Protofit: A program for determining surface protonation constants from titration data

NASA Astrophysics Data System (ADS)

Turner, Benjamin F.; Fein, Jeremy B.

2006-11-01

Determining the surface protonation behavior of natural adsorbents is essential to understand how they interact with their environments. ProtoFit is a tool for analysis of acid-base titration data and optimization of surface protonation models. The program offers a number of useful features including: (1) enables visualization of adsorbent buffering behavior; (2) uses an optimization approach independent of starting titration conditions or initial surface charge; (3) does not require an initial surface charge to be defined or to be treated as an optimizable parameter; (4) includes an error analysis intrinsically as part of the computational methods; and (5) generates simulated titration curves for comparison with observation. ProtoFit will typically be run through ProtoFit-GUI, a graphical user interface providing user-friendly control of model optimization, simulation, and data visualization. ProtoFit calculates an adsorbent proton buffering value as a function of pH from raw titration data (including pH and volume of acid or base added). The data is reduced to a form where the protons required to change the pH of the solution are subtracted out, leaving protons exchanged between solution and surface per unit mass of adsorbent as a function of pH. The buffering intensity function Qads* is calculated as the instantaneous slope of this reduced titration curve. Parameters for a surface complexation model are obtained by minimizing the sum of squares between the modeled (i.e. simulated) buffering intensity curve and the experimental data. The variance in the slope estimate, intrinsically produced as part of the Qads* calculation, can be used to weight the sum of squares calculation between the measured buffering intensity and a simulated curve. Effects of analytical error on data visualization and model optimization are discussed. Examples are provided of using ProtoFit for data visualization, model optimization, and model evaluation.

Time-of-flight measurement of ionic species generated during ablation for optimization of focusing condition at free-electron laser beamline

NASA Astrophysics Data System (ADS)

Senba, Y.; Nagasono, M.; Koyama, T.; Yumoto, H.; Ohashi, H.; Tono, K.; Togashi, T.; Inubushi, Y.; Sato, T.; Yabashi, M.; Ishikawa, T.

2013-03-01

Optimization of focusing conditions is important in free-electron laser applications. A time-of-flight mass analyzer has been designed and constructed for this purpose. The time-of-flight spectra of ionic species evolved from laser ablation of gold were measured. The yields of ionic species showed strong correlations with free-electron-laser intensity. This method conveniently allows for direct estimation of laser intensity on sample and determination of focusing position.

Enhancement of optical and structural quality of semipolar (11-22) GaN by introducing nanoporous SiNx interlayers

NASA Astrophysics Data System (ADS)

Monavarian, Morteza; Metzner, Sebastian; Izyumskaya, Natalia; Müller, Marcus; Okur, Serdal; Zhang, Fan; Can, Nuri; Das, Saikat; Avrutin, Vitaliy; Özgür, Ümit; Bertram, Frank; Christen, Juergen; Morkoç, Hadis

2015-03-01

Enhancement of optical and structural quality of semipolar (11‾22) GaN grown by metal-organic chemical vapor deposition on planar m-sapphire substrates was achieved by using an in-situ epitaxial lateral overgrowth (ELO) technique with nanoporous SiNx layers employed as masks. In order to optimize the procedure, the effect of SiNx deposition time was studied by steady-state photoluminescence (PL), and X-ray diffraction. The intensity of room temperature PL for the (11‾22) GaN layers grown under optimized conditions was about three times higher compared to those for the reference samples having the same thickness but no SiNx interlayers. This finding is attributed to the blockage of extended defect propagation toward the surface by the SiNx interlayers as evidenced from the suppression of emissions associated with basal-plane and prismatic stacking faults with regard to the intensity of donor bound excitons (D0X) in lowtemperature PL spectra. In agreement with the optical data, full width at half maximum values of (11‾22) X-ray rocking curves measured for two different in-plane rotational orientations of [1‾100] and [11‾23] reduced from 0.33º and 0.26º for the reference samples to 0.2º and 0.16º for the nano-ELO structures grown under optimized conditions, respectively.

Enhanced biofuel production potential with nutritional stress amelioration through optimization of carbon source and light intensity in Scenedesmus sp. CCNM 1077.

PubMed

Pancha, Imran; Chokshi, Kaumeel; Mishra, Sandhya

2015-03-01

Microalgal mixotrophic cultivation is one of the most potential ways to enhance biomass and biofuel production. In the present study, first of all ability of microalgae Scenedesmus sp. CCNM 1077 to utilize various carbon sources under mixotrophic growth condition was evaluated followed by optimization of glucose concentration and light intensity to obtain higher biomass, lipid and carbohydrate contents. Under optimized condition i.e. 4 g/L glucose and 150 μmol m(-2) s(-1) light intensity, Scenedesmus sp. CCNM 1077 produced 1.2g/L dry cell weight containing 23.62% total lipid and 42.68% carbohydrate. Addition of glucose shown nutritional stress ameliorating effects and around 70% carbohydrate and 25% total lipid content was found with only 21% reduction in dry cell weight under nitrogen starved condition. This study shows potential application of mixotrophically grown Scenedesmus sp. CCNM 1077 for bioethanol and biodiesel production feed stock. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reduced-Intensity Stem Cell Transplantation: "...whereof a little More than a little is by much too much." King Henry IV, part 1, I, 2.

PubMed

Antin, Joseph H

2007-01-01

The recognition that the immune system can play a major role in the control and cure of transplantable disorders led to the development of reduced-intensity allogeneic transplantation. The notion is that a compromise can be made between the intensity of conditioning and the fostering of graft-versus-host disease/ graft-versus-leukemia (GVHD/GVL), allowing the use of less intense conditioning with concomitantly less intense immediate toxicity. Reduced-intensity conditioning regimens have allowed the application of transplantation to older patients and to patients with underlying medical problems that preclude full-dose transplantation. Clearly, in some settings in which dose intensity is important, reduced-intensity regimens are less useful. However, for diseases that are either indolent, highly susceptible to GVL, or under good control before entering transplantation, this approach appears to have substantial benefits. Although the therapy appears to be valuable, concerns about delayed immune reconstitution and GVHD remain.

Using conditioned suppression to investigate compulsive drug seeking in rats.

PubMed

Limpens, Jules H W; Schut, Evelien H S; Voorn, Pieter; Vanderschuren, Louk J M J

2014-09-01

Persistent drug seeking despite harmful consequences is a defining characteristic of addiction. Recent preclinical studies have demonstrated the occurrence of this hallmark feature of addictive behaviour in rodents. For example, it has been shown that the ability of an aversive conditioned stimulus (CS) to suppress cocaine seeking was diminished after an extended self-administration history. The present study aimed to optimize the experimental conditions to examine conditioned suppression of sucrose and cocaine seeking in rats, and its dependence on the longevity of self-administration experience. We investigated whether conditioned suppression depends on the intensity and quantity of footshocks during conditioning. In addition, the effects of CS omission, extinction and reconditioning were investigated, as well as the influence of the CS interval sequence on conditioned suppression. We also compared conditioned suppression after a limited and extended sucrose or cocaine self-administration history. We found that conditioned suppression depended on the intensity rather than the quantity of footshocks, whereby a higher footshock intensity was necessary to induce suppression of cocaine seeking compared to sucrose seeking. Conditioned suppression was most pronounced when the test started with presentation of the aversive CS, and conditioned suppression could be extinguished and reacquired. In addition, conditioned suppression of cocaine, but not sucrose seeking was reduced after extended self-administration experience. These data provide a detailed analysis of conditioned suppression of cocaine and sucrose seeking. Importantly, we confirm the usefulness of conditioned suppression to study persistent drug seeking after prolonged drug self-administration. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Optimizing autologous cell grafts to improve stem cell gene therapy.

PubMed

Psatha, Nikoletta; Karponi, Garyfalia; Yannaki, Evangelia

2016-07-01

Over the past decade, stem cell gene therapy has achieved unprecedented curative outcomes for several genetic disorders. Despite the unequivocal success, clinical gene therapy still faces challenges. Genetically engineered hematopoietic stem cells are particularly vulnerable to attenuation of their repopulating capacity once exposed to culture conditions, ultimately leading to low engraftment levels posttransplant. This becomes of particular importance when transduction rates are low or/and competitive transplant conditions are generated by reduced-intensity conditioning in the absence of a selective advantage of the transduced over the unmodified cells. These limitations could partially be overcome by introducing megadoses of genetically modified CD34(+) cells into conditioned patients or by transplanting hematopoietic stem cells hematopoietic stem cells with high engrafting and repopulating potential. On the basis of the lessons gained from cord blood transplantation, we summarize the most promising approaches to date of increasing either the numbers of hematopoietic stem cells for transplantation or/and their engraftability, as a platform toward the optimization of engineered stem cell grafts. Copyright © 2016 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

[Coupling AFM fluid imaging with micro-flocculation filtration process for the technological optimization].

