooling levels (P < 0.05), but at BT + L-NAME sites CVC was not reduced below the precooling level (P = 0.29). These findings suggest that the rate of local cooling, but not functional NOS, is an important determinant of the early non-adrenergic vasodilator response to local cooling and that functional NOS, adrenergic nerves, as well as other mechanisms play roles in vasoconstriction during prolonged local cooling of skin.

Inverse Monte Carlo in a multilayered tissue model: merging diffuse reflectance spectroscopy and laser Doppler flowmetry.

PubMed

Fredriksson, Ingemar; Burdakov, Oleg; Larsson, Marcus; Strömberg, Tomas

2013-12-01

The tissue fraction of red blood cells (RBCs) and their oxygenation and speed-resolved perfusion are estimated in absolute units by combining diffuse reflectance spectroscopy (DRS) and laser Doppler flowmetry (LDF). The DRS spectra (450 to 850 nm) are assessed at two source-detector separations (0.4 and 1.2 mm), allowing for a relative calibration routine, whereas LDF spectra are assessed at 1.2 mm in the same fiber-optic probe. Data are analyzed using nonlinear optimization in an inverse Monte Carlo technique by applying an adaptive multilayered tissue model based on geometrical, scattering, and absorbing properties, as well as RBC flow-speed information. Simulations of 250 tissue-like models including up to 2000 individual blood vessels were used to evaluate the method. The absolute root mean square (RMS) deviation between estimated and true oxygenation was 4.1 percentage units, whereas the relative RMS deviations for the RBC tissue fraction and perfusion were 19% and 23%, respectively. Examples of in vivo measurements on forearm and foot during common provocations are presented. The method offers several advantages such as simultaneous quantification of RBC tissue fraction and oxygenation and perfusion from the same, predictable, sampling volume. The perfusion estimate is speed resolved, absolute (% RBC×mm/s), and more accurate due to the combination with DRS.

Inverse Monte Carlo in a multilayered tissue model: merging diffuse reflectance spectroscopy and laser Doppler flowmetry

NASA Astrophysics Data System (ADS)

Fredriksson, Ingemar; Burdakov, Oleg; Larsson, Marcus; Strömberg, Tomas

2013-12-01

The tissue fraction of red blood cells (RBCs) and their oxygenation and speed-resolved perfusion are estimated in absolute units by combining diffuse reflectance spectroscopy (DRS) and laser Doppler flowmetry (LDF). The DRS spectra (450 to 850 nm) are assessed at two source-detector separations (0.4 and 1.2 mm), allowing for a relative calibration routine, whereas LDF spectra are assessed at 1.2 mm in the same fiber-optic probe. Data are analyzed using nonlinear optimization in an inverse Monte Carlo technique by applying an adaptive multilayered tissue model based on geometrical, scattering, and absorbing properties, as well as RBC flow-speed information. Simulations of 250 tissue-like models including up to 2000 individual blood vessels were used to evaluate the method. The absolute root mean square (RMS) deviation between estimated and true oxygenation was 4.1 percentage units, whereas the relative RMS deviations for the RBC tissue fraction and perfusion were 19% and 23%, respectively. Examples of in vivo measurements on forearm and foot during common provocations are presented. The method offers several advantages such as simultaneous quantification of RBC tissue fraction and oxygenation and perfusion from the same, predictable, sampling volume. The perfusion estimate is speed resolved, absolute (% RBC×mm/s), and more accurate due to the combination with DRS.

Differences in laser-Doppler indices between skin-surface measurement sites in subjects with diabetes.

PubMed

Hsiu, Hsin; Hu, Hsiao-Feng; Tsai, Hung-Chi

2018-01-01

This study performed laser-Doppler flowmetry (LDF) measurements with the aim of identifying differences in diabetes-induced microcirculatory-blood-flow (MBF) responses between the following skin surface measurement sites: an acupoint around the wrist, an acupoint around the ankle, and a nearby nonacupoint around the ankle. The 67 study subjects were assigned to diabetic, prediabetic, and healthy groups according to the results of oral glucose tolerance tests. Beat-to-beat and spectral analyses were applied to the LDF waveform to obtain the foot delay time (FDT), the flow rise time (FRT), and the relative energy contributions (RECs) in five frequency bands. FRT and FDT were significantly shorter and the RECs of the endothelial-, neural-, and myogenic-related frequency bands were significantly smaller in the diabetic group than in the control group at the acupoint around the ankle, but there were no such prominent differences at the other sites. The acupoint around the ankle was better than the nearby nonacupoint and the acupoint around the wrist for distinguishing the age-matched diabetic, prediabetic, and healthy subjects. These findings imply that when monitoring diabetes-induced MBF responses, the measurement locations should be chosen carefully in order to minimize interference effects and to improve the ability to distinguish subjects with different conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

Roles of nitric oxide synthase isoforms in cutaneous vasodilation induced by local warming of the skin and whole body heat stress in humans

PubMed Central

Zhao, Joan L.; Wu, Yubo

2009-01-01

Nitric oxide (NO) participates in the cutaneous vasodilation caused by increased local skin temperature (Tloc) and whole body heat stress in humans. In forearm skin, endothelial NO synthase (eNOS) participates in vasodilation due to elevated Tloc and neuronal NO synthase (nNOS) participates in vasodilation due to heat stress. To explore the relative roles and interactions of these isoforms, we examined the effects of a relatively specific eNOS inhibitor, Nω-amino-l-arginine (LNAA), and a specific nNOS inhibitor, Nω-propyl-l-arginine (NPLA), both separately and in combination, on skin blood flow (SkBF) responses to increased Tloc and heat stress in two protocols. In each protocol, SkBF was monitored by laser-Doppler flowmetry (LDF) and mean arterial pressure (MAP) by Finapres. Cutaneous vascular conductance (CVC) was calculated (CVC = LDF/MAP). Intradermal microdialysis was used to treat one site with 5 mM LNAA, another with 5 mM NPLA, a third with combined 5 mM LNAA and 5 mM NPLA (Mix), and a fourth site with Ringer only. In protocol 1, Tloc was controlled with combined LDF/local heating units. Tloc was increased from 34°C to 41.5°C to cause local vasodilation. In protocol 2, after a period of normothermia, whole body heat stress was induced (water-perfused suits). At the end of each protocol, all sites were perfused with 58 mM nitroprusside to effect maximal vasodilation for data normalization. In protocol 1, at Tloc = 34°C, CVC did not differ between sites (P > 0.05). LNAA and Mix attenuated CVC increases at Tloc = 41.5°C to similar extents (P < 0.05, LNAA or Mix vs. untreated or NPLA). In protocol 2, in normothermia, CVC did not differ between sites (P > 0.05). During heat stress, NPLA and Mix attenuated CVC increases to similar extents, but no significant attenuation occurred with LNAA (P < 0.05, NPLA or Mix vs. untreated or LNAA). In forearm skin, eNOS mediates the vasodilator response to increased Tloc and nNOS mediates the vasodilator response to heat stress. The two isoforms do not appear to interact during either response. PMID:19745188

Biosensors for brain trauma and dual laser doppler flowmetry: enoxaparin simultaneously reduces stroke-induced dopamine and blood flow while enhancing serotonin and blood flow in motor neurons of brain, in vivo.

PubMed

Broderick, Patricia A; Kolodny, Edwin H

2011-01-01

Neuromolecular Imaging (NMI) based on adsorptive electrochemistry, combined with Dual Laser Doppler Flowmetry (LDF) is presented herein to investigate the brain neurochemistry affected by enoxaparin (Lovenox(®)), an antiplatelet/antithrombotic medication for stroke victims. NMI with miniature biosensors enables neurotransmitter and neuropeptide (NT) imaging; each NT is imaged with a response time in milliseconds. A semiderivative electronic reduction circuit images several NT's selectively and separately within a response time of minutes. Spatial resolution of NMI biosensors is in the range of nanomicrons and electrochemically-induced current ranges are in pico- and nano-amperes. Simultaneously with NMI, the LDF technology presented herein operates on line by illuminating the living brain, in this example, in dorso-striatal neuroanatomic substrates via a laser sensor with low power laser light containing optical fiber light guides. NMI biotechnology with BRODERICK PROBE(®) biosensors has a distinct advantage over conventional electrochemical methodologies both in novelty of biosensor formulations and on-line imaging capabilities in the biosensor field. NMI with unique biocompatible biosensors precisely images NT in the body, blood and brain of animals and humans using characteristic experimentally derived half-wave potentials driven by oxidative electron transfer. Enoxaparin is a first line clinical treatment prescribed to halt the progression of acute ischemic stroke (AIS). In the present studies, BRODERICK PROBE(®) laurate biosensors and LDF laser sensors are placed in dorsal striatum (DStr) dopaminergic motor neurons in basal ganglia of brain in living animals; basal ganglia influence movement disorders such as those correlated with AIS. The purpose of these studies is to understand what is happening in brain neurochemistry and cerebral blood perfusion after causal AIS by middle cerebral artery occlusion in vivo as well as to understand consequent enoxaparin and reperfusion effects actually while enoxaparin is inhibiting blood clots to alleviate AIS symptomatology. This research is directly correlated with the medical and clinical needs of stroke victims. The data are clinically relevant, not only to movement dysfunction but also to the depressive mood that stroke patients often endure. These are the first studies to image brain neurotransmitters while any stroke medications, such as anti-platelet/anti-thrombotic and/or anti-glycoprotein are working in organ systems to alleviate the debilitating consequences of brain trauma and stroke/brain attacks.

Biosensors for Brain Trauma and Dual Laser Doppler Flowmetry: Enoxaparin Simultaneously Reduces Stroke-Induced Dopamine and Blood Flow while Enhancing Serotonin and Blood Flow in Motor Neurons of Brain, In Vivo

PubMed Central

Broderick, Patricia A.; Kolodny, Edwin H.

2011-01-01

Neuromolecular Imaging (NMI) based on adsorptive electrochemistry, combined with Dual Laser Doppler Flowmetry (LDF) is presented herein to investigate the brain neurochemistry affected by enoxaparin (Lovenox®), an antiplatelet/antithrombotic medication for stroke victims. NMI with miniature biosensors enables neurotransmitter and neuropeptide (NT) imaging; each NT is imaged with a response time in milliseconds. A semiderivative electronic reduction circuit images several NT’s selectively and separately within a response time of minutes. Spatial resolution of NMI biosensors is in the range of nanomicrons and electrochemically-induced current ranges are in pico- and nano-amperes. Simultaneously with NMI, the LDF technology presented herein operates on line by illuminating the living brain, in this example, in dorso-striatal neuroanatomic substrates via a laser sensor with low power laser light containing optical fiber light guides. NMI biotechnology with BRODERICK PROBE® biosensors has a distinct advantage over conventional electrochemical methodologies both in novelty of biosensor formulations and on-line imaging capabilities in the biosensor field. NMI with unique biocompatible biosensors precisely images NT in the body, blood and brain of animals and humans using characteristic experimentally derived half-wave potentials driven by oxidative electron transfer. Enoxaparin is a first line clinical treatment prescribed to halt the progression of acute ischemic stroke (AIS). In the present studies, BRODERICK PROBE® laurate biosensors and LDF laser sensors are placed in dorsal striatum (DStr) dopaminergic motor neurons in basal ganglia of brain in living animals; basal ganglia influence movement disorders such as those correlated with AIS. The purpose of these studies is to understand what is happening in brain neurochemistry and cerebral blood perfusion after causal AIS by middle cerebral artery occlusion in vivo as well as to understand consequent enoxaparin and reperfusion effects actually while enoxaparin is inhibiting blood clots to alleviate AIS symptomatology. This research is directly correlated with the medical and clinical needs of stroke victims. The data are clinically relevant, not only to movement dysfunction but also to the depressive mood that stroke patients often endure. These are the first studies to image brain neurotransmitters while any stroke medications, such as anti-platelet/anti-thrombotic and/or anti-glycoprotein are working in organ systems to alleviate the debilitating consequences of brain trauma and stroke/brain attacks. PMID:22346571

Dredging Operations Technical Support Program. Mathematical Model of the Consolidation/Desiccation Processes in Dredged Material.

DTIC Science & Technology

1985-07-01

5695 BF(I) - BETA(LDF) * GOTO 7 5700 6 NN - N-i 5705 Ch - CI / (ES(N)-ES(NN)) 5710 AF(I) w ALPHA(N) + CM*(ALPHA(N)-ALPHA(NN)) 5715 DF(I) a BETA(N) 4...1OXP34t4SETTLEMENT DUE TO CONSOLIDATION - PF1O.4) 7845 113 FORMAT(/1OX932HSETTLEMENT DUE TO DESICCATION - PF1O.4) 7850 114 FORNAT(/1OX920HSURFACE

Effect of continuous negative-pressure breathing on skin blood flow during exercise in a hot environment.

PubMed

Nagashima, K; Nose, H; Takamata, A; Morimoto, T

1998-06-01

To assess the impact of continuous negative-pressure breathing (CNPB) on the regulation of skin blood flow, we measured forearm blood flow (FBF) by venous-occlusion plethysmography and laser-Doppler flow (LDF) at the anterior chest during exercise in a hot environment (ambient temperature = 30 degreesC, relative humidity = approximately 30%). Seven male subjects exercised in the upright position at an intensity of 60% peak oxygen consumption rate for 40 min with and without CNPB after 20 min of exercise. The esophageal temperature (Tes) in both conditions increased to 38.1 degreesC by the end of exercise, without any significant differences between the two trials. Mean arterial pressure (MAP) increased by approximately 15 mmHg by 8 min of exercise, without any significant difference between the two trials before CNPB. However, CNPB reduced MAP by approximately 10 mmHg after 24 min of exercise (P < 0.05). The increase in FBF and LDF in the control condition leveled off after 18 min of exercise above a Tes of 37.7 degreesC, whereas in the CNPB trial the increase continued, with a rise in Tes despite the decrease in MAP. These results suggest that CNPB enhances vasodilation of skin above a Tes of approximately 38 degrees C by stretching intrathoracic baroreceptors such as cardiopulmonary baroreceptors.

Acupuncture Treatment of Diabetic Peripheral Neuropathy in an American Indian Community.

PubMed

Bailey, Anne; Wingard, Deborah; Allison, Matthew; Summers, Priscilla; Calac, Daniel

2017-04-01

Diabetic peripheral neuropathy (DPN) develops in 30% of type 2 diabetes patients, increases the risk for foot ulcers and amputation, and is a significant source of disability and medical costs. Treatment remains challenging, propelling research to focus on therapeutic methods that aim to improve blood circulation or ameliorate oxidative stress that drives development of DPN. The aim of this study was to assess the effectiveness of acupuncture treatment for DPN symptoms and lower extremity arterial circulation in people with type 2 diabetes. Twenty-five patients seen at a Southern California Tribal Health Center who reported a threshold level of diabetic neuropathy symptoms in the lower extremities during the previous 4 weeks received acupuncture treatment once per week over a 10-week period between 2011 and 2013. The Neuropathy Total Symptom Scale (NTSS-6), Neuropathy Disability Score (NDS), and laser Doppler fluxmetry (LDF) were used for assessment at baseline and 10 weeks. A total of 19 of 25 study participants completed the study and reported a significant reduction in the NTSS symptoms of aching pain, burning pain, prickling sensation, numbness, and allodynia. Lancinating pain did not decrease significantly. LDF measures improved but not significantly. Acupuncture may effectively ameliorate selected DPN symptoms in these American Indian patients. Copyright © 2017 Medical Association of Pharmacopuncture Institute. Published by Elsevier B.V. All rights reserved.

Histamine response and local cooling in the human skin: involvement of H1- and H2-receptors.

PubMed

Grossmann, M; Jamieson, M J; Kirch, W

1999-08-01

Histamine may contribute locally to cutaneous blood flow control under normal and pathologic conditions. The objective of this study was to observe the influence of skin temperature on histamine vasodilation, and the roles of H1-and H2-receptors using novel noninvasive methods. Eleven healthy subjects received, double-blind, single doses of the H1-receptor antagonist cetirizine (10 mg), cetirizine (10 mg) plus the H2-receptor antagonist cimetidine (400 mg), or placebo on separate occasions. Histamine was dosed cumulatively by iontophoresis to the forearm skin at 34 degrees C and 14 degrees C. Laser-Doppler flux (LDF) was measured at the same sites using customised probeholder/iontophoretic chambers with Peltier cooling elements. Finger mean arterial pressure (MAP) was measured and cutaneous vascular conductance calculated as LDF/MAP. Histamine vasodilation was reduced in cold skin. Cetirizine shifted the histamine dose-response at both temperatures: statistically significantly at 14 degrees C only. Combined H1- and H2-receptor antagonism shifted the response significantly at both temperatures. H1- and H2-receptors mediate histamine-induced skin vasodilation. The sensitivity of these receptors, particularly the H1- receptor, is attenuated at low skin temperature. Whether the reduced effect in cold skin represents specific receptor or postreceptor desensitization, or nonspecific attenuation of cutaneous vasodilation remains to be elucidated.

Cascade phenomenon against subsequent failures in complex networks

NASA Astrophysics Data System (ADS)

Jiang, Zhong-Yuan; Liu, Zhi-Quan; He, Xuan; Ma, Jian-Feng

2018-06-01

Cascade phenomenon may lead to catastrophic disasters which extremely imperil the network safety or security in various complex systems such as communication networks, power grids, social networks and so on. In some flow-based networks, the load of failed nodes can be redistributed locally to their neighboring nodes to maximally preserve the traffic oscillations or large-scale cascading failures. However, in such local flow redistribution model, a small set of key nodes attacked subsequently can result in network collapse. Then it is a critical problem to effectively find the set of key nodes in the network. To our best knowledge, this work is the first to study this problem comprehensively. We first introduce the extra capacity for every node to put up with flow fluctuations from neighbors, and two extra capacity distributions including degree based distribution and average distribution are employed. Four heuristic key nodes discovering methods including High-Degree-First (HDF), Low-Degree-First (LDF), Random and Greedy Algorithms (GA) are presented. Extensive simulations are realized in both scale-free networks and random networks. The results show that the greedy algorithm can efficiently find the set of key nodes in both scale-free and random networks. Our work studies network robustness against cascading failures from a very novel perspective, and methods and results are very useful for network robustness evaluations and protections.

The BESCT Lung Cancer Program (Biology, Education, Screening, Chemoprevention, and Treatment)

DTIC Science & Technology

2005-03-01

So 0 lDF Ep < a 185Total Nti of No, of NoWo 5t 1I 282 ir 47:419%) IN " 81 t~rlr’ 3 r 35 47 74 7 Fwrs 12 5 0 12 130 24 24 1 23 60 6238 S 1A 83 S.II...drugs. (NSAIDs)? In vitro versus in vivo results and the relevance for the prevention and treatment of cancer. Biochemn Pharmacol 2002; 63:343- 347 , 21

Laser Doppler flowmetry in endodontics: a review.

PubMed

Jafarzadeh, H

2009-06-01

Vascular supply is the most accurate marker of pulp vitality. Tests for assessing vascular supply that rely on the passage of light through a tooth have been considered as possible methods for detecting pulp vitality. Laser Doppler flowmetry (LDF), which is a noninvasive, objective, painless, semi-quantitative method, has been shown to be reliable for measuring pulpal blood flow. The relevant literature on LDF in the context of endodontics up to March 2008 was reviewed using PubMed and MEDLINE database searches. This search identified papers published between June 1983 and March 2008. Laser light is transmitted to the pulp by means of a fibre optic probe. Scattered light from moving red blood cells will be frequency-shifted whilst that from the static tissue remains unshifted. The reflected light, composed of Doppler-shifted and unshifted light, is returned by afferent fibres and a signal is produced. This technique has been successfully employed for estimating pulpal vitality in adults and children, differential diagnosis of apical radiolucencies (on the basis of pulp vitality), examining the reactions to pharmacological agents or electrical and thermal stimulation, and monitoring of pulpal responses to orthodontic procedures and traumatic injuries. Assessments may be highly susceptible to environmental and technique-related factors. Nonpulpal signals, principally from periodontal blood flow, may contaminate the signal. Because this test produces no noxious stimuli, apprehensive or distressed patients accept it more readily than current methods of pulp vitality assessment. A review of the literature and a discussion of the application of this system in endodontics are presented.

Assessment of long-term donor-site morbidity after harvesting the latissimus dorsi flap for neonatal myelomeningocele repair.

PubMed

Osinga, R; Mazzone, L; Meuli, M; Meuli-Simmen, C; von Campe, A

2014-08-01

The latissimus dorsi flap (LDF) has been employed very successfully over decades to cover large soft-tissue defects. Its donor-site morbidity has been extensively investigated in adults - but not in children - and is considered to be nonrestrictive. The aim of this long-term study was to assess donor-site morbidity with the modified Constant score more than 8 years after coverage of large myelomeningocele (MMC) defects with a reverse latissimus dorsi flap. Within the first days after birth, the reverse latissimus dorsi muscle flap was used uni- or bilaterally in three neonates to cover a large MMC defect. Bilateral shoulder function was tested more than 8 years postoperatively according to the modified Constant score. The mean age at follow-up was 11.7 years. None of the patients experienced any pain or shoulder restrictions during normal daily activities. They all managed to position both of their arms comfortably above the head. Forward flexion was normal in all patients as was abduction and external rotation. Dorsal extension was minimally reduced on the operated side. Internal rotation was symmetric in all patients; the extent of active movement varied from excellent to poor. Our long-term data suggest that there is no specific and significant impairment of shoulder function after using the distally pedicled reverse LDF for neonatal MMC repair. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Predictive Simulation of Gas Adsorption in Fixed-Beds and Limitations due to the Ill-Posed Danckwerts Boundary Condition

NASA Technical Reports Server (NTRS)

Knox, James Clinton

2016-01-01

The 1-D axially dispersed plug flow model is a mathematical model widely used for the simulation of adsorption processes. Lumped mass transfer coefficients such as the Glueckauf linear driving force (LDF) term and the axial dispersion coefficient are generally obtained by fitting simulation results to the experimental breakthrough test data. An approach is introduced where these parameters, along with the only free parameter in the energy balance equations, are individually fit to specific test data that isolates the appropriate physics. It is shown that with this approach this model provides excellent simulation results for the C02 on zeolite SA sorbent/sorbate system; however, for the H20 on zeolite SA system, non-physical deviations from constant pattern behavior occur when fitting dispersive experimental results with a large axial dispersion coefficient. A method has also been developed that determines a priori what values of the LDF and axial dispersion terms will result in non-physical simulation results for a specific sorbent/sorbate system when using the one-dimensional axially dispersed plug flow model. A relationship between the steepness of the adsorption equilibrium isotherm as indicated by the distribution factor, the magnitude of the axial dispersion and mass transfer coefficient, and the resulting non-physical behavior is derived. This relationship is intended to provide a guide for avoiding non-physical behavior by limiting the magnitude of the axial dispersion term on the basis of the mass transfer coefficient and distribution factor.

Investigation of Doppler spectra of laser radiation scattered inside hand skin during occlusion test

NASA Astrophysics Data System (ADS)

Kozlov, I. O.; Zherebtsov, E. A.; Zherebtsova, A. I.; Dremin, V. V.; Dunaev, A. V.

2017-11-01

Laser Doppler flowmetry (LDF) is a method widely used in diagnosis of microcirculation diseases. It is well known that information about frequency distribution of Doppler spectrum of the laser radiation scattered by moving red blood cells (RBC) usually disappears after signal processing procedure. Photocurrent’s spectrum distribution contains valuable diagnostic information about velocity distribution of the RBC. In this research it is proposed to compute the indexes of microcirculation in the sub-ranges of the Doppler spectrum as well as investigate the frequency distribution of the computed indexes.

The effects of L-arginine on cerebral hemodynamics after controlled cortical impact injury in the mouse.

PubMed

Liu, Hao; Goodman, J Clay; Robertson, Claudia S

2002-03-01

Traumatic brain injury (TBI) induces vascular changes that may influence neurological outcome by causing the brain to be more susceptible to secondary ischemic insults. In rat models of TBI, L-arginine administration has been shown to restore cerebral blood flow and improve neurological outcome. The purpose of this study was to determine if hypoperfusion occurs in a mouse model of TBI and if L-arginine administration has the same beneficial effects after injury in the mouse. C57BL6 mice were anesthetized with isoflurane, intubated and mechanically ventilated, and underwent a 3-m/sec, 1.5-mm deformation cortical impact injury. Five minutes after injury, L-arginine, 300 mg/kg, or saline were administered. Arterial blood pressure, intracranial pressure, and laser Doppler flow at the impact site were monitored for 3 h after the injury. The cerebral hemodynamic effects of the TBI induced by cortical impact injury were similar to that previously observed in rats. Intracranial hypertension, with ICP peaking at 46+/-2 mm Hg, and systemic hypotension both contributed to a reduction in CPP. In addition, LDF decreased significantly at the impact site. L-Arginine administration restored LDF to near baseline levels without increasing ICP. These studies demonstrate that cerebral hemodynamics can be measured in mouse models of TBI. The changes in cerebral hemodynamics are relatively simlar to those see in the rat model of cortical impact injury and suggest an important role for nitric oxide metabolism in the maintenance of cerebral blood flow following TBI.

Flight microangiopathy on long-haul flights: prevention of edema and microcirculation alterations with Venoruton.

PubMed

Cesarone, M R; Belcaro, G; Geroulakos, G; Griffin, M; Ricci, A; Brandolini, R; Pellegrini, L; Dugall, M; Ippolito, E; Candiani, C; Simeone, E; Errichi, B M; Di Renzo, A

2003-04-01

The aim of this study was the evaluation of the effects of Venoruton (HR) on the prevention and control of flight microangiopathy and edema in subjects with varicose veins flying for more than 7 hours. A group of 80 patients with varicose veins, edema, and initial skin alterations due to chronic venous hypertension were included. Measurements of skin laser Doppler (LDF) resting flux (RF), PO2 and rate of ankle swelling (RAS), were made before and after the flights (within 2 hours before the flights and within 2 hours after the flights). The length of the flights was between 7 and 9 hours; all seats were in coach class. The two groups (treatment and control) were comparable for age and sex distribution. The variation (decrease) in PO2 was significant in both groups. In subjects treated with HR the decrease in PO2 was smaller (p < 0.05). The decrease in LDF-RF was significant in both groups with a higher flux at the end of the flight in the treated subjects (p < 0.05). The venoarteriolar response was decreased at the end of the flights. The decrease was less evident in the treatment group (p < 0.05). The increase in RAS was significant in the control group while it was limited in the HR group. In conclusion, HR is useful for reducing the increased capillary filtration and in controlling edema in patients with chronic venous disease in long-haul flights. HR is effective to control flight microangiopathy associated with edema.

Reliability of laser Doppler, near-infrared spectroscopy and Doppler ultrasound for peripheral blood flow measurements during and after exercise in the heat.

PubMed

Choo, Hui C; Nosaka, Kazunori; Peiffer, Jeremiah J; Ihsan, Mohammed; Yeo, Chow C; Abbiss, Chris R

2017-09-01

This study examined the test-retest reliability of near-infrared spectroscopy (NIRS), laser Doppler flowmetry (LDF) and Doppler ultrasound to assess exercise-induced haemodynamics. Nine men completed two identical trials consisting of 25-min submaximal cycling at first ventilatory threshold followed by repeated 30-s bouts of high-intensity (90% of peak power) cycling in 32.8 ± 0.4°C and 32 ± 5% relative humidity (RH). NIRS (tissue oxygenation index [TOI] and total haemoglobin [tHb]) and LDF (perfusion units [PU]) signals were monitored continuously during exercise, and leg blood flow was assessed by Doppler ultrasound at baseline and after exercise. Cutaneous vascular conductance (CVC; PU/mean arterial pressure (MAP)) was expressed as the percentage change from baseline (%CVC BL ). Coefficients of variation (CVs) as indicators of absolute reliability were 18.7-28.4%, 20.2-33.1%, 42.5-59.8%, 7.8-12.4% and 22.2-30.3% for PU, CVC, %CVC BL , TOI and tHb, respectively. CVs for these variables improved as exercise continued beyond 10 min. CVs for baseline and post-exercise leg blood flow were 17.8% and 10.5%, respectively. CVs for PU, tHb (r 2  = 0.062) and TOI (r 2  = 0.002) were not correlated (P > 0.05). Most variables demonstrated CVs lower than the expected changes (35%) induced by training or heat stress; however, minimum of 10 min exercise is recommended for more reliable measurements.

Combining functional and structural tests improves the diagnostic accuracy of relevance vector machine classifiers

PubMed Central

Racette, Lyne; Chiou, Christine Y.; Hao, Jiucang; Bowd, Christopher; Goldbaum, Michael H.; Zangwill, Linda M.; Lee, Te-Won; Weinreb, Robert N.; Sample, Pamela A.

2009-01-01

Purpose To investigate whether combining optic disc topography and short-wavelength automated perimetry (SWAP) data improves the diagnostic accuracy of relevance vector machine (RVM) classifiers for detecting glaucomatous eyes compared to using each test alone. Methods One eye of 144 glaucoma patients and 68 healthy controls from the Diagnostic Innovations in Glaucoma Study were included. RVM were trained and tested with cross-validation on optimized (backward elimination) SWAP features (thresholds plus age; pattern deviation (PD); total deviation (TD)) and on Heidelberg Retina Tomograph II (HRT) optic disc topography features, independently and in combination. RVM performance was also compared to two HRT linear discriminant functions (LDF) and to SWAP mean deviation (MD) and pattern standard deviation (PSD). Classifier performance was measured by the area under the receiver operating characteristic curves (AUROCs) generated for each feature set and by the sensitivities at set specificities of 75%, 90% and 96%. Results RVM trained on combined HRT and SWAP thresholds plus age had significantly higher AUROC (0.93) than RVM trained on HRT (0.88) and SWAP (0.76) alone. AUROCs for the SWAP global indices (MD: 0.68; PSD: 0.72) offered no advantage over SWAP thresholds plus age, while the LDF AUROCs were significantly lower than RVM trained on the combined SWAP and HRT feature set and on HRT alone feature set. Conclusions Training RVM on combined optimized HRT and SWAP data improved diagnostic accuracy compared to training on SWAP and HRT parameters alone. Future research may identify other combinations of tests and classifiers that can also improve diagnostic accuracy. PMID:19528827

Quantitative evaluation of deep and shallow tissue layers' contribution to fNIRS signal using multi-distance optodes and independent component analysis.

PubMed

Funane, Tsukasa; Atsumori, Hirokazu; Katura, Takusige; Obata, Akiko N; Sato, Hiroki; Tanikawa, Yukari; Okada, Eiji; Kiguchi, Masashi

2014-01-15

To quantify the effect of absorption changes in the deep tissue (cerebral) and shallow tissue (scalp, skin) layers on functional near-infrared spectroscopy (fNIRS) signals, a method using multi-distance (MD) optodes and independent component analysis (ICA), referred to as the MD-ICA method, is proposed. In previous studies, when the signal from the shallow tissue layer (shallow signal) needs to be eliminated, it was often assumed that the shallow signal had no correlation with the signal from the deep tissue layer (deep signal). In this study, no relationship between the waveforms of deep and shallow signals is assumed, and instead, it is assumed that both signals are linear combinations of multiple signal sources, which allows the inclusion of a "shared component" (such as systemic signals) that is contained in both layers. The method also assumes that the partial optical path length of the shallow layer does not change, whereas that of the deep layer linearly increases along with the increase of the source-detector (S-D) distance. Deep- and shallow-layer contribution ratios of each independent component (IC) are calculated using the dependence of the weight of each IC on the S-D distance. Reconstruction of deep- and shallow-layer signals are performed by the sum of ICs weighted by the deep and shallow contribution ratio. Experimental validation of the principle of this technique was conducted using a dynamic phantom with two absorbing layers. Results showed that our method is effective for evaluating deep-layer contributions even if there are high correlations between deep and shallow signals. Next, we applied the method to fNIRS signals obtained on a human head with 5-, 15-, and 30-mm S-D distances during a verbal fluency task, a verbal working memory task (prefrontal area), a finger tapping task (motor area), and a tetrametric visual checker-board task (occipital area) and then estimated the deep-layer contribution ratio. To evaluate the signal separation performance of our method, we used the correlation coefficients of a laser-Doppler flowmetry (LDF) signal and a nearest 5-mm S-D distance channel signal with the shallow signal. We demonstrated that the shallow signals have a higher temporal correlation with the LDF signals and with the 5-mm S-D distance channel than the deep signals. These results show the MD-ICA method can discriminate between deep and shallow signals. Copyright © 2013 Elsevier Inc. All rights reserved.

Levitated Duct Fan (LDF) Aircraft Auxiliary Generator

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J.; Emerson, Dawn C.; Gallo, Christopher A.; Thompson, William K.

2011-01-01

This generator concept includes a novel stator and rotor architecture made from composite material with blades attached to the outer rotating shell of a ducted fan drum rotor, a non-contact support system between the stator and rotor using magnetic fields to provide levitation, and an integrated electromagnetic generation system. The magnetic suspension between the rotor and the stator suspends and supports the rotor within the stator housing using permanent magnets attached to the outer circumference of the drum rotor and passive levitation coils in the stator shell. The magnets are arranged in a Halbach array configuration.

Spectral analysis of the microcirculatory laser Doppler signal at the Hoku acupuncture point.

PubMed

Hsiu, Hsin; Hsu, Wei-Chen; Huang, Shih-Ming; Hsu, Chia-Liang; Lin Wang, Yuh-Ying

2009-05-01

We aimed to characterize the frequency spectra of skin blood flow signals recorded at Hoku, an important acupuncture point (acupoint) in oriental medicine. Electrocardiogram (ECG) and laser Doppler flowmetry signals were measured simultaneously in 31 trials on seven volunteers aged 21-27 years. A four-level Haar wavelet transform was applied to the measured 20 min laser Doppler flowmetry (LDF) signals, and periodic oscillations with five characteristic frequency peaks were obtained within the following frequency bands: 0.0095-0.021 Hz, 0.021-0.052 Hz, 0.052-0.145 Hz, 0.145-0.6 Hz, and 0.6-1.6 Hz (defined as FR1-FR5), respectively. The relative energy contribution in FR3 was significantly larger at Hoku than at the two non-acupoints. Linear regression analysis revealed that the relative energy contribution in FR3 at Hoku significantly increased with the pulse pressure (R(2) = 0.48; P < 0.01 by F-test). Spectral analysis of the flux signal revealed that one of the major microcirculatory differences between acupoints and non-acupoints was in the different myogenic responses of their vascular beds. This information may aid the development of a method for the non-invasive study of the microcirculatory characteristics of the acupoint.

Hemodynamic parameters change earlier than tissue oxygen tension in hemorrhage.

PubMed

Pestel, Gunther J; Fukui, Kimiko; Kimberger, Oliver; Hager, Helmut; Kurz, Andrea; Hiltebrand, Luzius B

2010-05-15

Untreated hypovolemia results in impaired outcome. This study tests our hypothesis whether general hemodynamic parameters detect acute blood loss earlier than monitoring parameters of regional tissue beds. Eight pigs (23-25 kg) were anesthetized and mechanically ventilated. A pulmonary artery catheter and an arterial catheter were inserted. Tissue oxygen tension was measured with Clark-type electrodes in the jejunal and colonic wall, in the liver, and subcutaneously. Jejunal microcirculation was assessed by laser Doppler flowmetry (LDF). Intravascular volume was optimized using difference in pulse pressure (dPP) to keep dPP below 13%. Sixty minutes after preparation, baseline measurements were taken. At first, 5% of total blood volume was withdrawn, followed by another 5% increment, and then in 10% increments until death. After withdrawal of 5% of estimated blood volume, dPP increased from 6.1% +/- 3.0% to 20.8% +/- 2.7% (P < 0.01). Mean arterial pressure (MAP), mean pulmonary artery pressure (PAP) and pulmonary artery occlusion pressure (PAOP) decreased with a blood loss of 10% (P < 0.01). Cardiac output (CO) changed after a blood loss of 20% (P < 0.05). Tissue oxygen tension in central organs, and blood flow in the jejunal muscularis decreased (P < 0.05) after a blood loss of 20%. Tissue oxygen tension in the skin, and jejunal mucosa blood flow decreased (P < 0.05) after a blood loss of 40% and 50%, respectively. In this hemorrhagic pig model systemic hemodynamic parameters were more sensitive to detect acute hypovolemia than tissue oxygen tension measurements or jejunal LDF measurements. Acute blood loss was detected first by dPP. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Changes in human pulp blood flow during canine retraction.

PubMed

Sabuncuoglu, Fidan Alakus; Ersahan, Seyda

2016-08-01

To evaluate the effects of maxillary canine retraction on pulpal blood flow (PBF) in humans as recorded by laser Doppler flowmetry (LDF). Maxillary canines of 24 participants were divided into two groups (n = 12 each). Teeth in the study group underwent maxillary canine retraction using mini-implants as anchorage for approximately 4 months, with 100 g of force applied via coil springs. Subjects in the control group received no orthodontic treatment. LDF measurements were recorded at baseline (T0); during retraction, at 24 hours (T1), 3 days (T2), 7 days (T3) and 1 month (T4); and at the end of retraction (T5) in the study group and at similar time-points in control subjects. Data were analyzed using the Friedman, Wilcoxon signed rank and Mann-Whitney U tests, with the significance level set at 0.05. No significant changes in PBF perfusion units (PU) were observed in the control group over the course of the study. However, PBF in the study group increased significantly from T0 (3.6 ± 0.2 PU) to T1 (3.7 ± 0.2 PU, p < 0.001) and decreased severely from T1 to T2 (3.3 ± 0.1, p < 0.001). PBF in the study group was still significantly lower at T3 (3.4 ± 0.1 PU, p < 0.001) in comparison to T0; however, at T4 and T5, PBF was found to have returned to pre-retraction levels. The fact that PBF values returned to initial levels within one month of the initiation of retraction despite short-term, hyperaemic, regressive changes demonstrates that the changes observed in PBF during canine retraction are reversible.

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

Hentschke, Clemens M., E-mail: clemens.hentschke@gmail.com; Tönnies, Klaus D.; Beuing, Oliver

Purpose: The early detection of cerebral aneurysms plays a major role in preventing subarachnoid hemorrhage. The authors present a system to automatically detect cerebral aneurysms in multimodal 3D angiographic data sets. The authors’ system is parametrizable for contrast-enhanced magnetic resonance angiography (CE-MRA), time-of-flight magnetic resonance angiography (TOF-MRA), and computed tomography angiography (CTA). Methods: Initial volumes of interest are found by applying a multiscale sphere-enhancing filter. Several features are combined in a linear discriminant function (LDF) to distinguish between true aneurysms and false positives. The features include shape information, spatial information, and probability information. The LDF can either be parametrized bymore » domain experts or automatically by training. Vessel segmentation is avoided as it could heavily influence the detection algorithm. Results: The authors tested their method with 151 clinical angiographic data sets containing 112 aneurysms. The authors reach a sensitivity of 95% with CE-MRA data sets at an average false positive rate per data set (FP{sub DS}) of 8.2. For TOF-MRA, we achieve 95% sensitivity at 11.3 FP{sub DS}. For CTA, we reach a sensitivity of 95% at 22.8 FP{sub DS}. For all modalities, the expert parametrization led to similar or better results than the trained parametrization eliminating the need for training. 93% of aneurysms that were smaller than 5 mm were found. The authors also showed that their algorithm is capable of detecting aneurysms that were previously overlooked by radiologists. Conclusions: The authors present an automatic system to detect cerebral aneurysms in multimodal angiographic data sets. The system proved as a suitable computer-aided detection tool to help radiologists find cerebral aneurysms.« less

Association of MAOA and COMT gene polymorphisms with palatable food intake in children.