PubMed

Zheng, Bei; Ge, Xiao-peng; Yu, Zhi-yong; Yuan, Sheng-guang; Zhang, Wen-jing; Sun, Jing-fang

2012-08-01

Atomic force microscope (AFM) fluid imaging was applied to the study of micro-flocculation filtration process and the optimization of micro-flocculation time and the agitation intensity of G values. It can be concluded that AFM fluid imaging proves to be a promising tool in the observation and characterization of floc morphology and the dynamic coagulation processes under aqueous environmental conditions. Through the use of AFM fluid imaging technique, optimized conditions for micro-flocculation time of 2 min and the agitation intensity (G value) of 100 s(-1) were obtained in the treatment of dye-printing industrial tailing wastewater by the micro-flocculation filtration process with a good performance.

Thiotepa 10 mg/kg Treatment Regimen Is Superior to Thiotepa 5 mg/kg in TBF Conditioning in Patients Undergoing Allogeneic Stem-Cell Transplantation.

PubMed

El-Cheikh, Jean; Massoud, Radwan; Moukalled, Nour; Haffar, Basel; Assi, Hazem; Zahreddine, Ammar; Mahfouz, Rami; Bazarbachi, Ali

2018-05-01

The optimal intensity of myeloablation with a reduced-toxicity conditioning regimen to decrease relapse rate after allogeneic stem-cell transplantation without increasing transplant-related mortality (TRM) has not been well established. We compared outcomes between 5 mg/kg (T5) and 10 mg/kg (T10) thiotepa-based conditioning regimens in 29 adults who underwent allogeneic stem-cell transplantation for hematologic malignancies. After a median follow-up of 11 months, TRM was 0% and 14% at 100 days and 1 year, respectively, with TRM observed only in the T5 group (P = .016). The relapse incidence at 1 year was 20%. No patient had disease in first complete remission at the time of transplantation. At 1 year, progression-free and overall survival were 30% versus 87% (P = .012) and 46% versus 87% (P = .008) in the T5 and T10 groups, respectively. In univariate and multivariate analysis, only age at transplantation and total dose of thiotepa had a significant impact on TRM, overall, and progression-free survival. Patients deemed fit to receive T10-based conditioning for allogeneic stem-cell transplantation to treat high-risk hematologic malignancies had better overall and progression-free survival than those who received T5 with no additional toxicities. Patients should be stratified before conditioning, and those judged fit should receive T10, while the others should consider alternative reduced-intensity conditioning regimens. Copyright © 2018 Elsevier Inc. All rights reserved.

Optimization of combined electron and photon beams for breast cancer

NASA Astrophysics Data System (ADS)

Xiong, W.; Li, J.; Chen, L.; Price, R. A.; Freedman, G.; Ding, M.; Qin, L.; Yang, J.; Ma, C.-M.

2004-05-01

Recently, intensity-modulated radiation therapy and modulated electron radiotherapy have gathered a growing interest for the treatment of breast and head and neck tumours. In this work, we carried out a study to combine electron and photon beams to achieve differential dose distributions for multiple target volumes simultaneously. A Monte Carlo based treatment planning system was investigated, which consists of a set of software tools to perform accurate dose calculation, treatment optimization, leaf sequencing and plan analysis. We compared breast treatment plans generated using this home-grown optimization and dose calculation software for different treatment techniques. Five different planning techniques have been developed for this study based on a standard photon beam whole breast treatment and an electron beam tumour bed cone down. Technique 1 includes two 6 MV tangential wedged photon beams followed by an anterior boost electron field. Technique 2 includes two 6 MV tangential intensity-modulated photon beams and the same boost electron field. Technique 3 optimizes two intensity-modulated photon beams based on a boost electron field. Technique 4 optimizes two intensity-modulated photon beams and the weight of the boost electron field. Technique 5 combines two intensity-modulated photon beams with an intensity-modulated electron field. Our results show that technique 2 can reduce hot spots both in the breast and the tumour bed compared to technique 1 (dose inhomogeneity is reduced from 34% to 28% for the target). Techniques 3, 4 and 5 can deliver a more homogeneous dose distribution to the target (with dose inhomogeneities for the target of 22%, 20% and 9%, respectively). In many cases techniques 3, 4 and 5 can reduce the dose to the lung and heart. It is concluded that combined photon and electron beam therapy may be advantageous for treating breast cancer compared to conventional treatment techniques using tangential wedged photon beams followed by a boost electron field.

Carbohydrate availability and exercise training adaptation: too much of a good thing?

PubMed

Bartlett, Jonathan D; Hawley, John A; Morton, James P

2015-01-01

Traditional nutritional approaches to endurance training have typically promoted high carbohydrate (CHO) availability before, during and after training sessions to ensure adequate muscle substrate to meet the demands of high daily training intensities and volumes. However, during the past decade, data from our laboratories and others have demonstrated that deliberately training in conditions of reduced CHO availability can promote training-induced adaptations of human skeletal muscle (i.e. increased maximal mitochondrial enzyme activities and/or mitochondrial content, increased rates of lipid oxidation and, in some instances, improved exercise capacity). Such data have led to the concept of 'training low, but competing high' whereby selected training sessions are completed in conditions of reduced CHO availability (so as to promote training adaptation), but CHO reserves are restored immediately prior to an important competition. The augmented training response observed with training-low strategies is likely regulated by enhanced activation of key cell signalling kinases (e.g. AMPK, p38MAPK), transcription factors (e.g. p53, PPARδ) and transcriptional co-activators (e.g. PGC-1α), such that a co-ordinated up-regulation of both the nuclear and mitochondrial genomes occurs. Although the optimal practical strategies to train low are not currently known, consuming additional caffeine, protein, and practising CHO mouth-rinsing before and/or during training may help to rescue the reduced training intensities that typically occur when 'training low', in addition to preventing protein breakdown and maintaining optimal immune function. Finally, athletes should practise 'train-low' workouts in conjunction with sessions undertaken with normal or high CHO availability so that their capacity to oxidise CHO is not blunted on race day.

Excellent outcome of allogeneic hematopoietic SCT with reduced-intensity conditioning for the treatment of chronic active EBV infection.

PubMed

Kawa, K; Sawada, A; Sato, M; Okamura, T; Sakata, N; Kondo, O; Kimoto, T; Yamada, K; Tokimasa, S; Yasui, M; Inoue, M

2011-01-01

Since we reported the first successful case of allogeneic hematopoietic SCT (allo-HSCT), we have performed allo-HSCT for 29 patients with chronic active EBV infection (CAEBV), using either myeloablative conditioning (MAC) allo-HSCT (MAST) or reduced-intensity conditioning (RIC) allo-HSCT (RIST). In this retrospective analysis we compared the outcomes after MAST and RIST to identify the optimal conditioning for patients with CAEBV. Of 29 patients, 11 underwent allo-HSCT with MAC, consisting of TBI (12 Gy), etoposide (900 mg/m²) and CY (120 mg/kg) or melphalan (210 mg/m²), and the remaining 18 patients received allo-HSCT after RIC, consisting of fludarabine (∼ 180 mg/m²) and melphalan (140 mg/m²) or CY (120 mg/kg), with/without antithymocyte globulin and low-dose irradiation. Donor sources were 8 related BM, 2 related peripheral blood, 5 CD34 selected cells from HLA-haploidentical donors, 8 unrelated BM and 8 unrelated cord blood. The 3-year-EFS rate was 54.5 ± 15.0% for MAST group and 85.0 ± 8.0% for RIST group, and the 3-year OS rate was 54.5 ± 15.0% for MAST group and 95.0 ± 4.9% for RIST group (P = 0.016). Allo-HSCT after RIC seems to be a promising approach for the treatment of CAEBV.

Light intensity as major factor to maximize biomass and lipid productivity of Ettlia sp. in CO2-controlled photoautotrophic chemostat.