PubMed

Galvão, Ananda C S; Krüger, Raquel C; Campagnolo, Paula D B; Mattevi, Vanessa S; Vitolo, Márcia R; Almeida, Silvana

2012-03-01

Several studies have implicated dopamine (DA) in appetite regulation. The enzymes catechol-o-methyltransferase (COMT) and monoamine oxidase A (MAOA) control DA availability and their genes have well-characterized functional variants. In this study, we examined three polymorphisms in these genes, T941G and MAOAu-VNTR in the MAOA gene and Val158Met in the COMT gene, to investigate how heritable variations in enzymes that determine DA levels might influence food intake and nutritional status. This investigation was a cross-sectional examination of 354 Brazilian children of three to four years old. Polymorphisms were analyzed by PCR-based methods. Means of dietary and anthropometric data were compared among genotypes by one-way analyses of variance or Kruskal Wallis tests. The MAOAu-VNTR and COMT Val158Met polymorphisms were associated with the amount of palatable food intake in boys. Presence of the MAOAu-VNTR*long allele was associated with higher intake of lipid-dense foods (LDF) when compared with the *short allele (P=.009); the amount of sugar-dense foods (SDF) intake was also higher in males carriers of the MAOAu-VNTR *long allele than in carriers of the *short allele (P=.034). In the girls' sample, MAOAu-VNTR polymorphism was not associated with food intake and nutritional status. Carriers of the COMT Val158Met*Val allele presented higher intake of LDF when compared with Met/Met homozygotes (P=.008). This study provides the first indication that genetic variants of enzymes that control DA availability might be involved in determination of the amount of palatable food intake in children. Copyright © 2012 Elsevier Inc. All rights reserved.

Nitric oxide is not permissive for cutaneous active vasodilatation in humans.

PubMed

Wilkins, Brad W; Holowatz, Lacy A; Wong, Brett J; Minson, Christopher T

2003-05-01

The precise role of nitric oxide (NO) in cutaneous active vasodilatation in humans is unknown. We tested the hypothesis that NO is necessary to permit the action of an unknown vasodilator. Specifically, we investigated whether a low-dose infusion of exogenous NO, in the form of sodium nitroprusside (SNP), would fully restore vasodilatation in an area of skin in which endogenous NO was inhibited during hyperthermia. This finding would suggest a 'permissive' role for NO in active vasodilatation. Eight subjects were instrumented with three microdialysis fibres in forearm skin. Sites were randomly assigned to (1) Site A: control site; (2) Site B: NO synthase (NOS) inhibition during established hyperthermia; or (3) Site C: NOS inhibition throughout the protocol. Red blood cell flux was measured using laser-Doppler flowmetry (LDF) and cutaneous vascular conductance (CVC; LDF/mean arterial pressure) was normalized to maximal vasodilatation at each site. In Site B, NG-nitro-L-arginine methyl ester (L-NAME) infusion during hyperthermia reduced CVC by approximately 32 % (65 +/- 4 % CVCmax vs. 45 +/- 4 % CVCmax; P < 0.05). Vasodilatation was not restored to pre-NOS inhibition values in this site following low-dose SNP infusion (55 +/- 4 % CVCmax vs. 65 +/- 4 % CVCmax; P < 0.05). CVC remained significantly lower than the control site with low-dose SNP infusion in Site C (P < 0.05). The rise in CVC with low-dose SNP (deltaCVC) was significantly greater in Site B and Site C during hyperthermia compared to normothermia (P < 0.05). No difference in deltaCVC was observed between hyperthermia and normothermia in the control site (Site A). Thus, NO does not act permissively in cutaneous active vasodilatation in humans but may directly mediate vasodilatation and enhance the effect of an unknown active vasodilator.

Effects of dorzolamide on choroidal blood flow, ciliary blood flow, and aqueous production in rabbits.

PubMed

Reitsamer, Herbert A; Bogner, Barbara; Tockner, Birgit; Kiel, Jeffrey W

2009-05-01

To determine the effects of topical dorzolamide (a carbonic anhydrase inhibitor) on choroidal and ciliary blood flow and the relationship between ciliary blood flow and aqueous flow. The experiments were performed in four groups of pentobarbital-anesthetized rabbits treated with topical dorzolamide (2%, 50 microL). In all groups, intraocular pressure (IOP) and mean arterial pressure (MAP) at the eye level were measured continuously by direct cannulation. In group 1, aqueous flow was measured by fluorophotometry before and after dorzolamide treatment. In group 2, aqueous flow was measured after dorzolamide at normal MAP and while MAP was held constant at 80, 55, or 40 mm Hg with occluders on the aorta and vena cava. In group 3, the same MAP levels were used, and ciliary blood flow was measured transsclerally by laser Doppler flowmetry (LDF). In group 4, choroidal blood flow was measured by LDF with the probe tip positioned in the vitreous over the posterior pole during ramp increases and decreases in MAP before and after dorzolamide. Dorzolamide lowered IOP by 19% (P < 0.01) and aqueous flow by 17% (P < 0.01), and increased ciliary blood flow by 18% (P < 0.01), which was associated with a significant reduction in ciliary vasculature resistance (-7%, P < 0.01). Dorzolamide shifted the relationship between ciliary blood flow and aqueous flow downward relative to the previously determined control relationship in the rabbit. Dorzolamide did not alter choroidal blood flow, choroidal vascular resistance, or the choroidal pressure flow relationship. Acute topical dorzolamide is a ciliary vasodilator and has a direct inhibitory effect on aqueous production, but it does not have a detectable effect on choroidal hemodynamics at the posterior pole in the rabbit.

Gastrointestinal Impedance Spectroscopy to Detect Hypoperfusion During Hemorrhage.

PubMed

Bloch, Andreas; Kohler, Andreas; Posthaus, Horst; Berger, David; Santos, Laura; Jakob, Stephan; Takala, Jukka; Haenggi, Matthias

2017-08-01

Changes in tissue impedance (Ω) have been proposed as early signs of impaired tissue perfusion. We hypothesized that hemorrhage may induce early changes in alimentary tract tissue impedance and that these can be detected by impedance spectroscopy. We evaluated impedance spectroscopy in an acute hemorrhage model in pigs. Twenty anesthetized pigs were randomized to stepwise hemorrhage to mean arterial blood pressure (MAP) targets of 60 mm Hg, 50 mm Hg, 45 mm Hg, and 40 mm Hg, followed by retransfusion in two steps, or control (n = 10 each). In the end, 500 mL of enteral nutrition was administered in both groups. Ω in four sites (sublingually, esophagus, stomach, proximal jejunum) and cardiac output (Qtot thermodilution), superior mesenteric artery blood flow (QSMA; Doppler ultrasound), and jejunal mucosal blood flow (LDF; laser Doppler) were measured. The bleeding (total volume 838 ± 185 mL; mean ± SD) resulted in progressive hypotension (actual MAP 65 ± 3 mm Hg, 59 ± 4 mm Hg, 55 ± 5 mm Hg, and 46 ± 6 mm Hg) and decrease in Qtot, QSMA, and mucosal LDF. Bleeding did not change Ω in any of the monitoring sites. Retransfusion restored the blood flows to at least baseline levels, again without change in Ω. Enteral nutrition did not alter Ω or any of the blood flows.Five animals (three in the hemorrhage group, two in the control group) had histologically proven acute gastric focal necrosis at the site of It transducer. Gastrointestinal impedance spectroscopy does not detect early changes in tissue perfusion during progressive hemorrhage or retransfusion. Ω spectroscopy is unlikely to provide any additional information of hypovolemia-induced early changes in gastrointestinal perfusion.

Lower limb sympathectomy assessed by laser Doppler blood flow and transcutaneous oxygen measurements.

PubMed

Lantsberg, L; Goldman, M

1990-01-01

In a retrospective study of critical ischaemia of the lower limb, sympathectomy appeared to be of value in the majority of patients. We therefore assessed sympathectomy by measuring skin blood flow before and after the procedure using laser Doppler flowmetry (LDF) and transcutaneous oxygen tension (TCpO2) techniques. Twenty patients underwent chemical sympathectomy and there was one surgical procedure. Measurements were performed before and 1 week after sympathectomy below the knee and on the forefoot. Symptomatic improvement occurred in 20 of 21 patients. This study demonstrates that skin blood flow in the leg and foot is improved by sympathectomy and confirms objectively our clinical impression.

Initiation of primary cell culture from amphioxus Branchiostoma belcheri tsingtauense

NASA Astrophysics Data System (ADS)

Wang, Changliu; Zhang, Shicui; Su, Feng; Wang, Lei; Li, Hongyan

2009-02-01

Amphioxus, a cephalochordate, is an important model fish for studies in evolution and comparative biology. A successful cell culture from amphioxus tissues in vitro would help understanding some basic issues. To determine the optimal culture conditions for proliferation of amphioxus cells, primary cultures were initiated from buccal cirri, tail, gill, gut and metapleural fold of amphioxus Branchiostoma belcheri tsingtauense. The media tested were L-15, F-12, M 199, MEM, DMEM, PRMI 1640 and LDF, each was supplemented with 20% fetal bovine serum. The optimal conditions include tail tissue cultured in L-15 or F-12 with supplement of 20% FBS and 1.5% NaCl at about 25°C.

Carbon dioxide adsorption in Brazilian coals

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

Jose Luciano Soares; Andre L.B. Oberziner; Humberto J. Jose

Carbon dioxide (CO{sub 2}) is one of the most important greenhouse gases. In the period between 1980 and 1998, CO{sub 2} emissions increased more than 21% and projections suggest that the emissions will continue to increase globally by 2.2% between 2000 and 2020 and 3.3% in the developed countries. The sequestration of CO{sub 2} in deep unminable coal beds is one of the more promising of several methods of geological sequestration that are currently being investigated. CO{sub 2} can adsorb onto coal, and there are several studies demonstrating that CO{sub 2} dissolves in coals and swells them. At very lowmore » pressures (P {lt} 1 bar), CO{sub 2} dissolution does not seem to be a problem; however, high pressures are necessary for CO{sub 2} sequestration (P {gt} 50 bar). In this study, we evaluated the kinetics and equilibrium of sorption of CO{sub 2} on Brazilian coals at low pressures. The adsorption equilibrium isotherm at room temperature (30{sup o}C) was measured through the static method. The results showed that the Freundlich model or the Langmuir model is suitable to describe the equilibrium experimental results. The CO{sub 2} adsorption capacity of Brazilian coals are in the range of 0.089-0.186 mmol CO{sub 2}/g, which are typical values for coals with high ash content. The dynamics of adsorption in a fixed-bed column that contains granular coal (particle sizes of 0.8, 2.4, and 4.8 mm) showed that the adsorption rate is fast and a mathematical model was developed to describe the CO{sub 2} dynamics of the adsorption in a fixed-bed column. The linear driving force (LDF) was used to describe the rate of adsorption and the mass-transfer constants of the LDF model (K{sub s}) are in the range of 1.0-2.0 min{sup -1}. 29 refs., 5 figs., 3 tabs.« less

Effects of interstitial heating on the RIF-1 tumor using an Nd:YAG laser with multiple fibers.

PubMed

Tobin, K M; Waldow, S M

1996-01-01

Hyperthermia was induced in tumor-bearing C3H mice using a Nd:YAG laser emitting near-infrared radiation at 1,064 nm. The efficacy of multiple implanted fiberoptics in the control of the RIF-1 tumor was investigated. RIF-1 tumors in the right hind leg were heated interstitially at 42, 44, or 46 degrees C for 30 or 60 minutes. Two, three, or four 400-microns quartz fibers terminating in a 1.0-cm cylindrical diffusor were inserted into each tumor, as were five microthermocouples to monitor temperature during treatment. Laser Doppler Flow (LDF) was also recorded pre- and post-treatment to determine changes in red blood cell flux in overlying skin (42, 44, or 46 degrees C) and the center of the tumor (46 degrees C). These experiments indicated that interstitial heating at 42, 44, and 46 degrees C resulted in tumor growth delay, although long-term control of tumors was not achieved. Treatment using four fibers resulted in the greatest tumor growth delay at 42 and 44 degrees C, increasing tumor doubling time by 50% or greater compared to control tumors; tumor growth delay following 46 degrees C treatments was seven times greater than that in control tumors. Significant changes (decreases) in LDF (P < .05) were seen in four treatment groups, using two fibers at 42 degrees C for 30 minutes, four fibers at 44 and 46 degrees C for 60 minutes on the overlying skin, and 46 degrees C for 60 minutes in the center of the tumor. Initial data indicate that interstitial heating with multiple fibers increases tumor growth delay compared to previous single fiber treatments, with tumor growth delay increasing with increasing treatment temperature; however, long-term tumor control was not achieved under the conditions investigated. Follow-up studies will explore the use of higher temperatures and/or longer treatment times in order to optimize tumor response.

Noninvasive clinical assessment of port-wine stain birthmarks using current and future optical imaging technology: A review

PubMed Central

Sharif, S.A.; Taydas, E.; Mazhar, A.; Rahimian, R.; Kelly, K.M.; Choi, B.; Durkin, A.J.

2012-01-01

Port wine stain (PWS) birthmarks are one class of benign congenital vascular malformation. Laser therapy is the most successful treatment modality of PWS. Unfortunately, this approach has limited efficacy, with only 10% of patients experiencing complete blanching of the PWS. To address this problem, several research groups have developed technologies and methods designed to study treatment outcome and improve treatment efficacy. This paper reviews seven optical imaging techniques currently in use or under development to assess treatment efficacy, focusing on: Reflectance spectrophotometers/tristimulus colorimeters, Laser Doppler flowmetry (LDF) and Laser Doppler imaging (LDI), Cross-polarized diffuse reflectance color imaging system (CDR), Reflectance Confocal Microscopy (RCM), Optical Coherence Tomography (OCT), Spatial Frequency Domain Imaging (SFDI), and Laser Speckle Imaging (LSI). PMID:22804872

A link-adding strategy for transport efficiency of complex networks

NASA Astrophysics Data System (ADS)

Ma, Jinlong; Han, Weizhan; Guo, Qing; Wang, Zhenyong; Zhang, Shuai

2016-12-01

The transport efficiency is one of the critical parameters to evaluate the performance of a network. In this paper, we propose an improved efficient (IE) strategy to enhance the network transport efficiency of complex networks by adding a fraction of links to an existing network based on the node’s local degree centrality and the shortest path length. Simulation results show that the proposed strategy can bring better traffic capacity and shorter average shortest path length than the low-degree-first (LDF) strategy under the shortest path routing protocol. It is found that the proposed strategy is beneficial to the improvement of overall traffic handling and delivering ability of the network. This study can alleviate the congestion in networks, and is helpful to design and optimize realistic networks.

Dairy cheese consumption ameliorates single-meal sodium-induced cutaneous microvascular dysfunction by reducing ascorbate-sensitive oxidants in healthy older adults

PubMed Central

Stanhewicz, Anna E.; Alba, Billie K.; Kenney, W. Larry; Alexander, Lacy M.

2018-01-01

Chronic dairy intake is associated with improved cardiovascular outcomes while high dietary-sodium impairs endothelial function through increased oxidative stress and reduced nitric oxide (NO) bioavailability. The purpose of this study was to compare the effect of acute cheese consumption with consumption of sodium from non-dairy sources on microvascular function. We hypothesized that dairy-cheese ingestion would augment NO-dependent vasodilation compared to sodium from non-dairy sources. On 5 separate visits, 14 healthy subjects (61±2yrs, 8M/6F) consumed either 85g dairy cheese (560mg Na), 85g soy cheese (560mg Na), 65g pretzels (560mg Na), 170g dairy cheese (1120mg Na), or 130g pretzels (1120mg Na). Two intradermal microdialysis fibers were inserted in the ventral forearm for delivery of lactated Ringer’s or 10mM ascorbate (antioxidant) during local skin heating (~50 min). Red cell flux was measured continuously by laser-Doppler flowmetry (LDF) and cutaneous vascular conductance (CVC=LDF/MAP) was normalized as %CVCmax (28mM sodium nitroprusside). Following a plateau in CVC, 15mM NG-nitro-L-arginine methyl ester was perfused to quantify NO-dependent vasodilation (~45 min). NO-dependent vasodilation was greater following dairy (560mg Na 57±3%) (1120mg Na 55±5%) compared to soy (560mg Na 42±3%; p=0.002) or pretzel (560mg Na 43±4%; p=0.004) (1120mg Na 46±3%; p=0.04). Ascorbate augmented NO-dependent vasodilation following soy (control: 42±3 vs. ascorbate: 54±3%; p=0.01) or pretzel (560mg Na; control: 43±4 vs. ascorbate: 56±3%; p=0.006) (1120mg Na; control: 46±5 vs. ascorbate: 56±3%; p=0.02), but not dairy. Sodium ingestion in dairy was associated with greater NO-dependent vasodilation compared to non-dairy sodium, a difference that was ameliorated with ascorbate perfusion. Dairy nutrients may protect against sodium-induced reductions in NO-dependent dilation through ascorbate-sensitive mechanisms. PMID:27363679

The effect of 48 weeks of aerobic exercise training on cutaneous vasodilator function in post-menopausal females.

PubMed

Hodges, Gary J; Sharp, Lisa; Stephenson, Claire; Patwala, Ashish Y; George, Keith P; Goldspink, David F; Tim Cable, N

2010-04-01

Skin blood flow (SkBF) and endothelial-dependent vasodilatation decline with ageing and can be reversed with exercise training. We tested whether 48 weeks of training could improve SkBF and endothelial function in post-menopausal females; 20 post-menopausal subjects completed the study. SkBF was measured by laser-Doppler flowmetry (LDF). Cutaneous vascular conductance (CVC) was calculated as LDF/blood pressure. Resting CVC was measured at 32 degrees C and peak CVC at 42 degrees C. Cutaneous endothelial-dependent and -independent vasodilatations were determined by the iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP), respectively. All assessments described were performed at entry (week 0), and after 6, 12, 24, 36, and 48 weeks of training. Resting CVC measures did not change (P > 0.05) throughout the study. Peak CVC increased (P < 0.05) after 24 weeks (7.2 +/- 1.2 vs. 11.6 +/- 1.4 AU mmHg(-1)) and at the 36- and 48-week assessments (13.0 +/- 1.7 and 14.9 +/- 2.1 AU mmHg(-1), respectively). Responses to ACh also increased (P < 0.05) at the 24-week assessment (5.1 +/- 2.1 vs. 8.55 +/- 2.3 AU mmHg(-1)) and increased further at the 36 and 48-week assessments (11.6 +/- 3.7 and 13.2 +/- 3.9 AU mmHg(-1), respectively). Cutaneous responses to SNP increased (P < 0.05) after 36 weeks (8.7 +/- 2.1 vs. 13.02 +/- 2.23 AU mmHg(-1) at 36 weeks). VO(2max) increased after 12 weeks (23.5 +/- 0.7 vs. 25.4 +/- 0.9 ml kg(-1) min(-1)) and improved (P < 0.05) further throughout the study (31.6 +/- 1.8 ml kg(-1) min(-1) at week 48). Aerobic exercise produces positive adaptations in the cutaneous vasodilator function to local heating as well as in cutaneous endothelial and endothelial-independent vasodilator mechanisms. Aerobic capacity was also significantly improved. These adaptations were further enhanced with progressive increases in exercise intensity.

Relative roles of local and reflex components in cutaneous vasoconstriction during skin cooling in humans.

PubMed

Alvarez, Guy E; Zhao, Kun; Kosiba, Wojciech A; Johnson, John M

2006-06-01

The reduction in skin blood flow (SkBF) with cold exposure is partly due to the reflex vasoconstrictor response from whole body cooling (WBC) and partly to the direct effects of local cooling (LC). Although these have been examined independently, little is known regarding their roles when acting together, as occurs in environmental cooling. We tested the hypothesis that the vasoconstrictor response to combined LC and WBC would be additive, i.e., would equal the sum of their independent effects. We further hypothesized that LC would attenuate the reflex vasoconstrictor response to WBC. We studied 16 (7 women, 9 men) young (30.5+/-2 yr) healthy volunteers. LC and WBC were accomplished with metal Peltier cooler-heater probe holders and water-perfused suits, respectively. Forearm SkBF was monitored by laser-Doppler flowmetry (LDF). Cutaneous vascular conductance (CVC) was calculated as LDF/blood pressure. Subjects underwent 15 min of LC alone or 15 min of WBC with and without simultaneous LC, either at equal levels (34-31 degrees C) or as equipotent stimuli (34-28 degrees C LC; 34-31 degrees C WBC). The fall in CVC with combined WBC and LC was greater (P<0.05) than for either alone (57.0+/-5% combined vs. 39.2+/-6% WBC; 34.4+/-4% LC) with equipotent cooling, but it was only significantly greater than for LC alone with equal levels of cooling (51.3+/-8% combined vs. 29.5+/-4% LC). The sum of the independent effects of WBC and LC was greater than their combined effects (74.9+/-4 vs. 51.3+/-8% equal and 73.6+/-7 vs. 57.0+/-5% equipotent; P<0.05). The fall in CVC with WBC at LC sites was reduced compared with control sites (17.6+/-2 vs. 42.4+/-8%; P<0.05). Hence, LC contributes importantly to the reduction in SkBF with body cooling, but also suppresses the reflex response, resulting in a nonadditive effect of these two components.

Optimization of behavioural tests for the prediction of outcomes in mouse models of focal middle cerebral artery occlusion.

PubMed

Wen, Zhuoyu; Xu, Xiaomeng; Xu, Lili; Yang, Lian; Xu, Xiaohui; Zhu, Juehua; Wu, Li; Jiang, Yongjun; Liu, Xinfeng

2017-06-15

Intraluminal middle cerebral artery occlusion (MCAO) is the most widely used model of stroke. We aimed to predict the outcome of MCAO using a combination of fine behavioural tests for the prediction of unsuccessful surgery in mice leading to no infarction, haemorrhage and unexpected death. MCAO was performed on adult mice under the guidance of laser-Doppler flowmetry (LDF) to warrant a decrease in regional cerebral blood flow (rCBF) in the MCA territory. Four outcomes of MCAO were defined according to histological analysis: infarction, no infarction, haemorrhage and unexpected death (death within 24h post-surgery). Fine behavioural tests including the rotarod, modified neurological severity score (mNSS), Clark general and Clark focal tests were performed separately at 6h, 12h and 24h post-stroke. A total of 94 mice were included in the analysis. The infarction rate associated with MCAO was 58.5% (55/94). After optimization of the timing and behavioural tests, we found that higher Clark focal (>17.5) or higher mNSS scores (>10) were markedly related to early death, whereas a lower mNSS score (<3.5) was indicative of a tendency to show no infarction at 6h post-stroke. After 24h post-stroke, there was a positive correlation between the infarct volume and Clark focal results. Behavioural tests could help to predict the outcomes in the MCAO mouse model. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Changes in cochlear blood flow in mice due to loud sound exposure measured with Doppler optical microangiography and laser Doppler flowmetry.

PubMed

Reif, Roberto; Zhi, Zhongwei; Dziennis, Suzan; Nuttall, Alfred L; Wang, Ruikang K

2013-10-01

In this work we determined the contributions of loud sound exposure (LSE) on cochlear blood flow (CoBF) in an in vivo anesthetized mouse model. A broadband noise system (20 kHz bandwidth) with an intensity of 119 dB SPL, was used for a period of one hour to produce a loud sound stimulus. Two techniques were used to study the changes in blood flow, a Doppler optical microangiography (DOMAG) system; which can measure the blood flow within individual cochlear vessels, and a laser Doppler flowmetry (LDF) system; which averages the blood flow within a volume (a hemisphere of ~1.5 mm radius) of tissue. Both systems determined that the blood flow within the cochlea is reduced due to the LSE stimulation.

Early effects of modern electroconvulsive therapy on subjective memory in patients with mania or depression

PubMed Central

Bag, Sevda; Canbek, Ozge; Atagun, Ilhan Murat; Kutlar, Tarik Mehmet

2016-01-01

Context: Although electroconvulsive therapy (ECT) is considered a very effective tool for the treatment of psychiatric diseases, memory disturbances are among the most important adverse effects. Aims: This study aimed to assess prospectively early subjective memory complaints in depressive and manic patients due to bilateral, brief-pulse ECT, at different stages of the treatment, compare the associations between psychiatric diagnosis, sociodemographic characteristics, and ECT characteristics. Settings and Design: This prospective study was done with patients undergoing ECT between November 2008 and April 2009 at a tertiary care psychiatry hospital of 2000 beds. Materials and Methods: A total of 140 patients, scheduled for ECT with a diagnosis of bipolar disorder (depressive or manic episode) or unipolar depression according to Diagnostic and Statistical Manual of Mental Disorders IV diagnostic criteria, were included in the study and invited to complete the Squire Subjective Memory Questionnaire (SSMQ) before ECT, after the first and third sessions and end of ECT treatment. Statistical Analysis: Mean values were compared with the Kruskal–Wallis test and comparison of the longitudinal data was performed with a nonparametric longitudinal data analysis method, F1_LD_F1 design. Results: SSMQ scores of the patients before ECT were zero. SSMQ scores showed a decrease after the first and third ECT sessions and before discharge, showing a memory disturbance after ECT and were significantly less severe in patients with mania in comparison to those with depression. Conclusions: These findings suggest an increasing degree of subjective memory complaints with bilateral brief-pulse ECT parallel to the increasing number of ECT sessions. PMID:27385854

Noninvasive imaging analysis of biological tissue associated with laser thermal injury.

PubMed

Chang, Cheng-Jen; Yu, De-Yi; Hsiao, Yen-Chang; Ho, Kuang-Hua

2017-04-01

The purpose of our study is to use a noninvasive tomographic imaging technique with high spatial resolution to characterize and monitor biological tissue responses associated with laser thermal injury. Optical doppler tomography (ODT) combines laser doppler flowmetry (LDF) with optical coherence tomography (OCT) to obtain high resolution tomographic velocity and structural images of static and moving constituents in highly scattering biological tissues. A SurgiLase XJ150 carbon dioxide (CO 2 ) laser using a continuous mode of 3 watts (W) was used to create first, second or third degree burns on anesthetized Sprague-Dawley rats. Additional parameters for laser thermal injury were assessed as well. The rationale for using ODT in the evaluation of laser thermal injury offers a means of constructing a high resolution tomographic image of the structure and perfusion of laser damaged skin. In the velocity images, the blood flow is coded at 1300 μm/s and 0 velocity, 1000 μm/s and 0 velocity, 700 μm/s and 0 velocity adjacent to the first, second, and third degree injuries, respectively. ODT produces exceptional spatial resolution while having a non-invasive way of measurement, therefore, ODT is an accurate measuring method for high-resolution fluid flow velocity and structural images for biological tissue with laser thermal injury. Copyright © 2017 Chang Gung University. Published by Elsevier B.V. All rights reserved.

NASA Tech Briefs, September 2011

NASA Technical Reports Server (NTRS)

2011-01-01

Topics covered include: Fused Reality for Enhanced Flight Test Capabilities; Thermography to Inspect Insulation of Large Cryogenic Tanks; Crush Test Abuse Stand; Test Generator for MATLAB Simulations; Dynamic Monitoring of Cleanroom Fallout Using an Air Particle Counter; Enhancement to Non-Contacting Stress Measurement of Blade Vibration Frequency; Positively Verifying Mating of Previously Unverifiable Flight Connectors; Radiation-Tolerant Intelligent Memory Stack - RTIMS; Ultra-Low-Dropout Linear Regulator; Excitation of a Parallel Plate Waveguide by an Array of Rectangular Waveguides; FPGA for Power Control of MSL Avionics; UAVSAR Active Electronically Scanned Array; Lockout/Tagout (LOTO) Simulator; Silicon Carbide Mounts for Fabry-Perot Interferometers; Measuring the In-Process Figure, Final Prescription, and System Alignment of Large; Optics and Segmented Mirrors Using Lidar Metrology; Fiber-Reinforced Reactive Nano-Epoxy Composites; Polymerization Initiated at the Sidewalls of Carbon Nanotubes; Metal-Matrix/Hollow-Ceramic-Sphere Composites; Piezoelectrically Enhanced Photocathodes; Iridium-Doped Ruthenium Oxide Catalyst for Oxygen Evolution; Improved Mo-Re VPS Alloys for High-Temperature Uses; Data Service Provider Cost Estimation Tool; Hybrid Power Management-Based Vehicle Architecture; Force Limit System; Levitated Duct Fan (LDF) Aircraft Auxiliary Generator; Compact, Two-Sided Structural Cold Plate Configuration; AN Fitting Reconditioning Tool; Active Response Gravity Offload System; Method and Apparatus for Forming Nanodroplets; Rapid Detection of the Varicella Zoster Virus in Saliva; Improved Devices for Collecting Sweat for Chemical Analysis; Phase-Controlled Magnetic Mirror for Wavefront Correction; and Frame-Transfer Gating Raman Spectroscopy for Time-Resolved Multiscalar Combustion Diagnostics.

Basal sympathetic activity to the microcirculation in tetraplegic man revealed by wavelet transform of laser Doppler flowmetry.

PubMed

Bernjak, A; Deitrick, G A; Bauman, W A; Stefanovska, A; Tuckman, J

2011-05-01

The 1984/86 published neurogram results showing only rare sympathetic nerve activity (SNA) to the muscles and skin in tetraplegia are still accepted. The present study by a different method attempted to confirm or deny those findings. The effect of basal SNA to the microcirculation of the feet and calf in 10 complete (AIS A) traumatic tetraplegic and 10 healthy age matched subjects were evaluated by wavelet transform of laser Doppler flowmetry (LDF) recordings. The results clearly indicated there is significant basal SNA from the decentralized spinal cord in tetraplegia. In addition, wavelet analysis allowed a study of other influences on the microcirculation besides SNA. Collectively, in tetraplegia compared with controls, the powers of the low frequency oscillations in blood flow were reduced; in that the endothelium caused less vasodilatation while the SNA and intrinsic vascular smooth muscles induced smaller degrees of vasoconstriction. However, the high frequency and especially the cardiac powers were greater. The latter presenting an obvious important factor for the preservation of blood flow in the microcirculation. It is suggested that basal SNA to the cutaneous microcirculation occurs in complete tetraplegia, and the significant levels of circulating noradrenaline reported by others indicate this is also true in other parts of the body. This may explain the usual absence of severe, incapacitating, autonomic deficiency in this condition. Published by Elsevier Inc.

Representations and uses of light distribution functions

NASA Astrophysics Data System (ADS)

Lalonde, Paul Albert

1998-11-01

At their lowest level, all rendering algorithms depend on models of local illumination to define the interplay of light with the surfaces being rendered. These models depend both on the representations of light scattering at a surface due to reflection and to an equal extent on the representation of light sources and light fields. Both emission and reflection have in common that they describe how light leaves a surface as a function of direction. Reflection also depends on an incident light direction. Emission can depend on the position on the light source We call the functions representing emission and reflection light distribution functions (LDF's). There are some difficulties to using measured light distribution functions. The data sets are very large-the size of the data grows with the fourth power of the sampling resolution. For example, a bidirectional reflectance distribution function (BRDF) sampled at five degrees angular resolution, which is arguably insufficient to capture highlights and other high frequency effects in the reflection, can easily require one and a half million samples. Once acquired this data requires some form of interpolation to use them. Any compression method used must be efficient, both in space and in the time required to evaluate the function at a point or over a range of points. This dissertation examines a wavelet representation of light distribution functions that addresses these issues. A data structure is presented that allows efficient reconstruction of LDFs for a given set of parameters, making the wavelet representation feasible for rendering tasks. Texture mapping methods that take advantage of our LDF representations are examined, as well as techniques for filtering LDFs, and methods for using wavelet compressed bidirection reflectance distribution functions (BRDFs) and light sources with Monte Carlo path tracing algorithms. The wavelet representation effectively compresses BRDF and emission data while inducing only a small error in the reconstructed signal. The representation can be used to evaluate efficiently some integrals that appear in shading computation which allows fast, accurate computation of local shading. The representation can be used to represent light fields and is used to reconstruct views of environments interactively from a precomputed set of views. The representation of the BRDF also allows the efficient generation of reflected directions for Monte Carlo array tracing applications. The method can be integrated into many different global illumination algorithms, including ray tracers and wavelet radiosity systems.

Correlations of Neck/Shoulder Perfusion Characteristics and Pain Symptoms of the Female Office Workers with Sedentary Lifestyle.

PubMed

Bau, Jian-Guo; Chia, Taipau; Wei, Shan-Hua; Li, Yung-Hui; Kuo, Fun-Chie

2017-01-01

Modern office workers are often impacted by chronic neck/shoulder pain. Most of the previous studies which investigated the relationship of the occupational factors and musculoskeletal symptoms had adopted questionnaire survey. In this study the microcirculatory characteristics and perceived symptoms in neck/shoulder region were compared among office workers with sedentary lifestyle. Thirty-seven female office workers were recruited in this study. Microcirculatory flow in neck/shoulder region characterized by the mean blood flow (MMBF value), pulsatile blood flow (PMBF value), and the PMBF/MMBF ratio (perfusion pulsatility, PP) were investigated using Laser Doppler Flowmetry (LDF). A Chinese version of the Standardized Nordic Musculoskeletal Questionnaire (NMQ) were also administered to collect the information of perceived neck/shoulder symptoms. Correlations between the perfusion characteristics and the individual/occupational factors were analyzed using the Spearman test. The difference of the MMBF values between the low-pain group (pain level≤2) and the high-pain group (pain level>2) were compared using the Mann-Whitney U test. There were 81% participants reported neck or shoulder pain symptoms. The duration of shoulder pain was significantly correlated with the workers' age and the duration of employment (p<0.01) (n = 37). While both the MMBF and PMBF values in shoulder region were significantly reduced with the workers' age and the duration of employment (p<0.05) (n = 27). And there was a 54% reduction in the MMBF value of the workers from age of 23 to 47. And the MMBF value of the high-pain group (n = 15) was significantly lower than the value of the low-pain group (n = 15) (p<0.05). The duration of shoulder pain showed a moderately negative correlation with PMBF values (n = 19). Besides, the PP value was moderately correlated with shoulder pain level attributed by the rapid reduction of MMBF values (p = 0.07). In this study, the LDF method was used for the first time in the workplace in Taiwan. It was demonstrated that the MMBF in shoulder region were affected by aging effect and towards lower value at higher pain level. Impaired microcirculation caused by age effect, when coupled with sedentary lifestyle, was found to be more likely to evoke ischemia shoulder pain. Further studies are needed to assess current indicator, PP value, and the underlying mechanism of pain caused by sedentary lifestyle.

Mathematical analysis of frontal affinity chromatography in particle and membrane configurations.

PubMed

Tejeda-Mansir, A; Montesinos, R M; Guzmán, R

2001-10-30

The scaleup and optimization of large-scale affinity-chromatographic operations in the recovery, separation and purification of biochemical components is of major industrial importance. The development of mathematical models to describe affinity-chromatographic processes, and the use of these models in computer programs to predict column performance is an engineering approach that can help to attain these bioprocess engineering tasks successfully. Most affinity-chromatographic separations are operated in the frontal mode, using fixed-bed columns. Purely diffusive and perfusion particles and membrane-based affinity chromatography are among the main commercially available technologies for these separations. For a particular application, a basic understanding of the main similarities and differences between particle and membrane frontal affinity chromatography and how these characteristics are reflected in the transport models is of fundamental relevance. This review presents the basic theoretical considerations used in the development of particle and membrane affinity chromatography models that can be applied in the design and operation of large-scale affinity separations in fixed-bed columns. A transport model for column affinity chromatography that considers column dispersion, particle internal convection, external film resistance, finite kinetic rate, plus macropore and micropore resistances is analyzed as a framework for exploring further the mathematical analysis. Such models provide a general realistic description of almost all practical systems. Specific mathematical models that take into account geometric considerations and transport effects have been developed for both particle and membrane affinity chromatography systems. Some of the most common simplified models, based on linear driving-force (LDF) and equilibrium assumptions, are emphasized. Analytical solutions of the corresponding simplified dimensionless affinity models are presented. Particular methods for estimating the parameters that characterize the mass-transfer and adsorption mechanisms in affinity systems are described.

Cluster studies of La[sub 2]CuO[sub 4]: A mapping onto the Pariser--Parr--Pople (PPP) model

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

Martin, R.L.

1993-06-01

The techniques of [ital ab] [ital initio] electronic structure theory are used to study Cu[sub 2]O[sub 7] and Cu[sub 2]O[sub 11] cluster models of La[sub 2]CuO[sub 4]. Fair agreement is obtained with the experimentally determined spin exchange constant [ital J] (90 meV calculated vs 125 meV measured) at the expense of quite large configuration interactions (CI) expansions. Results for various charge states of the cluster are well described by a single-band'' Pariser--Parr--Pople (PPP) model. As in earlier local-density-functional (LDF) based parameter determinations, the present work suggests these materials fall in the strong coupling regime. However, a significant intersite Coulomb repulsionmore » is found in the present research. It is of sufficient strength [ital V][similar to][ital U]/5 to indicate that charge fluctuations may be more important in these materials than generally believed.« less

10 CFR 830.204 - Documented safety analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Documented safety analysis. 830.204 Section 830.204 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT Safety Basis Requirements § 830.204 Documented safety analysis... approval from DOE for the methodology used to prepare the documented safety analysis for the facility...

14 CFR Appendix B to Part 415 - Safety Review Document Outline

Code of Federal Regulations, 2013 CFR

2013-01-01

....0Flight Safety (§ 415.115) 4.1Initial Flight Safety Analysis 4.1.1Flight Safety Sub-Analyses, Methods, and... Analysis Data 4.2Radionuclide Data (where applicable) 4.3Flight Safety Plan 4.3.1Flight Safety Personnel 4... Safety (§ 415.117) 5.1Ground Safety Analysis Report 5.2Ground Safety Plan 6.0Launch Plans (§ 415.119 and...

14 CFR Appendix B to Part 415 - Safety Review Document Outline

Code of Federal Regulations, 2014 CFR

2014-01-01

....0Flight Safety (§ 415.115) 4.1Initial Flight Safety Analysis 4.1.1Flight Safety Sub-Analyses, Methods, and... Analysis Data 4.2Radionuclide Data (where applicable) 4.3Flight Safety Plan 4.3.1Flight Safety Personnel 4... Safety (§ 415.117) 5.1Ground Safety Analysis Report 5.2Ground Safety Plan 6.0Launch Plans (§ 415.119 and...

Oral l-tyrosine supplementation augments the vasoconstriction response to whole-body cooling in older adults.

PubMed

Lang, James A; Smaller, Kevin A

2017-07-01

What is the central question of this study? Ageing is associated with altered sympathetic responses to stress, which are explained in part by reduced noradrenergic function. The impact of supplementation with oral l-tyrosine, the amino acid precursor for catecholamine synthesis, on the effector responses to cold and exercise stress has yet to be examined. What is the main finding and its importance? Oral l-tyrosine ingestion augmented the sympathetically mediated vasoconstriction response to cold exposure in aged skin. This suggests that l-tyrosine supplementation might improve thermoregulatory function in older adults. l-Tyrosine is the primary substrate for noradrenaline biosynthesis within sympathetic axon terminals. In stressful conditions requiring increased catecholamine production, the axonal l-tyrosine concentration may limit the full expression of the sympathetic effector response and this may be particularly evident in older adults. We hypothesize that oral l-tyrosine supplementation will increase the sympathetic response to whole-body cooling and muscle metaboreflex activation. In a randomized, double-blind design, 11 young (Y = 24 ± 1 years) and 11 older participants (O = 68 ± 4 years) ingested either 150 mg kg -1 of l-tyrosine or placebo before commencing 30 min of whole-body cooling to induce a gradual decline in skin temperature from 34 to 30.5°C. Laser Doppler flux (LDF) was measured at the ventral forearm, and cutaneous vascular conductance (CVC) was calculated as CVC = LDF/mean arterial pressure and expressed as a percentage change from baseline (%ΔCVC). Two minutes of static hand-grip exercise (35% maximal voluntary contraction) followed by 3 min of postexercise ischaemia were implemented before and toward the end of the cooling bout. l-Tyrosine supplementation did not affect blood pressure or heart rate responses to exercise or postexercise ischaemia. However, the blunted vasoconstriction response to whole-body cooling in older adults (placebo: Y = 39 ± 5%ΔCVC and O = 16 ± 2 %ΔCVC; P < 0.05) was augmented after l-tyrosine supplementation (l-tyrosine: Y = 40 ± 4%ΔCVC and O = 32 ± 5 %ΔCVC; P < 0.05). These results suggest that l-tyrosine bioavailability might limit thermoregulatory function in an older population. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

The newly-discovered Late Cretaceous igneous rocks in the Nuocang district: Products of ancient crust melting trigged by Neo-Tethyan slab rollback in the western Gangdese

NASA Astrophysics Data System (ADS)

Jiang, Jun-Sheng; Zheng, You-Ye; Gao, Shun-Bao; Zhang, Yong-Chao; Huang, Jian; Liu, Jun; Wu, Song; Xu, Jing; Huang, Liang-Liang

2018-05-01

The newly discovered polymetallic Nuocang Pb-Zn skarn deposit is located in the southern Lhasa subterrane, western Gangdese, Tibet. The orebodies occur primarily at the contact zone between the Angjie Formation and the Linzizong volcanic rocks of Dianzhong Formation (LDF) that are dominated by basaltic andesitic tuff and rhyolite. Zircon U-Pb dating for two granite porphyries yield ages of 72.4 ± 0.2 Ma and 73.4 ± 0.9 Ma, which are different from the ages ( 69-60 Ma) of the LDF in the eastern Gangdese. The basaltic andesite tuff at Nuocang exhibits enrichment of MgO, TiO2, LILE, and LREE, with a relative depletion of SiO2, K2O, HFSE, and HREE, low Sr/Y ratios (32.9-38.0), and weak negative Eu anomalies (mean 0.86). They have 87Sr/86Sr(i) from 0.70695 to 0.70807 and εNd(t) values between -4.3 and -5.9. These features are similar to the Linzizong volcanic rocks of Dianzhong Formation in the Linzhou basin, indicating that they were associated with partial melting of mantle wedge mixing with 25-35% ancient Lhasa terrane basement. The rhyolite and granite porphyry show high SiO2 and K2O, and low Sr/Y ratio (1.2-9.9), enrichment of LILE and LREE and strong depletion of the HFSEs. They have pronounced negative Eu anomalies (mean 0.46), and εHf (t) values of the granite porphyry zircons range from -22.0 to -6.0. All these features suggest that they are the product of anatexis of ancient crustal materials heated by mantle-derived magma, the latter derived from Neo-Tethyan slab dehydration mechanisms. Combined with the previous geochronological and geochemical data, we proposed that the Nuocang district of western Gangdese in the southern Lhasa subterrane contains an ancient block, and the igneous rocks here were triggered by the Neo-Tethyan slab rollback starting at 82 Ma. The western Gangdese contains more ancient continental crustal materials and Late Cretaceous-Eocene Linzizong volcanic rocks and coeval intrusions than in the eastern Gangdese. Thus the western Gangdese block displays greater potential for deposits associated with Late Cretaceous-Eocene magmatism including porphyry Mo, polymetallic skarn (W-Sn-Mo-Pb-Zn-Ag), base and precious metal epithermal (Pb-Zn-Ag-Au), cryptoexplosive breccia (Pb-Zn-Ag), and hydrothermal vein Pb-Zn-Ag deposits.