PubMed

Seo, Seong-Hyun; Ha, Ji-San; Yoo, Chan; Srivastava, Ankita; Ahn, Chi-Yong; Cho, Dae-Hyun; La, Hyun-Joon; Han, Myung-Soo; Oh, Hee-Mock

2017-11-01

The optimal culture conditions are critical factors for high microalgal biomass and lipid productivity. To optimize the photoautotrophic culture conditions, combination of the pH (regulated by CO 2 supply), dilution rate, and light intensity was systematically investigated for Ettlia sp. YC001 cultivation in a chemostat during 143days. The biomass productivity increased with the increase in dilution rate and light intensity, but decreased with increasing pH. The average lipid content was 19.8% and statistically non-variable among the tested conditions. The highest biomass and lipid productivities were 1.48gL -1 d -1 and 291.4mgL -1 d -1 with a pH of 6.5, dilution rate of 0.78d -1 , and light intensity of 1500μmolphotonsm -2 s -1 . With a sufficient supply of CO 2 and nutrients, the light intensity was the main determinant of the photosynthetic rate. Therefore, the surface-to-volume ratio of a photobioreactor should enable efficient light distribution to enhance microalgal growth. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dynamic control of supplemental lighting for greenhouse

NASA Astrophysics Data System (ADS)

Wang, Yuanxv; Wei, Ruihua; Xu, Lihong

2018-04-01

The development of light-emitting diodes (LED) technology to a large extent reduce the energy consumption of greenhouse, however, the light control methods to realize the energy saving still have great potential. The aim of this paper is to develop a more efficient control method of dynamic control of the LED top-lighting (TL) intensity and the LED inter-lighting (IL) intensity for the greatest economic benefits. A dynamic lighting control algorithm (DLC) based on model is proposed, which defines the economic benefit performance criterion of the supplemental lighting control. The optimal light intensity of TL and IL is calculated in real time according to the algorithm. The simulation shows that economic benefit can be increased by up to 107.35% compared to TL on-off control. It is concluded that DLC is a feasible supplemental light control method, especially under low natural light conditions.

Sidewall passivation for InGaN/GaN nanopillar light emitting diodes

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

Choi, Won Hyuck; Abraham, Michael; Yu, Shih-Ying

2014-07-07

We studied the effect of sidewall passivation on InGaN/GaN multiquantum well-based nanopillar light emitting diode (LED) performance. In this research, the effects of varying etch rate, KOH treatment, and sulfur passivation were studied for reducing nanopillar sidewall damage and improving device efficiency. Nanopillars prepared under optimal etching conditions showed higher photoluminescence intensity compared with starting planar epilayers. Furthermore, nanopillar LEDs with and without sulfur passivation were compared through electrical and optical characterization. Suppressed leakage current under reverse bias and four times higher electroluminescence (EL) intensity were observed for passivated nanopillar LEDs compared with unpassivated nanopillar LEDs. The suppressed leakage currentmore » and EL intensity enhancement reflect the reduction of non-radiative recombination at the nanopillar sidewalls. In addition, the effect of sulfur passivation was found to be very stable, and further insight into its mechanism was gained through transmission electron microscopy.« less

TENS (transcutaneous electrical nerve stimulation) for labour pain.

PubMed

Francis, Richard

2012-05-01

Because TENS is applied inconsistently and not always in line with optimal TENS application theory, this may explain why TENS for labour pain appears to be effective in some individuals and not in others. This article reviews TENS theory, advises upon optimal TENS application for labour pain and discusses some of the limitations of TENS research on labour pain. TENS application for labour pain may include TENS applied to either side of the lower spine, set to 200 mus pulse duration and 100 pulses per second. As pain increases, TENS intensity should be increased and as pain decreases, TENS intensity should be reduced to maintain a strong but pain free intensity of stimulation. This application may particularly reduce back pain during labour.

Light intensity distribution optimization for tunnel lamps in different zones of a long tunnel.

PubMed

Lai, Wei; Liu, Xianming; Chen, Weimin; Lei, Xiaohua; Cheng, Xingfu

2014-09-22

The light distributions in different tunnel zones have different requirements in order to meet the driver's visual system. In this paper, the light intensity distributions of tunnel lamps in different zones of a long tunnel are optimized separately. A common nonlinear optimization approach is proposed to minimize the consuming power as well as satisfy the luminance and glare requirements both on the road surface and on the wall set by International Commission on Illumination (CIE). Compared with that of the reported linear optimization method, the optimization model can save energy from 11% to 57.6% under the same installation conditions.

Thermal Energy Storage for Electricity Peak-demand Mitigation: A Solution in Developing and Developed World Alike

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

DeForest, Nicholas; Mendes, Goncalo; Stadler, Michael

2013-06-02

In much of the developed world, air-conditioning in buildings is the dominant driver of summer peak electricity demand. In the developing world a steadily increasing utilization of air-conditioning places additional strain on already-congested grids. This common thread represents a large and growing threat to the reliable delivery of electricity around the world, requiring capital-intensive expansion of capacity and draining available investment resources. Thermal energy storage (TES), in the form of ice or chilled water, may be one of the few technologies currently capable of mitigating this problem cost effectively and at scale. The installation of TES capacity allows a buildingmore » to meet its on-peak air conditioning load without interruption using electricity purchased off-peak and operating with improved thermodynamic efficiency. In this way, TES has the potential to fundamentally alter consumption dynamics and reduce impacts of air conditioning. This investigation presents a simulation study of a large office building in four distinct geographical contexts: Miami, Lisbon, Shanghai, and Mumbai. The optimization tool DER-CAM (Distributed Energy Resources Customer Adoption Model) is applied to optimally size TES systems for each location. Summer load profiles are investigated to assess the effectiveness and consistency in reducing peak electricity demand. Additionally, annual energy requirements are used to determine system cost feasibility, payback periods and customer savings under local utility tariffs.« less

Low b-value diffusion-weighted cardiac magnetic resonance imaging: initial results in humans using an optimal time-window imaging approach.

PubMed

Rapacchi, Stanislas; Wen, Han; Viallon, Magalie; Grenier, Denis; Kellman, Peter; Croisille, Pierre; Pai, Vinay M

2011-12-01

Diffusion-weighted imaging (DWI) using low b-values permits imaging of intravoxel incoherent motion in tissues. However, low b-value DWI of the human heart has been considered too challenging because of additional signal loss due to physiological motion, which reduces both signal intensity and the signal-to-noise ratio (SNR). We address these signal loss concerns by analyzing cardiac motion during a heartbeat to determine the time-window during which cardiac bulk motion is minimal. Using this information to optimize the acquisition of DWI data and combining it with a dedicated image processing approach has enabled us to develop a novel low b-value diffusion-weighted cardiac magnetic resonance imaging approach, which significantly reduces intravoxel incoherent motion measurement bias introduced by motion. Simulations from displacement encoded motion data sets permitted the delineation of an optimal time-window with minimal cardiac motion. A number of single-shot repetitions of low b-value DWI cardiac magnetic resonance imaging data were acquired during this time-window under free-breathing conditions with bulk physiological motion corrected for by using nonrigid registration. Principal component analysis (PCA) was performed on the registered images to improve the SNR, and temporal maximum intensity projection (TMIP) was applied to recover signal intensity from time-fluctuant motion-induced signal loss. This PCATMIP method was validated with experimental data, and its benefits were evaluated in volunteers before being applied to patients. Optimal time-window cardiac DWI in combination with PCATMIP postprocessing yielded significant benefits for signal recovery, contrast-to-noise ratio, and SNR in the presence of bulk motion for both numerical simulations and human volunteer studies. Analysis of mean apparent diffusion coefficient (ADC) maps showed homogeneous values among volunteers and good reproducibility between free-breathing and breath-hold acquisitions. The PCATMIP DWI approach also indicated its potential utility by detecting ADC variations in acute myocardial infarction patients. Studying cardiac motion may provide an appropriate strategy for minimizing the impact of bulk motion on cardiac DWI. Applying PCATMIP image processing improves low b-value DWI and enables reliable analysis of ADC in the myocardium. The use of a limited number of repetitions in a free-breathing mode also enables easier application in clinical conditions.

Optimization of lipids' ultrasonic extraction and production from Chlorella sp. using response-surface methodology.

PubMed

Hadrich, Bilel; Akremi, Ismahen; Dammak, Mouna; Barkallah, Mohamed; Fendri, Imen; Abdelkafi, Slim

2018-04-17

Three steps are very important in order to produce microalgal lipids: (1) controlling microalgae cultivation via experimental and modeling investigations, (2) optimizing culture conditions to maximize lipids production and to determine the fatty acid profile the most appropriate for biodiesel synthesis, and (3) optimizing the extraction of the lipids accumulated in the microalgal cells. Firstly, three kinetics models, namely logistic, logistic-with-lag and modified Gompertz, were tested to fit the experimental kinetics of the Chlorella sp. microalga culture established on standard conditions. Secondly, the response-surface methodology was used for two optimizations in this study. The first optimization was established for lipids production from Chlorella sp. culture under different culture conditions. In fact, different levels of nitrate concentrations, salinities and light intensities were applied to the culture medium in order to study their influences on lipids production and determine their fatty acid profile. The second optimization was concerned with the lipids extraction factors: ultrasonic's time and temperature, and chloroform-methanol solvent ratio. All models (logistic, logistic-with-lag and modified Gompertz) applied for the experimental kinetics of Chlorella sp. show a very interesting fitting quality. The logistic model was chosen to describe the Chlorella sp. kinetics, since it yielded the most important statistical criteria: coefficient of determination of the order of 94.36%; adjusted coefficient of determination equal to 93.79% and root mean square error reaching 3.685 cells · ml - 1 . Nitrate concentration and the two interactions involving the light intensity (Nitrate concentration × light intensity, and salinities × light intensity) showed a very significant influence on lipids production in the first optimization (p < 0.05). Yet, only the quadratic term of chloroform-methanol solvent ratio showed a significant influence on lipids extraction relative to the second step of optimization (p < 0.05). The two most abundant fatty acid methyl esters (≈72%) derived from the Chlorella sp. microalga cultured in the determined optimal conditions are: palmitic acid (C16:0) and oleic acid (C18:1) with the corresponding yields of 51.69% and 20.55% of total fatty acids, respectively. Only the nitrate deficiency and the high intensity of light can influence the microalgal lipids production. The corresponding fatty acid methyl esters composition is very suitable for biodiesel production. Lipids extraction is efficient only over long periods of time when using a solvent with a 2/1 chloroform/methanol ratio.

Saturation Fluorescence Labeling of Proteins for Proteomic Analyses

PubMed Central

Pretzer, Elizabeth; Wiktorowicz, John E.

2008-01-01

We present here an optimized and cost-effective approach to saturation fluorescence labeling of protein thiols for proteomic analysis. We investigated a number of conditions and reagent concentrations including a disulfide reducing agent (TCEP), pH, incubation time, linearity of labeling, and saturating dye: protein thiol ratio with protein standards to gauge specific and non-specific labeling. Efficacy of labeling under these conditions was quantified using specific fluorescence estimation, defined as the ratio of fluorescence pixel intensities and Coomassie-stained pixel intensities of bands after digital imaging. Factors leading to specific vs. non-specific labeling in the presence of thiourea are also discussed. We have found that reproducible saturation of available Cys residues of the proteins used as labeling standards (human carbonic anhydrase I, enolase, α-lactalbumin) is achieved at 50-100-fold excess of the uncharged maleimide-functionalized BODIPY™ dyes over Cys. We confirm our previous findings and those of others that the maleimide dyes are not impacted by the presence of 2M thiourea. Moreover, we establish that 2 mM TCEP used as reductant is optimal. We also establish further that labeling is optimal at pH 7.5 and complete after 30 min. Low non-specific labeling was gauged by the inclusion of non-Cys containing proteins (horse myoglobin, bovine carbonic anhydrase) to the labeling mixture. We also show that the dye exhibits little to no effect on the two dimensional mobilities of labeled proteins derived from cells. PMID:18191033

Optimizing the "priming" effect: influence of prior exercise intensity and recovery duration on O2 uptake kinetics and severe-intensity exercise tolerance.

PubMed

Bailey, Stephen J; Vanhatalo, Anni; Wilkerson, Daryl P; Dimenna, Fred J; Jones, Andrew M

2009-12-01

It has been suggested that a prior bout of high-intensity exercise has the potential to enhance performance during subsequent high-intensity exercise by accelerating the O(2) uptake (Vo(2)) on-response. However, the optimal combination of prior exercise intensity and subsequent recovery duration required to elicit this effect is presently unclear. Eight male participants, aged 18-24 yr, completed step cycle ergometer exercise tests to 80% of the difference between the preestablished gas exchange threshold and maximal Vo(2) (i.e., 80%Delta) after no prior exercise (control) and after six different combinations of prior exercise intensity and recovery duration: 40%Delta with 3 min (40-3-80), 9 min (40-9-80), and 20 min (40-20-80) of recovery and 70%Delta with 3 min (70-3-80), 9 min (70-9-80), and 20 min (70-20-80) of recovery. Overall Vo(2) kinetics were accelerated relative to control in all conditions except for 40-9-80 and 40-20-80 conditions as a consequence of a reduction in the Vo(2) slow component amplitude; the phase II time constant was not significantly altered with any prior exercise/recovery combination. Exercise tolerance at 80%Delta was improved by 15% and 30% above control in the 70-9-80 and 70-20-80 conditions, respectively, but was impaired by 16% in the 70-3-80 condition. Prior exercise at 40%Delta did not significantly influence exercise tolerance regardless of the recovery duration. These data demonstrate that prior high-intensity exercise ( approximately 70%Delta) can enhance the tolerance to subsequent high-intensity exercise provided that it is coupled with adequate recovery duration (>or=9 min). This combination presumably optimizes the balance between preserving the effects of prior exercise on Vo(2) kinetics and providing sufficient time for muscle homeostasis (e.g., muscle phosphocreatine and H(+) concentrations) to be restored.

Optimal condition for employing an axicon-generated Bessel beam to fabricate cylindrical microlens arrays

NASA Astrophysics Data System (ADS)

Luo, Zhi; Yin, Kai; Dong, Xinran; Duan, Ji’an

2018-05-01

A numerical algorithm, modelling the transformation from a Gaussian beam to a Bessel beam, is presented for the purpose to study the optimal condition for employing an axicon-generated Bessel beam to fabricate cylindrical microlens arrays (CMLAs). By applying the numerical algorithm to simulate the spatial intensity distribution behind the axicon under different defects of a rotund-apex and different diameter ratios of an incident beam to the axicon, we find that the diffraction effects formed by the axicon edge can be almost eliminated when the diameter ratio is less than 1:2, but the spatial intensity distribution is disturbed dramatically even a few tens of microns deviation of the apex, especially for the front part of the axicon-generated Bessel beam. Fortunately, the lateral intensity profile in the rear part still maintains a desirable Bessel curve. Therefore, the rear part of the Bessel area and the less than 1:2 diameter ratio are the optimal choice for employing an axicon-generated Bessel beam to implement surface microstructures fabrication. Furthermore, by applying the optimal conditions to direct writing microstructures on fused silica with a femtosecond (fs) laser, a large area close-packed CMLA is fabricated. The CMLA presents high quality and uniformity and its optical performance is also demonstrated.

MIPs in Aqueous Environments.

PubMed

Wan, Ying-chun; Ma, Hui-ting; Lu, Bin

2015-01-01

When organic solvent-compatible molecularly imprinted polymers (MIPs) are used in aqueous environment, how to reduce nonspecific binding is a major challenge. By modifying the binding solvents and introducing appropriate washing and elution steps, even relatively hydrophobic MIPs can gain optimal rebinding selectivity in aqueous conditions. Furthermore, water-compatible MIPs that can be used to treat aqueous samples directly have been prepared. The use of hydrophilic co-monomers, the controlled surface modification through controlled radical polymerization, and the new interfacial molecular imprinting methods are different strategies to prepare water-compatible MIPs. By combining MIPs with other techniques, both organic solvent-compatible and water-compatible MIPs can display better functional performances in aqueous conditions. Intensive studies on MIPs in aqueous conditions can provide new MIPs with much-improved compatibilities that will lead to more interesting applications in biomedicine and biotechnology.

Microwave-assisted chemical pre-treatment of waste sorghum leaves: Process optimization and development of an intelligent model for determination of volatile compound fractions.

PubMed

Rorke, Daneal C S; Suinyuy, Terence N; Gueguim Kana, E B

2017-01-01

This study reports the profiling of volatile compounds generated during microwave-assisted chemical pre-treatment of sorghum leaves. Compounds including acetic acid (0-186.26ng/g SL), furfural (0-240.80ng/g SL), 5-hydroxymethylfurfural (HMF) (0-19.20ng/g SL) and phenol (0-7.76ng/g SL) were detected. The reducing sugar production was optimized. An intelligent model based on Artificial Neural Networks (ANNs) was developed and validated to predict a profile of 21 volatile compounds under novel pre-treatment conditions. This model gave R 2 -values of up to 0.93. Knowledge extraction revealed furfural and phenol exhibited high sensitivity to acid- and alkali concentration and S:L ratio, while phenol showed high sensitivity to microwave duration and intensity. Furthermore, furfural production was majorly dependent on acid concentration and fit a dosage-response relationship model with a 2.5% HCl threshold. Significant non-linearities were observed between pre-treatment conditions and the profile of various compounds. This tool reduces analytical costs through virtual analytical instrumentation, improving process economics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of growth conditions and surface reaction byproducts on GaN grown via metal organic molecular beam epitaxy: Toward an understanding of surface reaction chemistry

NASA Astrophysics Data System (ADS)

Pritchett, David; Henderson, Walter; Burnham, Shawn D.; Doolittle, W. Alan

2006-04-01

The surface reaction byproducts during the growth of GaN films via metal organic molecular beam epitaxy (MOMBE) were investigated as a means to optimize material properties. Ethylene and ethane were identified as the dominant surface reaction hydrocarbon byproducts, averaging 27.63% and 7.15% of the total gas content present during growth. Intense ultraviolet (UV) photoexcitation during growth was found to significantly increase the abundance of ethylene and ethane while reducing the presence of H2 and N2. At 920°C, UV excitation was shown to enhance growth rate and crystalline quality while reducing carbon incorporation. Over a limited growth condition range, a 4.5×1019-3.4×1020 cm-3 variation in carbon incorporation was achieved at constant high vacuum. Coupled with growth rate gains, UV excitation yielded films with ˜58% less integrated carbon content. Structural material property variations are reported for various ammonia flows and growth temperatures. The results suggest that high carbon incorporation can be achieved and regulated during MOMBE growth and that in-situ optimization through hydrocarbon analysis may provide further enhancement in the allowable carbon concentration range.