Correlations of Neck/Shoulder Perfusion Characteristics and Pain Symptoms of the Female Office Workers with Sedentary Lifestyle

PubMed Central

Wei, Shan-Hua; Li, Yung-Hui; Kuo, Fun-Chie

2017-01-01

Aim Modern office workers are often impacted by chronic neck/shoulder pain. Most of the previous studies which investigated the relationship of the occupational factors and musculoskeletal symptoms had adopted questionnaire survey. In this study the microcirculatory characteristics and perceived symptoms in neck/shoulder region were compared among office workers with sedentary lifestyle. Methods Thirty-seven female office workers were recruited in this study. Microcirculatory flow in neck/shoulder region characterized by the mean blood flow (MMBF value), pulsatile blood flow (PMBF value), and the PMBF/MMBF ratio (perfusion pulsatility, PP) were investigated using Laser Doppler Flowmetry (LDF). A Chinese version of the Standardized Nordic Musculoskeletal Questionnaire (NMQ) were also administered to collect the information of perceived neck/shoulder symptoms. Correlations between the perfusion characteristics and the individual/occupational factors were analyzed using the Spearman test. The difference of the MMBF values between the low-pain group (pain level≤2) and the high-pain group (pain level>2) were compared using the Mann-Whitney U test. Results There were 81% participants reported neck or shoulder pain symptoms. The duration of shoulder pain was significantly correlated with the workers’ age and the duration of employment (p<0.01) (n = 37). While both the MMBF and PMBF values in shoulder region were significantly reduced with the workers’ age and the duration of employment (p<0.05) (n = 27). And there was a 54% reduction in the MMBF value of the workers from age of 23 to 47. And the MMBF value of the high-pain group (n = 15) was significantly lower than the value of the low-pain group (n = 15) (p<0.05). The duration of shoulder pain showed a moderately negative correlation with PMBF values (n = 19). Besides, the PP value was moderately correlated with shoulder pain level attributed by the rapid reduction of MMBF values (p = 0.07). Conclusion In this study, the LDF method was used for the first time in the workplace in Taiwan. It was demonstrated that the MMBF in shoulder region were affected by aging effect and towards lower value at higher pain level. Impaired microcirculation caused by age effect, when coupled with sedentary lifestyle, was found to be more likely to evoke ischemia shoulder pain. Further studies are needed to assess current indicator, PP value, and the underlying mechanism of pain caused by sedentary lifestyle. PMID:28060875

Oral sapropterin augments reflex vasoconstriction in aged human skin through noradrenergic mechanisms.

PubMed

Stanhewicz, Anna E; Alexander, Lacy M; Kenney, W Larry

2013-10-01

Reflex vasoconstriction is attenuated in aged skin due to a functional loss of adrenergic vasoconstriction. Bioavailability of tetrahydrobiopterin (BH4), an essential cofactor for catecholamine synthesis, is reduced with aging. Locally administered BH4 increases vasoconstriction through adrenergic mechanisms in aged human skin. We hypothesized that oral sapropterin (Kuvan, a pharmaceutical BH4) would augment vasoconstriction elicited by whole-body cooling and tyramine perfusion in aged skin. Ten healthy subjects (age 75 ± 2 yr) ingested sapropterin (10 mg/kg) or placebo in a randomized, double-blind crossover design. Venous blood samples were collected prior to, and 3 h following ingestion. Three intradermal microdialysis fibers were placed in the forearm skin for local delivery of 1) lactated Ringer, 2) 5 mM BH4, and 3) 5 mM yohimbine + 1 mM propranolol (Y+P; to inhibit adrenergic vasoconstriction). Red cell flux was measured at each site by laser-Doppler flowmetry (LDF) as reflex vasoconstriction was induced by lowering and then clamping whole-body skin temperature (Tsk) using a water-perfused suit. Following whole-body cooling, subjects were rewarmed and 1 mM tyramine was perfused at each site to elicit endogenous norepinephrine release from the perivascular nerve terminal. Cutaneous vascular conductance was calculated as CVC = LDF/mean arterial pressure and expressed as change from baseline (ΔCVC). Plasma BH4 was elevated 3 h after ingestion of sapropterin (43.8 ± 3 vs. 19.1 ± 2 pmol/ml; P < 0.001). Sapropterin increased reflex vasoconstriction at the Ringer site at Tsk ≤ 32.5°C (P < 0.05). Local BH4 perfusion augmented reflex vasoconstriction at Tsk ≤ 31.5°C with placebo treatment only (P < 0.05). There was no treatment effect on reflex vasoconstriction at the BH4-perfused or Y+P-perfused sites. Sapropterin increased pharmacologically induced vasoconstriction at the Ringer site (-0.19 ± 0.03 vs. -0.08 ± 0.02 ΔCVC; P = 0.01). There was no difference in pharmacologically induced vasoconstriction between treatments at the BH4-perfused site (-0.16 ± 0.04 vs. -0.14 ± 0.03 ΔCVC; P = 0.60) or the Y+P-perfused site (-0.05 ± 0.02 vs.-0.06 ± 0.02 ΔCVC; P = 0.79). Sapropterin increases both reflex (cold-induced) and pharmacologically induced vasoconstriction through adrenergic mechanisms and may be a viable intervention to improve reflex vasoconstriction in aged humans.

Oral sapropterin augments reflex vasoconstriction in aged human skin through noradrenergic mechanisms

PubMed Central

Stanhewicz, Anna E.; Kenney, W. Larry

2013-01-01

Reflex vasoconstriction is attenuated in aged skin due to a functional loss of adrenergic vasoconstriction. Bioavailability of tetrahydrobiopterin (BH4), an essential cofactor for catecholamine synthesis, is reduced with aging. Locally administered BH4 increases vasoconstriction through adrenergic mechanisms in aged human skin. We hypothesized that oral sapropterin (Kuvan, a pharmaceutical BH4) would augment vasoconstriction elicited by whole-body cooling and tyramine perfusion in aged skin. Ten healthy subjects (age 75 ± 2 yr) ingested sapropterin (10 mg/kg) or placebo in a randomized, double-blind crossover design. Venous blood samples were collected prior to, and 3 h following ingestion. Three intradermal microdialysis fibers were placed in the forearm skin for local delivery of 1) lactated Ringer, 2) 5 mM BH4, and 3) 5 mM yohimbine + 1 mM propranolol (Y+P; to inhibit adrenergic vasoconstriction). Red cell flux was measured at each site by laser-Doppler flowmetry (LDF) as reflex vasoconstriction was induced by lowering and then clamping whole-body skin temperature (T̄sk) using a water-perfused suit. Following whole-body cooling, subjects were rewarmed and 1 mM tyramine was perfused at each site to elicit endogenous norepinephrine release from the perivascular nerve terminal. Cutaneous vascular conductance was calculated as CVC = LDF/mean arterial pressure and expressed as change from baseline (ΔCVC). Plasma BH4 was elevated 3 h after ingestion of sapropterin (43.8 ± 3 vs. 19.1 ± 2 pmol/ml; P < 0.001). Sapropterin increased reflex vasoconstriction at the Ringer site at T̄sk ≤ 32.5°C (P < 0.05). Local BH4 perfusion augmented reflex vasoconstriction at T̄sk ≤ 31.5°C with placebo treatment only (P < 0.05). There was no treatment effect on reflex vasoconstriction at the BH4-perfused or Y+P-perfused sites. Sapropterin increased pharmacologically induced vasoconstriction at the Ringer site (−0.19 ± 0.03 vs. −0.08 ± 0.02 ΔCVC; P = 0.01). There was no difference in pharmacologically induced vasoconstriction between treatments at the BH4-perfused site (−0.16 ± 0.04 vs. −0.14 ± 0.03 ΔCVC; P = 0.60) or the Y+P-perfused site (−0.05 ± 0.02 vs.−0.06 ± 0.02 ΔCVC; P = 0.79). Sapropterin increases both reflex (cold-induced) and pharmacologically induced vasoconstriction through adrenergic mechanisms and may be a viable intervention to improve reflex vasoconstriction in aged humans. PMID:23869061

75 FR 17604 - Federal Motor Vehicle Safety Standards; Roof Crush Resistance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

... Safety Analysis & Forensic Engineering, LLC (SAFE) brought to our attention errors in the preamble that incorrectly attributed to it the comments of another organization, Safety Analysis, Inc. Both of these... Safety Analysis, Inc. SAFE noted that there is no affiliation between SAFE and Safety Analysis, Inc. and...

14 CFR 415.115 - Flight safety.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Flight safety. 415.115 Section 415.115... From a Non-Federal Launch Site § 415.115 Flight safety. (a) Flight safety analysis. An applicant's safety review document must describe each analysis method employed to meet the flight safety analysis...

14 CFR 415.115 - Flight safety.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Flight safety. 415.115 Section 415.115... From a Non-Federal Launch Site § 415.115 Flight safety. (a) Flight safety analysis. An applicant's safety review document must describe each analysis method employed to meet the flight safety analysis...

14 CFR 415.115 - Flight safety.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Flight safety. 415.115 Section 415.115... From a Non-Federal Launch Site § 415.115 Flight safety. (a) Flight safety analysis. An applicant's safety review document must describe each analysis method employed to meet the flight safety analysis...

14 CFR 415.115 - Flight safety.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Flight safety. 415.115 Section 415.115... From a Non-Federal Launch Site § 415.115 Flight safety. (a) Flight safety analysis. An applicant's safety review document must describe each analysis method employed to meet the flight safety analysis...

14 CFR 415.115 - Flight safety.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Flight safety. 415.115 Section 415.115... From a Non-Federal Launch Site § 415.115 Flight safety. (a) Flight safety analysis. An applicant's safety review document must describe each analysis method employed to meet the flight safety analysis...

14 CFR 417.221 - Time delay analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.221 Time delay analysis. (a) General. A flight safety analysis must include a time delay analysis that establishes the mean elapsed time between the violation of a flight termination rule and the time when the flight safety system is...

14 CFR 417.221 - Time delay analysis.

Code of Federal Regulations, 2011 CFR

2011-01-01

... OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.221 Time delay analysis. (a) General. A flight safety analysis must include a time delay analysis that establishes the mean elapsed time between the violation of a flight termination rule and the time when the flight safety system is...

Transportation systems safety hazard analysis tool (SafetyHAT) user guide (version 1.0)

DOT National Transportation Integrated Search

2014-03-24

This is a user guide for the transportation system Safety Hazard Analysis Tool (SafetyHAT) Version 1.0. SafetyHAT is a software tool that facilitates System Theoretic Process Analysis (STPA.) This user guide provides instructions on how to download, ...

10 CFR 830.206 - Preliminary documented safety analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Preliminary documented safety analysis. 830.206 Section 830.206 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT Safety Basis Requirements § 830.206 Preliminary documented safety analysis. If construction begins after December 11, 2000, the contractor...

Model-Based Safety Analysis

NASA Technical Reports Server (NTRS)

Joshi, Anjali; Heimdahl, Mats P. E.; Miller, Steven P.; Whalen, Mike W.

2006-01-01

System safety analysis techniques are well established and are used extensively during the design of safety-critical systems. Despite this, most of the techniques are highly subjective and dependent on the skill of the practitioner. Since these analyses are usually based on an informal system model, it is unlikely that they will be complete, consistent, and error free. In fact, the lack of precise models of the system architecture and its failure modes often forces the safety analysts to devote much of their effort to gathering architectural details about the system behavior from several sources and embedding this information in the safety artifacts such as the fault trees. This report describes Model-Based Safety Analysis, an approach in which the system and safety engineers share a common system model created using a model-based development process. By extending the system model with a fault model as well as relevant portions of the physical system to be controlled, automated support can be provided for much of the safety analysis. We believe that by using a common model for both system and safety engineering and automating parts of the safety analysis, we can both reduce the cost and improve the quality of the safety analysis. Here we present our vision of model-based safety analysis and discuss the advantages and challenges in making this approach practical.

Making the Hubble Space Telescope servicing mission safe

NASA Technical Reports Server (NTRS)

Bahr, N. J.; Depalo, S. V.

1992-01-01

The implementation of the HST system safety program is detailed. Numerous safety analyses are conducted through various phases of design, test, and fabrication, and results are presented to NASA management for discussion during dedicated safety reviews. Attention is given to the system safety assessment and risk analysis methodologies used, i.e., hazard analysis, fault tree analysis, and failure modes and effects analysis, and to how they are coupled with engineering and test analysis for a 'synergistic picture' of the system. Some preliminary safety analysis results, showing the relationship between hazard identification, control or abatement, and finally control verification, are presented as examples of this safety process.

Safety analysts training

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

Bolton, P.

The purpose of this task was to support ESH-3 in providing Airborne Release Fraction and Respirable Fraction training to safety analysts at LANL who perform accident analysis, hazard analysis, safety analysis, and/or risk assessments at nuclear facilities. The task included preparation of materials for and the conduct of two 3-day training courses covering the following topics: safety analysis process; calculation model; aerosol physic concepts for safety analysis; and overview of empirically derived airborne release fractions and respirable fractions.

Improved processes for meeting the data requirements for implementing the Highway Safety Manual (HSM) and Safety Analyst in Florida.

DOT National Transportation Integrated Search

2014-03-01

Recent research in highway safety has focused on the more advanced and statistically proven techniques of highway : safety analysis. This project focuses on the two most recent safety analysis tools, the Highway Safety Manual (HSM) : and SafetyAnalys...

Bioactive nitric oxide concentration does not increase during reactive hyperemia in human skin.

PubMed

Zhao, J L; Pergola, P E; Roman, L J; Kellogg, D L

2004-02-01

This study examined whether nitric oxide (NO) is involved in the cutaneous response to reactive hyperemia (RH) in the human forearm. We enrolled seven healthy volunteers. NO concentrations were monitored using a NO selective amperometric electrode (ISO-NOP200, World Precision Instruments) inserted into the skin of the forearm. Laser-Doppler flowmetry (Moor Instruments) was used for monitoring skin blood flow (SkBF) at the same site. SkBF and NO levels were monitored and recorded continuously throughout the experiment. An intradermal microdialysis probe was inserted adjacent to the NO electrode for drug delivery. Data collection began 140 min after the NO electrodes and microdialysis probes were inserted. RH was achieved by the inflation of a blood pressure cuff to 25 mmHg above systolic pressure for 7 min after which the pressure in the cuff was abruptly released. Acetylcholine (ACh) was given by microdialysis probe at the end of RH study to verify the ability of the electrode system to detect changes in the NO concentration. SkBF and NO data before RH and immediately, 2, 5, 7, and 10 min after cuff deflation were used for analysis. SkBF increased immediately after release of the occlusion (P < 0.0001) and remained elevated for 2 min. No significant NO changes occurred with the increases in LDF. ACh induced increases in both SkBF and NO (P < 0.000 and P < 0.037, respectively). We conclude that RH increases SkBF by mechanisms that do not require a measurable increase in NO concentrations.

Reconstructing energy and Xmax of cosmic ray air showers using the radio lateral distribution measured with LOPES

NASA Astrophysics Data System (ADS)

Palmieri, N.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Chiavassa, A.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Falcke, H.; Fuchs, B.; Fuhrmann, D.; Gemmeke, H.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huber, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Krömer, O.; Kuijpers, J.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Melissas, M.; Morello, C.; Oehlschläger, J.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Rühle, C.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Weindl, A.; Wochele, J.; Zabierowski, J.; Zensus, J. A.

2013-05-01

The LOPES experiment, a digital radio interferometer located at KIT (Karlsruhe Institute of Technology), obtained remarkable results for the detection of radio emission from extensive air showers at MHz frequencies. Features of the radio lateral distribution function (LDF) measured by LOPES are explored in this work for a precise reconstruction of two fundamental air shower parameters: the primary energy and the shower Xmax. The method presented here has been developed on (REAS3-)simulations, and is applied to LOPES measurements. Despite the high human-made noise at the LOPES site, it is possible to reconstruct both the energy and Xmax for individual events. On the one hand, the energy resolution is promising and comparable to the one of the co-located KASCADE-Grande experiment. On the other hand, Xmax values are reconstructed with the LOPES measurements with a resolution of 90 g/cm2. A precision on Xmax better than 30 g/cm2 is predicted and achievable in a region with a lower human-made noise level.

14 CFR 417.231 - Collision avoidance analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Collision avoidance analysis. 417.231..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.231 Collision avoidance analysis. (a) General. A flight safety analysis must include a collision avoidance analysis that...

Adenosine receptor inhibition with theophylline attenuates the skin blood flow response to local heating in humans.

PubMed

Fieger, Sarah M; Wong, Brett J

2010-09-01

Mechanisms underlying the robust cutaneous vasodilatation in response to local heating of human skin remain unresolved. Adenosine receptor activation has been shown to induce vasodilatation via nitric oxide, and a substantial portion of the plateau phase to local heating of human skin has been shown to be dependent on nitric oxide. The purpose of this study was to investigate a potential role for adenosine receptor activation in cutaneous thermal hyperaemia in humans. Six subjects were equipped with four microdialysis fibres on the ventral forearm. Sites were randomly assigned to receive one of the following four treatments: (1) lactated Ringer solution to serve as a control; (2) 4 mM theophylline, a competitive, non-selective A(1)/A(2) adenosine receptor antagonist; (3) 10 mM Nomega(-)-nitro-L-arginine methyl ester (L-NAME) to inhibit NO synthase; or (4) combined 4 mm theophylline + 10 mM L-NAME. Following baseline measurements, each site was locally heated from a baseline temperature of 33 degrees C to 42 degrees C at a rate of 1 degrees C (10 s)(-1), and skin blood flow was monitored via laser-Doppler flowmetry (LDF). Cutaneous vascular conductance (CVC) was calculated as LDF divided by mean arterial pressure and normalized to maximal values (CVC(max)) via local heating to 43 degrees C and infusion of 28 mM sodium nitroprusside. The initial peak was significantly reduced in theophylline (68 +/- 2% CVC(max)) and L-NAME sites (54 +/- 5% CVC(max)) compared with control sites (81 +/- 2% CVC(max); P < 0.01 and P < 0.001, respectively). Combined theophylline + L-NAME (52 +/- 5% CVC(max)) reduced the initial peak compared with control and theophylline sites, but was not significantly different compared with L-NAME sites. The secondary plateau was attenuated in theophylline (77 +/- 2% CVC(max)), L-NAME (60 +/- 2% CVC(max)) and theophylline + L-NAME (53 +/- 1% CVC(max)) compared with control sites (94 +/- 2% CVC(max); P < 0.001 for all conditions). The secondary plateau was reduced in L-NAME compared with theophylline sites (P < 0.001), and combined theophylline + L-NAME further reduced the secondary plateau compared with theophylline- (P < 0.001) and L-NAME-only sites (P < 0.05). These data suggest that adenosine receptor activation directly contributes to cutaneous thermal hyperaemia, as evidenced by the reduced initial peak and secondary plateau in theophylline sites. These data further suggest that a portion of the NO response may be explained by adenosine receptor activation; however, a substantial portion of the NO response is independent of adenosine receptor activation.

Comprehensive Safety Analysis 2010 Safety Measurement System (SMS) Methodology, Version 2.1 Revised December 2010

DOT National Transportation Integrated Search

2010-12-01

This report documents the Safety Measurement System (SMS) methodology developed to support the Comprehensive Safety Analysis 2010 (CSA 2010) Initiative for the Federal Motor Carrier Safety Administration (FMCSA). The SMS is one of the major tools for...

Overview of Energy Systems` safety analysis report programs. Safety Analysis Report Update Program

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

Not Available

1992-03-01

The primary purpose of an Safety Analysis Report (SAR) is to provide a basis for judging the adequacy of a facility`s safety. The SAR documents the safety analyses that systematically identify the hazards posed by the facility, analyze the consequences and risk of potential accidents, and describe hazard control measures that protect the health and safety of the public and employees. In addition, some SARs document, as Technical Safety Requirements (TSRs, which include Technical Specifications and Operational Safety Requirements), technical and administrative requirements that ensure the facility is operated within prescribed safety limits. SARs also provide conveniently summarized information thatmore » may be used to support procedure development, training, inspections, and other activities necessary to facility operation. This ``Overview of Energy Systems Safety Analysis Report Programs`` Provides an introduction to the programs and processes used in the development and maintenance of the SARs. It also summarizes some of the uses of the SARs within Energy Systems and DOE.« less

Software Safety Progress in NASA

NASA Technical Reports Server (NTRS)

Radley, Charles F.

1995-01-01

NASA has developed guidelines for development and analysis of safety-critical software. These guidelines have been documented in a Guidebook for Safety Critical Software Development and Analysis. The guidelines represent a practical 'how to' approach, to assist software developers and safety analysts in cost effective methods for software safety. They provide guidance in the implementation of the recent NASA Software Safety Standard NSS-1740.13 which was released as 'Interim' version in June 1994, scheduled for formal adoption late 1995. This paper is a survey of the methods in general use, resulting in the NASA guidelines for safety critical software development and analysis.

C-Band Airport Surface Communications System Engineering-Initial High-Level Safety Risk Assessment and Mitigation

NASA Technical Reports Server (NTRS)

Zelkin, Natalie; Henriksen, Stephen

2011-01-01

This document is being provided as part of ITT's NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract: "New ATM Requirements--Future Communications, C-Band and L-Band Communications Standard Development." ITT has completed a safety hazard analysis providing a preliminary safety assessment for the proposed C-band (5091- to 5150-MHz) airport surface communication system. The assessment was performed following the guidelines outlined in the Federal Aviation Administration Safety Risk Management Guidance for System Acquisitions document. The safety analysis did not identify any hazards with an unacceptable risk, though a number of hazards with a medium risk were documented. This effort represents an initial high-level safety hazard analysis and notes the triggers for risk reassessment. A detailed safety hazards analysis is recommended as a follow-on activity to assess particular components of the C-band communication system after the profile is finalized and system rollout timing is determined. A security risk assessment has been performed by NASA as a parallel activity. While safety analysis is concerned with a prevention of accidental errors and failures, the security threat analysis focuses on deliberate attacks. Both processes identify the events that affect operation of the system; and from a safety perspective the security threats may present safety risks.

Safety System Design for Technology Education. A Safety Guide for Technology Education Courses K-12.

ERIC Educational Resources Information Center

North Carolina State Dept. of Public Instruction, Raleigh. Div. of Vocational Education.

This manual is designed to involve both teachers and students in planning and controlling a safety system for technology education classrooms. The safety program involves students in the design and maintenance of the system by including them in the analysis of the classroom environment, job safety analysis, safety inspection, and machine safety…

14 CFR Appendix B of Part 415 - Safety Review Document Outline

Code of Federal Regulations, 2010 CFR

2010-01-01

... Performed by Certified Personnel 4.0Flight Safety (§ 415.115) 4.1Initial Flight Safety Analysis 4.1.1Flight Safety Sub-Analyses, Methods, and Assumptions 4.1.2Sample Calculation and Products 4.1.3 Launch Specific Updates and Final Flight Safety Analysis Data 4.2Radionuclide Data (where applicable) 4.3Flight Safety...

14 CFR Appendix B of Part 415 - Safety Review Document Outline

Code of Federal Regulations, 2012 CFR

2012-01-01

... Performed by Certified Personnel 4.0Flight Safety (§ 415.115) 4.1Initial Flight Safety Analysis 4.1.1Flight Safety Sub-Analyses, Methods, and Assumptions 4.1.2Sample Calculation and Products 4.1.3 Launch Specific Updates and Final Flight Safety Analysis Data 4.2Radionuclide Data (where applicable) 4.3Flight Safety...

14 CFR Appendix B of Part 415 - Safety Review Document Outline

Code of Federal Regulations, 2011 CFR

2011-01-01

... Performed by Certified Personnel 4.0Flight Safety (§ 415.115) 4.1Initial Flight Safety Analysis 4.1.1Flight Safety Sub-Analyses, Methods, and Assumptions 4.1.2Sample Calculation and Products 4.1.3 Launch Specific Updates and Final Flight Safety Analysis Data 4.2Radionuclide Data (where applicable) 4.3Flight Safety...

14 CFR 417.227 - Toxic release hazard analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Toxic release hazard analysis. 417.227..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.227 Toxic release hazard analysis. A flight safety analysis must establish flight commit criteria that protect the public from any...

41 CFR 102-80.130 - Who must perform the equivalent level of safety analysis?

Code of Federal Regulations, 2010 CFR

2010-07-01

...-SAFETY AND ENVIRONMENTAL MANAGEMENT Accident and Fire Prevention Equivalent Level of Safety Analysis... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Who must perform the equivalent level of safety analysis? 102-80.130 Section 102-80.130 Public Contracts and Property Management...

A Synthetic Vision Preliminary Integrated Safety Analysis

NASA Technical Reports Server (NTRS)

Hemm, Robert; Houser, Scott

2001-01-01

This report documents efforts to analyze a sample of aviation safety programs, using the LMI-developed integrated safety analysis tool to determine the change in system risk resulting from Aviation Safety Program (AvSP) technology implementation. Specifically, we have worked to modify existing system safety tools to address the safety impact of synthetic vision (SV) technology. Safety metrics include reliability, availability, and resultant hazard. This analysis of SV technology is intended to be part of a larger effort to develop a model that is capable of "providing further support to the product design and development team as additional information becomes available". The reliability analysis portion of the effort is complete and is fully documented in this report. The simulation analysis is still underway; it will be documented in a subsequent report. The specific goal of this effort is to apply the integrated safety analysis to SV technology. This report also contains a brief discussion of data necessary to expand the human performance capability of the model, as well as a discussion of human behavior and its implications for system risk assessment in this modeling environment.

A Study on Urban Road Traffic Safety Based on Matter Element Analysis

PubMed Central

Hu, Qizhou; Zhou, Zhuping; Sun, Xu

2014-01-01

This paper examines a new evaluation of urban road traffic safety based on a matter element analysis, avoiding the difficulties found in other traffic safety evaluations. The issue of urban road traffic safety has been investigated through the matter element analysis theory. The chief aim of the present work is to investigate the features of urban road traffic safety. Emphasis was placed on the construction of a criterion function by which traffic safety achieved a hierarchical system of objectives to be evaluated. The matter element analysis theory was used to create the comprehensive appraisal model of urban road traffic safety. The technique was used to employ a newly developed and versatile matter element analysis algorithm. The matter element matrix solves the uncertainty and incompatibility of the evaluated factors used to assess urban road traffic safety. The application results showed the superiority of the evaluation model and a didactic example was included to illustrate the computational procedure. PMID:25587267

75 FR 74022 - Safety Analysis Requirements for Defining Adequate Protection for the Public and the Workers

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-30

... DEFENSE NUCLEAR FACILITIES SAFETY BOARD [Recommendation 2010-1] Safety Analysis Requirements for Defining Adequate Protection for the Public and the Workers AGENCY: Defense Nuclear Facilities Safety Board... Nuclear Facilities Safety Board has made a recommendation to the Secretary of Energy requesting an...

Canister Storage Building (CSB) Design Basis Accident Analysis Documentation

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

CROWE, R.D.; PIEPHO, M.G.

2000-03-23

This document provided the detailed accident analysis to support HNF-3553, Spent Nuclear Fuel Project Final Safety Analysis Report, Annex A, ''Canister Storage Building Final Safety Analysis Report''. All assumptions, parameters, and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the Canister Storage Building Final Safety Analysis Report.

Concept analysis of safety climate in healthcare providers.

PubMed

Lin, Ying-Siou; Lin, Yen-Chun; Lou, Meei-Fang

2017-06-01

To report an analysis of the concept of safety climate in healthcare providers. Compliance with safe work practices is essential to patient safety and care outcomes. Analysing the concept of safety climate from the perspective of healthcare providers could improve understanding of the correlations between safety climate and healthcare provider compliance with safe work practices, thus enhancing quality of patient care. Concept analysis. The electronic databases of CINAHL, MEDLINE, PubMed and Web of Science were searched for literature published between 1995-2015. Searches used the keywords 'safety climate' or 'safety culture' with 'hospital' or 'healthcare'. The concept analysis method of Walker and Avant analysed safety climate from the perspective of healthcare providers. Three attributes defined how healthcare providers define safety climate: (1) creation of safe working environment by senior management in healthcare organisations; (2) shared perception of healthcare providers about safety of their work environment; and (3) the effective dissemination of safety information. Antecedents included the characteristics of healthcare providers and healthcare organisations as a whole, and the types of work in which they are engaged. Consequences consisted of safety performance and safety outcomes. Most studies developed and assessed the survey tools of safety climate or safety culture, with a minority consisting of interventional measures for improving safety climate. More prospective studies are needed to create interventional measures for improving safety climate of healthcare providers. This study is provided as a reference for use in developing multidimensional safety climate assessment tools and interventional measures. The values healthcare teams emphasise with regard to safety can serve to improve safety performance. Having an understanding of the concept of and interventional measures for safety climate allows healthcare providers to ensure the safety of their operations and their patients. © 2016 John Wiley & Sons Ltd.

Interchange Safety Analysis Tool (ISAT) : user manual

DOT National Transportation Integrated Search

2007-06-01

This User Manual describes the usage and operation of the spreadsheet-based Interchange Safety Analysis Tool (ISAT). ISAT provides design and safety engineers with an automated tool for assessing the safety effects of geometric design and traffic con...

Safety culture assessment in petrochemical industry: a comparative study of two algerian plants.

PubMed

Boughaba, Assia; Hassane, Chabane; Roukia, Ouddai

2014-06-01

To elucidate the relationship between safety culture maturity and safety performance of a particular company. To identify the factors that contribute to a safety culture, a survey questionnaire was created based mainly on the studies of Fernández-Muñiz et al. The survey was randomly distributed to 1000 employees of two oil companies and realized a rate of valid answer of 51%. Minitab 16 software was used and diverse tests, including the descriptive statistical analysis, factor analysis, reliability analysis, mean analysis, and correlation, were used for the analysis of data. Ten factors were extracted using the analysis of factor to represent safety culture and safety performance. The results of this study showed that the managers' commitment, training, incentives, communication, and employee involvement are the priority domains on which it is necessary to stress the effort of improvement, where they had all the descriptive average values lower than 3.0 at the level of Company B. Furthermore, the results also showed that the safety culture influences the safety performance of the company. Therefore, Company A with a good safety culture (the descriptive average values more than 4.0), is more successful than Company B in terms of accident rates. The comparison between the two petrochemical plants of the group Sonatrach confirms these results in which Company A, the managers of which are English and Norwegian, distinguishes itself by the maturity of their safety culture has significantly higher evaluations than the company B, who is constituted of Algerian staff, in terms of safety management practices and safety performance.

Safety Culture Assessment in Petrochemical Industry: A Comparative Study of Two Algerian Plants

PubMed Central

Boughaba, Assia; Hassane, Chabane; Roukia, Ouddai

2014-01-01

Background To elucidate the relationship between safety culture maturity and safety performance of a particular company. Methods To identify the factors that contribute to a safety culture, a survey questionnaire was created based mainly on the studies of Fernández-Muñiz et al. The survey was randomly distributed to 1000 employees of two oil companies and realized a rate of valid answer of 51%. Minitab 16 software was used and diverse tests, including the descriptive statistical analysis, factor analysis, reliability analysis, mean analysis, and correlation, were used for the analysis of data. Ten factors were extracted using the analysis of factor to represent safety culture and safety performance. Results The results of this study showed that the managers' commitment, training, incentives, communication, and employee involvement are the priority domains on which it is necessary to stress the effort of improvement, where they had all the descriptive average values lower than 3.0 at the level of Company B. Furthermore, the results also showed that the safety culture influences the safety performance of the company. Therefore, Company A with a good safety culture (the descriptive average values more than 4.0), is more successful than Company B in terms of accident rates. Conclusion The comparison between the two petrochemical plants of the group Sonatrach confirms these results in which Company A, the managers of which are English and Norwegian, distinguishes itself by the maturity of their safety culture has significantly higher evaluations than the company B, who is constituted of Algerian staff, in terms of safety management practices and safety performance. PMID:25180135

Mine safety assessment using gray relational analysis and bow tie model

PubMed Central

2018-01-01

Mine safety assessment is a precondition for ensuring orderly and safety in production. The main purpose of this study was to prevent mine accidents more effectively by proposing a composite risk analysis model. First, the weights of the assessment indicators were determined by the revised integrated weight method, in which the objective weights were determined by a variation coefficient method and the subjective weights determined by the Delphi method. A new formula was then adopted to calculate the integrated weights based on the subjective and objective weights. Second, after the assessment indicator weights were determined, gray relational analysis was used to evaluate the safety of mine enterprises. Mine enterprise safety was ranked according to the gray relational degree, and weak links of mine safety practices identified based on gray relational analysis. Third, to validate the revised integrated weight method adopted in the process of gray relational analysis, the fuzzy evaluation method was used to the safety assessment of mine enterprises. Fourth, for first time, bow tie model was adopted to identify the causes and consequences of weak links and allow corresponding safety measures to be taken to guarantee the mine’s safe production. A case study of mine safety assessment was presented to demonstrate the effectiveness and rationality of the proposed composite risk analysis model, which can be applied to other related industries for safety evaluation. PMID:29561875

49 CFR 229.307 - Safety analysis.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Safety analysis. 229.307 Section 229.307 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Electronics § 229.307 Safety...

49 CFR 229.307 - Safety analysis.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Safety analysis. 229.307 Section 229.307 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Electronics § 229.307 Safety...

49 CFR 229.307 - Safety analysis.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Safety analysis. 229.307 Section 229.307 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Locomotive Electronics § 229.307 Safety...

K Basin Hazard Analysis

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

PECH, S.H.

This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Final Safety Analysis Report. This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report.

75 FR 69648 - Safety Analysis Requirements for Defining Adequate Protection for the Public and the Workers

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-15

... DEFENSE NUCLEAR FACILITIES SAFETY BOARD [Recommendation 2010-1] Safety Analysis Requirements for Defining Adequate Protection for the Public and the Workers AGENCY: Defense Nuclear Facilities Safety Board... Facilities Safety Board has made a recommendation to the Secretary of Energy requesting an amendment to the...

14 CFR 417.221 - Time delay analysis.

Code of Federal Regulations, 2012 CFR

2012-01-01

... occurs; (2) A flight safety official's decision and reaction time, including variation in human response... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Time delay analysis. 417.221 Section 417... OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.221 Time delay analysis. (a...

14 CFR 417.221 - Time delay analysis.

Code of Federal Regulations, 2014 CFR

2014-01-01

... occurs; (2) A flight safety official's decision and reaction time, including variation in human response... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Time delay analysis. 417.221 Section 417... OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.221 Time delay analysis. (a...

14 CFR 417.221 - Time delay analysis.

Code of Federal Regulations, 2013 CFR

2013-01-01

... occurs; (2) A flight safety official's decision and reaction time, including variation in human response... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Time delay analysis. 417.221 Section 417... OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.221 Time delay analysis. (a...

14 CFR 417.217 - Overflight gate analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Overflight gate analysis. 417.217 Section..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.217 Overflight gate analysis. For a launch that involves flight over a populated or other protected area, the flight safety...

10 CFR 52.157 - Contents of applications; technical information in final safety analysis report.

Code of Federal Regulations, 2013 CFR

2013-01-01

...; technical information in final safety analysis report. The application must contain a final safety analysis...) Information sufficient to demonstrate compliance with the applicable requirements regarding testing, analysis... 10 Energy 2 2013-01-01 2013-01-01 false Contents of applications; technical information in final...

10 CFR 52.157 - Contents of applications; technical information in final safety analysis report.

Code of Federal Regulations, 2012 CFR

2012-01-01

...; technical information in final safety analysis report. The application must contain a final safety analysis...) Information sufficient to demonstrate compliance with the applicable requirements regarding testing, analysis... 10 Energy 2 2012-01-01 2012-01-01 false Contents of applications; technical information in final...

14 CFR Appendix J to Part 417 - Ground Safety Analysis Report

Code of Federal Regulations, 2014 CFR

2014-01-01

... information required by this appendix. J417.3Ground safety analysis report chapters (a) Introduction. A ground... analysis report must include a chapter that provides detailed safety information about each launch vehicle... data. A hazard analysis form must contain or reference all information necessary to understand the...

10 CFR 52.157 - Contents of applications; technical information in final safety analysis report.

Code of Federal Regulations, 2014 CFR

2014-01-01

...; technical information in final safety analysis report. The application must contain a final safety analysis...) Information sufficient to demonstrate compliance with the applicable requirements regarding testing, analysis... 10 Energy 2 2014-01-01 2014-01-01 false Contents of applications; technical information in final...

14 CFR Appendix J to Part 417 - Ground Safety Analysis Report

Code of Federal Regulations, 2013 CFR

2013-01-01

... information required by this appendix. J417.3Ground safety analysis report chapters (a) Introduction. A ground... analysis report must include a chapter that provides detailed safety information about each launch vehicle... data. A hazard analysis form must contain or reference all information necessary to understand the...

14 CFR Appendix J to Part 417 - Ground Safety Analysis Report

Code of Federal Regulations, 2010 CFR

2010-01-01

... information required by this appendix. J417.3Ground safety analysis report chapters (a) Introduction. A ground... analysis report must include a chapter that provides detailed safety information about each launch vehicle... data. A hazard analysis form must contain or reference all information necessary to understand the...

14 CFR Appendix J to Part 417 - Ground Safety Analysis Report

Code of Federal Regulations, 2011 CFR

2011-01-01

... information required by this appendix. J417.3Ground safety analysis report chapters (a) Introduction. A ground... analysis report must include a chapter that provides detailed safety information about each launch vehicle... data. A hazard analysis form must contain or reference all information necessary to understand the...

10 CFR 52.157 - Contents of applications; technical information in final safety analysis report.

Code of Federal Regulations, 2011 CFR

2011-01-01

...; technical information in final safety analysis report. The application must contain a final safety analysis...) Information sufficient to demonstrate compliance with the applicable requirements regarding testing, analysis... 10 Energy 2 2011-01-01 2011-01-01 false Contents of applications; technical information in final...

14 CFR Appendix J to Part 417 - Ground Safety Analysis Report

Code of Federal Regulations, 2012 CFR

2012-01-01

... information required by this appendix. J417.3Ground safety analysis report chapters (a) Introduction. A ground... analysis report must include a chapter that provides detailed safety information about each launch vehicle... data. A hazard analysis form must contain or reference all information necessary to understand the...

Information Services at the Nuclear Safety Analysis Center.

ERIC Educational Resources Information Center

Simard, Ronald

This paper describes the operations of the Nuclear Safety Analysis Center. Established soon after an accident at the Three Mile Island nuclear power plant near Harrisburg, Pennsylvania, its efforts were initially directed towards a detailed analysis of the accident. Continuing functions include: (1) the analysis of generic nuclear safety issues,…

41 CFR 102-80.105 - What information must be included in an equivalent level of safety analysis?

Code of Federal Regulations, 2011 CFR

2011-01-01

... of Safety Analysis § 102-80.105 What information must be included in an equivalent level of safety... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false What information must be included in an equivalent level of safety analysis? 102-80.105 Section 102-80.105 Public Contracts and...

41 CFR 102-80.105 - What information must be included in an equivalent level of safety analysis?

Code of Federal Regulations, 2014 CFR

2014-01-01

... of Safety Analysis § 102-80.105 What information must be included in an equivalent level of safety... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false What information must be included in an equivalent level of safety analysis? 102-80.105 Section 102-80.105 Public Contracts and...

41 CFR 102-80.105 - What information must be included in an equivalent level of safety analysis?

Code of Federal Regulations, 2013 CFR

2013-07-01

... of Safety Analysis § 102-80.105 What information must be included in an equivalent level of safety... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false What information must be included in an equivalent level of safety analysis? 102-80.105 Section 102-80.105 Public Contracts and...

41 CFR 102-80.105 - What information must be included in an equivalent level of safety analysis?

Code of Federal Regulations, 2012 CFR

2012-01-01

... of Safety Analysis § 102-80.105 What information must be included in an equivalent level of safety... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false What information must be included in an equivalent level of safety analysis? 102-80.105 Section 102-80.105 Public Contracts and...

Systems Analysis of NASA Aviation Safety Program: Final Report

NASA Technical Reports Server (NTRS)

Jones, Sharon M.; Reveley, Mary S.; Withrow, Colleen A.; Evans, Joni K.; Barr, Lawrence; Leone, Karen

2013-01-01

A three-month study (February to April 2010) of the NASA Aviation Safety (AvSafe) program was conducted. This study comprised three components: (1) a statistical analysis of currently available civilian subsonic aircraft data from the National Transportation Safety Board (NTSB), the Federal Aviation Administration (FAA), and the Aviation Safety Information Analysis and Sharing (ASIAS) system to identify any significant or overlooked aviation safety issues; (2) a high-level qualitative identification of future safety risks, with an assessment of the potential impact of the NASA AvSafe research on the National Airspace System (NAS) based on these risks; and (3) a detailed, top-down analysis of the NASA AvSafe program using an established and peer-reviewed systems analysis methodology. The statistical analysis identified the top aviation "tall poles" based on NTSB accident and FAA incident data from 1997 to 2006. A separate examination of medical helicopter accidents in the United States was also conducted. Multiple external sources were used to develop a compilation of ten "tall poles" in future safety issues/risks. The top-down analysis of the AvSafe was conducted by using a modification of the Gibson methodology. Of the 17 challenging safety issues that were identified, 11 were directly addressed by the AvSafe program research portfolio.

Sources of Safety Data and Statistical Strategies for Design and Analysis: Clinical Trials.

PubMed

Zink, Richard C; Marchenko, Olga; Sanchez-Kam, Matilde; Ma, Haijun; Jiang, Qi

2018-03-01

There has been an increased emphasis on the proactive and comprehensive evaluation of safety endpoints to ensure patient well-being throughout the medical product life cycle. In fact, depending on the severity of the underlying disease, it is important to plan for a comprehensive safety evaluation at the start of any development program. Statisticians should be intimately involved in this process and contribute their expertise to study design, safety data collection, analysis, reporting (including data visualization), and interpretation. In this manuscript, we review the challenges associated with the analysis of safety endpoints and describe the safety data that are available to influence the design and analysis of premarket clinical trials. We share our recommendations for the statistical and graphical methodologies necessary to appropriately analyze, report, and interpret safety outcomes, and we discuss the advantages and disadvantages of safety data obtained from clinical trials compared to other sources. Clinical trials are an important source of safety data that contribute to the totality of safety information available to generate evidence for regulators, sponsors, payers, physicians, and patients. This work is a result of the efforts of the American Statistical Association Biopharmaceutical Section Safety Working Group.

Limited-scope probabilistic safety analysis for the Los Alamos Meson Physics Facility (LAMPF)

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

Sharirli, M.; Rand, J.L.; Sasser, M.K.

1992-01-01

The reliability of instrumentation and safety systems is a major issue in the operation of accelerator facilities. A probabilistic safety analysis was performed or the key safety and instrumentation systems at the Los Alamos Meson Physics Facility (LAMPF). in Phase I of this unique study, the Personnel Safety System (PSS) and the Current Limiters (XLs) were analyzed through the use of the fault tree analyses, failure modes and effects analysis, and criticality analysis. Phase II of the program was done to update and reevaluate the safety systems after the Phase I recommendations were implemented. This paper provides a brief reviewmore » of the studies involved in Phases I and II of the program.« less

Limited-scope probabilistic safety analysis for the Los Alamos Meson Physics Facility (LAMPF)

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

Sharirli, M.; Rand, J.L.; Sasser, M.K.

1992-12-01

The reliability of instrumentation and safety systems is a major issue in the operation of accelerator facilities. A probabilistic safety analysis was performed or the key safety and instrumentation systems at the Los Alamos Meson Physics Facility (LAMPF). in Phase I of this unique study, the Personnel Safety System (PSS) and the Current Limiters (XLs) were analyzed through the use of the fault tree analyses, failure modes and effects analysis, and criticality analysis. Phase II of the program was done to update and reevaluate the safety systems after the Phase I recommendations were implemented. This paper provides a brief reviewmore » of the studies involved in Phases I and II of the program.« less

41 CFR 102-80.115 - Is there more than one option for establishing that an equivalent level of safety exists?

Code of Federal Regulations, 2010 CFR

2010-07-01

... equivalent level of safety. (c) As a third option, other technical analysis procedures, as approved by the... Equivalent Level of Safety Analysis § 102-80.115 Is there more than one option for establishing that an... areas of safety. Available safe egress times would be developed based on analysis of a number of assumed...

Requirements Analysis for the Army Safety Management Information System (ASMIS)

DTIC Science & Technology

1989-03-01

8217_>’ Telephone Number « .. PNL-6819 Limited Distribution Requirements Analysis for the Army Safety Management Information System (ASMIS) Final...PNL-6819 REQUIREMENTS ANALYSIS FOR THE ARMY SAFETY MANAGEMENT INFORMATION SYSTEM (ASMIS) FINAL REPORT J. S. Littlefield A. L. Corrigan March...accidents. This accident data is available under the Army Safety Management Information System (ASMIS) which is an umbrella for many databases

On the Limitations of Breakthrough Curve Analysis in Fixed-Bed Adsorption

NASA Technical Reports Server (NTRS)

Knox, James C.; Ebner, Armin D.; LeVan, M. Douglas; Coker, Robert F.; Ritter, James A.

2016-01-01

This work examined in detail the a priori prediction of the axial dispersion coefficient from available correlations versus obtaining it and also mass transfer information from experimental breakthrough data and the consequences that may arise when doing so based on using a 1-D axially dispersed plug flow model and its associated Danckwerts outlet boundary condition. These consequences mainly included determining the potential for erroneous extraction of the axial dispersion coefficient and/or the LDF mass transfer coefficient from experimental data, especially when non-plug flow conditions prevailed in the bed. Two adsorbent/adsorbate cases were considered, i.e., carbon dioxide and water vapor in zeolite 5A, because they both experimentally exhibited significant non-plug flow behavior, and the water-zeolite 5A system exhibited unusual concentration front sharpening that destroyed the expected constant pattern behavior (CPB) when modeled with the 1-D axially dispersed plug flow model. Overall, this work showed that it was possible to extract accurate mass transfer and dispersion information from experimental breakthrough curves using a 1-D axial dispersed plug flow model when they were measured both inside and outside the bed. To ensure the extracted information was accurate, the inside the bed breakthrough curves and their derivatives from the model were plotted to confirm whether or not the adsorbate/adsorbent system was exhibiting CPB or any concentration front sharpening near the bed exit. Even when concentration front sharpening was occurring with the water-zeolite 5A system, it was still possible to use the experimental inside and outside the bed breakthrough curves to extract fundamental mass transfer and dispersion information from the 1-D axial dispersed plug flow model based on the systematic methodology developed in this work.

Anti-apoptotic effect of insulin in the control of cell death and neurologic deficit after acute spinal cord injury in rats.

PubMed

Wu, Xing-Huo; Yang, Shu-Hua; Duan, De-Yu; Cheng, Heng-Hui; Bao, Yu-Ting; Zhang, Yukun

2007-09-01

Recent studies confirmed that the new cell survival signal pathway of Insulin-PI3K-Akt exerted cyto-protective actions involving anti-apoptosis. This study was undertaken to investigate the potential neuroprotective effects of insulin in the pathogenesis of spinal cord injury (SCI) and evaluate its therapeutic effects in adult rats. SCI was produced by extradural compression using modified Allen's stall with damage energy of 40 g-cm force. One group of rats was subjected to SCI in combination with the administration of recombinant human insulin dissolved in 50% glucose solution at the dose of 1 IU/kg day, for 7 days. At the same time, another group of rats was subjected to SCI in combination with the administration of an equal volume of sterile saline solution. Functional recovery was evaluated using open-field walking, inclined plane tests, and motor evoked potentials (MEPs) during the first 14 days post-trauma. Levels of protein for B-cell lymphoma/leukemia-2 gene (Bcl-2), Caspase-3, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) were quantified in the injured spinal cord by Western blot analysis. Neuronal apoptosis was detected by TUNEL, and spinal cord blood flow (SCBF) was measured by laser-Doppler flowmetry (LDF). Ultimately, the data established the effectiveness of insulin treatment in improving neurologic recovery, increasing the expression of anti-apoptotic bcl-2 proteins, inhibiting caspase-3 expression decreasing neuronal apoptosis, reducing the expression of proinflammatory cytokines iNOS and COX-2, and ameliorating microcirculation of injured spinal cord after moderate contusive SCI in rats. In sum, this study reported the beneficial effects of insulin in the treatment of SCI, with the suggestion that insulin should be considered as a potential therapeutic agent.

Viewpoint on ISA TR84.0.02--simplified methods and fault tree analysis.

PubMed

Summers, A E

2000-01-01

ANSI/ISA-S84.01-1996 and IEC 61508 require the establishment of a safety integrity level for any safety instrumented system or safety related system used to mitigate risk. Each stage of design, operation, maintenance, and testing is judged against this safety integrity level. Quantitative techniques can be used to verify whether the safety integrity level is met. ISA-dTR84.0.02 is a technical report under development by ISA, which discusses how to apply quantitative analysis techniques to safety instrumented systems. This paper discusses two of those techniques: (1) Simplified equations and (2) Fault tree analysis.

Improving safety on rural local and tribal roads site safety analysis - user guide #1.

DOT National Transportation Integrated Search

2014-08-01

This User Guide presents an example of how rural local and Tribal practitioners can study conditions at a preselected site. It demonstrates the step-by-step safety analysis process presented in Improving Safety on Rural Local and Tribal Roads Saf...

Safety and operational performance evaluation of four types of exit ramps on Florida's freeways (final report).

DOT National Transportation Integrated Search

2010-12-01

This project mainly focuses on exit ramp performance analysis of safety and operations. In addition, issues of advance guide sign for exit ramp are also mentioned. : Safety analysis evaluates safety performances of different exit ramps used in Florid...

Infusing Reliability Techniques into Software Safety Analysis

NASA Technical Reports Server (NTRS)

Shi, Ying

2015-01-01

Software safety analysis for a large software intensive system is always a challenge. Software safety practitioners need to ensure that software related hazards are completely identified, controlled, and tracked. This paper discusses in detail how to incorporate the traditional reliability techniques into the entire software safety analysis process. In addition, this paper addresses how information can be effectively shared between the various practitioners involved in the software safety analyses. The author has successfully applied the approach to several aerospace applications. Examples are provided to illustrate the key steps of the proposed approach.

Relationships between psychological safety climate facets and safety behavior in the rail industry: a dominance analysis.

PubMed

Morrow, Stephanie L; McGonagle, Alyssa K; Dove-Steinkamp, Megan L; Walker, Curtis T; Marmet, Matthew; Barnes-Farrell, Janet L

2010-09-01

The goals of this study were twofold: (1) to confirm a relationship between employee perceptions of psychological safety climate and safety behavior for a sample of workers in the rail industry and (2) to explore the relative strengths of relationships between specific facets of safety climate and safety behavior. Non-management rail maintenance workers employed by a large North American railroad completed a survey (n=421) regarding workplace safety perceptions and behaviors. Three facets of safety climate (management safety, coworker safety, and work-safety tension) were assessed as relating to individual workers' reported safety behavior. All three facets were significantly associated with safety behavior. Dominance analysis was used to assess the relative importance of each facet as related to the outcome, and work-safety tension evidenced the strongest relationship with safety behavior. Published by Elsevier Ltd.

14 CFR 417.405 - Ground safety analysis.

Code of Federal Regulations, 2013 CFR

2013-01-01

... qualified to perform the ground safety analysis through training, education, and experience. (c) A launch... unfenced boundary of an entire industrial complex or multi-user launch site. A launch location hazard may.... (j) A launch operator must verify all information in a ground safety analysis, including design...

14 CFR 417.405 - Ground safety analysis.

Code of Federal Regulations, 2014 CFR

2014-01-01

... qualified to perform the ground safety analysis through training, education, and experience. (c) A launch... unfenced boundary of an entire industrial complex or multi-user launch site. A launch location hazard may.... (j) A launch operator must verify all information in a ground safety analysis, including design...

14 CFR 417.405 - Ground safety analysis.

Code of Federal Regulations, 2012 CFR

2012-01-01

... qualified to perform the ground safety analysis through training, education, and experience. (c) A launch... unfenced boundary of an entire industrial complex or multi-user launch site. A launch location hazard may.... (j) A launch operator must verify all information in a ground safety analysis, including design...

14 CFR 417.205 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

... one analysis must be compatible in form and content with the data input requirements of any other... TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.205 General. (a) Public risk management. A flight safety analysis must demonstrate that a launch operator will, for each launch, control the risk to...

10 CFR 72.248 - Safety analysis report updating.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Safety analysis report updating. 72.248 Section 72.248 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF... Approval of Spent Fuel Storage Casks § 72.248 Safety analysis report updating. (a) Each certificate holder...

Reliability Modeling Methodology for Independent Approaches on Parallel Runways Safety Analysis

NASA Technical Reports Server (NTRS)

Babcock, P.; Schor, A.; Rosch, G.

1998-01-01

This document is an adjunct to the final report An Integrated Safety Analysis Methodology for Emerging Air Transport Technologies. That report presents the results of our analysis of the problem of simultaneous but independent, approaches of two aircraft on parallel runways (independent approaches on parallel runways, or IAPR). This introductory chapter presents a brief overview and perspective of approaches and methodologies for performing safety analyses for complex systems. Ensuing chapter provide the technical details that underlie the approach that we have taken in performing the safety analysis for the IAPR concept.

Demonstration of a Safety Analysis on a Complex System

NASA Technical Reports Server (NTRS)

Leveson, Nancy; Alfaro, Liliana; Alvarado, Christine; Brown, Molly; Hunt, Earl B.; Jaffe, Matt; Joslyn, Susan; Pinnell, Denise; Reese, Jon; Samarziya, Jeffrey;

Space Station Furnace Facility. Volume 2: Requirements Definition and Conceptual Design Study. Appendix 3: Environment Analysis. Volume 2; Appendix 3

NASA Technical Reports Server (NTRS)

1992-01-01

A Preliminary Safety Analysis (PSA) is being accomplished as part of the Space Station Furnace Facility (SSFF) contract. This analysis is intended to support SSFF activities by analyzing concepts and designs as they mature to develop essential safety requirements for inclusion in the appropriate specifications, and designs, as early as possible. In addition, the analysis identifies significant safety concerns that may warrant specific trade studies or design definition, etc. The analysis activity to date concentrated on hazard and hazard cause identification and requirements development with the goal of developing a baseline set of detailed requirements to support trade study, specifications development, and preliminary design activities. The analysis activity will continue as the design and concepts mature. Section 2 defines what was analyzed, but it is likely that the SSFF definitions will undergo further changes. The safety analysis activity will reflect these changes as they occur. The analysis provides the foundation for later safety activities. The hazards identified will in most cases have Preliminary Design Review (PDR) applicability. The requirements and recommendations developed for each hazard will be tracked to ensure proper and early resolution of safety concerns.

Applying design principles to fusion reactor configurations for propulsion in space

NASA Technical Reports Server (NTRS)

Carpenter, Scott A.; Deveny, Marc E.; Schulze, Norman R.

1993-01-01

The application of fusion power to space propulsion requires rethinking the engineering-design solution to controlled-fusion energy. Whereas the unit cost of electricity (COE) drives the engineering-design solution for utility-based fusion reactor configurations; initial mass to low earth orbit (IMLEO), specific jet power (kW(thrust)/kg(engine)), and reusability drive the engineering-design solution for successful application of fusion power to space propulsion. We applied three design principles (DP's) to adapt and optimize three candidate-terrestrial-fusion-reactor configurations for propulsion in space. The three design principles are: provide maximum direct access to space for waste radiation, operate components as passive radiators to minimize cooling-system mass, and optimize the plasma fuel, fuel mix, and temperature for best specific jet power. The three candidate terrestrial fusion reactor configurations are: the thermal barrier tandem mirror (TBTM), field reversed mirror (FRM), and levitated dipole field (LDF). The resulting three candidate space fusion propulsion systems have their IMLEO minimized and their specific jet power and reusability maximized. We performed a preliminary rating of these configurations and concluded that the leading engineering-design solution to space fusion propulsion is a modified TBTM that we call the Mirror Fusion Propulsion System (MFPS).

Changes in Maxillary Canine Pulpal Blood Flow During Dentoalveolar Distraction Osteogenesis.

PubMed

Ersahan, Seyda; Sabuncuoglu, Fidan Alakus

2016-05-01

The aim of this study was to assess the effects of dentoalveolar distraction osteogenesis (DD) on the pulpal blood flow (PBF) of maxillary canines. A laser Doppler flowmeter (LDF) was used to measure PBF in maxillary canines of 10 patients undergoing DD (study group) and 10 nonsurgical subjects who received no orthodontic treatment (control group). PBF was measured at baseline, at 4 and 7 days postoperatively, at the end of distraction and at the end of consolidation in the study group and at similar time-points in nonsurgical control subjects. Data were analyzed using paired and Student t tests, with the significance level set at 0.05. Study findings showed that baseline PBF values did not differ significantly between groups. PBF in the control group did not vary over time; however, in the study group, an initial decrease in PBF was observed at 4 days postoperatively and was followed by a gradual increase to preoperative levels at the end of distraction. During the DD latency period, there appears to be a short-lived ischemic phase when perfusion of pulp tissue declines; however, blood-flow returns to normal by the end of distraction.

Modern Diagnostic Techniques for the Assessment of Ocular Blood Flow in Myopia: Current State of Knowledge.

PubMed

Grudzińska, Ewa; Modrzejewska, Monika

2018-01-01

Myopia is the most common refractive error and the subject of interest of various studies assessing ocular blood flow. Increasing refractive error and axial elongation of the eye result in the stretching and thinning of the scleral, choroid, and retinal tissues and the decrease in retinal vessel diameter, disturbing ocular blood flow. Local and systemic factors known to change ocular blood flow include glaucoma, medications and fluctuations in intraocular pressure, and metabolic parameters. Techniques and tools assessing ocular blood flow include, among others, laser Doppler flowmetry (LDF), retinal function imager (RFI), laser speckle contrast imaging (LSCI), magnetic resonance imaging (MRI), optical coherence tomography angiography (OCTA), pulsatile ocular blood flowmeter (POBF), fundus pulsation amplitude (FPA), colour Doppler imaging (CDI), and Doppler optical coherence tomography (DOCT). Many researchers consistently reported lower blood flow parameters in myopic eyes regardless of the used diagnostic method. It is unclear whether this is a primary change that causes secondary thinning of ocular tissues or quite the opposite; that is, the mechanical stretching of the eye wall reduces its thickness and causes a secondary lower demand of tissues for oxygen. This paper presents a review of studies assessing ocular blood flow in myopes.

Defining attributes of patient safety through a concept analysis.

PubMed

Kim, Linda; Lyder, Courtney H; McNeese-Smith, Donna; Leach, Linda Searle; Needleman, Jack

2015-11-01

The aim of this study was to report an analysis of the concept of patient safety. Despite recent increase in the number of work being done to clarify the concept and standardize measurement of patient safety, there are still huge variations in how the term is conceptualized and how to measure patient safety data across various healthcare settings and in research. Concept analysis. A literature search was conducted through PubMed and Cumulative Index to Nursing and Allied Health Literature, Plus using the terms 'patient safety' in the title and 'concept analysis,' 'attributes' or 'definition' in the title and or abstract. All English language literature published between 2002-2014 were considered for the review. Walker and Avant's method guided this analysis. The defining attributes of patient safety include prevention of medical errors and avoidable adverse events, protection of patients from harm or injury and collaborative efforts by individual healthcare providers and a strong, well-integrated healthcare system. The application of Collaborative Alliance of Nursing Outcomes indicators as empirical referents would facilitate the measurement of patient safety. With the knowledge gained from this analysis, nurses may improve patient surveillance efforts that identify potential hazards before they become adverse events and have a stronger voice in health policy decision-making that influence implementation efforts aimed at promoting patient safety, worldwide. Further studies are needed on development of a conceptual model and framework that can aid with collection and measurement of standardized patient safety data. © 2015 John Wiley & Sons Ltd.

European Workshop Industrical Computer Science Systems approach to design for safety

NASA Technical Reports Server (NTRS)

Zalewski, Janusz

1992-01-01

This paper presents guidelines on designing systems for safety, developed by the Technical Committee 7 on Reliability and Safety of the European Workshop on Industrial Computer Systems. The focus is on complementing the traditional development process by adding the following four steps: (1) overall safety analysis; (2) analysis of the functional specifications; (3) designing for safety; (4) validation of design. Quantitative assessment of safety is possible by means of a modular questionnaire covering various aspects of the major stages of system development.

Meta-analysis of surgical safety checklist effects on teamwork, communication, morbidity, mortality, and safety.

PubMed

Lyons, Vanessa E; Popejoy, Lori L

2014-02-01

The purpose of this study is to examine the effectiveness of surgical safety checklists on teamwork, communication, morbidity, mortality, and compliance with safety measures through meta-analysis. Four meta-analyses were conducted on 19 studies that met the inclusion criteria. The effect size of checklists on teamwork and communication was 1.180 (p = .003), on morbidity and mortality was 0.123 (p = .003) and 0.088 (p = .001), respectively, and on compliance with safety measures was 0.268 (p < .001). The results indicate that surgical safety checklists improve teamwork and communication, reduce morbidity and mortality, and improve compliance with safety measures. This meta-analysis is limited in its generalizability based on the limited number of studies and the inclusion of only published research. Future research is needed to examine possible moderating variables for the effects of surgical safety checklists.

77 FR 45282 - NRC Position on the Relationship Between General Design Criteria and Technical Specification...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-31

..., are described in the final safety analysis report (FSAR). The staff safety evaluation documents the acceptability of these analyses, and it is the combination of the FSAR analyses and the staff safety evaluation... analysis, maintain their capability to perform their safety functions. Technical Specification Operability...

Overview of Energy Systems' safety analysis report programs

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

Not Available

1992-03-01

The primary purpose of an Safety Analysis Report (SAR) is to provide a basis for judging the adequacy of a facility's safety. The SAR documents the safety analyses that systematically identify the hazards posed by the facility, analyze the consequences and risk of potential accidents, and describe hazard control measures that protect the health and safety of the public and employees. In addition, some SARs document, as Technical Safety Requirements (TSRs, which include Technical Specifications and Operational Safety Requirements), technical and administrative requirements that ensure the facility is operated within prescribed safety limits. SARs also provide conveniently summarized information thatmore » may be used to support procedure development, training, inspections, and other activities necessary to facility operation. This Overview of Energy Systems Safety Analysis Report Programs'' Provides an introduction to the programs and processes used in the development and maintenance of the SARs. It also summarizes some of the uses of the SARs within Energy Systems and DOE.« less

Nuclear Safety Information Center, Its Products and Services

ERIC Educational Resources Information Center

Buchanan, J. R.

1970-01-01

The Nuclear Safety Information Center (NSIC) serves as a focal point for the collection, analysis and dissemination of information related to safety problems encountered in the design, analysis, and operation of nuclear facilities. (Author/AB)

Software Safety Analysis of a Flight Guidance System

NASA Technical Reports Server (NTRS)

Butler, Ricky W. (Technical Monitor); Tribble, Alan C.; Miller, Steven P.; Lempia, David L.

2004-01-01

This document summarizes the safety analysis performed on a Flight Guidance System (FGS) requirements model. In particular, the safety properties desired of the FGS model are identified and the presence of the safety properties in the model is formally verified. Chapter 1 provides an introduction to the entire project, while Chapter 2 gives a brief overview of the problem domain, the nature of accidents, model based development, and the four-variable model. Chapter 3 outlines the approach. Chapter 4 presents the results of the traditional safety analysis techniques and illustrates how the hazardous conditions associated with the system trace into specific safety properties. Chapter 5 presents the results of the formal methods analysis technique model checking that was used to verify the presence of the safety properties in the requirements model. Finally, Chapter 6 summarizes the main conclusions of the study, first and foremost that model checking is a very effective verification technique to use on discrete models with reasonable state spaces. Additional supporting details are provided in the appendices.

Safety analysis and review system (SARS) assessment report

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

Browne, E.T.

1981-03-01

Under DOE Order 5481.1, Safety Analysis and Review System for DOE Operations, safety analyses are required for DOE projects in order to ensure that: (1) potential hazards are systematically identified; (2) potential impacts are analyzed; (3) reasonable measures have been taken to eliminate, control, or mitigate the hazards; and (4) there is documented management authorization of the DOE operation based on an objective assessment of the adequacy of the safety analysis. This report is intended to provide the DOE Office of Plans and Technology Assessment (OPTA) with an independent evaluation of the adequacy of the ongoing safety analysis effort. Asmore » part of this effort, a number of site visits and interviews were conducted, and FE SARS documents were reviewed. The latter included SARS Implementation Plans for a number of FE field offices, as well as safety analysis reports completed for certain FE operations. This report summarizes SARS related efforts at the DOE field offices visited and evaluates the extent to which they fulfill the requirements of DOE 5481.1.« less

75 FR 8239 - School Food Safety Program Based on Hazard Analysis and Critical Control Point Principles (HACCP...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-24

... 0584-AD65 School Food Safety Program Based on Hazard Analysis and Critical Control Point Principles... Safety Program Based on Hazard Analysis and Critical Control Point Principles (HACCP) was published on... of Management and Budget (OMB) cleared the associated information collection requirements (ICR) on...

A Framework for Assessment of Aviation Safety Technology Portfolios

NASA Technical Reports Server (NTRS)

Jones, Sharon M.; Reveley, Mary S.

2014-01-01

The programs within NASA's Aeronautics Research Mission Directorate (ARMD) conduct research and development to improve the national air transportation system so that Americans can travel as safely as possible. NASA aviation safety systems analysis personnel support various levels of ARMD management in their fulfillment of system analysis and technology prioritization as defined in the agency's program and project requirements. This paper provides a framework for the assessment of aviation safety research and technology portfolios that includes metrics such as projected impact on current and future safety, technical development risk and implementation risk. The paper also contains methods for presenting portfolio analysis and aviation safety Bayesian Belief Network (BBN) output results to management using bubble charts and quantitative decision analysis techniques.

Integrated Safety Risk Reduction Approach to Enhancing Human-Rated Spaceflight Safety

NASA Astrophysics Data System (ADS)

Mikula, J. F. Kip

2005-12-01

This paper explores and defines the current accepted concept and philosophy of safety improvement based on a Reliability enhancement (called here Reliability Enhancement Based Safety Theory [REBST]). In this theory a Reliability calculation is used as a measure of the safety achieved on the program. This calculation may be based on a math model or a Fault Tree Analysis (FTA) of the system, or on an Event Tree Analysis (ETA) of the system's operational mission sequence. In each case, the numbers used in this calculation are hardware failure rates gleaned from past similar programs. As part of this paper, a fictional but representative case study is provided that helps to illustrate the problems and inaccuracies of this approach to safety determination. Then a safety determination and enhancement approach based on hazard, worst case analysis, and safety risk determination (called here Worst Case Based Safety Theory [WCBST]) is included. This approach is defined and detailed using the same example case study as shown in the REBST case study. In the end it is concluded that an approach combining the two theories works best to reduce Safety Risk.

Multilevel model of safety climate for furniture industries.

PubMed

Rodrigues, Matilde A; Arezes, Pedro M; Leão, Celina P

2015-01-01

Furniture companies can analyze their safety status using quantitative measures. However, the data needed are not always available and the number of accidents is under-reported. Safety climate scales may be an alternative. However, there are no validated Portuguese scales that account for the specific attributes of the furniture sector. The current study aims to develop and validate an instrument that uses a multilevel structure to measure the safety climate of the Portuguese furniture industry. The Safety Climate in Wood Industries (SCWI) model was developed and applied to the safety climate analysis using three different scales: organizational, group and individual. A multilevel exploratory factor analysis was performed to analyze the factorial structure. The studied companies' safety conditions were also analyzed. Different factorial structures were found between and within levels. In general, the results show the presence of a group-level safety climate. The scores of safety climates are directly and positively related to companies' safety conditions; the organizational scale is the one that best reflects the actual safety conditions. The SCWI instrument allows for the identification of different safety climates in groups that comprise the same furniture company and it seems to reflect those groups' safety conditions. The study also demonstrates the need for a multilevel analysis of the studied instrument.

Motorcoach and school bus fire safety analysis.

DOT National Transportation Integrated Search

2016-11-01

This report documents a motorcoach and school bus fire safety analysis performed by the John A. Volpe National Transportation Systems Center (Volpe) for the Federal Motor Carrier Safety Administration. This report aims to: 1) identify the causes, fre...

Tracking the use of onboard safety technologies across the truck fleet.

DOT National Transportation Integrated Search

2009-03-01

The Transportation Safety Analysis and the Automotive Analysis Divisons at the University of Michigan Transportation Research Institute (UMTRI) initiated the Onboard Safety Technologies project in 2007, supported by FMCSA, to collect detailed informa...

Motorcoach and school bus fire safety analysis : technology brief.

DOT National Transportation Integrated Search

2016-11-01

In 2009, the Federal Motor Carrier Safety Administration (FMCSA) published findings from a study entitled Motorcoach Fire Safety Analysis. The objective of this study was to gather and analyze information regarding the causes, frequency, and se...

L-Band Digital Aeronautical Communications System Engineering - Initial Safety and Security Risk Assessment and Mitigation

NASA Technical Reports Server (NTRS)

Zelkin, Natalie; Henriksen, Stephen

2011-01-01

This document is being provided as part of ITT's NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: "New ATM Requirements--Future Communications, C-Band and L-Band Communications Standard Development." ITT has completed a safety hazard analysis providing a preliminary safety assessment for the proposed L-band (960 to 1164 MHz) terrestrial en route communications system. The assessment was performed following the guidelines outlined in the Federal Aviation Administration Safety Risk Management Guidance for System Acquisitions document. The safety analysis did not identify any hazards with an unacceptable risk, though a number of hazards with a medium risk were documented. This effort represents a preliminary safety hazard analysis and notes the triggers for risk reassessment. A detailed safety hazards analysis is recommended as a follow-on activity to assess particular components of the L-band communication system after the technology is chosen and system rollout timing is determined. The security risk analysis resulted in identifying main security threats to the proposed system as well as noting additional threats recommended for a future security analysis conducted at a later stage in the system development process. The document discusses various security controls, including those suggested in the COCR Version 2.0.

Development and Psychometric Analysis of a Nurses’ Attitudes and Skills Safety Scale: Initial Results

PubMed Central

Armstrong, Gail E.; Dietrich, Mary; Norman, Linda; Barnsteiner, Jane; Mion, Lorraine

2016-01-01

Health care organizations have incorporated updated safety principles in the analysis of errors and in norms and standards. Yet no research exists that assesses bedside nurses’ perceived skills or attitudes toward updated safety concepts. The aims of this study were to develop a scale assessing nurses’ perceived skills and attitudes toward updated safety concepts, determine content validity, and examine internal consistency of the scale and subscales. Understanding nurses’ perceived skills and attitudes about safety concepts can be used in targeting strategies to enhance their safety practices. PMID:27479518

Development and Psychometric Analysis of a Nurses' Attitudes and Skills Safety Scale: Initial Results.

PubMed

Armstrong, Gail E; Dietrich, Mary; Norman, Linda; Barnsteiner, Jane; Mion, Lorraine

Health care organizations have incorporated updated safety principles in the analysis of errors and in norms and standards. Yet no research exists that assesses bedside nurses' perceived skills or attitudes toward updated safety concepts. The aims of this study were to develop a scale assessing nurses' perceived skills and attitudes toward updated safety concepts, determine content validity, and examine internal consistency of the scale and subscales. Understanding nurses' perceived skills and attitudes about safety concepts can be used in targeting strategies to enhance their safety practices.

Applying Failure Modes, Effects, And Criticality Analysis And Human Reliability Analysis Techniques To Improve Safety Design Of Work Process In Singapore Armed Forces

DTIC Science & Technology

2016-09-01

an instituted safety program that utilizes a generic risk assessment method involving the 5-M (Mission, Man, Machine , Medium and Management) factor...the Safety core value is hinged upon three key principles—(1) each soldier has a crucial part to play, by adopting safety as a core value and making...it a way of life in his unit; (2) safety is an integral part of training, operations and mission success, and (3) safety is an individual, team and

Modelling safety of multistate systems with ageing components

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

Kołowrocki, Krzysztof; Soszyńska-Budny, Joanna

An innovative approach to safety analysis of multistate ageing systems is presented. Basic notions of the ageing multistate systems safety analysis are introduced. The system components and the system multistate safety functions are defined. The mean values and variances of the multistate systems lifetimes in the safety state subsets and the mean values of their lifetimes in the particular safety states are defined. The multi-state system risk function and the moment of exceeding by the system the critical safety state are introduced. Applications of the proposed multistate system safety models to the evaluation and prediction of the safty characteristics ofmore » the consecutive “m out of n: F” is presented as well.« less

Statewide crash analysis and forecasting.

DOT National Transportation Integrated Search

2008-11-20

There is a need for the development of safety analysis tools to allow Penn DOT to better assess the safety performance of road : segments in the Commonwealth. The project utilized a safety management system database at Penn DOT that integrates crash,...

Initial empirical analysis of nuclear power plant organization and its effect on safety performance

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

Olson, J.; McLaughlin, S.D.; Osborn, R.N.

This report contains an analysis of the relationship between selected aspects of organizational structure and the safety-related performance of nuclear power plants. The report starts by identifying and operationalizing certain key dimensions of organizational structure that may be expected to be related to plant safety performance. Next, indicators of plant safety performance are created by combining existing performance measures into more reliable indicators. Finally, the indicators of plant safety performance using correlational and discriminant analysis. The overall results show that plants with better developed coordination mechanisms, shorter vertical hierarchies, and a greater number of departments tend to perform more safely.

ASIL determination for motorbike's Electronics Throttle Control System (ETCS) mulfunction

NASA Astrophysics Data System (ADS)

Zaman Rokhani, Fakhrul; Rahman, Muhammad Taqiuddin Abdul; Ain Kamsani, Noor; Sidek, Roslina Mohd; Saripan, M. Iqbal; Samsudin, Khairulmizam; Khair Hassan, Mohd

2017-11-01

Electronics Throttle Control System (ETCS) is the principal electronic unit in all fuel injection engine motorbike, augmenting the engine performance efficiency in comparison to the conventional carburetor based engine. ETCS is regarded as a safety-critical component, whereby ETCS malfunction can cause unintended acceleration or deceleration event, which can be hazardous to riders. In this study, Hazard Analysis and Risk Assessment, an ISO26262 functional safety standard analysis has been applied on motorbike's ETCS to determine the required automotive safety integrity level. Based on the analysis, the established automotive safety integrity level can help to derive technical and functional safety measures for ETCS development.

Partnerships: The Path to Improving Crisis Communication

DTIC Science & Technology

2007-03-01

News Media Perceives Relationships with Public Safety.................32 Table 4. Public Safety SWOT Analysis ...opportunities and threats ( SWOT ) of the Seattle fire and police departments. The SWOT analysis is an assessment tool common to strategic planning for...requirements for training • Lack of strategic planning experience Table 4. Public Safety SWOT Analysis 46 Table 4 compares the strengths and

Systemic safety project selection tool.

DOT National Transportation Integrated Search

2013-07-01

"The Systemic Safety Project Selection Tool presents a process for incorporating systemic safety planning into traditional safety management processes. The Systemic Tool provides a step-by-step process for conducting systemic safety analysis; conside...

TA-55 Final Safety Analysis Report Comparison Document and DOE Safety Evaluation Report Requirements

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

Alan Bond

2001-04-01

This document provides an overview of changes to the currently approved TA-55 Final Safety Analysis Report (FSAR) that are included in the upgraded FSAR. The DOE Safety Evaluation Report (SER) requirements that are incorporated into the upgraded FSAR are briefly discussed to provide the starting point in the FSAR with respect to the SER requirements.

A root cause analysis project in a medication safety course.

PubMed

Schafer, Jason J

2012-08-10

To develop, implement, and evaluate team-based root cause analysis projects as part of a required medication safety course for second-year pharmacy students. Lectures, in-class activities, and out-of-class reading assignments were used to develop students' medication safety skills and introduce them to the culture of medication safety. Students applied these skills within teams by evaluating cases of medication errors using root cause analyses. Teams also developed error prevention strategies and formally presented their findings. Student performance was assessed using a medication errors evaluation rubric. Of the 211 students who completed the course, the majority performed well on root cause analysis assignments and rated them favorably on course evaluations. Medication error evaluation and prevention was successfully introduced in a medication safety course using team-based root cause analysis projects.

System safety engineering analysis handbook

NASA Technical Reports Server (NTRS)

Ijams, T. E.

1972-01-01

The basic requirements and guidelines for the preparation of System Safety Engineering Analysis are presented. The philosophy of System Safety and the various analytic methods available to the engineering profession are discussed. A text-book description of each of the methods is included.

Roadway safety analysis methodology for Utah : final report.

DOT National Transportation Integrated Search

2016-12-01

This research focuses on the creation of a three-part Roadway Safety Analysis methodology that applies and automates the cumulative work of recently-completed roadway safety research. The first part is to prepare the roadway and crash data for analys...

DOE standard 3009 - a reasoned, practical approach to integrating criticality safety into SARs

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

Vessard, S.G.

1995-12-31

In the past there have been efforts by the U.S. Department of Energy (DOE) to provide guidance on those elements that should be included in a facility`s safety analysis report (SAR). In particular, there are two DOE Orders (5480.23, {open_quotes}Nuclear Safety Analysis Reports,{close_quotes} and 5480.24, {open_quotes}Nuclear Criticality Safety{close_quotes}), an interpretive guidance document (NE-70, Interpretive Guidance for DOE Order 5480.24, {open_quotes}Nuclear Criticality Safety{close_quotes}), and DOE Standard DOE-STD-3009-94 {open_quotes}Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports.{close_quotes} Of these, the most practical and useful (pertaining to the application of criticality safety) is DOE-STD-3009-94. This paper is a reviewmore » of Chapters 3, 4, and 6 of this standard and how they provide very clear, helpful, and reasoned criticality safety guidance.« less

Why the Eurocontrol Safety Regulation Commission Policy on Safety Nets and Risk Assessment is Wrong

NASA Astrophysics Data System (ADS)

Brooker, Peter

2004-05-01

Current Eurocontrol Safety Regulation Commission (SRC) policy says that the Air Traffic Management (ATM) system (including safety minima) must be demonstrated through risk assessments to meet the Target Level of Safety (TLS) without needing to take safety nets (such as Short Term Conflict Alert) into account. This policy is wrong. The policy is invalid because it does not build rationally and consistently from ATM's firm foundations of TLS and hazard analysis. The policy is bad because it would tend to retard safety improvements. Safety net policy must rest on a clear and rational treatment of integrated ATM system safety defences. A new safety net policy, appropriate to safe ATM system improvements, is needed, which recognizes that safety nets are an integrated part of ATM system defences. The effects of safety nets in reducing deaths from mid-air collisions should be fully included in hazard analysis and safety audits in the context of the TLS for total system design.