The power of auditory-motor synchronization in sports: enhancing running performance by coupling cadence with the right beats.

PubMed

Bood, Robert Jan; Nijssen, Marijn; van der Kamp, John; Roerdink, Melvyn

2013-01-01

Acoustic stimuli, like music and metronomes, are often used in sports. Adjusting movement tempo to acoustic stimuli (i.e., auditory-motor synchronization) may be beneficial for sports performance. However, music also possesses motivational qualities that may further enhance performance. Our objective was to examine the relative effects of auditory-motor synchronization and the motivational impact of acoustic stimuli on running performance. To this end, 19 participants ran to exhaustion on a treadmill in 1) a control condition without acoustic stimuli, 2) a metronome condition with a sequence of beeps matching participants' cadence (synchronization), and 3) a music condition with synchronous motivational music matched to participants' cadence (synchronization+motivation). Conditions were counterbalanced and measurements were taken on separate days. As expected, time to exhaustion was significantly longer with acoustic stimuli than without. Unexpectedly, however, time to exhaustion did not differ between metronome and motivational music conditions, despite differences in motivational quality. Motivational music slightly reduced perceived exertion of sub-maximal running intensity and heart rates of (near-)maximal running intensity. The beat of the stimuli -which was most salient during the metronome condition- helped runners to maintain a consistent pace by coupling cadence to the prescribed tempo. Thus, acoustic stimuli may have enhanced running performance because runners worked harder as a result of motivational aspects (most pronounced with motivational music) and more efficiently as a result of auditory-motor synchronization (most notable with metronome beeps). These findings imply that running to motivational music with a very prominent and consistent beat matched to the runner's cadence will likely yield optimal effects because it helps to elevate physiological effort at a high perceived exertion, whereas the consistent and correct cadence induced by auditory-motor synchronization helps to optimize running economy.

Biased three-intensity decoy-state scheme on the measurement-device-independent quantum key distribution using heralded single-photon sources.

PubMed

Zhang, Chun-Hui; Zhang, Chun-Mei; Guo, Guang-Can; Wang, Qin

2018-02-19

At present, most of the measurement-device-independent quantum key distributions (MDI-QKD) are based on weak coherent sources and limited in the transmission distance under realistic experimental conditions, e.g., considering the finite-size-key effects. Hence in this paper, we propose a new biased decoy-state scheme using heralded single-photon sources for the three-intensity MDI-QKD, where we prepare the decoy pulses only in X basis and adopt both the collective constraints and joint parameter estimation techniques. Compared with former schemes with WCS or HSPS, after implementing full parameter optimizations, our scheme gives distinct reduced quantum bit error rate in the X basis and thus show excellent performance, especially when the data size is relatively small.

U.S. Air Force Energy Program

DTIC Science & Technology

2011-05-01

prepared to acquire 50% of domestic aviation fuel requirements via an alternative fuel blend by 2016 Installation Energy  Reduce energy intensity by...FY10  On track to certify fleet on synthetic fuel blend by early 2011 Installation Energy  Reduced installation energy intensity nearly 15% since... Winglets Manufacturing Methods Propulsion Integration Alt Fuels Analysis New Efficient Engines Legacy Aircraft Energy Harvesting Weight-optimized

The Cost of Hematopoietic Stem-Cell Transplantation in the United States

PubMed Central

Broder, Michael S.; Quock, Tiffany P.; Chang, Eunice; Reddy, Sheila R.; Agarwal-Hashmi, Rajni; Arai, Sally; Villa, Kathleen F.

2017-01-01

Background Hematopoietic stem-cell transplantation (HSCT) requires highly specialized, resource-intensive care. Myeloablative conditioning regimens used before HSCT generally require inpatient stays and are more intensive than other preparative regimens, and may therefore be more costly. Objective To estimate the costs associated with inpatient HSCT according to the type of the conditioning regimen used and other potential contributors to the overall cost of the procedure. Method We used data from the Truven Health MarketScan insurance claims database to analyze healthcare costs for pediatric (age <18 years) and adult (age ≥18 years) patients who had autologous or allogeneic inpatient HSCT between January 1, 2010, and September 23, 2013. We developed an algorithm to determine whether conditioning regimens were myeloablative or nonmyeloablative/reduced intensity. Results We identified a sample of 1562 patients who had inpatient HSCT during the study period for whom the transplant type and the conditioning regimen were determinable: 398 patients had myeloablative allogeneic HSCT; 195 patients had nonmyeloablative/reduced-intensity allogeneic HSCT; and 969 patients had myeloablative autologous HSCT. The median total healthcare cost at 100 days was $289,283 for the myeloablative allogeneic regimen cohort compared with $253,467 for the nonmyeloablative/reduced-intensity allogeneic regimen cohort, and $140,792 for the myeloablative autologous regimen cohort. The mean hospital length of stay for the index (first claim of) HSCT was 35.6 days in the myeloablative allogeneic regimen cohort, 26.6 days in the nonmyeloablative/reduced-intensity allogeneic cohort, and 21.8 days in the myeloablative autologous regimen cohort. Conclusion Allogeneic HSCT was more expensive than autologous HSCT, regardless of the regimen used. Myeloablative conditioning regimens led to higher overall costs than nonmyeloablative/reduced-intensity regimens in the allogeneic HSCT cohort, indicating a greater cost burden associated with inpatient services for higher-intensity preparative conditioning regimens. Pediatric patients had higher costs than adult patients. Future research should involve validating the algorithm for identifying conditioning regimens using clinical data. PMID:29263771

Anticipating on amplifying water stress: Optimal crop production supported by anticipatory water management

NASA Astrophysics Data System (ADS)

Bartholomeus, Ruud; van den Eertwegh, Gé; Simons, Gijs

2015-04-01

Agricultural crop yields depend largely on the soil moisture conditions in the root zone. Drought but especially an excess of water in the root zone and herewith limited availability of soil oxygen reduces crop yield. With ongoing climate change, more prolonged dry periods alternate with more intensive rainfall events, which changes soil moisture dynamics. With unaltered water management practices, reduced crop yield due to both drought stress and waterlogging will increase. Therefore, both farmers and water management authorities need to be provided with opportunities to reduce risks of decreasing crop yields. In The Netherlands, agricultural production of crops represents a market exceeding 2 billion euros annually. Given the increased variability in meteorological conditions and the resulting larger variations in soil moisture contents, it is of large economic importance to provide farmers and water management authorities with tools to mitigate risks of reduced crop yield by anticipatory water management, both at field and at regional scale. We provide the development and the field application of a decision support system (DSS), which allows to optimize crop yield by timely anticipation on drought and waterlogging situations. By using this DSS, we will minimize plant water stress through automated drainage and irrigation management. In order to optimize soil moisture conditions for crop growth, the interacting processes in the soil-plant-atmosphere system need to be considered explicitly. Our study comprises both the set-up and application of the DSS on a pilot plot in The Netherlands, in order to evaluate its implementation into daily agricultural practice. The DSS focusses on anticipatory water management at the field scale, i.e. the unit scale of interest to a farmer. We combine parallel field measurements ('observe'), process-based model simulations ('predict'), and the novel Climate Adaptive Drainage (CAD) system ('adjust') to optimize soil moisture conditions. CAD is used both for controlled drainage practices and for sub-irrigation. The DSS has a core of the plot-scale SWAP model (soil-water-atmosphere-plant), extended with a process-based module for the simulation of oxygen stress for plant roots. This module involves macro-scale and micro-scale gas diffusion, as well as the plant physiological demand of oxygen, to simulate transpiration reduction due to limited oxygen availability. Continuous measurements of soil moisture content, groundwater level, and drainage level are used to calibrate the SWAP model each day. This leads to an optimal reproduction of the actual soil moisture conditions by data assimilation in the first step in the DSS process. During the next step, near-future (+10 days) soil moisture conditions and drought and oxygen stress are predicted using weather forecasts. Finally, optimal drainage levels to minimize stress are simulated, which can be established by CAD. Linkage to a grid-based hydrological simulation model (SPHY) facilitates studying the spatial dynamics of soil moisture and associated implications for management at the regional scale. Thus, by using local-scale measurements, process-based models and weather forecasts to anticipate on near-future conditions, not only field-scale water management but also regional surface water management can be optimized both in space and time.