A method for identifying EMI critical circuits during development of a large C3

NASA Astrophysics Data System (ADS)

Barr, Douglas H.

The circuit analysis methods and process Boeing Aerospace used on a large, ground-based military command, control, and communications (C3) system are described. This analysis was designed to help identify electromagnetic interference (EMI) critical circuits. The methodology used the MIL-E-6051 equipment criticality categories as the basis for defining critical circuits, relational database technology to help sort through and account for all of the approximately 5000 system signal cables, and Macintosh Plus personal computers to predict critical circuits based on safety margin analysis. The EMI circuit analysis process systematically examined all system circuits to identify which ones were likely to be EMI critical. The process used two separate, sequential safety margin analyses to identify critical circuits (conservative safety margin analysis, and detailed safety margin analysis). These analyses used field-to-wire and wire-to-wire coupling models using both worst-case and detailed circuit parameters (physical and electrical) to predict circuit safety margins. This process identified the predicted critical circuits that could then be verified by test.

Safety and business benefit analysis of NASA's aviation safety program

DOT National Transportation Integrated Search

2004-09-20

NASA Aviation Safety Program elements encompass a wide range of products that require both public and private investment. Therefore, two methods of analysis, one relating to the public and the other to the private industry, must be combined to unders...

Galileo and Ulysses missions safety analysis and launch readiness status

NASA Technical Reports Server (NTRS)

Cork, M. Joseph; Turi, James A.

1989-01-01

The Galileo spacecraft, which will release probes to explore the Jupiter system, was launched in October, 1989 as the payload on STS-34, and the Ulysses spacecraft, which will fly by Jupiter en route to a polar orbit of the sun, is presently entering system-test activity in preparation for an October, 1990 launch. This paper reviews the Galileo and Ulysses mission objectives and design approaches and presents details of the missions' safety analysis. The processes used to develop the safety analysis are described and the results of safety tests are presented.

System safety education focused on flight safety

NASA Technical Reports Server (NTRS)

Holt, E.

1971-01-01

The measures necessary for achieving higher levels of system safety are analyzed with an eye toward maintaining the combat capability of the Air Force. Several education courses were provided for personnel involved in safety management. Data include: (1) Flight Safety Officer Course, (2) Advanced Safety Program Management, (3) Fundamentals of System Safety, and (4) Quantitative Methods of Safety Analysis.

Safety Analysis and Protection Measures of the Control System of the Pulsed High Magnetic Field Facility in WHMFC

NASA Astrophysics Data System (ADS)

Shi, J. T.; Han, X. T.; Xie, J. F.; Yao, L.; Huang, L. T.; Li, L.

2013-03-01

A Pulsed High Magnetic Field Facility (PHMFF) has been established in Wuhan National High Magnetic Field Center (WHMFC) and various protection measures are applied in its control system. In order to improve the reliability and robustness of the control system, the safety analysis of the PHMFF is carried out based on Fault Tree Analysis (FTA) technique. The function and realization of 5 protection systems, which include sequence experiment operation system, safety assistant system, emergency stop system, fault detecting and processing system and accident isolating protection system, are given. The tests and operation indicate that these measures improve the safety of the facility and ensure the safety of people.

An Elementary Algorithm for Autonomous Air Terminal Merging and Interval Management

NASA Technical Reports Server (NTRS)

White, Allan L.

2017-01-01

A central element of air traffic management is the safe merging and spacing of aircraft during the terminal area flight phase. This paper derives and examines an algorithm for the merging and interval managing problem for Standard Terminal Arrival Routes. It describes a factor analysis for performance based on the distribution of arrivals, the operating period of the terminal, and the topology of the arrival routes; then presents results from a performance analysis and from a safety analysis for a realistic topology based on typical routes for a runway at Phoenix International Airport. The heart of the safety analysis is a statistical derivation on how to conduct a safety analysis for a local simulation when the safety requirement is given for the entire airspace.

Bayesian-network-based safety risk assessment for steel construction projects.

PubMed

Leu, Sou-Sen; Chang, Ching-Miao

2013-05-01

There are four primary accident types at steel building construction (SC) projects: falls (tumbles), object falls, object collapse, and electrocution. Several systematic safety risk assessment approaches, such as fault tree analysis (FTA) and failure mode and effect criticality analysis (FMECA), have been used to evaluate safety risks at SC projects. However, these traditional methods ineffectively address dependencies among safety factors at various levels that fail to provide early warnings to prevent occupational accidents. To overcome the limitations of traditional approaches, this study addresses the development of a safety risk-assessment model for SC projects by establishing the Bayesian networks (BN) based on fault tree (FT) transformation. The BN-based safety risk-assessment model was validated against the safety inspection records of six SC building projects and nine projects in which site accidents occurred. The ranks of posterior probabilities from the BN model were highly consistent with the accidents that occurred at each project site. The model accurately provides site safety-management abilities by calculating the probabilities of safety risks and further analyzing the causes of accidents based on their relationships in BNs. In practice, based on the analysis of accident risks and significant safety factors, proper preventive safety management strategies can be established to reduce the occurrence of accidents on SC sites. Copyright © 2013 Elsevier Ltd. All rights reserved.

10 CFR 830.205 - Technical safety requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... must: (1) Develop technical safety requirements that are derived from the documented safety analysis... 10 Energy 4 2010-01-01 2010-01-01 false Technical safety requirements. 830.205 Section 830.205 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT Safety Basis Requirements § 830.205 Technical...

10 CFR 830.205 - Technical safety requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... must: (1) Develop technical safety requirements that are derived from the documented safety analysis... 10 Energy 4 2011-01-01 2011-01-01 false Technical safety requirements. 830.205 Section 830.205 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT Safety Basis Requirements § 830.205 Technical...

Deep Borehole Disposal Safety Analysis.

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

Freeze, Geoffrey A.; Stein, Emily; Price, Laura L.

This report presents a preliminary safety analysis for the deep borehole disposal (DBD) concept, using a safety case framework. A safety case is an integrated collection of qualitative and quantitative arguments, evidence, and analyses that substantiate the safety, and the level of confidence in the safety, of a geologic repository. This safety case framework for DBD follows the outline of the elements of a safety case, and identifies the types of information that will be required to satisfy these elements. At this very preliminary phase of development, the DBD safety case focuses on the generic feasibility of the DBD concept.more » It is based on potential system designs, waste forms, engineering, and geologic conditions; however, no specific site or regulatory framework exists. It will progress to a site-specific safety case as the DBD concept advances into a site-specific phase, progressing through consent-based site selection and site investigation and characterization.« less

Safety climate and mindful safety practices in the oil and gas industry.

PubMed

Dahl, Øyvind; Kongsvik, Trond

2018-02-01

The existence of a positive association between safety climate and the safety behavior of sharp-end workers in high-risk organizations is supported by a considerable body of research. Previous research has primarily analyzed two components of safety behavior, namely safety compliance and safety participation. The present study extends previous research by looking into the relationship between safety climate and another component of safety behavior, namely mindful safety practices. Mindful safety practices are defined as the ability to be aware of critical factors in the environment and to act appropriately when dangers arise. Regression analysis was used to examine whether mindful safety practices are, like compliance and participation, promoted by a positive safety climate, in a questionnaire-based study of 5712 sharp-end workers in the oil and gas industry. The analysis revealed that a positive safety climate promotes mindful safety practices. The regression model accounted for roughly 31% of the variance in mindful safety practices. The most important safety climate factor was safety leadership. The findings clearly demonstrate that mindful safety practices are highly context-dependent, hence, manageable and susceptible to change. In order to improve safety climate in a direction which is favorable for mindful safety practices, the results demonstrate that it is important to give the fundamental features of safety climate high priority and in particular that of safety leadership. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

Development and Validation of a Safety Climate Scale for Manufacturing Industry

PubMed Central

Ghahramani, Abolfazl; Khalkhali, Hamid R.

2015-01-01

Background This paper describes the development of a scale for measuring safety climate. Methods This study was conducted in six manufacturing companies in Iran. The scale developed through conducting a literature review about the safety climate and constructing a question pool. The number of items was reduced to 71 after performing a screening process. Results The result of content validity analysis showed that 59 items had excellent item content validity index (≥ 0.78) and content validity ratio (> 0.38). The exploratory factor analysis resulted in eight safety climate dimensions. The reliability value for the final 45-item scale was 0.96. The result of confirmatory factor analysis showed that the safety climate model is satisfactory. Conclusion This study produced a valid and reliable scale for measuring safety climate in manufacturing companies. PMID:26106508

Effectiveness of maritime safety control in different navigation zones using a spatial sequential DEA model: Yangtze River case.

PubMed

Wu, Bing; Wang, Yang; Zhang, Jinfen; Savan, Emanuel Emil; Yan, Xinping

2015-08-01

This paper aims to analyze the effectiveness of maritime safety control from the perspective of safety level along the Yangtze River with special considerations for navigational environments. The influencing variables of maritime safety are reviewed, including ship condition, maritime regulatory system, human reliability and navigational environment. Because the former three variables are generally assumed to be of the same level of safety, this paper focuses on studying the impact of navigational environments on the level of safety in different waterways. An improved data envelopment analysis (DEA) model is proposed by treating the navigational environment factors as inputs and ship accident data as outputs. Moreover, because the traditional DEA model cannot provide an overall ranking of different decision making units (DMUs), the spatial sequential frontiers and grey relational analysis are incorporated into the DEA model to facilitate a refined assessment. Based on the empirical study results, the proposed model is able to solve the problem of information missing in the prior models and evaluate the level of safety with a better accuracy. The results of the proposed DEA model are further compared with an evidential reasoning (ER) method, which has been widely used for level of safety evaluations. A sensitivity analysis is also conducted to better understand the relationship between the variation of navigational environments and level of safety. The sensitivity analysis shows that the level of safety varies in terms of traffic flow. It indicates that appropriate traffic control measures should be adopted for different waterways to improve their safety. This paper presents a practical method of conducting maritime level of safety assessments under dynamic navigational environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

40 CFR 1611.3 - Scope of permissible testimony.

Code of Federal Regulations, 2010 CFR

2010-07-01

... other types of CSB documents, including but not limited to safety recommendations, safety studies, safety proposals, safety accomplishments, reports labeled studies, and analysis reports, as they contain...

Efficacy and safety of biologic therapies for systemic lupus erythematosus treatment: systematic review and meta-analysis.

PubMed

Borba, Helena Hiemisch Lobo; Wiens, Astrid; de Souza, Thais Teles; Correr, Cassyano Januário; Pontarolo, Roberto

2014-04-01

The objectives of this study were to evaluate the efficacy, safety, and tolerability of biologic drugs compared with placebo for systemic lupus erythematosus (SLE) treatment. A systematic review evaluating the efficacy and safety of biologic therapies compared with placebo in adult SLE patients treatment was performed. Data from studies performed before September 2013 were collected from several databases (MEDLINE, Cochrane Library, SCIELO, Scopus, and International Pharmaceutical Abstracts). Study eligibility criteria included randomized, double-blind, placebo-controlled trials; regarding treatment with biologic agents in SLE adult patients; and published in English, German, Portuguese, and Spanish. Extracted data were statistically analyzed in a meta-analysis using the Review Manager (RevMan) 5.1 software. Efficacy outcomes included the SELENA-SLEDAI (Safety of Estrogens in Lupus Erythematosus National Assessment version of the SLE Disease Activity Index) score, the SRI (Systemic Lupus Erythematosus Responder Index), normalization of low C3 (<90 mg/dL), anti-double-stranded DNA positive to negative, and no new BILAG (British Isles Lupus Assessment Group index) 1A or 2B flares. Data on safety profile included adverse events, serious and severe adverse events, death, malignancy, infections, and infusion reactions. We also evaluated withdrawals from treatment due to lack of efficacy or adverse events. Thirteen randomized placebo-controlled trials met the criteria for data extraction for systematic review. A meta-analysis regarding the efficacy and safety of belimumab compared with placebo involving four of these trials was undertaken and the remainder contributed to a meta-analysis of the safety of biologic agents. In addition, two trials allowed the performance of a meta-analysis regarding the efficacy and safety of rituximab compared with placebo. Belimumab was more effective than placebo in most evaluated outcomes. No significant differences in the safety and tolerability data were observed between the belimumab and placebo groups. No differences were observed between the rituximab and placebo groups for the efficacy outcomes or safety parameters. Extracted data from the 13 studies were pooled, allowing assessment of the safety of biologic drugs. The meta-analysis revealed a satisfactory safety profile of these agents when used for SLE treatment, as there were no significant differences between the two evaluated groups (biologic agents and placebo) for all outcomes analyzed. Belimumab exhibited a satisfactory profile regarding efficacy, safety, and tolerability. Rituximab showed no superiority over placebo in terms of efficacy, despite its suitable safety profile. Biologic agents exhibited a good safety profile for SLE treatment, indicating that these agents are promising therapies and should be further investigated.

Development of Flight Safety Prediction Methodology for U. S. Naval Safety Center. Revision 1

DTIC Science & Technology

1970-02-01

Safety Center. The methodology develoned encompassed functional analysis of the F-4J aircraft, assessment of the importance of safety- sensitive ... Sensitivity ... ....... . 4-8 V 4.5 Model Implementation ........ ......... . 4-10 4.5.1 Functional Analysis ..... ........... . 4-11 4. 5. 2 Major...Function Sensitivity Assignment ........ ... 4-13 i 4.5.3 Link Dependency Assignment ... ......... . 4-14 4.5.4 Computer Program for Sensitivity

Knowledge and perceived implementation of food safety risk analysis framework in Latin America and the Caribbean region.

PubMed

Cherry, C; Mohr, A Hofelich; Lindsay, T; Diez-Gonzalez, F; Hueston, W; Sampedro, F

2014-12-01

Risk analysis is increasingly promoted as a tool to support science-based decisions regarding food safety. An online survey comprising 45 questions was used to gather information on the implementation of food safety risk analysis within the Latin American and Caribbean regions. Professionals working in food safety in academia, government, and private sectors in Latin American and Caribbean countries were contacted by email and surveyed to assess their individual knowledge of risk analysis and perceptions of its implementation in the region. From a total of 279 participants, 97% reported a familiarity with risk analysis concepts; however, fewer than 25% were able to correctly identify its key principles. The reported implementation of risk analysis among the different professional sectors was relatively low (46%). Participants from industries in countries with a long history of trade with the United States and the European Union, such as Mexico, Brazil, and Chile, reported perceptions of a higher degree of risk analysis implementation (56, 50, and 20%, respectively) than those from the rest of the countries, suggesting that commerce may be a driver for achieving higher food safety standards. Disagreement among respondents on the extent of the use of risk analysis in national food safety regulations was common, illustrating a systematic lack of understanding of the current regulatory status of the country. The results of this survey can be used to target further risk analysis training on selected sectors and countries.

14 CFR 415.117 - Ground safety.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Ground safety. 415.117 Section 415.117... From a Non-Federal Launch Site § 415.117 Ground safety. (a) General. An applicant's safety review document must include a ground safety analysis report, and a ground safety plan for its launch processing...

14 CFR 415.117 - Ground safety.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Ground safety. 415.117 Section 415.117... From a Non-Federal Launch Site § 415.117 Ground safety. (a) General. An applicant's safety review document must include a ground safety analysis report, and a ground safety plan for its launch processing...

A path analysis model for explaining unsafe behavior in workplaces: the effect of perceived work pressure.

PubMed

Ghasemi, Fakhradin; Kalatpour, Omid; Moghimbeigi, Abbas; Mohhamadfam, Iraj

2018-06-01

Unsafe behavior is closely related to occupational accidents. Work pressure is one the main factors affecting employees' behavior. The aim of the present study was to provide a path analysis model for explaining how work pressure affects safety behavior. Using a self-administered questionnaire, six variables supposed to affect safety employees' behavior were measured. The path analysis model was constructed based on several hypotheses. The goodness of fit of the model was assessed using both absolute and comparative fit indices. Work pressure was determined not to influence safety behavior directly. However, it negatively influenced other variables. Group attitude and personal attitude toward safety were the main factors mediating the effect of work pressure on safety behavior. Among the variables investigated in the present study, group attitude, personal attitude and work pressure had the strongest effects on safety behavior. Managers should consider that in order to improve employees' safety behavior, work pressure should be reduced to a reasonable level, and concurrently a supportive environment, which ensures a positive group attitude toward safety, should be provided. Replication of the study is recommended.

Track train dynamics analysis and test program: Methodology development for the derailment safety analysis of six-axle locomotives

NASA Technical Reports Server (NTRS)

Marcotte, P. P.; Mathewson, K. J. R.

1982-01-01

The operational safety of six axle locomotives is analyzed. A locomotive model with corresponding data on suspension characteristics, a method of track defect characterization, and a method of characterizing operational safety are used. A user oriented software package was developed as part of the methodology and was used to study the effect (on operational safety) of various locomotive parameters and operational conditions such as speed, tractive effort, and track curvature. The operational safety of three different locomotive designs was investigated.

Dimensions of Safety Climate among Iranian Nurses.

PubMed

Konjin, Z Naghavi; Shokoohi, Y; Zarei, F; Rahimzadeh, M; Sarsangi, V

2015-10-01

Workplace safety has been a concern of workers and managers for decades. Measuring safety climate is crucial in improving safety performance. It is also a method of benchmarking safety perception. To develop and validate a psychometrics scale for measuring nurses' safety climate. Literature review, subject matter experts and nurse's judgment were used in items developing. Content validity and reliability for new tool were tested by content validity index (CVI) and test-retest analysis, respectively. Exploratory factor analysis (EFA) with varimax rotation was used to improve the interpretation of latent factors. A 40-item scale in 6 factors was developed, which could explain 55% of the observed variance. The 6 factors included employees' involvement in safety and management support, compliance with safety rules, safety training and accessibility to personal protective equipment, hindrance to safe work, safety communication and job pressure, and individual risk perception. The proposed scale can be used in identifying the needed areas to implement interventions in safety climate of nurses.

14 CFR 415.204-415.400 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-01-01

... Subsystem Design Information 10.4Flight Safety System Analyses 10.5Flight Termination System Environmental... Analysis 4.1.1Flight Safety Sub-Analyses, Methods, and Assumptions 4.1.2Sample Calculation and Products 4.1.3 Launch Specific Updates and Final Flight Safety Analysis Data 4.2Radionuclide Data (where...

14 CFR 415.204-415.400 - [Reserved

Code of Federal Regulations, 2012 CFR

2012-01-01

... Subsystem Design Information 10.4Flight Safety System Analyses 10.5Flight Termination System Environmental... Analysis 4.1.1Flight Safety Sub-Analyses, Methods, and Assumptions 4.1.2Sample Calculation and Products 4.1.3 Launch Specific Updates and Final Flight Safety Analysis Data 4.2Radionuclide Data (where...

14 CFR 415.204-415.400 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-01-01

... Subsystem Design Information 10.4Flight Safety System Analyses 10.5Flight Termination System Environmental... Analysis 4.1.1Flight Safety Sub-Analyses, Methods, and Assumptions 4.1.2Sample Calculation and Products 4.1.3 Launch Specific Updates and Final Flight Safety Analysis Data 4.2Radionuclide Data (where...

Traffic safety facts 1997 : a compilation of motor vehicle crash data from the fatality analysis reporting system and the general estimates system

DOT National Transportation Integrated Search

1998-11-01

In this annual report, Traffic Safety Facts 1997: A Compilation of Motor Vehicle Crash Data from the Fatality Analysis Reporting System and the General Estimates System, the National Highway Traffic Safety Administration (NHTSA) presents descriptive ...

Traffic safety facts 2007 : a compilation of motor vehicle crash data from the fatality analysis reporting system and the general estimates system

DOT National Transportation Integrated Search

2007-01-01

In this annual report, Traffic Safety Facts 2007: A Compilation of Motor Vehicle Crash Data from the Fatality : Analysis Reporting System and the General Estimates System, the National Highway Traffic Safety Administration : (NHTSA) presents descript...

Traffic safety facts 2008 : a compilation of motor vehicle crash data from the fatality analysis reporting system and the general estimates system

DOT National Transportation Integrated Search

2008-01-01

In this annual report, Traffic Safety Facts 2008: A Compilation of Motor Vehicle Crash Data from the Fatality Analysis Reporting System and the General Estimates System, the National Highway Traffic Safety Administration (NHTSA) presents descriptive ...

Traffic safety facts 2009 : a compilation of motor vehicle crash data from the fatality analysis reporting system and the general estimates system

DOT National Transportation Integrated Search

2009-01-01

In this annual report, Traffic Safety Facts 2009: A Compilation of Motor Vehicle Crash Data from the Fatality Analysis Reporting System and the General Estimates System, the National Highway Traffic Safety Administration (NHTSA) presents descriptive ...

Management system of health and safety work (SMK3) with job safety analysis (JSA) in PT. Nira Murni construction

NASA Astrophysics Data System (ADS)

Melliana, Armen, Yusrizal, Akmal, Syarifah

2017-11-01

PT Nira Murni construction is a contractor of PT Chevron Pacific Indonesia which engaged in contractor, fabrication, maintenance construction suppliers, and labor services. The high of accident rate in this company is caused the lack of awareness of workplace safety. Therefore, it requires an effort to reduce the accident rate on the company so that the financial losses can be minimized. In this study, Safe T-Score method is used to analyze the accident rate by measuring the level of frequency. Analysis is continued using risk management methods which identify hazards, risk measurement and risk management. The last analysis uses Job safety analysis (JSA) which will identify the effect of accidents. From the result of this study can be concluded that Job Safety Analysis (JSA) methods has not been implemented properly. Therefore, JSA method needs to follow-up in the next study, so that can be well applied as prevention of occupational accidents.

Mines Systems Safety Improvement Using an Integrated Event Tree and Fault Tree Analysis

NASA Astrophysics Data System (ADS)

Kumar, Ranjan; Ghosh, Achyuta Krishna

2017-04-01

Mines systems such as ventilation system, strata support system, flame proof safety equipment, are exposed to dynamic operational conditions such as stress, humidity, dust, temperature, etc., and safety improvement of such systems can be done preferably during planning and design stage. However, the existing safety analysis methods do not handle the accident initiation and progression of mine systems explicitly. To bridge this gap, this paper presents an integrated Event Tree (ET) and Fault Tree (FT) approach for safety analysis and improvement of mine systems design. This approach includes ET and FT modeling coupled with redundancy allocation technique. In this method, a concept of top hazard probability is introduced for identifying system failure probability and redundancy is allocated to the system either at component or system level. A case study on mine methane explosion safety with two initiating events is performed. The results demonstrate that the presented method can reveal the accident scenarios and improve the safety of complex mine systems simultaneously.

Archetypes for Organisational Safety

NASA Technical Reports Server (NTRS)

Marais, Karen; Leveson, Nancy G.

2003-01-01

We propose a framework using system dynamics to model the dynamic behavior of organizations in accident analysis. Most current accident analysis techniques are event-based and do not adequately capture the dynamic complexity and non-linear interactions that characterize accidents in complex systems. In this paper we propose a set of system safety archetypes that model common safety culture flaws in organizations, i.e., the dynamic behaviour of organizations that often leads to accidents. As accident analysis and investigation tools, the archetypes can be used to develop dynamic models that describe the systemic and organizational factors contributing to the accident. The archetypes help clarify why safety-related decisions do not always result in the desired behavior, and how independent decisions in different parts of the organization can combine to impact safety.

Analysis on Dangerous Source of Large Safety Accident in Storage Tank Area

NASA Astrophysics Data System (ADS)

Wang, Tong; Li, Ying; Xie, Tiansheng; Liu, Yu; Zhu, Xueyuan

2018-01-01

The difference between a large safety accident and a general accident is that the consequences of a large safety accident are particularly serious. To study the tank area which factors directly or indirectly lead to the occurrence of large-sized safety accidents. According to the three kinds of hazard source theory and the consequence cause analysis of the super safety accident, this paper analyzes the dangerous source of the super safety accident in the tank area from four aspects, such as energy source, large-sized safety accident reason, management missing, environmental impact Based on the analysis of three kinds of hazard sources and environmental analysis to derive the main risk factors and the AHP evaluation model is established, and after rigorous and scientific calculation, the weights of the related factors in four kinds of risk factors and each type of risk factors are obtained. The result of analytic hierarchy process shows that management reasons is the most important one, and then the environmental factors and the direct cause and Energy source. It should be noted that although the direct cause is relatively low overall importance, the direct cause of Failure of emergency measures and Failure of prevention and control facilities in greater weight.

Thermal-hydraulic interfacing code modules for CANDU reactors

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

Liu, W.S.; Gold, M.; Sills, H.

1997-07-01

The approach for CANDU reactor safety analysis in Ontario Hydro Nuclear (OHN) and Atomic Energy of Canada Limited (AECL) is presented. Reflecting the unique characteristics of CANDU reactors, the procedure of coupling the thermal-hydraulics, reactor physics and fuel channel/element codes in the safety analysis is described. The experience generated in the Canadian nuclear industry may be useful to other types of reactors in the areas of reactor safety analysis.

Transit safety & security statistics & analysis 2003 annual report (formerly SAMIS)

DOT National Transportation Integrated Search

2005-12-01

The Transit Safety & Security Statistics & Analysis 2003 Annual Report (formerly SAMIS) is a compilation and analysis of mass transit accident, casualty, and crime statistics reported under the Federal Transit Administrations (FTAs) National Tr...

Transit safety & security statistics & analysis 2002 annual report (formerly SAMIS)

DOT National Transportation Integrated Search

2004-12-01

The Transit Safety & Security Statistics & Analysis 2002 Annual Report (formerly SAMIS) is a compilation and analysis of mass transit accident, casualty, and crime statistics reported under the Federal Transit Administrations (FTAs) National Tr...

Ares I Integrated Vehicle System Safety Team

NASA Technical Reports Server (NTRS)

Wetherholt, Jon; McNairy, Lisa; Shackelford, Carla

2009-01-01

Complex systems require integrated analysis teams which sometimes are divided into subsystem teams. Proper division of the analysis in to subsystem teams is important. Safety analysis is one of the most difficult aspects of integration.

Analysis of occupational accidents: prevention through the use of additional technical safety measures for machinery.

PubMed

Dźwiarek, Marek; Latała, Agata

2016-01-01

This article presents an analysis of results of 1035 serious and 341 minor accidents recorded by Poland's National Labour Inspectorate (PIP) in 2005-2011, in view of their prevention by means of additional safety measures applied by machinery users. Since the analysis aimed at formulating principles for the application of technical safety measures, the analysed accidents should bear additional attributes: the type of machine operation, technical safety measures and the type of events causing injuries. The analysis proved that the executed tasks and injury-causing events were closely connected and there was a relation between casualty events and technical safety measures. In the case of tasks consisting of manual feeding and collecting materials, the injuries usually occur because of the rotating motion of tools or crushing due to a closing motion. Numerous accidents also happened in the course of supporting actions, like removing pollutants, correcting material position, cleaning, etc.

Analysis of occupational accidents: prevention through the use of additional technical safety measures for machinery

PubMed Central

Dźwiarek, Marek; Latała, Agata

2016-01-01

This article presents an analysis of results of 1035 serious and 341 minor accidents recorded by Poland's National Labour Inspectorate (PIP) in 2005–2011, in view of their prevention by means of additional safety measures applied by machinery users. Since the analysis aimed at formulating principles for the application of technical safety measures, the analysed accidents should bear additional attributes: the type of machine operation, technical safety measures and the type of events causing injuries. The analysis proved that the executed tasks and injury-causing events were closely connected and there was a relation between casualty events and technical safety measures. In the case of tasks consisting of manual feeding and collecting materials, the injuries usually occur because of the rotating motion of tools or crushing due to a closing motion. Numerous accidents also happened in the course of supporting actions, like removing pollutants, correcting material position, cleaning, etc. PMID:26652689

Comparison of a Traditional Probabilistic Risk Assessment Approach with Advanced Safety Analysis

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

Smith, Curtis L; Mandelli, Diego; Zhegang Ma

2014-11-01

As part of the Light Water Sustainability Program (LWRS) [1], the purpose of the Risk Informed Safety Margin Characterization (RISMC) [2] Pathway research and development (R&D) is to support plant decisions for risk-informed margin management with the aim to improve economics, reliability, and sustain safety of current NPPs. In this paper, we describe the RISMC analysis process illustrating how mechanistic and probabilistic approaches are combined in order to estimate a safety margin. We use the scenario of a “station blackout” (SBO) wherein offsite power and onsite power is lost, thereby causing a challenge to plant safety systems. We describe themore » RISMC approach, illustrate the station blackout modeling, and contrast this with traditional risk analysis modeling for this type of accident scenario. We also describe our approach we are using to represent advanced flooding analysis.« less

49 CFR 238.603 - Safety planning requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... or potential safety hazards over the life cycle of the equipment; (3) Identify safety issues during... issues, reducing hazards, and meeting safety requirements; (6) Develop a program of testing or analysis...

49 CFR 238.603 - Safety planning requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... or potential safety hazards over the life cycle of the equipment; (3) Identify safety issues during... issues, reducing hazards, and meeting safety requirements; (6) Develop a program of testing or analysis...

Visualizing variations in organizational safety culture across an inter-hospital multifaceted workforce.

PubMed

Kobuse, Hiroe; Morishima, Toshitaka; Tanaka, Masayuki; Murakami, Genki; Hirose, Masahiro; Imanaka, Yuichi

2014-06-01

To develop a reliable and valid questionnaire that can distinguish features of organizational culture for patient safety across subgroups such as hospitals, professions, management/non-management positions and units/wards. We developed a Hospital Organizational Culture Questionnaire based on a conceptual framework incorporating items from a review of existing literature. The questionnaire was administered to hospital staff including doctors, nurses, allied health personnel, and administrative staff at six public hospitals in Japan. Reliability and validity were assessed through exploratory factor analysis, multitrait scaling analysis, Cronbach's alpha coefficient and multiple regression analysis using staff-perceived achievement of safety as the response variable. Discriminative power across subgroups was assessed with radar chart profiling. Of the 3304 hospital staff surveyed, 2924 (88.5%) responded. After exploratory factor analysis and multitrait analysis, the finalized questionnaire was composed of 24 items in the following eight dimensions: improvement orientation, passion for mission, professional growth, resource allocation prioritization, inter-sectional collaboration, responsibility and authority, teamwork, and information sharing. Construct validity and internal consistency of dimensions were confirmed with multitrait analysis and Cronbach's alpha coefficients, respectively. Multiple regression analysis showed that improvement orientation, passion for mission, resource allocation prioritization and information sharing were significantly associated with higher achievement in safety practices. Our questionnaire tool was able to distinguish features of safety culture among different subgroups. Our questionnaire demonstrated excellent validity and reliability, and revealed distinct cultural patterns among different subgroups. Quantitative assessment of organizational safety culture with this tool may further the understanding of associated characteristics of each subgroup and provide insight into organizational readiness for patient safety improvement. © 2014 John Wiley & Sons, Ltd.

Hazard Analysis and Safety Requirements for Small Drone Operations: To What Extent Do Popular Drones Embed Safety?

PubMed

Plioutsias, Anastasios; Karanikas, Nektarios; Chatzimihailidou, Maria Mikela

2018-03-01

Currently, published risk analyses for drones refer mainly to commercial systems, use data from civil aviation, and are based on probabilistic approaches without suggesting an inclusive list of hazards and respective requirements. Within this context, this article presents: (1) a set of safety requirements generated from the application of the systems theoretic process analysis (STPA) technique on a generic small drone system; (2) a gap analysis between the set of safety requirements and the ones met by 19 popular drone models; (3) the extent of the differences between those models, their manufacturers, and the countries of origin; and (4) the association of drone prices with the extent they meet the requirements derived by STPA. The application of STPA resulted in 70 safety requirements distributed across the authority, manufacturer, end user, or drone automation levels. A gap analysis showed high dissimilarities regarding the extent to which the 19 drones meet the same safety requirements. Statistical results suggested a positive correlation between drone prices and the extent that the 19 drones studied herein met the safety requirements generated by STPA, and significant differences were identified among the manufacturers. This work complements the existing risk assessment frameworks for small drones, and contributes to the establishment of a commonly endorsed international risk analysis framework. Such a framework will support the development of a holistic and methodologically justified standardization scheme for small drone flights. © 2017 Society for Risk Analysis.

Analysis of cost regression and post-accident absence

NASA Astrophysics Data System (ADS)

Wojciech, Drozd

2017-07-01

The article presents issues related with costs of work safety. It proves the thesis that economic aspects cannot be overlooked in effective management of occupational health and safety and that adequate expenditures on safety can bring tangible benefits to the company. Reliable analysis of this problem is essential for the description the problem of safety the work. In the article attempts to carry it out using the procedures of mathematical statistics [1, 2, 3].

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

MITCHELL,GERRY W.; LONGLEY,SUSAN W.; PHILBIN,JEFFREY S.

This Safety Analysis Report (SAR) is prepared in compliance with the requirements of DOE Order 5480.23, Nuclear Safety Analysis Reports, and has been written to the format and content guide of DOE-STD-3009-94 Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Safety Analysis Reports. The Hot Cell Facility is a Hazard Category 2 nonreactor nuclear facility, and is operated by Sandia National Laboratories for the Department of Energy. This SAR provides a description of the HCF and its operations, an assessment of the hazards and potential accidents which may occur in the facility. The potential consequences and likelihood ofmore » these accidents are analyzed and described. Using the process and criteria described in DOE-STD-3009-94, safety-related structures, systems and components are identified, and the important safety functions of each SSC are described. Additionally, information which describes the safety management programs at SNL are described in ancillary chapters of the SAR.« less

Making safety an integral part of 5S in healthcare.

PubMed

Ikuma, Laura H; Nahmens, Isabelina

2014-01-01

Healthcare faces major challenges with provider safety and rising costs, and many organizations are using Lean to instigate change. One Lean tool, 5S, is becoming popular for improving efficiency of physical work environments, and it can also improve safety. This paper demonstrates that safety is an integral part of 5S by examining five specific 5S events in acute care facilities. We provide two arguments for how safety is linked to 5S:1. Safety is affected by 5S events, regardless of whether safety is a specific goal and 2. Safety can and should permeate all five S's as part of a comprehensive plan for system improvement. Reports of 5S events from five departments in one health system were used to evaluate how changes made at each step of the 5S impacted safety. Safety was affected positively in each step of the 5S through initial safety goals and side effects of other changes. The case studies show that 5S can be a mechanism for improving safety. Practitioners may reap additional safety benefits by incorporating safety into 5S events through a safety analysis before the 5S, safety goals and considerations during the 5S, and follow-up safety analysis.

The carrier safety measurement system (CSMS) effectiveness test by behavior analysis and safety improvement categories (BASICs)

DOT National Transportation Integrated Search

2014-01-24

The Carrier Safety Measurement System (CSMS) is the Federal Motor Carrier Safety Administrations (FMCSA's) workload prioritization tool. This tool is used to identify carriers with potential safety issues so that they are subject to interventions ...

Transportation safety data and analysis : Volume 1, Analyzing the effectiveness of safety measures using Bayesian methods.

DOT National Transportation Integrated Search

2010-12-01

Recent research suggests that traditional safety evaluation methods may be inadequate in accurately determining the effectiveness of roadway safety measures. In recent years, advanced statistical methods are being utilized in traffic safety studies t...

14 CFR 417.225 - Debris risk analysis.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Debris risk analysis. 417.225 Section 417.225 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.225 Debris risk analysis. A...

14 CFR 417.225 - Debris risk analysis.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Debris risk analysis. 417.225 Section 417.225 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.225 Debris risk analysis. A...

14 CFR 417.225 - Debris risk analysis.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Debris risk analysis. 417.225 Section 417.225 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.225 Debris risk analysis. A...

14 CFR 417.211 - Debris analysis.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Debris analysis. 417.211 Section 417.211 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.211 Debris analysis. (a) General. A flight...

14 CFR 417.225 - Debris risk analysis.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Debris risk analysis. 417.225 Section 417.225 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.225 Debris risk analysis. A...

14 CFR 417.211 - Debris analysis.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Debris analysis. 417.211 Section 417.211 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.211 Debris analysis. (a) General. A flight...

14 CFR 417.211 - Debris analysis.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Debris analysis. 417.211 Section 417.211 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.211 Debris analysis. (a) General. A flight...

14 CFR 417.225 - Debris risk analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Debris risk analysis. 417.225 Section 417.225 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.225 Debris risk analysis. A...

76 FR 31507 - Domestic Licensing of Source Material-Amendments/Integrated Safety Analysis

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-01

... Licensing of Source Material--Amendments/Integrated Safety Analysis AGENCY: Nuclear Regulatory Commission... rule announced the availability of a draft regulatory analysis for public comment. This document... in Section XI, ``Regulatory Analysis.'' The correct ADAMS accession number is ML102380243. DATES: The...

14 CFR 417.211 - Debris analysis.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Debris analysis. 417.211 Section 417.211 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.211 Debris analysis. (a) General. A flight...

14 CFR 417.211 - Debris analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Debris analysis. 417.211 Section 417.211 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.211 Debris analysis. (a) General. A flight...

How Agricultural Media Cover Safety Compared with Periodicals in Two Other Hazardous Industries.

PubMed

Marolf, Amanda; Heiberger, Scott; Evans, James; Joseph, Lura

2017-01-26

This analysis featured a uniquely broad look at challenges and potentials for engaging agricultural and other industrial media more effectively in covering safety. It involved a content analysis of selected industry periodicals serving agriculture, mining, and transportation, which are three of the nation's most hazardous industries, in terms of human safety. Use of the social amplification of risk framework (SARF) provided insight on safety coverage. In particular, it tested previous research indicating that media coverage tends to amplify (increase) more than attenuate (decrease) a sense of risk. Analysis involved 18 periodicals (9 agriculture, 7 transportation, and 2 mining) spanning a five-year period from 2008 to 2012. Full-text digital analysis identified terms found in safety articles across all three industries. A manual review of articles revealed the quantity and nature of safety coverage within and among these industries. Results identified 528 safety-related articles published during the period. Transportation and mining periodicals averaged more than twice as many safety articles as the agricultural periodicals. The amount of coverage within the three industries also varied greatly. Findings on the nature of coverage supported previous media research within the SARF. Coverage across all three industries was clearly oriented more to amplifying than to attenuating risk. This study adds to the understanding of variations, commonalities, challenges, and potentials for enhancing safety coverage by media serving these three industries. It also provides direction for engaging industry media more effectively in the public safety mission. The authors recommend seven areas of opportunity for further research. Copyright© by the American Society of Agricultural Engineers.

49 CFR 209.501 - Review of rail transportation safety and security route analysis.

Code of Federal Regulations, 2010 CFR

2010-10-01

... establish that the route chosen by the carrier poses the least overall safety and security risk, the... analysis, including a clear description of the risks on the selected route that have not been... commercially practicable alternative route poses fewer overall safety and security risks than the route...

16 CFR § 1101.13 - Public ability to ascertain readily identity of manufacturer or private labeler.

Code of Federal Regulations, 2013 CFR

2013-01-01

... PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INFORMATION DISCLOSURE UNDER SECTION 6(b) OF THE CONSUMER PRODUCT SAFETY ACT Information Subject to Notice and Analysis Provisions of Section 6... advance notice and analysis provisions of section 6(b)(1) apply only when a reasonable person receiving...

16 CFR 1101.13 - Public ability to ascertain readily identity of manufacturer or private labeler.

Code of Federal Regulations, 2014 CFR

2014-01-01

... SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INFORMATION DISCLOSURE UNDER SECTION 6(b) OF THE CONSUMER PRODUCT SAFETY ACT Information Subject to Notice and Analysis Provisions of Section 6(b... advance notice and analysis provisions of section 6(b)(1) apply only when a reasonable person receiving...

16 CFR 1101.13 - Public ability to ascertain readily identity of manufacturer or private labeler.

Code of Federal Regulations, 2011 CFR

2011-01-01

... SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INFORMATION DISCLOSURE UNDER SECTION 6(b) OF THE CONSUMER PRODUCT SAFETY ACT Information Subject to Notice and Analysis Provisions of Section 6(b... advance notice and analysis provisions of section 6(b)(1) apply only when a reasonable person receiving...