Characteristic of fermented spinach (Amaranthus spp.) polyphenol by kombucha culture for antioxidant compound

NASA Astrophysics Data System (ADS)

Aspiyanto, Susilowati, Agustine; Iskandar, Jeti M.; Melanie, Hakiki; Maryati, Yati; Lotulung, Puspa D.

2017-01-01

Fermentation on spinach (Amaranthus sp.) vegetable by kombucha culture as an effort to get poliphenol as antioxidant compound had been done. Purification of fermented spinach extract suspension was carried out through microfiltration (MF) membrane (pore size 0.15 µm) fitted in dead-end Stirred Ultrafiltration Cell (SUFC) mode at fixed condition (stirrer rotation 400 rpm, room temperature, pressure 40 psia). Result of the experimental activity showed that long fermentation time increased total acids, total polyphenol and Total Plate Count (TPC), and decreased total solids and reducing sugar in biomass. The optimal fermentation time was reached for 2 weeks with total polyphenol recovery increasing of 92.76 % from before and after fermentation. On this optimal fermentation time, biomass had identified galic acid with relative intensity of 8 %, while as polyphenol monomer was resulted 5 kinds of polyphenol compounds with total intensity 27.97 % and molecular weight (MW) 191.1736, 193.1871 and 194.2170 at T2.5, T2.86 and T3.86. Long fermentation time increased functional properties of polyphenol as antioxidant.

Optimized two- and three-colour laser pulses for the intense terahertz wave generation

NASA Astrophysics Data System (ADS)

Zhang, Lei; Wang, Guo-Li; Zhou, Xiao-Xin

2016-11-01

Based on the photocurrent model, we perform a theoretical study on the optimization of terahertz (THz) wave emission from argon gas irradiated by the two- and three-colour laser fields. To obtain stronger THz radiation for the given conditions, a genetic algorithm method is applied to search for the optimum laser parameters. For the two-colour field, our optimizations reveal two types of optimal scheme, and each one dominates the THz generation in different regions of intensity ratio for a given total laser intensity. One scheme is the combination of a fundamental laser pulse and its second harmonic, while the other is the fundamental pulse with its fourth harmonic. For each scheme, the optimal intensity ratio and phase delay are obtained. For the three-colour case, our optimization shows that the excellent waveform for the strongest THz radiation is composed of a fundamental laser pulse, and its second, third harmonics, with appropriate intensity ratio and carrier-envelope phase. Such a 3-colour field can generate strong THz radiation comparable with a 10-colour sawtooth wave [Martínez et al., Phys. Rev. Lett. 114, 183901 (2015)]. The physical mechanisms for the enhancement of THz wave emission in gases are also discussed in detail. Our results give helpful guidance for intense THz generation with tabletop femtosecond laser device in experiment.

Emotional intensity reduces later generalized anxiety disorder symptoms when fear of anxiety and negative problem-solving appraisal are low.

PubMed

Sugiura, Yoshinori; Sugiura, Tomoko

2015-08-01

While research based on the emotion dysregulation model indicates a positive relationship between intense emotions and generalized anxiety disorder (GAD) symptoms, emotion-focused intervention involves the use of techniques to enhance emotional experiences, based on the notion that GAD patients are engaging in avoidance strategies. To reveal the conditions under which intense emotions lead to reduced GAD symptoms, we designed a longitudinal study to monitor changes in GAD symptoms among students (N = 129) over 3 months. Our focus was on possible moderators of the effect of emotional intensity. Results indicated that when fear of emotions and negative appraisals about problem solving were low, negative emotional intensity reduced later GAD symptoms. Moreover, under the condition of high responsibility to continue thinking, emotional intensity tended to reduce later GAD symptoms. Results suggest that reduced fear of emotions and reduced negative appraisals about problem solving may enhance the use of emotional processing techniques (e.g., emotional exposure). The interaction between responsibility to continue thinking and emotional intensity requires further examination. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Wakefield acceleration in planetary atmospheres: A possible source of MeV electrons. The collisionless case

NASA Astrophysics Data System (ADS)

Arrayás, M.; Cubero, D.; Montanya, J.; Seviour, R.; Trueba, J. L.

2018-07-01

Intense electromagnetic pulses interacting with a plasma can create a wake of plasma oscillations. Electrons trapped in such oscillations can be accelerated under certain conditions to very high energies. We study the optimal conditions for the wakefield acceleration to produce MeV electrons in planetary plasmas under collisionless conditions. The conditions for the optimal plasma densities can be found in the Earth atmosphere at higher altitudes than 10-15 km, which are the altitudes where lightning leaders can take place.

The Power of Auditory-Motor Synchronization in Sports: Enhancing Running Performance by Coupling Cadence with the Right Beats

PubMed Central

Bood, Robert Jan; Nijssen, Marijn; van der Kamp, John; Roerdink, Melvyn

2013-01-01

Acoustic stimuli, like music and metronomes, are often used in sports. Adjusting movement tempo to acoustic stimuli (i.e., auditory-motor synchronization) may be beneficial for sports performance. However, music also possesses motivational qualities that may further enhance performance. Our objective was to examine the relative effects of auditory-motor synchronization and the motivational impact of acoustic stimuli on running performance. To this end, 19 participants ran to exhaustion on a treadmill in 1) a control condition without acoustic stimuli, 2) a metronome condition with a sequence of beeps matching participants’ cadence (synchronization), and 3) a music condition with synchronous motivational music matched to participants’ cadence (synchronization+motivation). Conditions were counterbalanced and measurements were taken on separate days. As expected, time to exhaustion was significantly longer with acoustic stimuli than without. Unexpectedly, however, time to exhaustion did not differ between metronome and motivational music conditions, despite differences in motivational quality. Motivational music slightly reduced perceived exertion of sub-maximal running intensity and heart rates of (near-)maximal running intensity. The beat of the stimuli –which was most salient during the metronome condition– helped runners to maintain a consistent pace by coupling cadence to the prescribed tempo. Thus, acoustic stimuli may have enhanced running performance because runners worked harder as a result of motivational aspects (most pronounced with motivational music) and more efficiently as a result of auditory-motor synchronization (most notable with metronome beeps). These findings imply that running to motivational music with a very prominent and consistent beat matched to the runner’s cadence will likely yield optimal effects because it helps to elevate physiological effort at a high perceived exertion, whereas the consistent and correct cadence induced by auditory-motor synchronization helps to optimize running economy. PMID:23951000

Investigation of an Anomaly Observed in Impedance Eduction Techniques

NASA Technical Reports Server (NTRS)

Watson, W. R.; Jones, M. G.; Parrott, T. L.

2008-01-01

An intensive investigation into the cause of anomalous behavior commonly observed in impedance eduction techniques is performed. The investigation consists of grid refinement studies, detailed evaluation of results at and near anti-resonance frequencies, comparisons of different model results with synthesized and measured data, assessment or optimization techniques, and evaluation or boundary condition effects. Results show that the root cause of the anomalous behavior is the sensitivity of the educed impedance to small errors in the measured termination resistance at frequencies near anti-resonance or cut-on of a higher-order mode. Evidence is presented to show that the common usage of an anechoic, plane wave termination boundary condition in ducts where the "true" termination is reflective may act as a trigger for these anomalies. Replacing the exit impedance boundary condition by an exit pressure condition is shown to reduce the anomalous results.

Successful Reduced Intensity Allogeneic Transplant With Full Donor Chimerism and Good Quality of Life in Adolescent Patient With Wiskott-Aldrich Syndrome.

PubMed

Ali, Salah; Gacsadi, Anna; McDougall, Elizabeth; Armstrong, Christine; Krueger, Joerg; Schechter, Tal; Ali, Muhammad

2017-07-01

Wiskott-Aldrich syndrome (WAS) is an X-linked disease characterized by microthrombocytopenia, eczema, immune deficiency, and autoimmune phenomena. Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment. Myeloablative conditioning is the most common regimen used for HSCT in patients with WAS to avoid the risk of mixed donor chimerism and autoimmunity post-HSCT. There is limited data on the use of reduced intensity conditioning for HSCT in patients with WAS. Here, we report a case with severe phenotype of WAS transplanted successfully with reduced intensity conditioning, which is an acceptable conditioning regimen and can be considered in patients with WAS with significantly impaired organ functions.