16 CFR 1101.13 - Public ability to ascertain readily identity of manufacturer or private labeler.

Code of Federal Regulations, 2010 CFR

2010-01-01

... SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INFORMATION DISCLOSURE UNDER SECTION 6(b) OF THE CONSUMER PRODUCT SAFETY ACT Information Subject to Notice and Analysis Provisions of Section 6(b... advance notice and analysis provisions of section 6(b)(1) apply only when a reasonable person receiving...

16 CFR 1101.13 - Public ability to ascertain readily identity of manufacturer or private labeler.

Code of Federal Regulations, 2012 CFR

2012-01-01

... SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INFORMATION DISCLOSURE UNDER SECTION 6(b) OF THE CONSUMER PRODUCT SAFETY ACT Information Subject to Notice and Analysis Provisions of Section 6(b... advance notice and analysis provisions of section 6(b)(1) apply only when a reasonable person receiving...

Georgia Highway Safety 1997 fact book : a report on highway safety In Georgia

DOT National Transportation Integrated Search

1997-01-01

The goal of this fact book is to present highway safety statistics and fact-based analysis that will increase public awareness on highway safety issues, and to provide information that will assist policy makers and highway safety advocates in making ...

10 CFR 70.62 - Safety program and integrated safety analysis.

Code of Federal Regulations, 2013 CFR

2013-01-01

...; (iv) Potential accident sequences caused by process deviations or other events internal to the... of occurrence of each potential accident sequence identified pursuant to paragraph (c)(1)(iv) of this... have experience in nuclear criticality safety, radiation safety, fire safety, and chemical process...

10 CFR 70.62 - Safety program and integrated safety analysis.

Code of Federal Regulations, 2014 CFR

2014-01-01

...; (iv) Potential accident sequences caused by process deviations or other events internal to the... of occurrence of each potential accident sequence identified pursuant to paragraph (c)(1)(iv) of this... have experience in nuclear criticality safety, radiation safety, fire safety, and chemical process...

10 CFR 70.62 - Safety program and integrated safety analysis.

Code of Federal Regulations, 2012 CFR

2012-01-01

...; (iv) Potential accident sequences caused by process deviations or other events internal to the... of occurrence of each potential accident sequence identified pursuant to paragraph (c)(1)(iv) of this... have experience in nuclear criticality safety, radiation safety, fire safety, and chemical process...

14 CFR 437.55 - Hazard analysis.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Hazard analysis. 437.55 Section 437.55... TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Safety Requirements § 437.55 Hazard analysis. (a) A permittee must... safety of property resulting from each permitted flight. This hazard analysis must— (1) Identify and...

14 CFR 437.55 - Hazard analysis.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Hazard analysis. 437.55 Section 437.55... TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Safety Requirements § 437.55 Hazard analysis. (a) A permittee must... safety of property resulting from each permitted flight. This hazard analysis must— (1) Identify and...

14 CFR 417.209 - Malfunction turn analysis.

Code of Federal Regulations, 2013 CFR

2013-01-01

... turn behavior for each cause of a malfunction turn. For each malfunction turn envelope, the analysis... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Malfunction turn analysis. 417.209 Section..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.209 Malfunction turn...

14 CFR 417.209 - Malfunction turn analysis.

Code of Federal Regulations, 2012 CFR

2012-01-01

... turn behavior for each cause of a malfunction turn. For each malfunction turn envelope, the analysis... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Malfunction turn analysis. 417.209 Section..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.209 Malfunction turn...

14 CFR 417.209 - Malfunction turn analysis.

Code of Federal Regulations, 2014 CFR

2014-01-01

... turn behavior for each cause of a malfunction turn. For each malfunction turn envelope, the analysis... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Malfunction turn analysis. 417.209 Section..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.209 Malfunction turn...

Key performance outcomes of patient safety curricula: root cause analysis, failure mode and effects analysis, and structured communications skills.

PubMed

Fassett, William E

2011-10-10

As colleges and schools of pharmacy develop core courses related to patient safety, course-level outcomes will need to include both knowledge and performance measures. Three key performance outcomes for patient safety coursework, measured at the course level, are the ability to perform root cause analyses and healthcare failure mode effects analyses, and the ability to generate effective safety communications using structured formats such as the Situation-Background-Assessment-Recommendation (SBAR) situational briefing model. Each of these skills is widely used in patient safety work and competence in their use is essential for a pharmacist's ability to contribute as a member of a patient safety team.

Investigation of safety analysis methods using computer vision techniques

NASA Astrophysics Data System (ADS)

Shirazi, Mohammad Shokrolah; Morris, Brendan Tran

2017-09-01

This work investigates safety analysis methods using computer vision techniques. The vision-based tracking system is developed to provide the trajectory of road users including vehicles and pedestrians. Safety analysis methods are developed to estimate time to collision (TTC) and postencroachment time (PET) that are two important safety measurements. Corresponding algorithms are presented and their advantages and drawbacks are shown through their success in capturing the conflict events in real time. The performance of the tracking system is evaluated first, and probability density estimation of TTC and PET are shown for 1-h monitoring of a Las Vegas intersection. Finally, an idea of an intersection safety map is introduced, and TTC values of two different intersections are estimated for 1 day from 8:00 a.m. to 6:00 p.m.

Analysis of Aviation Safety Reporting System Incident Data Associated With the Technical Challenges of the Vehicle Systems Safety Technology Project

NASA Technical Reports Server (NTRS)

Withrow, Colleen A.; Reveley, Mary S.

2014-01-01

This analysis was conducted to support the Vehicle Systems Safety Technology (VSST) Project of the Aviation Safety Program (AVsP) milestone VSST4.2.1.01, "Identification of VSST-Related Trends." In particular, this is a review of incident data from the NASA Aviation Safety Reporting System (ASRS). The following three VSST-related technical challenges (TCs) were the focus of the incidents searched in the ASRS database: (1) Vechicle health assurance, (2) Effective crew-system interactions and decisions in all conditions; and (3) Aircraft loss of control prevention, mitigation, and recovery.

UV laser-induced fluorescence spectroscopy and laser Doppler flowmetry in the diagnostics of alopecia

NASA Astrophysics Data System (ADS)

Skomorokha, Diana P.; Pigoreva, Yulia N.; Salmin, Vladimir V.

2016-04-01

Development of optical biopsy methods has a great interest for medical diagnostics. In clinical and experimental studies it is very important to analyze blood circulation quickly and accurately, thereby laser Doppler flowmetry (LDF) is widely used. UV laser-induced fluorescence spectroscopy (UV LIFS) is express highly sensitive and widely-spread method with no destructive impact, high excitation selectivity and the possibility to use in highly scattering media. The goal of this work was to assess a correlation of UV laser-induced fluorescence spectroscopy and laser Doppler flowmetry parameters, and a possibility to identify or to differentiate various types of pathological changes in tissues according to their autofluorescence spectra. Three groups of patients with diffuse (symptomatic) alopecia, androgenic alopecia, and focal alopecia have been tested. Each groups consisted of not less than 20 persons. The measurements have been done in the parietal and occipital regions of the sculls. We used the original automated spectrofluorimeter to record autofluorescence spectra, and standard laser Doppler flowmeter BLF-21 (Transonic Systems, Inc., USA) to analyze the basal levels of blood circulation. Our results show that UV LIFS accurately distinguishes the zones with different types of alopecia. We found high correlation of the basal levels of blood circulation and the integrated intensity of autofluorescence in the affected tissue.

The effect of three different surgical techniques for colon anastomosis on regional postoperative microperfusion: Laser Doppler Flowmetry study in pigs.

PubMed

Kaska, Milan; Blazej, Slavomir; Turek, Zdenek; Ryska, Ales; Jegorov, Boris; Radochova, Vera; Bezouska, Jan; Paral, Jiri

2018-01-01

The optimal surgical approach to reconnecting bowel ends safely after resection is of great importance. This project is focused on assessment of the perianastomotic microcirculation quality in the short postoperative period when using three different anastomosis techniques in experimental animal. The experimental study involved 27 young female domestic pigs divided into three subgroups of 9 animals according to each surgical method of anastomosis construction in the sigmoid colon region: by manual suture, by stapler, or by gluing. Blood microcirculation in the anastomosis region was monitored using Laser Doppler Flowmetry (LDF). Anastomosis healing was evaluated by macroscopic and histological examination. Evaluation of the microcirculation in the anastomosis region showed the smallest decrease in perfusion values in animals reconstructed by suturing (Δ= -38.01%). A significantly more profound drop was observed postoperatively after stapling or gluing (Δ= -52.42% and Δ= -59.53%, respectively). All performed anastomoses healed without any signs of tissue and function pathology. Sewing, stapling, and gluing techniques for bowel anastomosis each have a different effect on regional microcirculation during 120 min. postoperatively. Nevertheless, the final results of anastomosis healing were found without of any pathology in all experimental animals managed by above mentioned anastomotic techniques.

Ocular haemodynamic changes after single treatment with photodynamic therapy assessed with non-invasive techniques.

PubMed

Maar, Noemi; Pemp, Berthold; Kircher, Karl; Luksch, Alexandra; Weigert, Günther; Polska, Elzbieta; Tittl, Michael; Stur, Michael; Schmetterer, Leopold

2009-09-01

To investigate in patients with neovascular age-related macular degeneration (ARMD) the changes in ocular perfusion caused by single treatment with photodynamic therapy (PDT) by different non-invasive methods; to evaluate correlations between relative changes of ocular haemodynamic parameters after PDT among each other and compared to morphological parameters; and to assess this in relation to early changes of visual acuity. 17 consecutive patients with subfoveal choroidal neovascularization (CNV) caused by ARMD scheduled for PDT without previous PDT treatment (four patients with predominantly classic CNV and 13 patients with occult CNV). best-corrected visual acuity (before PDT, 6 and 8 weeks after PDT), fundus photography, fluorescein angiography, haemodynamic measurements with laser Doppler flowmetry (LDF), laser interferometry and ocular blood flow (OBF) tonometry (baseline and 1, 2, 6 and 8 weeks after treatment). choroidal blood flow (CHBF), fundus pulsation amplitude (FPA), pulsatile ocular blood flow (POBF), visual acuity. Changes smaller than 20% were considered clinically irrelevant. Ocular haemodynamic parameters did not change significantly in the follow-up period. Changes of haemodynamic parameters showed no correlation to treatment spot, morphological changes or visual acuity. Changes of visual acuity were comparable to results of earlier studies. Single treatment with PDT did not modify ocular blood flow parameters above 20% as assessed with different non-invasive methods.

Recent Progresses in Nanobiosensing for Food Safety Analysis

PubMed Central

Yang, Tao; Huang, Huifen; Zhu, Fang; Lin, Qinlu; Zhang, Lin; Liu, Junwen

2016-01-01

With increasing adulteration, food safety analysis has become an important research field. Nanomaterials-based biosensing holds great potential in designing highly sensitive and selective detection strategies necessary for food safety analysis. This review summarizes various function types of nanomaterials, the methods of functionalization of nanomaterials, and recent (2014–present) progress in the design and development of nanobiosensing for the detection of food contaminants including pathogens, toxins, pesticides, antibiotics, metal contaminants, and other analytes, which are sub-classified according to various recognition methods of each analyte. The existing shortcomings and future perspectives of the rapidly growing field of nanobiosensing addressing food safety issues are also discussed briefly. PMID:27447636

Recent Progresses in Nanobiosensing for Food Safety Analysis.

PubMed

Yang, Tao; Huang, Huifen; Zhu, Fang; Lin, Qinlu; Zhang, Lin; Liu, Junwen

2016-07-19

With increasing adulteration, food safety analysis has become an important research field. Nanomaterials-based biosensing holds great potential in designing highly sensitive and selective detection strategies necessary for food safety analysis. This review summarizes various function types of nanomaterials, the methods of functionalization of nanomaterials, and recent (2014-present) progress in the design and development of nanobiosensing for the detection of food contaminants including pathogens, toxins, pesticides, antibiotics, metal contaminants, and other analytes, which are sub-classified according to various recognition methods of each analyte. The existing shortcomings and future perspectives of the rapidly growing field of nanobiosensing addressing food safety issues are also discussed briefly.

Efficacy and safety profile of xanthines in COPD: a network meta-analysis.

PubMed

Cazzola, Mario; Calzetta, Luigino; Barnes, Peter J; Criner, Gerard J; Martinez, Fernando J; Papi, Alberto; Gabriella Matera, Maria

2018-06-30

Theophylline can still have a role in the management of stable chronic obstructive pulmonary disease (COPD), but its use remains controversial, mainly due to its narrow therapeutic window. Doxofylline, another xanthine, is an effective bronchodilator and displays a better safety profile than theophylline. Therefore, we performed a quantitative synthesis to compare the efficacy and safety profile of different xanthines in COPD.The primary end-point of this meta-analysis was the impact of xanthines on lung function. In addition, we assessed the risk of adverse events by normalising data on safety as a function of person-weeks. Data obtained from 998 COPD patients were selected from 14 studies and meta-analysed using a network approach.The combined surface under the cumulative ranking curve (SUCRA) analysis of efficacy (change from baseline in forced expiratory volume in 1 s) and safety (risk of adverse events) showed that doxofylline was superior to aminophylline (comparable efficacy and significantly better safety), bamiphylline (significantly better efficacy and comparable safety), and theophylline (comparable efficacy and significantly better safety).Considering the overall efficacy/safety profile of the investigated agents, the results of this quantitative synthesis suggest that doxofylline seems to be the best xanthine for the treatment of COPD. Copyright ©ERS 2018.

Safety and reliability analysis in a polyvinyl chloride batch process using dynamic simulator-case study: Loss of containment incident.

PubMed

Rizal, Datu; Tani, Shinichi; Nishiyama, Kimitoshi; Suzuki, Kazuhiko

2006-10-11

In this paper, a novel methodology in batch plant safety and reliability analysis is proposed using a dynamic simulator. A batch process involving several safety objects (e.g. sensors, controller, valves, etc.) is activated during the operational stage. The performance of the safety objects is evaluated by the dynamic simulation and a fault propagation model is generated. By using the fault propagation model, an improved fault tree analysis (FTA) method using switching signal mode (SSM) is developed for estimating the probability of failures. The timely dependent failures can be considered as unavailability of safety objects that can cause the accidents in a plant. Finally, the rank of safety object is formulated as performance index (PI) and can be estimated using the importance measures. PI shows the prioritization of safety objects that should be investigated for safety improvement program in the plants. The output of this method can be used for optimal policy in safety object improvement and maintenance. The dynamic simulator was constructed using Visual Modeler (VM, the plant simulator, developed by Omega Simulation Corp., Japan). A case study is focused on the loss of containment (LOC) incident at polyvinyl chloride (PVC) batch process which is consumed the hazardous material, vinyl chloride monomer (VCM).

Effectiveness of Direct Safety Regulations on Manufacturers and Users of Industrial Machines: Its Implications on Industrial Safety Policies in Republic of Korea.

PubMed

Choi, Gi Heung

2017-03-01

Despite considerable efforts made in recent years, the industrial accident rate and the fatality rate in the Republic of Korea are much higher than those in most developed countries in Europe and North America. Industrial safety policies and safety regulations are also known to be ineffective and inefficient in some cases. This study focuses on the quantitative evaluation of the effectiveness of direct safety regulations such as safety certification, self-declaration of conformity, and safety inspection of industrial machines in the Republic of Korea. Implications on safety policies to restructure the industrial safety system associated with industrial machines are also explored. Analysis of causes in industrial accidents associated with industrial machines confirms that technical causes need to be resolved to reduce both the frequency and the severity of such industrial accidents. Statistical analysis also confirms that the indirect effects of safety device regulation on users are limited for a variety of reasons. Safety device regulation needs to be shifted to complement safety certification and self-declaration of conformity for more balanced direct regulations on manufacturers and users. An example of cost-benefit analysis on conveyor justifies such a transition. Industrial safety policies and regulations associated with industrial machines must be directed towards eliminating the sources of danger at the stage of danger creation, thereby securing the safe industrial machines. Safety inspection further secures the safety of workers at the stage of danger use. The overall balance between such safety regulations is achieved by proper distribution of industrial machines subject to such regulations and the intensity of each regulation. Rearrangement of industrial machines subject to safety certification and self-declaration of conformity to include more movable industrial machines and other industrial machines with a high level of danger is also suggested.

Analysis of dynamical response of air blast loaded safety device

NASA Astrophysics Data System (ADS)

Tropkin, S. N.; Tlyasheva, R. R.; Bayazitov, M. I.; Kuzeev, I. R.

2018-03-01

Equipment of many oil and gas processing plants in the Russian Federation is considerably worn-out. This causes the decrease of reliability and durability of equipment and rises the accident rate. An air explosion is the one of the most dangerous cases for plants in oil and gas industry, usually caused by uncontrolled emission and inflammation of oil products. Air explosion can lead to significant danger for life and health of plant staff, so it necessitates safety device usage. A new type of a safety device is designed. Numerical simulation is necessary to analyse design parameters and performance of the safety device, subjected to air blast loading. Coupled fluid-structure interaction analysis is performed to determine strength of the protective device and its performance. The coupled Euler-Lagrange method, allowable in Abaqus by SIMULIA, is selected as the most appropriate analysis tool to study blast wave interaction with the safety device. Absorption factors of blast wave are evaluated for the safety device. This factors allow one to assess efficiency of the safety device, and its main structural component – dampener. Usage of CEL allowed one to model fast and accurately the dampener behaviour, and to develop the parametric model to determine safety device sizes.

Physics of reactor safety. Quarterly report, January--March 1977. [LMFBR

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

None

1977-06-01

This report summarizes work done on reactor safety, Monte Carlo analysis of safety-related critical assembly experiments, and planning of DEMI safety-related critical experiments. Work on reactor core thermal-hydraulics is also included.

FMCSA safety program effectiveness measurement : carrier intervention effectiveness model, version 1.0 : [analysis brief].

DOT National Transportation Integrated Search

2015-01-01

The Carrier Intervention Effectiveness Model (CIEM) : provides the Federal Motor Carrier Safety : Administration (FMCSA) with a tool for measuring : the safety benefits of carrier interventions conducted : under the Compliance, Safety, Accountability...

FMCSA safety program effectiveness measurement : Roadside Intervention Effectiveness Model FY 2012, [analysis brief].

DOT National Transportation Integrated Search

2016-02-01

Roadside Inspection and Traffic Enforcement are two of : the Federal Motor Carrier Safety Administrations : (FMCSAs) key safety programs. The Roadside : Inspection Program consists of roadside inspections : performed by qualified safety inspect...

FMCSA safety program effectiveness measurement : roadside intervention effectiveness model FY 2011 : [analysis brief].

DOT National Transportation Integrated Search

2015-06-01

Roadside Inspection and Traffic Enforcement are two of the Federal Motor Carrier Safety Administrations (FMCSAs) key safety programs. The Roadside Inspection program consists of roadside inspections performed by qualified safety inspectors. The...

Enhancing Safety of Artificially Ventilated Patients Using Ambient Process Analysis.

PubMed

Lins, Christian; Gerka, Alexander; Lüpkes, Christian; Röhrig, Rainer; Hein, Andreas

2018-01-01

In this paper, we present an approach for enhancing the safety of artificially ventilated patients using ambient process analysis. We propose to use an analysis system consisting of low-cost ambient sensors such as power sensor, RGB-D sensor, passage detector, and matrix infrared temperature sensor to reduce risks for artificially ventilated patients in both home and clinical environments. We describe the system concept and our implementation and show how the system can contribute to patient safety.

Analysis of Material Handling Safety in Construction Sites and Countermeasures for Effective Enhancement

PubMed Central

Anil Kumar, C. N.; Sakthivel, M.; Elangovan, R. K.; Arularasu, M.

2015-01-01

One of many hazardous workplaces includes the construction sites as they involve several dangerous tasks. Many studies have revealed that material handling equipment is a major cause of accidents at these sites. Though safety measures are being followed and monitored continuously, accident rates are still high as either workers are unaware of hazards or the safety regulations are not being strictly followed. This paper analyses the safety management systems at construction sites through means of questionnaire surveys with employees, specifically referring to safety of material handling equipment. Based on results of the questionnaire surveys, two construction sites were selected for a safety education program targeting worker safety related to material handling equipment. Knowledge levels of the workers were gathered before and after the program and results obtained were subjected to a t-test analysis to mark significance level of the conducted safety education program. PMID:26446572

Assessment of the Impact of Scheduled Postmarketing Safety Summary Analyses on Regulatory Actions

PubMed Central

Sekine, S; Pinnow, EE; Wu, E; Kurtzig, R; Hall, M; Dal Pan, GJ

2016-01-01

In addition to standard postmarketing drug safety monitoring, Section 915 of the Food and Drug Administration Amendments Act of 2007 (FDAAA) requires the US Food and Drug Administration (FDA) to conduct a summary analysis of adverse event reports to identify risks of a drug or biologic product 18 months after product approval, or after 10,000 patients have used the product, whichever is later. We assessed the extent to which these analyses identified new safety signals and resultant safety-related label changes. Among 458 newly approved products, 300 were the subjects of a scheduled analysis; a new safety signal that resulted in a safety-related label change was found for 11 of these products. Less than 2% of 713 safety-related label changes were based on the scheduled analyses. Our study suggests that the safety summary analyses provide only marginal value over other pharmacovigilance activities. PMID:26853718

Implementation of a patient safety program at a tertiary health system: A longitudinal analysis of interventions and serious safety events.

PubMed

Cropper, Douglas P; Harb, Nidal H; Said, Patricia A; Lemke, Jon H; Shammas, Nicolas W

2018-04-01

We hypothesize that implementation of a safety program based on high reliability organization principles will reduce serious safety events (SSE). The safety program focused on 7 essential elements: (a) safety rounding, (b) safety oversight teams, (c) safety huddles, (d) safety coaches, (e) good catches/safety heroes, (f) safety education, and (g) red rule. An educational curriculum was implemented focusing on changing high-risk behaviors and implementing critical safety policies. All unusual occurrences were captured in the Midas system and investigated by risk specialists, the safety officer, and the chief medical officer. A multidepartmental committee evaluated these events, and a root cause analysis (RCA) was performed. Events were tabulated and serious safety event (SSE) recorded and plotted over time. Safety success stories (SSSs) were also evaluated over time. A steady drop in SSEs was seen over 9 years. Also a rise in SSSs was evident, reflecting on staff engagement in the program. The parallel change in SSEs, SSSs, and the implementation of various safety interventions highly suggest that the program was successful in achieving its goals. A safety program based on high-reliability organization principles and made a core value of the institution can have a significant positive impact on reducing SSEs. © 2018 American Society for Healthcare Risk Management of the American Hospital Association.

14 CFR Appendix A to Part 417 - Flight Safety Analysis Methodologies and Products for a Launch Vehicle Flown With a Flight Safety...

Code of Federal Regulations, 2013 CFR

2013-01-01

... approach provides an equivalent level of safety. If a Federal launch range performs the launch operator's... FAA will measure any proposed alternative analysis approach. This appendix also identifies the... control systems; (ix) Steering misalignment; and (x) Winds. (2) Each three-sigma trajectory must account...

Regulatory assessment with regulatory flexibility analysis and paperwork reduction act analysis : draft regulatory evaluation : Notice of Proposed Rulemaking -- Pipeline Safety : Polyamide-11 (PA-11) plastic pipe design pressures

DOT National Transportation Integrated Search

2007-06-01

The Pipeline and Hazardous Materials Safety Administration (PHMSA) is proposing changes to the Federal pipeline safety regulations in 49 CFR Part 192, which cover the transportation of natural gas by pipeline. Specifically, PHMSA is proposing to chan...

14 CFR Appendix A to Part 417 - Flight Safety Analysis Methodologies and Products for a Launch Vehicle Flown With a Flight Safety...

Code of Federal Regulations, 2012 CFR

2012-01-01

... approach provides an equivalent level of safety. If a Federal launch range performs the launch operator's... FAA will measure any proposed alternative analysis approach. This appendix also identifies the... control systems; (ix) Steering misalignment; and (x) Winds. (2) Each three-sigma trajectory must account...

14 CFR Appendix A to Part 417 - Flight Safety Analysis Methodologies and Products for a Launch Vehicle Flown With a Flight Safety...

Code of Federal Regulations, 2010 CFR

2010-01-01

... approach provides an equivalent level of safety. If a Federal launch range performs the launch operator's... FAA will measure any proposed alternative analysis approach. This appendix also identifies the... control systems; (ix) Steering misalignment; and (x) Winds. (2) Each three-sigma trajectory must account...

14 CFR Appendix A to Part 417 - Flight Safety Analysis Methodologies and Products for a Launch Vehicle Flown With a Flight Safety...

Code of Federal Regulations, 2014 CFR

2014-01-01

... approach provides an equivalent level of safety. If a Federal launch range performs the launch operator's... FAA will measure any proposed alternative analysis approach. This appendix also identifies the... control systems; (ix) Steering misalignment; and (x) Winds. (2) Each three-sigma trajectory must account...

Transportation safety data and analysis : Volume 2, Calibration of the highway safety manual and development of new safety performance functions.

DOT National Transportation Integrated Search

2011-03-01

This report documents the calibration of the Highway Safety Manual (HSM) safety performance function (SPF) : for rural two-lane two-way roadway segments in Utah and the development of new models using negative : binomial and hierarchical Bayesian mod...

Persuasive appeals in road safety communication campaigns: Theoretical frameworks and practical implications from the analysis of a decade of road safety campaign materials.

PubMed

Guttman, Nurit

2015-11-01

Communication campaigns are employed as an important tool to promote road safety practices. Researchers maintain road safety communication campaigns are more effective when their persuasive appeals, which are central to their communicative strategy, are based on explicit theoretical frameworks. This study's main objectives were to develop a detailed categorization of persuasive appeals used in road safety communication campaigns that differentiate between appeals that appear to be similar but differ conceptually, and to indicate the advantages, limitations and ethical issues associated with each type, drawing on behavior change theories. Materials from over 300 campaigns were obtained from 41 countries, mainly using road safety organizations' websites. Drawing on the literature, five types of main approaches were identified, and the analysis yielded a more detailed categorizations of appeals within these general categories. The analysis points to advantages, limitations, ethical issues and challenges in using different types of appeals. The discussion summarizes challenges in designing persuasive-appeals for road safety communication campaigns. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reprint of "Persuasive appeals in road safety communication campaigns: Theoretical frameworks and practical implications from the analysis of a decade of road safety campaign materials".

PubMed

Guttman, Nurit

2016-12-01

Communication campaigns are employed as an important tool to promote road safety practices. Researchers maintain road safety communication campaigns are more effective when their persuasive appeals, which are central to their communicative strategy, are based on explicit theoretical frameworks. This study's main objectives were to develop a detailed categorization of persuasive appeals used in road safety communication campaigns that differentiate between appeals that appear to be similar but differ conceptually, and to indicate the advantages, limitations and ethical issues associated with each type, drawing on behavior change theories. Materials from over 300 campaigns were obtained from 41 countries, mainly using road safety organizations' websites. Drawing on the literature, five types of main approaches were identified, and the analysis yielded a more detailed categorizations of appeals within these general categories. The analysis points to advantages, limitations, ethical issues and challenges in using different types of appeals. The discussion summarizes challenges in designing persuasive-appeals for road safety communication campaigns. Copyright © 2015 Elsevier Ltd. All rights reserved.

Combining System Safety and Reliability to Ensure NASA CoNNeCT's Success

NASA Technical Reports Server (NTRS)

Havenhill, Maria; Fernandez, Rene; Zampino, Edward

2012-01-01

Hazard Analysis, Failure Modes and Effects Analysis (FMEA), the Limited-Life Items List (LLIL), and the Single Point Failure (SPF) List were applied by System Safety and Reliability engineers on NASA's Communications, Navigation, and Networking reConfigurable Testbed (CoNNeCT) Project. The integrated approach involving cross reviews of these reports by System Safety, Reliability, and Design engineers resulted in the mitigation of all identified hazards. The outcome was that the system met all the safety requirements it was required to meet.

Analysis of microgravity space experiments Space Shuttle programmatic safety requirements

NASA Technical Reports Server (NTRS)

Terlep, Judith A.

1996-01-01

This report documents the results of an analysis of microgravity space experiments space shuttle programmatic safety requirements and recommends the creation of a Safety Compliance Data Package (SCDP) Template for both flight and ground processes. These templates detail the programmatic requirements necessary to produce a complete SCDP. The templates were developed from various NASA centers' requirement documents, previously written guidelines on safety data packages, and from personal experiences. The templates are included in the back as part of this report.

Just Culture: A Foundation for Balanced Accountability and Patient Safety

PubMed Central

Boysen, Philip G.

2013-01-01

Background The framework of a just culture ensures balanced accountability for both individuals and the organization responsible for designing and improving systems in the workplace. Engineering principles and human factors analysis influence the design of these systems so they are safe and reliable. Methods Approaches for improving patient safety introduced here are (1) analysis of error, (2) specific tools to enhance safety, and (3) outcome engineering. Conclusion The just culture is a learning culture that is constantly improving and oriented toward patient safety. PMID:24052772

Safety analysis report for the Waste Storage Facility. Revision 2

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

Bengston, S.J.

1994-05-01

This safety analysis report outlines the safety concerns associated with the Waste Storage Facility located in the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory. The three main objectives of the report are: define and document a safety basis for the Waste Storage Facility activities; demonstrate how the activities will be carried out to adequately protect the workers, public, and environment; and provide a basis for review and acceptance of the identified risk that the managers, operators, and owners will assume.

[Study of post marketing safety reevaluation of shenqi fuzheng injection].

PubMed

Ai, Qing-Hua; Li, Yuan-Yuan; Xie, Yan-Ming

2014-09-01

In order to promote the Shenqifuzheng injection (SQFZ) clinical medication safety, this study reevaluate on SQFZ post marketing safety study systematically. Including multi center large sample registration type safety monitoring research, the analysis based on national spontaneous reporting system data, the analysis based on the 20 national hospital information system data and literature research. Above the analysis, it suggests that SQFZ has good security. The more adverse drug reaction (ADR) as allergic reactions, mainly involved in the damage of skin, appendages and its systemic damage, serious person can appear allergic shock. ADR/E is more common in the elderly, may be related to medication (tumor) populations. Early warning analysis based on SRS data and literature research are of the view that "phlebitis" has a strong association with SQFZ used.

Analysis of Aviation Safety Reporting System Incident Data Associated with the Technical Challenges of the System-Wide Safety and Assurance Technologies Project

NASA Technical Reports Server (NTRS)

Withrow, Colleen A.; Reveley, Mary S.

2015-01-01

The Aviation Safety Program (AvSP) System-Wide Safety and Assurance Technologies (SSAT) Project asked the AvSP Systems and Portfolio Analysis Team to identify SSAT-related trends. SSAT had four technical challenges: advance safety assurance to enable deployment of NextGen systems; automated discovery of precursors to aviation safety incidents; increasing safety of human-automation interaction by incorporating human performance, and prognostic algorithm design for safety assurance. This report reviews incident data from the NASA Aviation Safety Reporting System (ASRS) for system-component-failure- or-malfunction- (SCFM-) related and human-factor-related incidents for commercial or cargo air carriers (Part 121), commuter airlines (Part 135), and general aviation (Part 91). The data was analyzed by Federal Aviation Regulations (FAR) part, phase of flight, SCFM category, human factor category, and a variety of anomalies and results. There were 38 894 SCFM-related incidents and 83 478 human-factorrelated incidents analyzed between January 1993 and April 2011.

FMCSA safety program effectiveness measurement : carrier intervention effectiveness Model, version 1.1, analysis brief.

DOT National Transportation Integrated Search

2016-11-01

The Carrier Intervention Effectiveness Model (CIEM) provides the Federal Motor Carrier Safety Administration (FMCSA) with a tool for measuring the safety benefits of carrier interventions conducted under the Compliance, Safety, Accountability (CSA) e...

FMCSA safety program effectiveness measurement : Roadside Intervention Effectiveness Model, fiscal year 2010 : [analysis brief].

DOT National Transportation Integrated Search

2014-11-01

Two of the Federal Motor Carrier Safety Administrations (FMCSAs) key safety programs are the Roadside Inspection and Traffic Enforcement programs. The Roadside Inspection program consists of roadside inspections performed by qualified safety in...

An Operational Safety and Health Program.

ERIC Educational Resources Information Center

Uhorchak, Robert E.

1983-01-01

Describes safety/health program activities at Research Triangle Institute (North Carolina). These include: radioisotope/radiation and hazardous chemical/carcinogen use, training, monitoring, disposal; chemical waste management; air monitoring and analysis; medical program; fire safety/training, including emergency planning; Occupational Safety and…

A fully Bayesian before-after analysis of permeable friction course (PFC) pavement wet weather safety.

PubMed

Buddhavarapu, Prasad; Smit, Andre F; Prozzi, Jorge A

2015-07-01

Permeable friction course (PFC), a porous hot-mix asphalt, is typically applied to improve wet weather safety on high-speed roadways in Texas. In order to warrant expensive PFC construction, a statistical evaluation of its safety benefits is essential. Generally, the literature on the effectiveness of porous mixes in reducing wet-weather crashes is limited and often inconclusive. In this study, the safety effectiveness of PFC was evaluated using a fully Bayesian before-after safety analysis. First, two groups of road segments overlaid with PFC and non-PFC material were identified across Texas; the non-PFC or reference road segments selected were similar to their PFC counterparts in terms of site specific features. Second, a negative binomial data generating process was assumed to model the underlying distribution of crash counts of PFC and reference road segments to perform Bayesian inference on the safety effectiveness. A data-augmentation based computationally efficient algorithm was employed for a fully Bayesian estimation. The statistical analysis shows that PFC is not effective in reducing wet weather crashes. It should be noted that the findings of this study are in agreement with the existing literature, although these studies were not based on a fully Bayesian statistical analysis. Our study suggests that the safety effectiveness of PFC road surfaces, or any other safety infrastructure, largely relies on its interrelationship with the road user. The results suggest that the safety infrastructure must be properly used to reap the benefits of the substantial investments. Copyright © 2015 Elsevier Ltd. All rights reserved.

Manned space flight nuclear system safety. Volume 3: Reactor system preliminary nuclear safety analysis. Part 3: Nuclear Safety Analysis Document (NSAD)

NASA Technical Reports Server (NTRS)

1972-01-01

Nuclear safety analysis as applied to a space base mission is presented. The nuclear safety analysis document summarizes the mission and the credible accidents/events which may lead to nuclear hazards to the general public. The radiological effects and associated consequences of the hazards are discussed in detail. The probability of occurrence is combined with the potential number of individuals exposed to or above guideline values to provide a measure of accident and total mission risk. The overall mission risk has been determined to be low with the potential exposure to or above 25 rem limited to less than 4 individuals per every 1000 missions performed. No radiological risk to the general public occurs during the prelaunch phase at KSC. The most significant risks occur from prolonged exposure to reactor debris following land impact generally associated with the disposal phase of the mission where fission product inventories can be high.

Can Leader–Member Exchange Contribute to Safety Performance in An Italian Warehouse?

PubMed Central

Mariani, Marco G.; Curcuruto, Matteo; Matic, Mirna; Sciacovelli, Paolo; Toderi, Stefano

2017-01-01

Introduction: The research considers safety climate in a warehouse and wants to analyze the Leader–Member Exchange (LMX) role in respect to safety performance. Griffin and Neal’s safety model was adopted and Leader-Member Exchange was inserted as moderator in the relationships between safety climate and proximal antecedents (motivation and knowledge) of safety performance constructs (compliance and participation). Materials and Methods: Survey data were collected from a sample of 133 full-time employees in an Italian warehouse. The statistical framework of Hayes (2013) was adopted for moderated mediation analysis. Results: Proximal antecedents partially mediated the relationship between Safety climate and safety participation, but not safety compliance. Moreover, the results from the moderation analysis showed that the Leader–Member Exchange moderated the influence of safety climate on proximal antecedents and the mediation exist only at the higher level of LMX. Conclusion: The study shows that the different aspects of leadership processes interact in explaining individual proficiency in safety practices. Practical Implications: Organizations as warehouses should improve the quality of the relationship between a leader and a subordinate based upon the dimensions of respect, trust, and obligation for high level of safety performance. PMID:28553244

Can Leader-Member Exchange Contribute to Safety Performance in An Italian Warehouse?

PubMed

Mariani, Marco G; Curcuruto, Matteo; Matic, Mirna; Sciacovelli, Paolo; Toderi, Stefano

2017-01-01

Introduction: The research considers safety climate in a warehouse and wants to analyze the Leader-Member Exchange (LMX) role in respect to safety performance. Griffin and Neal's safety model was adopted and Leader-Member Exchange was inserted as moderator in the relationships between safety climate and proximal antecedents (motivation and knowledge) of safety performance constructs (compliance and participation). Materials and Methods: Survey data were collected from a sample of 133 full-time employees in an Italian warehouse. The statistical framework of Hayes (2013) was adopted for moderated mediation analysis. Results: Proximal antecedents partially mediated the relationship between Safety climate and safety participation, but not safety compliance. Moreover, the results from the moderation analysis showed that the Leader-Member Exchange moderated the influence of safety climate on proximal antecedents and the mediation exist only at the higher level of LMX. Conclusion: The study shows that the different aspects of leadership processes interact in explaining individual proficiency in safety practices. Practical Implications: Organizations as warehouses should improve the quality of the relationship between a leader and a subordinate based upon the dimensions of respect, trust, and obligation for high level of safety performance.

Assessing the safety effects of cooperative intelligent transport systems: A bowtie analysis approach.

PubMed

Ehlers, Ute Christine; Ryeng, Eirin Olaussen; McCormack, Edward; Khan, Faisal; Ehlers, Sören

2017-02-01

The safety effects of cooperative intelligent transport systems (C-ITS) are mostly unknown and associated with uncertainties, because these systems represent emerging technology. This study proposes a bowtie analysis as a conceptual framework for evaluating the safety effect of cooperative intelligent transport systems. These seek to prevent road traffic accidents or mitigate their consequences. Under the assumption of the potential occurrence of a particular single vehicle accident, three case studies demonstrate the application of the bowtie analysis approach in road traffic safety. The approach utilizes exemplary expert estimates and knowledge from literature on the probability of the occurrence of accident risk factors and of the success of safety measures. Fuzzy set theory is applied to handle uncertainty in expert knowledge. Based on this approach, a useful tool is developed to estimate the effects of safety-related cooperative intelligent transport systems in terms of the expected change in accident occurrence and consequence probability. Copyright © 2016 Elsevier Ltd. All rights reserved.

Demographic variables in coal miners’ safety attitude

NASA Astrophysics Data System (ADS)

Yin, Wen-wen; Wu, Xiang; Ci, Hui-Peng; Qin, Shu-Qi; Liu, Jia-Long

2017-03-01

To change unsafe behavior through adjusting people’s safety attitudes has become an important measure to prevent accidents. Demographic variables, as influential factors of safety attitude, are fundamental and essential for the research. This research does a questionnaire survey among coal mine industry workers, and makes variance analysis and correlation analysis of the results in light of age, length of working years, educational level and experiences of accidents. The results show that the coal miners’ age, length of working years and accident experiences correlate lowly with safety attitudes, and those older coal miners with longer working years have better safety attitude, as coal miners without experiences of accident do.However, educational level has nothing to do with the safety attitude. Therefore, during the process of safety management, coal miners with different demographic characteristics should be put more attention to.

Linguistic analysis of large-scale medical incident reports for patient safety.

PubMed

Fujita, Katsuhide; Akiyama, Masanori; Park, Keunsik; Yamaguchi, Etsuko Nakagami; Furukawa, Hiroyuki

2012-01-01

The analysis of medical incident reports is indispensable for patient safety. The cycles between analysis of incident reports and proposals to medical staffs are a key point for improving the patient safety in the hospital. Most incident reports are composed from freely written descriptions, but an analysis of such free descriptions is not sufficient in the medical field. In this study, we aim to accumulate and reinterpret findings using structured incident information, to clarify improvements that should be made to solve the root cause of the accident, and to ensure safe medical treatment through such improvements. We employ natural language processing (NLP) and network analysis to identify effective categories of medical incident reports. Network analysis can find various relationships that are not only direct but also indirect. In addition, we compare bottom-up results obtained by NLP with existing categories based on experts' judgment. By the bottom-up analysis, the class of patient managements regarding patients' fallings and medicines in top-down analysis is created clearly. Finally, we present new perspectives on ways of improving patient safety.