Visualization of Porphyrin-Based Photosensitizer Distribution from Fluorescence Images In Vivo Using an Optimized RGB Camera

NASA Astrophysics Data System (ADS)

Liu, L.; Huang, Zh.; Qiu, Zh.; Li, B.

2018-01-01

A handheld RGB camera was developed to monitor the in vivo distribution of porphyrin-based photosensitizer (PS) hematoporphyrin monomethyl ether (HMME) in blood vessels during photodynamic therapy (PDT). The focal length, f-number, International Standardization Organization (ISO) sensitivity, and shutter speed of the camera were optimized for the solution sample with various HMME concentrations. After the parameter optimization, it was found that the red intensity value of the fluorescence image was linearly related to the fluorescence intensity under investigated conditions. The RGB camera was then used to monitor the in vivo distribution of HMME in blood vessels in a skin-fold window chamber model. The red intensity value of the recorded RGB fluorescence image was found to be linearly correlated to HMME concentrations in the range 0-24 μM. Significant differences in the red to green intensity ratios were observed between the blood vessels and the surrounding tissue.

Drilling force and temperature of bone under dry and physiological drilling conditions

NASA Astrophysics Data System (ADS)

Xu, Linlin; Wang, Chengyong; Jiang, Min; He, Huiyu; Song, Yuexian; Chen, Hanyuan; Shen, Jingnan; Zhang, Jiayong

2014-11-01

Many researches on drilling force and temperature have been done with the aim to reduce the labour intensiveness of surgery, avoid unnecessary damage and improve drilling quality. However, there has not been a systematic study of mid- and high-speed drilling under dry and physiological conditions(injection of saline). Furthermore, there is no consensus on optimal drilling parameters. To study these parameters under dry and physiological drilling conditions, pig humerus bones are drilled with medical twist drills operated using a wide range of drilling speeds and feed rates. Drilling force and temperature are measured using a YDZ-II01W dynamometer and a NEC TVS-500EX thermal infrared imager, respectively, to evaluate internal bone damage. To evaluate drilling quality, bone debris and hole morphology are observed by SEM(scanning electron microscopy). Changes in drilling force and temperature give similar results during drilling such that the value of each parameter peaks just before the drill penetrates through the osteon of the compact bone into the trabeculae of the spongy bone. Drilling temperatures under physiological conditions are much lower than those observed under dry conditions, while a larger drilling force occurs under physiological conditions than dry conditions. Drilling speed and feed rate have a significant influence on drilling force, temperature, bone debris and hole morphology. The investigation of the effect of drilling force and temperature on internal bone damage reveals that a drilling speed of 4500 r/min and a feed rate of 50 mm/min are recommended for bone drilling under physiological conditions. Drilling quality peaks under these optimal parameter conditions. This paper proposes the optimal drilling parameters under mid- and high-speed surgical drilling, considering internal bone damage and drilling quality, which can be looked as a reference for surgeons performing orthopedic operations.

Influence of stationary and non-stationary conditions on drying time and mechanical properties of a porcelain slab

NASA Astrophysics Data System (ADS)

Hammouda, Imen; Mihoubi, Daoued

2017-12-01

This work deals with a numerical study of the response of a porcelain slab when subjected to convective drying in stationary and non-stationary conditions. The used model describes heat, mass, and momentum transfers is applied to an unsaturated viscoelastic medium described by a Maxwell model. The numerical code allows us to determine the effect of the surrounding air temperature on drying kinetics and on mechanical stress intensities. Von Mises stresses are analysed in order to foresee an eventual damage that may occur during drying. Simulation results for several temperatures in the range of [30 °C, 90 °C] shows that for the temperature from 30 °C to 60 °C, Von Mises stresses are always lower than the yield strength. But above 70 °C, Von Mises stresses are higher than the ultimate strength, and consequently there is a risk of crack at the end of the constant drying rate period. The idea proposed in this work is to integrate a reducing temperature phase when the predicted Von Mises stress intensity exceeds the admissible stress. Simulation results shows that a non-stationary convective drying (90-60 °C) allows us to optimize costs and quality by reducing the drying time and maintaining Von Mises stress values under the admissible stress.

Particle swarm optimizer for weighting factor selection in intensity-modulated radiation therapy optimization algorithms.

PubMed

Yang, Jie; Zhang, Pengcheng; Zhang, Liyuan; Shu, Huazhong; Li, Baosheng; Gui, Zhiguo

2017-01-01

In inverse treatment planning of intensity-modulated radiation therapy (IMRT), the objective function is typically the sum of the weighted sub-scores, where the weights indicate the importance of the sub-scores. To obtain a high-quality treatment plan, the planner manually adjusts the objective weights using a trial-and-error procedure until an acceptable plan is reached. In this work, a new particle swarm optimization (PSO) method which can adjust the weighting factors automatically was investigated to overcome the requirement of manual adjustment, thereby reducing the workload of the human planner and contributing to the development of a fully automated planning process. The proposed optimization method consists of three steps. (i) First, a swarm of weighting factors (i.e., particles) is initialized randomly in the search space, where each particle corresponds to a global objective function. (ii) Then, a plan optimization solver is employed to obtain the optimal solution for each particle, and the values of the evaluation functions used to determine the particle's location and the population global location for the PSO are calculated based on these results. (iii) Next, the weighting factors are updated based on the particle's location and the population global location. Step (ii) is performed alternately with step (iii) until the termination condition is reached. In this method, the evaluation function is a combination of several key points on the dose volume histograms. Furthermore, a perturbation strategy - the crossover and mutation operator hybrid approach - is employed to enhance the population diversity, and two arguments are applied to the evaluation function to improve the flexibility of the algorithm. In this study, the proposed method was used to develop IMRT treatment plans involving five unequally spaced 6MV photon beams for 10 prostate cancer cases. The proposed optimization algorithm yielded high-quality plans for all of the cases, without human planner intervention. A comparison of the results with the optimized solution obtained using a similar optimization model but with human planner intervention revealed that the proposed algorithm produced optimized plans superior to that developed using the manual plan. The proposed algorithm can generate admissible solutions within reasonable computational times and can be used to develop fully automated IMRT treatment planning methods, thus reducing human planners' workloads during iterative processes. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

High-Throughput Screening Assay for Embryoid Body Differentiation of Human Embryonic Stem Cells

PubMed Central

Outten, Joel T.; Gadue, Paul; French, Deborah L.; Diamond, Scott L.

2012-01-01

Serum-free human pluripotent stem cell media offer the potential to develop reproducible clinically applicable differentiation strategies and protocols. The vast array of possible growth factor and cytokine combinations for media formulations makes differentiation protocol optimization both labor and cost-intensive. This unit describes a 96-well plate, 4-color flow cytometry-based screening assay to optimize pluripotent stem cell differentiation protocols. We provide conditions both to differentiate human embryonic stem cells (hESCs) to the three primary germ layers, ectoderm, endoderm, and mesoderm, and to utilize flow cytometry to distinguish between them. This assay exhibits low inter-well variability and can be utilized to efficiently screen a variety of media formulations, reducing cost, incubator space, and labor. Protocols can be adapted to a variety of differentiation stages and lineages. PMID:22415836

Participants with pharmacologically impaired taste function seek out more intense, higher calorie stimuli.

PubMed

Noel, Corinna A; Sugrue, Meaghan; Dando, Robin

2017-10-01

Research suggests a weaker sense of taste in people with obesity, with the assumption that a debilitated taste response increases the desire for more intensely tasting stimuli to compensate for decreased taste input. However, empirical testing of this supposition remains largely absent. In a randomized, repeated measures design, 51 healthy subjects were treated with varying concentrations of a tea containing Gymnema sylvestre (GS), to temporarily and selectively diminish sweet taste perception, or a control tea. Following treatment in the four testing sessions, taste intensity ratings for various sweet stimuli were captured on the generalized Labeled Magnitude Scale (gLMS), liking for real foods assessed on the hedonic gLMS, and optimal level of sweetness quantified via an ad-libitum mixing task. Data were analyzed with mixed models assessing both treatment condition and each subject's resultant sweet response with various taste-related outcomes, controlling for covariates. GS treatment diminished sweet intensity perception (p < 0.001), reduced liking for sweet foods (p < 0.001), and increased the desired sucrose content of these foods (p < 0.001). Regression modeling revealed a 1% reduction in sweet taste response was associated with a 0.40 g/L increase in optimal concentration of sucrose (p < 0.001). Our results show that an attenuation in the perceived taste intensity of sweeteners correlates with shifted preference and altered hedonic response to select sweet foods. This suggests that those with a diminished sense of taste may desire more intense stimuli to attain a satisfactory level of reward, potentially influencing eating habits to compensate for a lower gustatory input. Copyright © 2017. Published by Elsevier Ltd.