A structural equation modelling approach examining the pathways between safety climate, behaviour performance and workplace slipping

PubMed Central

Swedler, David I; Verma, Santosh K; Huang, Yueng-Hsiang; Lombardi, David A; Chang, Wen-Ruey; Brennan, Melayne; Courtney, Theodore K

2015-01-01

Objective Safety climate has previously been associated with increasing safe workplace behaviours and decreasing occupational injuries. This study seeks to understand the structural relationship between employees’ perceptions of safety climate, performing a safety behaviour (ie, wearing slip-resistant shoes) and risk of slipping in the setting of limited-service restaurants. Methods At baseline, we surveyed 349 employees at 30 restaurants for their perceptions of their safety training and management commitment to safety as well as demographic data. Safety performance was identified as wearing slip-resistant shoes, as measured by direct observation by the study team. We then prospectively collected participants’ hours worked and number of slips weekly for the next 12 weeks. Using a confirmatory factor analysis, we modelled safety climate as a higher order factor composed of previously identified training and management commitment factors. Results The 349 study participants experienced 1075 slips during the 12-week follow-up. Confirmatory factor analysis supported modelling safety climate as a higher order factor composed of safety training and management commitment. In a structural equation model, safety climate indirectly affected prospective risk of slipping through safety performance, but no direct relationship between safety climate and slips was evident. Conclusions Results suggest that safety climate can reduce workplace slips through performance of a safety behaviour as well as suggesting a potential causal mechanism through which safety climate can reduce workplace injuries. Safety climate can be modelled as a higher order factor composed of safety training and management commitment. PMID:25710968

Does attenuated skin blood flow lower sweat rate and the critical environmental limit for heat balance during severe heat exposure?

PubMed

Cramer, Matthew N; Gagnon, Daniel; Crandall, Craig G; Jay, Ollie

2017-02-01

What is the central question of this study? Does attenuated skin blood flow diminish sweating and reduce the critical environmental limit for heat balance, which indicates maximal heat loss potential, during severe heat stress? What is the main finding and its importance? Isosmotic hypovolaemia attenuated skin blood flow by ∼20% but did not result in different sweating rates, mean skin temperatures or critical environmental limits for heat balance compared with control and volume-infusion treatments, suggesting that the lower levels of skin blood flow commonly observed in aged and diseased populations may not diminish maximal whole-body heat dissipation. Attenuated skin blood flow (SkBF) is often assumed to impair core temperature (T c ) regulation. Profound pharmacologically induced reductions in SkBF (∼85%) lead to impaired sweating, but whether the smaller attenuations in SkBF (∼20%) more often associated with ageing and certain diseases lead to decrements in sweating and maximal heat loss potential is unknown. Seven healthy men (28 ± 4 years old) completed a 30 min equilibration period at 41°C and a vapour pressure (P a ) of 2.57 kPa followed by incremental steps in P a of 0.17 kPa every 6 min to 5.95 kPa. Differences in heat loss potential were assessed by identifying the critical vapour pressure (P crit ) at which an upward inflection in T c occurred. The following three separate treatments elicited changes in plasma volume to achieve three distinct levels of SkBF: control (CON); diuretic-induced isosmotic dehydration to lower SkBF (DEH); and continuous saline infusion to maintain SkBF (SAL). The T c , mean skin temperature (T sk ), heart rate, mean laser-Doppler flux (forearm and thigh; LDF mean ), mean local sweat rate (forearm and thigh; LSR mean ) and metabolic rate were measured. In DEH, a 14.2 ± 5.7% lower plasma volume resulted in a ∼20% lower LDF mean in perfusion units (PU) (DEH, 139 ± 23 PU; CON, 176 ± 22 PU; and SAL, 186 ± 22 PU; P = 0.034). However, LSR mean and whole-body sweat losses were unaffected by treatment throughout (P > 0.482). The P crit for T c was similar between treatments (CON, 5.05 ± 0.30 kPa; DEH, 4.93 ± 0.16 kPa; and SAL, 5.12 ± 0.10 kPa; P = 0.166). Furthermore, no differences were observed in the skin-air temperature gradient, metabolic rate or changes in T c (P > 0.197). In conclusion, a ∼20% reduction in SkBF alters neither sweat rate nor the upper limit for heat loss from the skin during non-encapsulated passive heat stress. © 2016 The Authors. Experimental Physiology © 2016 The Physiological Society.

Preliminary Results Obtained in Integrated Safety Analysis of NASA Aviation Safety Program Technologies

NASA Technical Reports Server (NTRS)

Reveley, Mary S.

2003-01-01

The goal of the NASA Aviation Safety Program (AvSP) is to develop and demonstrate technologies that contribute to a reduction in the aviation fatal accident rate by a factor of 5 by the year 2007 and by a factor of 10 by the year 2022. Integrated safety analysis of day-to-day operations and risks within those operations will provide an understanding of the Aviation Safety Program portfolio. Safety benefits analyses are currently being conducted. Preliminary results for the Synthetic Vision Systems (SVS) and Weather Accident Prevention (WxAP) projects of the AvSP have been completed by the Logistics Management Institute under a contract with the NASA Glenn Research Center. These analyses include both a reliability analysis and a computer simulation model. The integrated safety analysis method comprises two principal components: a reliability model and a simulation model. In the reliability model, the results indicate how different technologies and systems will perform in normal, degraded, and failed modes of operation. In the simulation, an operational scenario is modeled. The primary purpose of the SVS project is to improve safety by providing visual-flightlike situation awareness during instrument conditions. The current analyses are an estimate of the benefits of SVS in avoiding controlled flight into terrain. The scenario modeled has an aircraft flying directly toward a terrain feature. When the flight crew determines that the aircraft is headed toward an obstruction, the aircraft executes a level turn at speed. The simulation is ended when the aircraft completes the turn.

Designing for auto safety

NASA Technical Reports Server (NTRS)

Driver, E. T.

1971-01-01

Safety design features in the motor vehicle and highway construction fields result from systems analysis approach to prevent or lessen death, injury, and property damage results. Systems analysis considers the prevention of crashes, increased survivability in crashes, and prompt medical attention to injuries as well as other postcrash salvage measures. The interface of these system elements with the driver, the vehicle, and the environment shows that action on the vehicle system produces the greatest safety payoff through design modifications. New and amended safety standards developed through hazard analysis technique improved accident statistics in the 70'; these regulations include driver qualifications and countermeasures to identify the chronic drunken driver who is involved in more than two-thirds of all auto deaths.

14 CFR 417.403 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Ground Safety § 417.403 General. (a) Public safety. A launch operator must... with launch processing and post-launch operations. (b) Ground safety analysis. A launch operator must...

14 CFR Appendix A to Part 417 - Flight Safety Analysis Methodologies and Products for a Launch Vehicle Flown With a Flight Safety...

Code of Federal Regulations, 2011 CFR

2011-01-01

... time duration of the turn and must show increments not to exceed one second. The series of tumble turns... FAA will measure any proposed alternative analysis approach. This appendix also identifies the... approach provides an equivalent level of safety. If a Federal launch range performs the launch operator's...

Accident Journalism and Traffic Safety Education: A Three-Phase Investigation of Accident Reporting in the Canadian Daily Press.

ERIC Educational Resources Information Center

Wilde, Gerald J. S.; Ackersviller, Melody J.

A study examined the potential for development of a traffic accident-reporting form in the Canadian daily press that strengthens concern for road safety in the general population and enhances knowledge, attitudes, and behavior leading to greater safety. The investigation was conducted on three levels: a content analysis, a readership analysis, and…

Analysis of safety impacts of access management alternatives using the surrogate safety assessment model : final report.

DOT National Transportation Integrated Search

2017-06-01

The purpose of this study was to evaluate if the Surrogate Safety Assessment Model (SSAM) could be used to assess the safety of a highway segment or an intersection in terms of the number and type of conflicts and to compare the safety effects of mul...

Comparative efficacy and safety of six antidepressants and anticonvulsants in painful diabetic neuropathy: a network meta-analysis.

PubMed

Rudroju, Neelima; Bansal, Dipika; Talakokkula, Shiva Teja; Gudala, Kapil; Hota, Debasish; Bhansali, Anil; Ghai, Babita

2013-01-01

Anticonvulsants and antidepressants are mostly used in management of painful diabetic neuropathy (PDN). However there are few direct comparisons between drugs of these classes, making evidence-based decision-making in the treatment of painful diabetic neuropathy difficult. This study aimed to perform a network meta-analysis and benefit-risk analysis to evaluate the comparative efficacy and safety of these drugs in PDN treatment. Comparative effectiveness study. Medical Education and Research facility in India. A comprehensive data search was done in PubMed, Cochrane, and Embase up to August 2012. We then systematically reviewed the studies which compared any of 6 drugs for the management of PDN: amitriptyline, duloxetine, gabapentin, pregabalin, valproate, and venlafaxine or any of their combinations. We performed a random-effects network meta-analysis to rank treatments in terms of efficacy and safety. We chose the number of patients experiencing = 50% reduction in pain and number of patient withdrawals due to adverse events (AE) as primary outcomes for efficacy and safety, respectively. We also performed benefit-risk analysis, taking efficacy outcome as benefit and safety outcome as risk. Analysis was intention-to-treat. We included 21 published trials in the analysis. Duloxetine, gabapentin, pregabalin, and venlafaxine were shown to be significantly efficacious compared to placebo with odds ratios (OR) of 2.12, 3.98, 2.78, and 4.43, respectively. Amitriptyline (OR: 7.03, 95% confidence interval [CI]: 1.87, 29.05) and duloxetine (OR: 3.26, 95% CI: 1.04, 9.97) caused more withdrawals than gabapentin. The ranking order of efficacy was gabapentin, venlafaxine, pregabalin, duloxetine/gabapentin, duloxetine, amitriptyline, and placebo and the ranking order of safety was placebo, gabapentin, pregabalin, venlafaxine, duloxetine/gabapentin combination, duloxetine, and amitriptyline. Benefit-risk balance favored the order: gabapentin, venlafaxine, pregabalin, duloxetine/gabapentin combination, duloxetine, placebo, and amitriptyline. We could not include valproate in our analysis owing to the lack of studies reporting the dichotomous efficacy and safety outcomes. Gabapentin was found to be most efficacious and amitriptyline to be least safe among the treatments included in the study. Gabapentin showed most favorable balance between efficacy and safety.

Analysis of factors influencing safety management for metro construction in China.

PubMed

Yu, Q Z; Ding, L Y; Zhou, C; Luo, H B

2014-07-01

With the rapid development of urbanization in China, the number and size of metro construction projects are increasing quickly. At the same time, and increasing number of accidents in metro construction make it a disturbing focus of social attention. In order to improve safety management in metro construction, an investigation of the participants' perspectives on safety factors in China metro construction has been conducted to identify the key safety factors, and their ranking consistency among the main participants, including clients, consultants, designers, contractors and supervisors. The result of factor analysis indicates that there are five key factors which influence the safety of metro construction including safety attitude, construction site safety, government supervision, market restrictions and task unpredictability. In addition, ANOVA and Spearman rank correlation coefficients were performed to test the consistency of the means rating and the ranking of safety factors. The results indicated that the main participants have significant disagreement about the importance of safety factors on more than half of the items. Suggestions and recommendations on practical countermeasures to improve metro construction safety management in China are proposed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Safety perception referents of permanent and temporary employees: safety climate boundaries in the industrial workplace.

PubMed

Luria, Gil; Yagil, Dana

2010-09-01

To explore the significant referents of safety perceptions among permanent and temporary employees in order to identify the boundaries of safety climate in a heterogeneous workforce. Collection of data from semi-structured interviews with employees in manufacturing organizations, using a combination of qualitative and quantitative methods to identify basic safety perceptions. Independent raters used content analysis to examine the data. Analysis of the data revealed differences between safety themes at organization, group and individual levels. Themes relating to the individual were more prevalent among temporary employees, while those relating to the group and the organization prevailed among permanent employees. Permanent employees view organizational and group levels as significant referents of safety perceptions, while temporary employees focus on the individual level. The results challenge the current view of safety climate as a uniform concept for all employees and prescribe boundary conditions for safety climate. It is suggested that organizations should implement "tailor-made" safety-climate practices according to the referents of employee sub-groups. 2009 Elsevier Ltd. All rights reserved.

Posttest analysis of the FFTF inherent safety tests

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

Padilla, A. Jr.; Claybrook, S.W.

Inherent safety tests were performed during 1986 in the 400-MW (thermal) Fast Flux Test Facility (FFTF) reactor to demonstrate the effectiveness of an inherent shutdown device called the gas expansion module (GEM). The GEM device provided a strong negative reactivity feedback during loss-of-flow conditions by increasing the neutron leakage as a result of an expanding gas bubble. The best-estimate pretest calculations for these tests were performed using the IANUS plant analysis code (Westinghouse Electric Corporation proprietary code) and the MELT/SIEX3 core analysis code. These two codes were also used to perform the required operational safety analyses for the FFTF reactormore » and plant. Although it was intended to also use the SASSYS systems (core and plant) analysis code, the calibration of the SASSYS code for FFTF core and plant analysis was not completed in time to perform pretest analyses. The purpose of this paper is to present the results of the posttest analysis of the 1986 FFTF inherent safety tests using the SASSYS code.« less

The relationship between organizational leadership for safety and learning from patient safety events.

PubMed

Ginsburg, Liane R; Chuang, You-Ta; Berta, Whitney Blair; Norton, Peter G; Ng, Peggy; Tregunno, Deborah; Richardson, Julia

2010-06-01

To examine the relationship between organizational leadership for patient safety and five types of learning from patient safety events (PSEs). Forty-nine general acute care hospitals in Ontario, Canada. A nonexperimental design using cross-sectional surveys of hospital patient safety officers (PSOs) and patient care managers (PCMs). PSOs provided data on organization-level learning from (a) minor events, (b) moderate events, (c) major near misses, (d) major event analysis, and (e) major event dissemination/communication. PCMs provided data on organizational leadership (formal and informal) for patient safety. Hospitals were the unit of analysis. Seemingly unrelated regression was used to examine the influence of formal and informal leadership for safety on the five types of learning from PSEs. The interaction between leadership and hospital size was also examined. Formal organizational leadership for patient safety is an important predictor of learning from minor, moderate, and major near-miss events, and major event dissemination. This relationship is significantly stronger for small hospitals (<100 beds). We find support for the relationship between patient safety leadership and patient safety behaviors such as learning from safety events. Formal leadership support for safety is of particular importance in small organizations where the economic burden of safety programs is disproportionately large and formal leadership is closer to the front lines.

An Educational Intervention to Enhance Nurse Leaders' Perceptions of Patient Safety Culture

PubMed Central

Ginsburg, Liane; Norton, Peter G; Casebeer, Ann; Lewis, Steven

2005-01-01

Objective To design a training intervention and then test its effect on nurse leaders' perceptions of patient safety culture. Study Setting Three hundred and fifty-six nurses in clinical leadership roles (nurse managers and educators/CNSs) in two Canadian multi-site teaching hospitals (study and control). Study Design A prospective evaluation of a patient safety training intervention using a quasi-experimental untreated control group design with pretest and posttest. Nurses in clinical leadership roles in the study group were invited to participate in two patient safety workshops over a 6-month period. Individuals in the study and control groups completed surveys measuring patient safety culture and leadership for improvement prior to training and 4 months following the second workshop. Extraction Methods Individual nurse clinical leaders were the unit of analysis. Exploratory factor analysis of the safety culture items was conducted; repeated-measures analysis of variance and paired t-tests were used to evaluate the effect of the training intervention on perceived safety culture (three factors). Hierarchical regression analyses looked at the influence of demographics, leadership for improvement, and the training intervention on nurse leaders' perceptions of safety culture. Principal Findings A statistically significant improvement in one of three safety culture measures was shown for the study group (p<.001) and a significant decline was seen on one of the safety culture measures for the control group (p<.05). Leadership support for improvement was found to explain significant amounts of variance in all three patient safety culture measures; workshop attendance explained significant amounts of variance in one of the three safety culture measures. The total R2 for the three full hierarchical regression models ranged from 0.338 and 0.554. Conclusions Sensitively delivered training initiatives for nurse leaders can help to foster a safety culture. Organizational leadership support for improvement is, however, also critical for fostering a culture of safety. Together, training interventions and leadership support may have the most significant impact on patient safety culture. PMID:16033489

Patient safety culture: finding meaning in patient experiences.

PubMed

Bishop, Andrea C; Cregan, Brianna R

2015-01-01

The purpose of this paper is to determine what patient and family stories can tell us about patient safety culture within health care organizations and how patients experience patient safety culture. A total of 11 patient and family stories of adverse event experiences were examined in September 2013 using publicly available videos on the Canadian Patient Safety Insitute web site. Videos were transcribed verbatim and collated as one complete data set. Thematic analysis was used to perform qualitative inquiry. All qualitative analysis was done using NVivo 10 software. A total of three themes were identified: first, Being Passed Around; second, Not Having the Conversation; and third, the Person Behind the Patient. Results from this research also suggest that while health care organizations and providers might expect patients to play a larger role in managing their health, there may be underlying reasons as to why patients are not doing so. The findings indicate that patient experiences and narratives are useful sources of information to better understand organizational safety culture and patient experiences of safety while hospitalized. Greater inclusion and analysis of patient safety narratives is important in understanding the needs of patients and how patient safety culture interventions can be improved to ensure translation of patient safety strategies at the frontlines of care. Greater acknowledgement of the patient and family experience provides organizations with an integral perspective to assist in defining and addressing deficiencies within their patient safety culture and to identify opportunities for improvement.

Sources of Safety Data and Statistical Strategies for Design and Analysis: Postmarket Surveillance.

PubMed

Izem, Rima; Sanchez-Kam, Matilde; Ma, Haijun; Zink, Richard; Zhao, Yueqin

2018-03-01

Safety data are continuously evaluated throughout the life cycle of a medical product to accurately assess and characterize the risks associated with the product. The knowledge about a medical product's safety profile continually evolves as safety data accumulate. This paper discusses data sources and analysis considerations for safety signal detection after a medical product is approved for marketing. This manuscript is the second in a series of papers from the American Statistical Association Biopharmaceutical Section Safety Working Group. We share our recommendations for the statistical and graphical methodologies necessary to appropriately analyze, report, and interpret safety outcomes, and we discuss the advantages and disadvantages of safety data obtained from passive postmarketing surveillance systems compared to other sources. Signal detection has traditionally relied on spontaneous reporting databases that have been available worldwide for decades. However, current regulatory guidelines and ease of reporting have increased the size of these databases exponentially over the last few years. With such large databases, data-mining tools using disproportionality analysis and helpful graphics are often used to detect potential signals. Although the data sources have many limitations, analyses of these data have been successful at identifying safety signals postmarketing. Experience analyzing these dynamic data is useful in understanding the potential and limitations of analyses with new data sources such as social media, claims, or electronic medical records data.

Integrating natural language processing expertise with patient safety event review committees to improve the analysis of medication events.

PubMed

Fong, Allan; Harriott, Nicole; Walters, Donna M; Foley, Hanan; Morrissey, Richard; Ratwani, Raj R

2017-08-01

Many healthcare providers have implemented patient safety event reporting systems to better understand and improve patient safety. Reviewing and analyzing these reports is often time consuming and resource intensive because of both the quantity of reports and length of free-text descriptions in the reports. Natural language processing (NLP) experts collaborated with clinical experts on a patient safety committee to assist in the identification and analysis of medication related patient safety events. Different NLP algorithmic approaches were developed to identify four types of medication related patient safety events and the models were compared. Well performing NLP models were generated to categorize medication related events into pharmacy delivery delays, dispensing errors, Pyxis discrepancies, and prescriber errors with receiver operating characteristic areas under the curve of 0.96, 0.87, 0.96, and 0.81 respectively. We also found that modeling the brief without the resolution text generally improved model performance. These models were integrated into a dashboard visualization to support the patient safety committee review process. We demonstrate the capabilities of various NLP models and the use of two text inclusion strategies at categorizing medication related patient safety events. The NLP models and visualization could be used to improve the efficiency of patient safety event data review and analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Safety diagnosis: are we doing a good job?

PubMed

Park, Peter Y; Sahaji, Rajib

2013-03-01

Collision diagnosis is the second step in the six-step road safety management process described in the AASHTO Highway Safety Manual (HSM). Diagnosis is designed to identify a dominant or abnormally high proportion of particular collision configurations (e.g., rear end, right angle, etc.) at a target location. The primary diagnosis method suggested in the HSM is descriptive data analysis. This type of analysis relies on, for example, pie charts, histograms, and/or collision diagrams. Using location specific collision data (e.g., collision frequency per collision configuration for a target location), safety engineers identify (the most) frequent collision configurations. Safety countermeasures are then likely to concentrate on preventing the selected collision configurations. Although its real-world application in engineering practice is limited, an additional collision diagnosis method, known as the beta-binomial (BB) test, is also presented as the secondary diagnosis tool in the HSM. The BB test compares the proportion of a particular collision configuration observed at one location with the proportion of the same collision configuration found at other reference locations which are similar to the target location in terms of selected traffic and roadway characteristics (e.g., traffic volume, traffic control, and number of lanes). This study compared the outcomes obtained from descriptive data analysis and the BB test, and investigates two questions: (1) Do descriptive data analysis and the BB tests produce the same results (i.e., do they select the same collision configurations at the same locations)? and (2) If the tests produce different results, which result should be adopted in engineering practice? This study's analysis was based on a sample of the most recent five years (2005-2009) of collision and roadway configuration data for 143 signalized intersections in the City of Saskatoon, Saskatchewan. The study results show that the BB test's role in diagnosing safety concerns in road safety engineering projects such as safety review projects for existing roadways may be just as important as the descriptive data analysis method. Copyright © 2012 Elsevier Ltd. All rights reserved.

Safety evaluation of joint and conventional lane merge configurations for freeway work zones.

PubMed

Ishak, Sherif; Qi, Yan; Rayaprolu, Pradeep

2012-01-01

Inefficient operation of traffic in work zone areas not only leads to an increase in travel time delays, queue length, and fuel consumption but also increases the number of forced merges and roadway accidents. This study evaluated the safety performance of work zones with a conventional lane merge (CLM) configuration in Louisiana. Analysis of variance (ANOVA) was used to compare the crash rates for accidents involving fatalities, injuries, and property damage only (PDO) in each of the following 4 areas: (1) advance warning area, (2) transition area, (3) work area, and (4) termination area. The analysis showed that the advance warning area had higher fatality, injury, and PDO crash rates when compared to the transition area, work area, and termination area. This finding confirmed the need to make improvements in the advance warning area where merging maneuvers take place. Therefore, a new lane merge configuration, called joint lane merge (JLM), was proposed and its safety performance was examined and compared to the conventional lane merge configuration using a microscopic simulation model (VISSIM), which was calibrated with real-world data from an existing work zone on I-55 and used to simulate a total of 25 different scenarios with different levels of demand and traffic composition. Safety performance was evaluated using 2 surrogate measures: uncomfortable decelerations and speed variance. Statistical analysis was conducted to determine whether the differences in safety performance between both configurations were significant. The safety analysis indicated that JLM outperformed CLM in most cases with low to moderate flow rates and that the percentage of trucks did not have a significant impact on the safety performance of either configuration. Though the safety analysis did not clearly indicate which lane merge configuration is safer for the overall work zone area, it was able to identify the possibly associated safety changes within the work zone area under different traffic conditions. Copyright © 2012 Taylor & Francis Group, LLC

Study of Ultra-High Energy Cosmic Rays from Extensive Air Showers Radio Emission

NASA Astrophysics Data System (ADS)

Petrov, Igor; Kozlov, Vladimir; Petrov, Zim; Knurenko, Stanislav; Pravdin, Mikhail

The study of cosmic rays with the help of radio detection from extensive air showers may be an alternative to traditional detecting methods, which use a large area array installed with hundreds and thousands of scintillation detectors for charged particles, or the detectors of measuring the emission produced by relativistic particles of EAS in the optical wavelengths. Processes that lead to the emission of electromagnetic radiation are well known and calculations show that the air shower radio emission depends on the processes of development of the electromagnetic cascade, i.e. related with the longitudinal development of the shower, with the magnetic field near sea level etc. In this regard, there is a question to establish the correlation between characteristics of EAS both longitudinal and lateral development and radio emission parameters observed when air shower particles pass through the atmosphere. For this purpose, in Yakutsk, radio array for detecting air shower radio emission was established. The array consists of the antenna field on which crossed antennas are installed; antennas oriented E - W and N - S. Radio emission measurements are conducted at frequency 32 MHz, free from industrial noise. In 2008 - 2013 years, Yakutsk array has measured several seasons of registration of EAS events, including showers with energies above 10 (19) eV. In the course of the data analysis the following results were obtained: a) lateral distribution of the radio signal plotted as a function of distance from the shower axis ; b) a correlation between the amplitude of the radio signal with the energy of the shower, which is determined by measuring the fluxes of charged particles , muons and EAS Cerenkov radiation (energy balance method); c) we made evaluation of the depth of maximum development of the shower using form of radio emission LDF measured in ultra-high energy showers; g) a comparison of the Yakutsk array data with data from other arrays.

Experience of creating a multifunctional safety system at the coal mining enterprise

NASA Astrophysics Data System (ADS)

Reshetnikov, V. V.; Davkaev, K. S.; Korolkov, M. V.; Lyakhovets, M. V.

2018-05-01

The principles of creating multifunctional safety systems (MFSS) based on mathematical models with Markov properties are considered. The applicability of such models for the analysis of the safety of the created systems and their effectiveness is substantiated. The method of this analysis and the results of its testing are discussed. The variant of IFSB implementation in the conditions of the operating coal-mining enterprise is given. The functional scheme, data scheme and operating modes of the MFSS are given. The automated workplace of the industrial safety controller is described.

Model-Driven Safety Analysis of Closed-Loop Medical Systems

PubMed Central

Pajic, Miroslav; Mangharam, Rahul; Sokolsky, Oleg; Arney, David; Goldman, Julian; Lee, Insup

2013-01-01

In modern hospitals, patients are treated using a wide array of medical devices that are increasingly interacting with each other over the network, thus offering a perfect example of a cyber-physical system. We study the safety of a medical device system for the physiologic closed-loop control of drug infusion. The main contribution of the paper is the verification approach for the safety properties of closed-loop medical device systems. We demonstrate, using a case study, that the approach can be applied to a system of clinical importance. Our method combines simulation-based analysis of a detailed model of the system that contains continuous patient dynamics with model checking of a more abstract timed automata model. We show that the relationship between the two models preserves the crucial aspect of the timing behavior that ensures the conservativeness of the safety analysis. We also describe system design that can provide open-loop safety under network failure. PMID:24177176

Model-Driven Safety Analysis of Closed-Loop Medical Systems.

PubMed

Pajic, Miroslav; Mangharam, Rahul; Sokolsky, Oleg; Arney, David; Goldman, Julian; Lee, Insup

2012-10-26

In modern hospitals, patients are treated using a wide array of medical devices that are increasingly interacting with each other over the network, thus offering a perfect example of a cyber-physical system. We study the safety of a medical device system for the physiologic closed-loop control of drug infusion. The main contribution of the paper is the verification approach for the safety properties of closed-loop medical device systems. We demonstrate, using a case study, that the approach can be applied to a system of clinical importance. Our method combines simulation-based analysis of a detailed model of the system that contains continuous patient dynamics with model checking of a more abstract timed automata model. We show that the relationship between the two models preserves the crucial aspect of the timing behavior that ensures the conservativeness of the safety analysis. We also describe system design that can provide open-loop safety under network failure.

SCAP: a new methodology for safety management based on feedback from credible accident-probabilistic fault tree analysis system.

PubMed

Khan, F I; Iqbal, A; Ramesh, N; Abbasi, S A

2001-10-12

As it is conventionally done, strategies for incorporating accident--prevention measures in any hazardous chemical process industry are developed on the basis of input from risk assessment. However, the two steps-- risk assessment and hazard reduction (or safety) measures--are not linked interactively in the existing methodologies. This prevents a quantitative assessment of the impacts of safety measures on risk control. We have made an attempt to develop a methodology in which risk assessment steps are interactively linked with implementation of safety measures. The resultant system tells us the extent of reduction of risk by each successive safety measure. It also tells based on sophisticated maximum credible accident analysis (MCAA) and probabilistic fault tree analysis (PFTA) whether a given unit can ever be made 'safe'. The application of the methodology has been illustrated with a case study.

Simulation for Prediction of Entry Article Demise (SPEAD): An Analysis Tool for Spacecraft Safety Analysis and Ascent/Reentry Risk Assessment

NASA Technical Reports Server (NTRS)

Ling, Lisa

2014-01-01

For the purpose of performing safety analysis and risk assessment for a potential off-nominal atmospheric reentry resulting in vehicle breakup, a synthesis of trajectory propagation coupled with thermal analysis and the evaluation of node failure is required to predict the sequence of events, the timeline, and the progressive demise of spacecraft components. To provide this capability, the Simulation for Prediction of Entry Article Demise (SPEAD) analysis tool was developed. The software and methodology have been validated against actual flights, telemetry data, and validated software, and safety/risk analyses were performed for various programs using SPEAD. This report discusses the capabilities, modeling, validation, and application of the SPEAD analysis tool.

Patient safety challenges in a case study hospital--of relevance for transfusion processes?

PubMed

Aase, Karina; Høyland, Sindre; Olsen, Espen; Wiig, Siri; Nilsen, Stein Tore

2008-10-01

The paper reports results from a research project with the objective of studying patient safety, and relates the finding to safety issues within transfusion medicine. The background is an increased focus on undesired events related to diagnosis, medication, and patient treatment in general in the healthcare sector. The study is designed as a case study within a regional Norwegian hospital conducting specialised health care services. The study includes multiple methods such as interviews, document analysis, analysis of error reports, and a questionnaire survey. Results show that the challenges for improved patient safety, based on employees' perceptions, are hospital management support, reporting of accidents/incidents, and collaboration across hospital units. Several of these generic safety challenges are also found to be of relevance for a hospital's transfusion service. Positive patient safety factors are identified as teamwork within hospital units, a non-punitive response to errors, and unit manager's actions promoting safety.

A Quantitative Analysis of Nursing Students' Perceptions of Patient Safety Competencies

ERIC Educational Resources Information Center

Steighner, Tammy Rose

2017-01-01

The purpose of the study was to determine nursing students' perceptions of patient safety competencies as it related to Quality and Safety Education for Nurses (QSEN) competencies and the Safety Competencies Framework developed by The Canadian Patient Safety Institute. The study determined if nursing students knew how to provide safe patient care…

School Safety, Severe Disciplinary Actions, and School Characteristics: A Secondary Analysis of the School Survey on Crime and Safety

ERIC Educational Resources Information Center

Han, Seunghee; Akiba, Motoko

2011-01-01

On the basis of a secondary analysis of survey data collected from 1,872 secondary school principals in the 2005-2006 School Survey on Crime and Safety, we examined the frequency of and reasons for severe disciplinary actions and the relationship between school characteristics and severe disciplinary actions. We found that severe disciplinary…

In-space propellant logistics. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1972-01-01

The study addresses the systems and operational problems associated with the transport, transfer, and storage of cryogenic propellants in low earth orbits. The safety problems connected with in-space propellant logistics operations are also considered.Correlation between the two projects was maintained by including safety considerations, resulting from the system safety analysis, in the trade studies and evaluations of alternate operating concepts in the systems operations analysis.

A benefit/cost analysis of the National Transportation Safety Board's safety recommendation P-01-2

DOT National Transportation Integrated Search

2003-09-01

On June 22, 2001, the National Transportation Safety Board (NTSB) issued Safety : Recommendation P-0 1-2, which recommended that the U.S. Department of Transportations : (U.S. DOTS) Research and Special Programs Administration (RSPA) require th...

Evaluation Of The Vehicle Radar Safety Systems Rashid Radar Safety Brake Collision Warning System, Final Report

DOT National Transportation Integrated Search

1988-02-01

THIS EVALUATION OF THE VEHICLE RADAR SAFETY SYSTEMS? ANTI-COLLISION DEVICE (HEREAFTER VRSS) WAS UNDERTAKEN BY THE OPERATOR PERFORMANCE AND SAFETY ANALYSIS DIVISION OF THE TRANSPORTATION SYSTEMS CENTER AT THE REQUEST OF THE NATIONAL HIGHWAY TRAFFIC SA...

FMCSA Safety Program Effectiveness Measurement: Carrier Intervention Effectiveness Model, Version 1.1-Report for FY 2014 Interventions - Analysis Brief

DOT National Transportation Integrated Search

2018-04-01

The Carrier Intervention Effectiveness Model (CIEM) provides the Federal Motor Carrier Safety Administration (FMCSA) with a tool for measuring the safety benefits of carrier interventions conducted under the Compliance, Safety, Accountability (CSA) e...

FMCSA safety program effectiveness measurement : carrier intervention effectiveness model, version 1.1 - report for FY 2013 interventions : analysis brief

DOT National Transportation Integrated Search

2017-04-01

The Carrier Intervention Effectiveness Model (CIEM) provides the Federal Motor Carrier Safety Administration (FMCSA) with a tool for measuring the safety benefits of carrier interventions conducted under the Compliance, Safety, Accountability (CSA) e...

Factors associated with the patient safety climate at a teaching hospital1

PubMed Central

Luiz, Raíssa Bianca; Simões, Ana Lúcia de Assis; Barichello, Elizabeth; Barbosa, Maria Helena

2015-01-01

Objectives: to investigate the association between the scores of the patient safety climate and socio-demographic and professional variables. Methods: an observational, sectional and quantitative study, conducted at a large public teaching hospital. The Safety Attitudes Questionnaire was used, translated and validated for Brazil. Data analysis used the software Statistical Package for Social Sciences. In the bivariate analysis, we used Student's t-test, analysis of variance and Spearman's correlation of (α=0.05). To identify predictors for the safety climate scores, multiple linear regression was used, having the safety climate domain as the main outcome (α=0.01). Results: most participants were women, nursing staff, who worked in direct care to adult patients in critical areas, without a graduate degree and without any other employment. The average and median total score of the instrument corresponded to 61.8 (SD=13.7) and 63.3, respectively. The variable professional performance was found as a factor associated with the safety environment for the domain perception of service management and hospital management (p=0.01). Conclusion: the identification of factors associated with the safety environment permits the construction of strategies for safe practices in the hospitals. PMID:26487138

Station Blackout: A case study in the interaction of mechanistic and probabilistic safety analysis

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

Curtis Smith; Diego Mandelli; Cristian Rabiti

2013-11-01

The ability to better characterize and quantify safety margins is important to improved decision making about nuclear power plant design, operation, and plant life extension. As research and development (R&D) in the light-water reactor (LWR) Sustainability (LWRS) Program and other collaborative efforts yield new data, sensors, and improved scientific understanding of physical processes that govern the aging and degradation of plant SSCs needs and opportunities to better optimize plant safety and performance will become known. The purpose of the Risk Informed Safety Margin Characterization (RISMC) Pathway R&D is to support plant decisions for risk-informed margin management with the aim tomore » improve economics, reliability, and sustain safety of current NPPs. In this paper, we describe the RISMC analysis process illustrating how mechanistic and probabilistic approaches are combined in order to estimate a safety margin. We use the scenario of a “station blackout” wherein offsite power and onsite power is lost, thereby causing a challenge to plant safety systems. We describe the RISMC approach, illustrate the station blackout modeling, and contrast this with traditional risk analysis modeling for this type of accident scenario.« less

Development and initial validation of an Aviation Safety Climate Scale.

PubMed

Evans, Bronwyn; Glendon, A Ian; Creed, Peter A

2007-01-01

A need was identified for a consistent set of safety climate factors to provide a basis for aviation industry benchmarking. Six broad safety climate themes were identified from the literature and consultations with industry safety experts. Items representing each of the themes were prepared and administered to 940 Australian commercial pilots. Data from half of the sample (N=468) were used in an exploratory factor analysis that produced a 3-factor model of Management commitment and communication, Safety training and equipment, and Maintenance. A confirmatory factor analysis on the remaining half of the sample showed the 3-factor model to be an adequate fit to the data. The results of this study have produced a scale of safety climate for aviation that is both reliable and valid. This study developed a tool to assess the level of perceived safety climate, specifically of pilots, but may also, with minor modifications, be used to assess other groups' perceptions of safety climate.

Multimorbidity and Patient Safety Incidents in Primary Care: A Systematic Review and Meta-Analysis

PubMed Central

Panagioti, Maria; Stokes, Jonathan; Esmail, Aneez; Coventry, Peter; Cheraghi-Sohi, Sudeh; Alam, Rahul; Bower, Peter

2015-01-01

Background Multimorbidity is increasingly prevalent and represents a major challenge in primary care. Patients with multimorbidity are potentially more likely to experience safety incidents due to the complexity of their needs and frequency of their interactions with health services. However, rigorous syntheses of the link between patient safety incidents and multimorbidity are not available. This review examined the relationship between multimorbidity and patient safety incidents in primary care. Methods We followed our published protocol (PROSPERO registration number: CRD42014007434). Medline, Embase and CINAHL were searched up to May 2015. Study design and quality were assessed. Odds ratios (OR) and 95% confidence intervals (95% CIs) were calculated for the associations between multimorbidity and two categories of patient safety outcomes: ‘active patient safety incidents’ (such as adverse drug events and medical complications) and ‘precursors of safety incidents’ (such as prescription errors, medication non-adherence, poor quality of care and diagnostic errors). Meta-analyses using random effects models were undertaken. Results Eighty six relevant comparisons from 75 studies were included in the analysis. Meta-analysis demonstrated that physical-mental multimorbidity was associated with an increased risk for ‘active patient safety incidents’ (OR = 2.39, 95% CI = 1.40 to 3.38) and ‘precursors of safety incidents’ (OR = 1.69, 95% CI = 1.36 to 2.03). Physical multimorbidity was associated with an increased risk for active safety incidents (OR = 1.63, 95% CI = 1.45 to 1.80) but was not associated with precursors of safety incidents (OR = 1.02, 95% CI = 0.90 to 1.13). Statistical heterogeneity was high and the methodological quality of the studies was generally low. Conclusions The association between multimorbidity and patient safety is complex, and varies by type of multimorbidity and type of safety incident. Our analyses suggest that multimorbidity involving mental health may be a key driver of safety incidents, which has important implication for the design and targeting of interventions to improve safety. High quality studies examining the mechanisms of patient safety incidents in patients with multimorbidity are needed, with the goal of promoting effective service delivery and ameliorating threats to safety in this group of patients. PMID:26317435

A framework for a cost benefit analysis of the Fairfax County, Virginia Alcohol Safety Action Project.

DOT National Transportation Integrated Search

1973-01-01

Cost-benefit analysis is sometimes a useful tool for evaluating the advantages and disadvantages of alternative courses of action. The first half of this study was an attempt to further the use of such analysis in the evaluation of a highway safety p...

78 FR 4477 - Review of Safety Analysis Reports for Nuclear Power Plants, Introduction

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-22

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0268] Review of Safety Analysis Reports for Nuclear Power... Analysis Reports for Nuclear Power Plants: LWR Edition.'' The new subsection is the Standard Review Plan... Nuclear Power Plants: Integral Pressurized Water Reactor (iPWR) Edition.'' DATES: Comments must be filed...

Vortex Advisory System Safety Analysis : Volume III, Summary of Laser Data Collection and Analysis

DOT National Transportation Integrated Search

1979-08-01

A Laser-Doppler velocimeter (LDV) was used to monitor the wake vortices shed by 5300 landing aircraft at a point 10,000 feet from the runway threshold. The data were collected to verify the analysis in Volume I of the safety of decreasing interarriva...

Advanced uncertainty modelling for container port risk analysis.

PubMed

Alyami, Hani; Yang, Zaili; Riahi, Ramin; Bonsall, Stephen; Wang, Jin

2016-08-13

Globalization has led to a rapid increase of container movements in seaports. Risks in seaports need to be appropriately addressed to ensure economic wealth, operational efficiency, and personnel safety. As a result, the safety performance of a Container Terminal Operational System (CTOS) plays a growing role in improving the efficiency of international trade. This paper proposes a novel method to facilitate the application of Failure Mode and Effects Analysis (FMEA) in assessing the safety performance of CTOS. The new approach is developed through incorporating a Fuzzy Rule-Based Bayesian Network (FRBN) with Evidential Reasoning (ER) in a complementary manner. The former provides a realistic and flexible method to describe input failure information for risk estimates of individual hazardous events (HEs) at the bottom level of a risk analysis hierarchy. The latter is used to aggregate HEs safety estimates collectively, allowing dynamic risk-based decision support in CTOS from a systematic perspective. The novel feature of the proposed method, compared to those in traditional port risk analysis lies in a dynamic model capable of dealing with continually changing operational conditions in ports. More importantly, a new sensitivity analysis method is developed and carried out to rank the HEs by taking into account their specific risk estimations (locally) and their Risk Influence (RI) to a port's safety system (globally). Due to its generality, the new approach can be tailored for a wide range of applications in different safety and reliability engineering and management systems, particularly when real time risk ranking is required to measure, predict, and improve the associated system safety performance. Copyright © 2016 Elsevier Ltd. All rights reserved.

The influence of authentic leadership on safety climate in nursing.

PubMed

Dirik, Hasan Fehmi; Seren Intepeler, Seyda

2017-07-01

This study analysed nurses' perceptions of authentic leadership and safety climate and examined the contribution of authentic leadership to the safety climate. It has been suggested and emphasised that authentic leadership should be used as a guidance to ensure quality care and the safety of patients and health-care personnel. This predictive study was conducted with 350 nurses in three Turkish hospitals. The data were collected using the Authentic Leadership Questionnaire and the Safety Climate Survey and analysed using hierarchical regression analysis. The mean authentic leadership perception and the safety climate scores of the nurses were 2.92 and 3.50, respectively. The percentage of problematic responses was found to be less than 10% for only four safety climate items. Hierarchical regression analysis revealed that authentic leadership significantly predicted the safety climate. Procedural and political improvements are required in terms of the safety climate in institutions, where the study was conducted, and authentic leadership increases positive perceptions of safety climate. Exhibiting the characteristics of authentic leadership, or improving them and reflecting them on to personnel can enhance the safety climate. Planning information sharing meetings to raise the personnel's awareness of safety climate and systemic improvements can contribute to creating safe care climates. © 2017 John Wiley & Sons Ltd.

Exploring Typical and Atypical Safety Climate Perceptions of Practitioners in the Repair, Maintenance, Minor Alteration and Addition (RMAA) Sector in Hong Kong.

PubMed

Hon, Carol K H; Liu, Yulin

2016-09-22

The safety of repair, maintenance, minor alteration and addition (RMAA) work is an under-explored area. This study explored the typical and atypical safety climate perceptions of practitioners in the RMAA sector in Hong Kong, based on a self-administered questionnaire survey of 662 local practitioners in the industry. Profile analysis, via multidimensional scaling of the respondents' scores of three safety climate scales, identified one typical perception: high in management commitment to occupational health and safety (OHS) and employee involvement, low in applicability for safety rules and regulations, and low in responsibility for OHS. The respondents were clustered into typical and atypical perception groups according to their safety climate scores' match to the typical perception. A comparison of demographics between the two groups with logistic regression found that work level and direct employer significantly affect their classification. A multivariate analysis of variance of safety performance measures between the two groups indicated that the typical group had a significantly higher level of safety compliance than the atypical group, with no significant difference in safety participation or injury. The significance of this study lies in revealing the typical safety climate perception profile pattern of RMAA works and offering a new perspective of safety climate research.

Exploring Typical and Atypical Safety Climate Perceptions of Practitioners in the Repair, Maintenance, Minor Alteration and Addition (RMAA) Sector in Hong Kong

PubMed Central

Hon, Carol K.H.; Liu, Yulin

2016-01-01

The safety of repair, maintenance, minor alteration and addition (RMAA) work is an under-explored area. This study explored the typical and atypical safety climate perceptions of practitioners in the RMAA sector in Hong Kong, based on a self-administered questionnaire survey of 662 local practitioners in the industry. Profile analysis, via multidimensional scaling of the respondents’ scores of three safety climate scales, identified one typical perception: high in management commitment to occupational health and safety (OHS) and employee involvement, low in applicability for safety rules and regulations, and low in responsibility for OHS. The respondents were clustered into typical and atypical perception groups according to their safety climate scores’ match to the typical perception. A comparison of demographics between the two groups with logistic regression found that work level and direct employer significantly affect their classification. A multivariate analysis of variance of safety performance measures between the two groups indicated that the typical group had a significantly higher level of safety compliance than the atypical group, with no significant difference in safety participation or injury. The significance of this study lies in revealing the typical safety climate perception profile pattern of RMAA works and offering a new perspective of safety climate research. PMID:27669269

Effects of metric change on safety in the workplace for selected occupations

NASA Astrophysics Data System (ADS)

Lefande, J. M.; Pokorney, J. L.

1982-04-01

The study assesses the potential safety issues of metric conversion in the workplace. A purposive sample of 35 occupations based on injury and illnesses indexes were assessed. After an analysis of workforce population, hazard analysis and measurement sensitivity of the occupations, jobs were analyzed to identify potential safety hazards by industrial hygienists, safety engineers and academia. The study's major findings were as follows: No metric hazard experience was identified. An increased exposure might occur when particular jobs and their job tasks are going the transition from customary measurement to metric measurement. Well planned metric change programs reduce hazard potential. Metric safety issues are unresolved in the aviation industry.

Establishing a culture for patient safety - the role of education.

PubMed

Milligan, Frank J

2007-02-01

This paper argues that the process of making significant moves towards a patient safety culture requires changes in healthcare education. Improvements in patient safety are a shared international priority as too many errors and other forms of unnecessary harm are currently occurring in the process of caring for and treating patients. A description of the patient safety agenda is given followed by a brief analysis of human factors theory and its use in other safety critical industries, most notably aviation. The all too common problem of drug administration errors is used to illustrate the relevance of human factors theory to healthcare education with specific mention made of the Human Factors Analysis and Classification System (HFACS).

Incorporating organisational safety culture within ergonomics practice.

PubMed

Bentley, Tim; Tappin, David

2010-10-01

This paper conceptualises organisational safety culture and considers its relevance to ergonomics practice. Issues discussed in the paper include the modest contribution that ergonomists and ergonomics as a discipline have made to this burgeoning field of study and the significance of safety culture to a systems approach. The relevance of safety culture to ergonomics work with regard to the analysis, design, implementation and evaluation process, and implications for participatory ergonomics approaches, are also discussed. A potential user-friendly, qualitative approach to assessing safety culture as part of ergonomics work is presented, based on a recently published conceptual framework that recognises the dynamic and multi-dimensional nature of safety culture. The paper concludes by considering the use of such an approach, where an understanding of different aspects of safety culture within an organisation is seen as important to the success of ergonomics projects. STATEMENT OF RELEVANCE: The relevance of safety culture to ergonomics practice is a key focus of this paper, including its relationship with the systems approach, participatory ergonomics and the ergonomics analysis, design, implementation and evaluation process. An approach to assessing safety culture as part of ergonomics work is presented.

Assessment of documentation requirements under DOE 5481. 1, Safety Analysis and Review System (SARS)

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

Browne, E.T.

1981-03-01

This report assesses the requirements of DOE Order 5481.1, Safety Analysis and Review System for DOE Operations (SARS) in regard to maintaining SARS documentation. Under SARS, all pertinent details of the entire safety analysis and review process for each DOE operation are to be traceable from the initial identification of a hazard. This report is intended to provide assistance in identifying the points in the SARS cycle at which documentation is required, what type of documentation is most appropriate, and where it ultimately should be maintained.

A Discussion of Patient Safety Programs in the United States Air Force Ground Medical Expeditionary Environment and an Analysis of Potential Solutions for Increasing Their Effectiveness

DTIC Science & Technology

2017-05-01

and 4N to work Patient Safety together, and it has worked out fine in our environment .” • “It is my opinion that there needs to be a permanent full...GROUND MEDICAL EXPEDITIONARY ENVIRONMENT AND AN ANALYSIS OF POTENTIAL SOLUTIONS FOR INCREASING THEIR EFFECTIVENESS By: James Lee...DISCUSSION OF PATIENT SAFETY PROGRAMS IN THE UNITED STATES AIR FORCE GROUND MEDICAL EXPEDITIONARY ENVIRONMENT AND AN ANALYSIS OF POTENTIAL SOLUTIONS FOR

Evaluation of the safety performance of highway alignments based on fault tree analysis and safety boundaries.

PubMed

Chen, Yikai; Wang, Kai; Xu, Chengcheng; Shi, Qin; He, Jie; Li, Peiqing; Shi, Ting

2018-05-19

To overcome the limitations of previous highway alignment safety evaluation methods, this article presents a highway alignment safety evaluation method based on fault tree analysis (FTA) and the characteristics of vehicle safety boundaries, within the framework of dynamic modeling of the driver-vehicle-road system. Approaches for categorizing the vehicle failure modes while driving on highways and the corresponding safety boundaries were comprehensively investigated based on vehicle system dynamics theory. Then, an overall crash probability model was formulated based on FTA considering the risks of 3 failure modes: losing steering capability, losing track-holding capability, and rear-end collision. The proposed method was implemented on a highway segment between Bengbu and Nanjing in China. A driver-vehicle-road multibody dynamics model was developed based on the 3D alignments of the Bengbu to Nanjing section of Ning-Luo expressway using Carsim, and the dynamics indices, such as sideslip angle and, yaw rate were obtained. Then, the average crash probability of each road section was calculated with a fixed-length method. Finally, the average crash probability was validated against the crash frequency per kilometer to demonstrate the accuracy of the proposed method. The results of the regression analysis and correlation analysis indicated good consistency between the results of the safety evaluation and the crash data and that it outperformed the safety evaluation methods used in previous studies. The proposed method has the potential to be used in practical engineering applications to identify crash-prone locations and alignment deficiencies on highways in the planning and design phases, as well as those in service.

Advanced missions safety. Volume 2: Technical discussion, Part 2: Experiment safety, guidelines

NASA Technical Reports Server (NTRS)

Hinton, M. G., Jr.

1972-01-01

A technical analysis of a portion of the advanced missions safety study is presented. The potential hazards introduced when experimental equipment is carried aboard the Earth Orbit Shuttle are identified. Safety guidelines and requirements for eliminating or reducing these hazards are recommended.

Final safety analysis report for the Ground Test Accelerator (GTA), Phase 2

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

NONE

1994-10-01

This document is the second volume of a 3 volume safety analysis report on the Ground Test Accelerator (GTA). The GTA program at the Los Alamos National Laboratory (LANL) is the major element of the national Neutral Particle Beam (NPB) program, which is supported by the Strategic Defense Initiative Office (SDIO). A principal goal of the national NPB program is to assess the feasibility of using hydrogen and deuterium neutral particle beams outside the Earth`s atmosphere. The main effort of the NPB program at Los Alamos concentrates on developing the GTA. The GTA is classified as a low-hazard facility, exceptmore » for the cryogenic-cooling system, which is classified as a moderate-hazard facility. This volume consists of failure modes and effects analysis; accident analysis; operational safety requirements; quality assurance program; ES&H management program; environmental, safety, and health systems critical to safety; summary of waste-management program; environmental monitoring program; facility expansion, decontamination, and decommissioning; summary of emergency response plan; summary plan for employee training; summary plan for operating procedures; glossary; and appendices A and B.« less

Analysis of vehicle's safety envelope under car-following model

NASA Astrophysics Data System (ADS)

Tang, Tie-Qiao; Zhang, Jian; Chen, Liang; Shang, Hua-Yan

2017-05-01

In this paper, we propose an improved car-following model to explore the impacts of vehicle's two safety distances (i.e., the front safety distance and back safety distance) on the traffic safety during the starting process. The numerical results show that our model is prominently safer than the FVD (full velocity difference) model, i.e., our model is better than the FVD model from the perspective of the traffic safety, which shows that each driver should consider his two safety distances during his driving process.

Hazard Identification and Risk Assessment of Health and Safety Approach JSA (Job Safety Analysis) in Plantation Company

NASA Astrophysics Data System (ADS)

Sugarindra, Muchamad; Ragil Suryoputro, Muhammad; Tiya Novitasari, Adi

2017-06-01

Plantation company needed to identify hazard and perform risk assessment as an Identification of Hazard and Risk Assessment Crime and Safety which was approached by using JSA (Job Safety Analysis). The identification was aimed to identify the potential hazards that might be the risk of workplace accidents so that preventive action could be taken to minimize the accidents. The data was collected by direct observation to the workers concerned and the results were recorded on a Job Safety Analysis form. The data were as forklift operator, macerator worker, worker’s creeper, shredder worker, workers’ workshop, mechanical line worker, trolley cleaning workers and workers’ crepe decline. The result showed that shredder worker value was 30 and had the working level with extreme risk with the risk value range was above 20. So to minimize the accidents could provide Personal Protective Equipment (PPE) which were appropriate, information about health and safety, the company should have watched the activities of workers, and rewards for the workers who obey the rules that applied in the plantation.

Portable Wireless LAN Device and Two-Way Radio Threat Assessment for Aircraft VHF Communication Radio Band

NASA Technical Reports Server (NTRS)

Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Williams, Reuben A.; Smith, Laura J.; Salud, Maria Theresa P.

2004-01-01

This document summarizes the safety analysis performed on a Flight Guidance System (FGS) requirements model. In particular, the safety properties desired of the FGS model are identified and the presence of the safety properties in the model is formally verified. Chapter 1 provides an introduction to the entire project, while Chapter 2 gives a brief overview of the problem domain, the nature of accidents, model based development, and the four-variable model. Chapter 3 outlines the approach. Chapter 4 presents the results of the traditional safety analysis techniques and illustrates how the hazardous conditions associated with the system trace into specific safety properties. Chapter 5 presents the results of the formal methods analysis technique model checking that was used to verify the presence of the safety properties in the requirements model. Finally, Chapter 6 summarizes the main conclusions of the study, first and foremost that model checking is a very effective verification technique to use on discrete models with reasonable state spaces. Additional supporting details are provided in the appendices.

Analysis of event data recorder data for vehicle safety improvement

DOT National Transportation Integrated Search

2008-04-01

The Volpe Center performed a comprehensive engineering analysis of Event Data Recorder (EDR) data supplied by the National Highway Traffic Safety Administration (NHTSA) to assess its accuracy and usefulness in crash reconstruction and improvement of ...

Data collection and analysis for local roadway safety assessment.

DOT National Transportation Integrated Search

2014-11-01

The project Data Analysis for Local Roadway : Assessment conducted systematic road-safety : assessment and identified major risks that can be el : iminated or reduced by pr : actical road-improvement : measures. Specifically, the primary task o...

System safety education focused on system management

NASA Technical Reports Server (NTRS)

Grose, V. L.

1971-01-01

System safety is defined and characteristics of the system are outlined. Some of the principle characteristics include role of humans in hazard analysis, clear language for input and output, system interdependence, self containment, and parallel analysis of elements.

From the traditional concept of safety management to safety integrated with quality.

PubMed

García Herrero, Susana; Mariscal Saldaña, Miguel Angel; Manzanedo del Campo, Miguel Angel; Ritzel, Dale O

2002-01-01

This editorial reviews the evolution of the concepts of safety and quality that have been used in the traditional workplace. The traditional programs of safety are explored showing strengths and weaknesses. The concept of quality management is also viewed. Safety management and quality management principles, stages, and measurement are highlighted. The concepts of quality and safety guarantee are assessed. Total Quality Management concepts are reviewed and applied to safety quality. Total safety management principles are discussed. Finally, an analysis of the relationship between quality and safety from data collected from a company in Spain is presented.

The effect of challenge and hindrance stressors on safety behavior and safety outcomes: a meta-analysis.

PubMed

Clarke, Sharon

2012-10-01

The significance of occupational stressors as a risk factor in accidents has long been recognized; however, the behavioral mechanisms underlying this relationship are currently not well-understood. Meta-analysis was utilized to test the relationships between occupational stressors (challenge and hindrance), safety behaviors (compliance and participation), and safety outcomes (occupational injuries and near-misses). It was hypothesized that hindrance stressors would have negative effects on both safety compliance and safety participation, and subsequently, safety outcomes, whereas challenge stressors would have positive effects. The hypotheses relating to hindrance stressors were supported, suggesting that hindrance stressors lead to a significant reduction in both compliance with safety rules and participation in safety-related activities. Hindrance stressors were also associated with higher levels of occupational injuries and near-misses. The relationship between hindrance stressors and occupational injuries was fully mediated by safety behaviors. However, the hypotheses related to challenge stressors were not supported. Challenge stressors had a nonsignificant, near-zero association with compliance and occupational injuries, a small negative association with participation, and a small positive association with near-misses. The theoretical and practical implications of the meta-analytic findings are discussed, as well as avenues for further research.

Formal Foundations for Hierarchical Safety Cases

NASA Technical Reports Server (NTRS)

Denney, Ewen; Pai, Ganesh; Whiteside, Iain

2015-01-01

Safety cases are increasingly being required in many safety-critical domains to assure, using structured argumentation and evidence, that a system is acceptably safe. However, comprehensive system-wide safety arguments present appreciable challenges to develop, understand, evaluate, and manage, partly due to the volume of information that they aggregate, such as the results of hazard analysis, requirements analysis, testing, formal verification, and other engineering activities. Previously, we have proposed hierarchical safety cases, hicases, to aid the comprehension of safety case argument structures. In this paper, we build on a formal notion of safety case to formalise the use of hierarchy as a structuring technique, and show that hicases satisfy several desirable properties. Our aim is to provide a formal, theoretical foundation for safety cases. In particular, we believe that tools for high assurance systems should be granted similar assurance to the systems to which they are applied. To this end, we formally specify and prove the correctness of key operations for constructing and managing hicases, which gives the specification for implementing hicases in AdvoCATE, our toolset for safety case automation. We motivate and explain the theory with the help of a simple running example, extracted from a real safety case and developed using AdvoCATE.

A multi-agent safety response model in the construction industry.

PubMed

Meliá, José L

2015-01-01

The construction industry is one of the sectors with the highest accident rates and the most serious accidents. A multi-agent safety response approach allows a useful diagnostic tool in order to understand factors affecting risk and accidents. The special features of the construction sector can influence the relationships among safety responses along the model of safety influences. The purpose of this paper is to test a model explaining risk and work-related accidents in the construction industry as a result of the safety responses of the organization, the supervisors, the co-workers and the worker. 374 construction employees belonging to 64 small Spanish construction companies working for two main companies participated in the study. Safety responses were measured using a 45-item Likert-type questionnaire. The structure of the measure was analyzed using factor analysis and the model of effects was tested using a structural equation model. Factor analysis clearly identifies the multi-agent safety dimensions hypothesized. The proposed safety response model of work-related accidents, involving construction specific results, showed a good fit. The multi-agent safety response approach to safety climate is a useful framework for the assessment of organizational and behavioral risks in construction.

Probabilistic safety analysis of earth retaining structures during earthquakes

NASA Astrophysics Data System (ADS)

Grivas, D. A.; Souflis, C.

1982-07-01

A procedure is presented for determining the probability of failure of Earth retaining structures under static or seismic conditions. Four possible modes of failure (overturning, base sliding, bearing capacity, and overall sliding) are examined and their combined effect is evaluated with the aid of combinatorial analysis. The probability of failure is shown to be a more adequate measure of safety than the customary factor of safety. As Earth retaining structures may fail in four distinct modes, a system analysis can provide a single estimate for the possibility of failure. A Bayesian formulation of the safety retaining walls is found to provide an improved measure for the predicted probability of failure under seismic loading. The presented Bayesian analysis can account for the damage incurred to a retaining wall during an earthquake to provide an improved estimate for its probability of failure during future seismic events.

Safety analysis report for packaging (onsite) steel drum

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

McCormick, W.A.

This Safety Analysis Report for Packaging (SARP) provides the analyses and evaluations necessary to demonstrate that the steel drum packaging system meets the transportation safety requirements of HNF-PRO-154, Responsibilities and Procedures for all Hazardous Material Shipments, for an onsite packaging containing Type B quantities of solid and liquid radioactive materials. The basic component of the steel drum packaging system is the 208 L (55-gal) steel drum.

Safety Verification of the Small Aircraft Transportation System Concept of Operations

NASA Technical Reports Server (NTRS)

Carreno, Victor; Munoz, Cesar

2005-01-01

A critical factor in the adoption of any new aeronautical technology or concept of operation is safety. Traditionally, safety is accomplished through a rigorous process that involves human factors, low and high fidelity simulations, and flight experiments. As this process is usually performed on final products or functional prototypes, concept modifications resulting from this process are very expensive to implement. This paper describe an approach to system safety that can take place at early stages of a concept design. It is based on a set of mathematical techniques and tools known as formal methods. In contrast to testing and simulation, formal methods provide the capability of exhaustive state exploration analysis. We present the safety analysis and verification performed for the Small Aircraft Transportation System (SATS) Concept of Operations (ConOps). The concept of operations is modeled using discrete and hybrid mathematical models. These models are then analyzed using formal methods. The objective of the analysis is to show, in a mathematical framework, that the concept of operation complies with a set of safety requirements. It is also shown that the ConOps has some desirable characteristic such as liveness and absence of dead-lock. The analysis and verification is performed in the Prototype Verification System (PVS), which is a computer based specification language and a theorem proving assistant.

Modeling level-of-safety for bus stops in China.

PubMed

Ye, Zhirui; Wang, Chao; Yu, Yongbo; Shi, Xiaomeng; Wang, Wei

2016-08-17

Safety performance at bus stops is generally evaluated by using historical traffic crash data or traffic conflict data. However, in China, it is quite difficult to obtain such data mainly due to the lack of traffic data management and organizational issues. In light of this, the primary objective of this study is to develop a quantitative approach to evaluate bus stop safety performance. The concept of level-of-safety for bus stops is introduced and corresponding models are proposed to quantify safety levels, which consider conflict points, traffic factors, geometric characteristics, traffic signs and markings, pavement conditions, and lighting conditions. Principal component analysis and k-means clustering methods were used to model and quantify safety levels for bus stops. A case study was conducted to show the applicability of the proposed model with data collected from 46 samples for the 7 most common types of bus stops in China, using 32 of the samples for modeling and 14 samples for illustration. Based on the case study, 6 levels of safety for bus stops were defined. Finally, a linear regression analysis between safety levels and the number of traffic conflicts showed that they had a strong relationship (R(2) value of 0.908). The results indicated that the method was well validated and could be practically used for the analysis and evaluation of bus stop safety in China. The proposed model was relatively easy to implement without the requirement of traffic crash data and/or traffic conflict data. In addition, with the proposed method, it was feasible to evaluate countermeasures to improve bus stop safety (e.g., exclusive bus lanes).

Investigating ethnic minorities' perceptions of safety climate in the construction industry.

PubMed

Chan, Albert P C; Wong, Francis K W; Hon, Carol K H; Lyu, Sainan; Javed, Arshad Ali

2017-12-01

An increasing number of ethnic minorities (EMs) have been employed in the construction industry to alleviate severe labor shortages in many countries. Unfortunately, statistics show that EMs have higher fatal and non-fatal occupational injury rates than their local counterparts. However, EMs are often underrepresented in safety climate (SC) research as they are difficult to reach and gauge their perception. A positive relationship has been widely found between SC and safety performance. Understanding the safety perceptions of EMs helps to reduce injuries and improve their safety performance. Based on a sample of 320 EMs from 20 companies in the construction industry, exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to identify the SC factors of EMs, and validate the extracted factors, respectively. Multivariate analysis of variance was undertaken to examine mean differences in perceptions of SC by personal characteristics. Three SC factors for EMs encapsulating 16 variables were identified through EFA. The hypothesized CFA model for a three-factor structure derived from EFA showed a satisfactory goodness-of-fit, composite reliability, and construct validity. Three SC factors were identified, namely: (a) safety management commitment, safety resources, and safety communication; (b) employee's involvement and workmate's influence; and (c) perception of safety rules, procedures and risks. The perceptions of SC differed significantly by nationality, marital status, the number of family members supported, and drinking habit. This study reveals the perception of EMs toward SC. The findings highlight the areas for safety improvement and provide leading indicators for safety performance of EMs. The findings are also enlightening for countries with a number of EMs, such as the United Sates, the United Kingdom, Australia, Singapore, and the Middle East. Copyright © 2017. Published by Elsevier Ltd.

Modeling and analyzing traffic safety perceptions: An application to the speed limit reduction pilot project in Edmonton, Alberta.

PubMed

El-Basyouny, Karim; El-Bassiouni, Mohamed Yahia

2013-03-01

To address the speeding problem in residential areas, the City of Edmonton initiated a pilot project to reduce the posted speed limit from 50km/h to 40km/h within six residential communities. This paper investigates the community perceptions of traffic safety within the six pilot communities in two phases: prior to project initiation (pre-pilot) and following the end of the project (post-pilot). This objective was accomplished by analyzing the results of two random dialing telephone surveys comprising 300 residents each. A preliminary analysis showed compatible demographic configurations for the two samples and confirmed that the residents were aware of both the posted speed limits and the adopted speed management controls. For the confirmatory factor analysis (CFA), a two-group (pre-pilot and post-pilot) three-factor model was used to assess the residents' perceptions of the speeding behavior (Speeding), their concerns about traffic safety issues (Concerns), and their perceptions of traffic safety (Safety). Comparing the CFA results of the post-pilot survey versus those of the pre-pilot survey, it was evident that there was a significant decrease in Speeding and Concerns accompanied by a significant increase in Safety. A structural equations model (SEM) was also fitted to the data in order to assess the impact of Speeding and Concerns on Safety. The results showed that Concerns increase significantly with Speeding, and that both factors have significant negative impacts on Safety. However, while the impact of Concerns on Safety was direct, that of Speeding on Safety was largely indirect (i.e., mediated through Concerns). Overall, the multivariate analysis has demonstrated that the pilot project was successful in improving the residents' perceptions of traffic safety in their community. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Analysis of School Food Safety Programs Based on HACCP Principles

ERIC Educational Resources Information Center

Roberts, Kevin R.; Sauer, Kevin; Sneed, Jeannie; Kwon, Junehee; Olds, David; Cole, Kerri; Shanklin, Carol

2014-01-01

Purpose/Objectives: The purpose of this study was to determine how school districts have implemented food safety programs based on HACCP principles. Specific objectives included: (1) Evaluate how schools are implementing components of food safety programs; and (2) Determine foodservice employees food-handling practices related to food safety.…

32 CFR 989.27 - Occupational safety and health.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 6 2011-07-01 2011-07-01 false Occupational safety and health. 989.27 Section... PROTECTION ENVIRONMENTAL IMPACT ANALYSIS PROCESS (EIAP) § 989.27 Occupational safety and health. Assess direct and indirect impacts of proposed actions on the safety and health of Air Force employees and...

32 CFR 989.27 - Occupational safety and health.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 6 2013-07-01 2013-07-01 false Occupational safety and health. 989.27 Section... PROTECTION ENVIRONMENTAL IMPACT ANALYSIS PROCESS (EIAP) § 989.27 Occupational safety and health. Assess direct and indirect impacts of proposed actions on the safety and health of Air Force employees and...

32 CFR 989.27 - Occupational safety and health.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Occupational safety and health. 989.27 Section... PROTECTION ENVIRONMENTAL IMPACT ANALYSIS PROCESS (EIAP) § 989.27 Occupational safety and health. Assess direct and indirect impacts of proposed actions on the safety and health of Air Force employees and...

32 CFR 989.27 - Occupational safety and health.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 6 2012-07-01 2012-07-01 false Occupational safety and health. 989.27 Section... PROTECTION ENVIRONMENTAL IMPACT ANALYSIS PROCESS (EIAP) § 989.27 Occupational safety and health. Assess direct and indirect impacts of proposed actions on the safety and health of Air Force employees and...

75 FR 35366 - Pipeline Safety: Applying Safety Regulation to All Rural Onshore Hazardous Liquid Low-Stress Lines

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-22

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Part... Onshore Hazardous Liquid Low-Stress Lines AGENCY: Pipeline and Hazardous Materials Safety Administration... pipelines to perform a complete ``could affect'' analysis to determine which rural low-stress pipeline...

Professional Preparation for Careers in Safety.

ERIC Educational Resources Information Center

Della-Giustina, Daniel

There has been a long existing need for individuals with extensive training and concentration in safety studies. The foundation areas upon which a curriculum for training safety practitioners is based should include: (1) trends in accident prevention and control; (2) safety analysis of human and machine tasks; (3) hazard identification and control…

32 CFR 989.27 - Occupational safety and health.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 6 2014-07-01 2014-07-01 false Occupational safety and health. 989.27 Section... PROTECTION ENVIRONMENTAL IMPACT ANALYSIS PROCESS (EIAP) § 989.27 Occupational safety and health. Assess direct and indirect impacts of proposed actions on the safety and health of Air Force employees and...

78 FR 12042 - Public Availability of Defense Nuclear Facilities Safety Board FY 2011 Service Contract Inventory...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-21

... DEFENSE NUCLEAR FACILITIES SAFETY BOARD Public Availability of Defense Nuclear Facilities Safety Board FY 2011 Service Contract Inventory Analysis/FY 2012 Service Contract Inventory AGENCY: Defense Nuclear Facilities Safety Board (DNFSB). ACTION: Notice of Public Availability of FY 2011 Service Contract...

77 FR 7139 - Public Availability of Defense Nuclear Facilities Safety Board; FY 2010 Service Contract...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-10

... DEFENSE NUCLEAR FACILITIES SAFETY BOARD Public Availability of Defense Nuclear Facilities Safety Board; FY 2010 Service Contract Inventory Analysis/FY 2011 Service Contract Inventory AGENCY: Defense Nuclear Facilities Safety Board (DNFSB). ACTION: Notice of Public Availability of FY 2010 Service Contract...

Safety analysis of interchanges

DOT National Transportation Integrated Search

2007-06-01

The objectives of this research are to synthesize the current state of knowledge concerning the safety assessment of new or modified interchanges; develop a spreadsheet-based computational tool for performing safety assessments of interchanges; and i...

Automated Pedestrian Detection, Count and Analysis System

DOT National Transportation Integrated Search

2015-04-15

Pedestrian and bicycle count data is necessary for transportation planning, implementing safety countermeasures, and traffic management. This data is critical when evaluating the pedestrian level of service of safety (LOSS) and pedestrian safety perf...

10 CFR 70.62 - Safety program and integrated safety analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... conclusion of each failure investigation of an item relied on for safety or management measure. (b) Process... methodology being used. (3) Requirements for existing licensees. Individuals holding an NRC license on...

High-Explosives Applications Facility (HEAF)

NASA Astrophysics Data System (ADS)

Morse, J. L.; Weingart, R. C.

1989-03-01

This Safety Analysis Report (SAR) reviews the safety and environmental aspects of the High Explosives Applications Facility (HEAF). Topics covered include the site selected for the HEAF, safety design criteria, operations planned within the facility, and the safety and environmental analyses performed on this project to date. Provided in the Summary section is a review of hazards and the analyses, conclusions, and operating limits developed in this SAR. Appendices provide supporting documents relating to this SAR. This SAR is required by the LLNL Health and Safety Manual and DOE Order 5481.1B(2) to document the safety analysis efforts. The SAR was assembled by the Hazards Control Department, B-Division, and HEAF project personnel. This document was reviewed by B Division, the Chemistry Department, the Hazards Control Department, the Laboratory Associate Director for Administration and Operations, and the Associate Directors ultimately responsible for HEAF operations.

Food-safety educational goals for dietetics and hospitality students.

PubMed

Scheule, B

2000-08-01

To identify food-safety educational goals for dietetics and hospitality management students. Written questionnaires were used to identify educational goals and the most important food safety competencies for entry-level dietitians and foodservice managers. The sample included all directors of didactic programs in dietetics approved by the American Dietetic Association and baccalaureate-degree hospitality programs with membership in the Council on Hotel, Restaurant, and Institutional Education. Fifty-one percent of the directors responded. Descriptive statistics were calculated. chi 2 analysis and independent t tests were used to compare educators' responses for discrete and continuous variables, respectively. Exploratory factor analysis grouped statements about food safety competence. Internal consistency of factors was measured using Cronbach alpha. Thirty-four percent of dietetics programs and 70% of hospitality programs required or offered food safety certification. Dietetics educators reported multiple courses with food safety information, whereas hospitality educators identified 1 or 2 courses. In general, the educators rated food-safety competencies as very important or essential. Concepts related to Hazard Analysis and Critical Control Points (HAACP), irradiation, and pasteurization were rated less highly, compared with other items. Competencies related to reasons for outbreaks of foodborne illness were rated as most important. Food safety certification of dietitians and an increased emphasis on HAACP at the undergraduate level or during the practice component are suggested. Research is recommended to assess the level of food-safety competence expected by employers of entry-level dietitians and foodservice managers.

9 CFR 417.2 - Hazard Analysis and HACCP Plan.

Code of Federal Regulations, 2012 CFR

2012-01-01

... more food safety hazards that are reasonably likely to occur, based on the hazard analysis conducted in... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Hazard Analysis and HACCP Plan. 417.2 Section 417.2 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

9 CFR 417.2 - Hazard Analysis and HACCP Plan.

Code of Federal Regulations, 2014 CFR

2014-01-01

... more food safety hazards that are reasonably likely to occur, based on the hazard analysis conducted in... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Hazard Analysis and HACCP Plan. 417.2 Section 417.2 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

9 CFR 417.2 - Hazard Analysis and HACCP Plan.

Code of Federal Regulations, 2011 CFR

2011-01-01

... more food safety hazards that are reasonably likely to occur, based on the hazard analysis conducted in... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Hazard Analysis and HACCP Plan. 417.2 Section 417.2 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

9 CFR 417.2 - Hazard Analysis and HACCP Plan.

Code of Federal Regulations, 2013 CFR

2013-01-01

... more food safety hazards that are reasonably likely to occur, based on the hazard analysis conducted in... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Hazard Analysis and HACCP Plan. 417.2 Section 417.2 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

9 CFR 417.2 - Hazard Analysis and HACCP Plan.

Code of Federal Regulations, 2010 CFR

2010-01-01

... more food safety hazards that are reasonably likely to occur, based on the hazard analysis conducted in... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Hazard Analysis and HACCP Plan. 417.2 Section 417.2 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

10 CFR 52.79 - Contents of applications; technical information in final safety analysis report.

Code of Federal Regulations, 2010 CFR

2010-01-01

... assurance program will be implemented; (26) The applicant's organizational structure, allocations or... presents a safety analysis of the structures, systems, and components of the facility as a whole. The final... contain an analysis and evaluation of the major structures, systems, and components of the facility that...

Development of guidance for states transitioning to new safety analysis tools

NASA Astrophysics Data System (ADS)

Alluri, Priyanka

With about 125 people dying on US roads each day, the US Department of Transportation heightened the awareness of critical safety issues with the passage of SAFETEA-LU (Safe Accountable Flexible Efficient Transportation Equity Act---a Legacy for Users) legislation in 2005. The legislation required each of the states to develop a Strategic Highway Safety Plan (SHSP) and incorporate data-driven approaches to prioritize and evaluate program outcomes: Failure to do so resulted in funding sanctioning. In conjunction with the legislation, research efforts have also been progressing toward the development of new safety analysis tools such as IHSDM (Interactive Highway Safety Design Model), SafetyAnalyst, and HSM (Highway Safety Manual). These software and analysis tools are comparatively more advanced in statistical theory and level of accuracy, and have a tendency to be more data intensive. A review of the 2009 five-percent reports and excerpts from the nationwide survey revealed astonishing facts about the continuing use of traditional methods including crash frequencies and rates for site selection and prioritization. The intense data requirements and statistical complexity of advanced safety tools are considered as a hindrance to their adoption. In this context, this research aims at identifying the data requirements and data availability for SafetyAnalyst and HSM by working with both the tools. This research sets the stage for working with the Empirical Bayes approach by highlighting some of the biases and issues associated with the traditional methods of selecting projects such as greater emphasis on traffic volume and regression-to-mean phenomena. Further, the not-so-obvious issue with shorter segment lengths, which effect the results independent of the methods used, is also discussed. The more reliable and statistically acceptable Empirical Bayes methodology requires safety performance functions (SPFs), regression equations predicting the relation between crashes and exposure for a subset of roadway network. These SPFs, specific to a region and the analysis period are often unavailable. Calibration of already existing default national SPFs to the state's data could be a feasible solution, but, how well the state's data is represented is a legitimate question. With this background, SPFs were generated for various classifications of segments in Georgia and compared against the national default SPFs used in SafetyAnalyst calibrated to Georgia data. Dwelling deeper into the development of SPFs, the influence of actual and estimated traffic data on the fit of the equations is also studied questioning the accuracy and reliability of traffic estimations. In addition to SafetyAnalyst, HSM aims at performing quantitative safety analysis. Applying HSM methodology to two-way two-lane rural roads, the effect of using multiple CMFs (Crash Modification Factors) is studied. Lastly, data requirements, methodology, constraints, and results are compared between SafetyAnalyst and HSM.

Event Reports Promoting Root Cause Analysis.

PubMed

Pandit, Swananda; Gong, Yang

2016-01-01

Improving health is the sole objective of medical care. Unfortunately, mishaps or patient safety events happen during the care. If the safety events were collected effectively, they would help identify patterns, underlying causes, and ultimately generate proactive and remedial solutions for prevention of recurrence. Based on the AHRQ Common Formats, we examine the quality of patient safety incident reports and describe the initial data requirement that can support and accelerate effective root cause analysis. The ultimate goal is to develop a knowledge base of patient safety events and their common solutions which can be readily available for sharing and learning.

Mission safety evaluation report for STS-35: Postflight edition

NASA Technical Reports Server (NTRS)

Hill, William C.; Finkel, Seymour I.

1991-01-01

Space Transportation System 35 (STS-35) safety risk factors that represent a change from previous flights that had an impact on this flight, and factors that were unique to this flight are discussed. While some changes to the safety risk baseline since the previous flight are included to highlight their significance in risk level change, the primary purpose is to insure that changes which were too late too include in formal changes through the Failure Modes and Effects Analysis/Critical Items List (FMEA/CIL) and Hazard Analysis process are documented along with the safety position, which includes the acceptance rationale.

Food safety attitudes in college students: a structural equation modeling analysis of a conceptual model.

PubMed

Booth, Rachelle; Hernandez, Magaly; Baker, Erica L; Grajales, Tevni; Pribis, Peter

2013-01-30

College students are one of the most at-risk population groups for food poisoning, due to risky food safety behaviors. Using the Likert Scale, undergraduate students were asked to participate in a Food Safety Survey which was completed by 499 students ages 18-25. Data was analyzed using SPSS and AMOS statistical software. Four conceptual definitions regarding food safety were defined as: general food safety, bacterial food safety, produce food safety, and politics associated with food safety. Knowledge seems to be an important factor in shaping students attitudes regarding general and bacterial safety. Ethnicity plays a role in how people view the politics of food safety, and the safety of organic foods.

SRB Safety Analysis

NASA Image and Video Library

2003-09-11

Jeff Thon, an SRB mechanic with United Space Alliance, is lowered into a mockup of a segment of a solid rocket booster. He is testing a technique for vertical SRB propellant grain inspection. The inspection of segments is required as part of safety analysis.

Safety and design in airplane construction

NASA Technical Reports Server (NTRS)

Teichmann, Alfred

1934-01-01

The author gives a survey of the principles of stress analysis and design of airplane structures, and discusses the fundamental strength specifications and their effect on the stress analysis as compared with the safety factors used in other branches of engineering.

Early warning reporting categories analysis of recall and complaints data.

DOT National Transportation Integrated Search

2001-12-31

This analysis was performed to assist the National Highway Traffic Safety Administration (NHTSA) in identifying components and systems to be included in early warning reporting (EWR) categories that would be based upon historical safety-related recal...

14 CFR 33.75 - Safety analysis.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.75 Safety analysis. (a) (1) The applicant must analyze the engine, including the control system, to assess the likely...

Safety analysis report for the SR-101 inert reservoir package

DOT National Transportation Integrated Search

1998-11-01

Department of Energy (DOE) AL Weapons Surety Division (WSD) requires the SR-101 Inert Reservoir Package to : meet applicable hazardous material transportation requirements. This Safety Analysis Report (SAR) is based on : requirements in place at the ...

Flight deck party line issues : an Aviation Safety Reporting System analysis

DOT National Transportation Integrated Search

1995-06-01

This document describes an analysis of the Aviation Safety Reporting System : (ASRS) database with regards to human factors aspects concerning the : implementation of Data Link into the flightdeck. The ASRS database contains : thousands of reports co...

Crash Simulation and Animation: 'A New Approach for Traffic Safety Analysis'

DOT National Transportation Integrated Search

2001-02-01

This researchs objective is to present a methodology to supplement the conventional traffic safety analysis techniques. This methodology aims at using computer simulation to animate and visualize crash occurrence at high-risk locations. This methodol...