Optimal conditions for tissue perforation using high intensity focused ultrasound

NASA Astrophysics Data System (ADS)

Mochizuki, Takashi; Kihara, Taizo; Ogawa, Kouji; Tanabe, Ryoko; Yosizawa, Shin; Umemura, Shin-ichiro; Kakimoto, Takashi; Yamashita, Hiromasa; Chiba, Toshio

2012-10-01

To perforate tissue lying deep part in body, a large size transducer was assembled by combining four spherical-shaped transducers, and the optimal conditions for tissue perforation have studied using ventricle muscle of chicken as a target. The ex vivo experiments showed that ventricle muscle was successfully perforated both when it was exposed to High Intensity Focused Ultrasound (HIFU) directly and when it was exposed to HIFU through atrial muscle layer. Moreover, it was shown that calculated acoustic power distributions are well similar to the perforation patterns, and that the acoustic energy distributes very complexly near the focus. Lastly, perforation on the living rabbit bladder wall was demonstrated as a preliminary in vivo experiment.

Study on optimization method of test conditions for fatigue crack detection using lock-in vibrothermography

NASA Astrophysics Data System (ADS)

Min, Qing-xu; Zhu, Jun-zhen; Feng, Fu-zhou; Xu, Chao; Sun, Ji-wei

2017-06-01

In this paper, the lock-in vibrothermography (LVT) is utilized for defect detection. Specifically, for a metal plate with an artificial fatigue crack, the temperature rise of the defective area is used for analyzing the influence of different test conditions, i.e. engagement force, excitation intensity, and modulated frequency. The multivariate nonlinear and logistic regression models are employed to estimate the POD (probability of detection) and POA (probability of alarm) of fatigue crack, respectively. The resulting optimal selection of test conditions is presented. The study aims to provide an optimized selection method of the test conditions in the vibrothermography system with the enhanced detection ability.

Study of residue type defect formation mechanism and the effect of advanced defect reduction (ADR) rinse process

NASA Astrophysics Data System (ADS)

Arima, Hiroshi; Yoshida, Yuichi; Yoshihara, Kosuke; Shibata, Tsuyoshi; Kushida, Yuki; Nakagawa, Hiroki; Nishimura, Yukio; Yamaguchi, Yoshikazu

2009-03-01

Residue type defect is one of yield detractors in lithography process. It is known that occurrence of the residue type defect is dependent on resist development process and the defect is reduced by optimized rinsing condition. However, the defect formation is affected by resist materials and substrate conditions. Therefore, it is necessary to optimize the development process condition by each mask level. Those optimization steps require a large amount of time and effort. The formation mechanism is investigated from viewpoint of both material and process. The defect formation is affected by resist material types, substrate condition and development process condition (D.I.W. rinse step). Optimized resist formulation and new rinse technology significantly reduce the residue type defect.

Haploidentical transplant with posttransplant cyclophosphamide vs matched unrelated donor transplant for acute myeloid leukemia

PubMed Central

Zhang, Mei-Jie; Bacigalupo, Andrea A.; Bashey, Asad; Appelbaum, Frederick R.; Aljitawi, Omar S.; Armand, Philippe; Antin, Joseph H.; Chen, Junfang; Devine, Steven M.; Fowler, Daniel H.; Luznik, Leo; Nakamura, Ryotaro; O’Donnell, Paul V.; Perales, Miguel-Angel; Pingali, Sai Ravi; Porter, David L.; Riches, Marcie R.; Ringdén, Olle T. H.; Rocha, Vanderson; Vij, Ravi; Weisdorf, Daniel J.; Champlin, Richard E.; Horowitz, Mary M.; Fuchs, Ephraim J.; Eapen, Mary

2015-01-01

We studied adults with acute myeloid leukemia (AML) after haploidentical (n = 192) and 8/8 HLA-matched unrelated donor (n = 1982) transplantation. Haploidentical recipients received calcineurin inhibitor (CNI), mycophenolate, and posttransplant cyclophosphamide for graft-versus-host disease (GVHD) prophylaxis; 104 patients received myeloablative and 88 received reduced intensity conditioning regimens. Matched unrelated donor transplant recipients received CNI with mycophenolate or methotrexate for GVHD prophylaxis; 1245 patients received myeloablative and 737 received reduced intensity conditioning regimens. In the myeloablative setting, day 30 neutrophil recovery was lower after haploidentical compared with matched unrelated donor transplants (90% vs 97%, P = .02). Corresponding rates after reduced intensity conditioning transplants were 93% and 96% (P = .25). In the myeloablative setting, 3-month acute grade 2-4 (16% vs 33%, P < .0001) and 3-year chronic GVHD (30% vs 53%, P < .0001) were lower after haploidentical compared with matched unrelated donor transplants. Similar differences were observed after reduced intensity conditioning transplants, 19% vs 28% (P = .05) and 34% vs 52% (P = .002). Among patients receiving myeloablative regimens, 3-year probabilities of overall survival were 45% (95% CI, 36-54) and 50% (95% CI, 47-53) after haploidentical and matched unrelated donor transplants (P = .38). Corresponding rates after reduced intensity conditioning transplants were 46% (95% CI, 35-56) and 44% (95% CI, 0.40-47) (P = .71). Although statistical power is limited, these data suggests that survival for patients with AML after haploidentical transplantation with posttransplant cyclophosphamide is comparable with matched unrelated donor transplantation. PMID:26130705

An image morphing technique based on optimal mass preserving mapping.

PubMed

Zhu, Lei; Yang, Yan; Haker, Steven; Tannenbaum, Allen

2007-06-01

Image morphing, or image interpolation in the time domain, deals with the metamorphosis of one image into another. In this paper, a new class of image morphing algorithms is proposed based on the theory of optimal mass transport. The L(2) mass moving energy functional is modified by adding an intensity penalizing term, in order to reduce the undesired double exposure effect. It is an intensity-based approach and, thus, is parameter free. The optimal warping function is computed using an iterative gradient descent approach. This proposed morphing method is also extended to doubly connected domains using a harmonic parameterization technique, along with finite-element methods.

An Image Morphing Technique Based on Optimal Mass Preserving Mapping

PubMed Central

Zhu, Lei; Yang, Yan; Haker, Steven; Tannenbaum, Allen

2013-01-01

Image morphing, or image interpolation in the time domain, deals with the metamorphosis of one image into another. In this paper, a new class of image morphing algorithms is proposed based on the theory of optimal mass transport. The L2 mass moving energy functional is modified by adding an intensity penalizing term, in order to reduce the undesired double exposure effect. It is an intensity-based approach and, thus, is parameter free. The optimal warping function is computed using an iterative gradient descent approach. This proposed morphing method is also extended to doubly connected domains using a harmonic parameterization technique, along with finite-element methods. PMID:17547128

FLORIS 2017

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

2017-08-04

This code is an enhancement to the existing FLORIS code, SWR 14-20. In particular, this enhancement computes overall thrust and turbulence intensity throughout a wind plant. This information is used to form a description of the fatigue loads experienced throughtout the wind plant. FLORIS has been updated to include an optimization routine that optimizes FLORIS to minimize thrust and turbulence intensity (and therefore loads) across the wind plant. Previously, FLORIS had been designed to optimize power out of a wind plant. However, as turbines age, more wind plant owner/operators are looking for ways to reduce their fatigue loads without sacrificingmore » too much power.« less

[The patient blood management concept : Joint recommendation of the German Society of Anaesthesiology and Intensive Care Medicine and the German Society of Surgery].

PubMed

Meybohm, P; Schmitz-Rixen, T; Steinbicker, A; Schwenk, W; Zacharowski, K

2017-10-01

Patient blood management is a multimodal concept that aims to detect, prevent and treat anemia, optimize hemostasis, minimize iatrogenic blood loss, and support a patient-centered decision to provide optimal use of allogeneic blood products. Although the World Health Organization (WHO) has already recommended patient blood management as a new standard in 2010, many hospitals have not implemented it at all or only in part in clinical practice. The German Society of Anaesthesiology and Intensive Care Medicine and the German Society of Surgery therefore demand that i) all professionals involved in the treatment should implement important aspects of patient blood management considering local conditions, and ii) the structural, administrative and budgetary conditions should be created in the health care system to implement more intensively many of the measures in Germany.

The anaerobic threshold: over-valued or under-utilized? A novel concept to enhance lipid optimization!

PubMed

Connolly, Declan A J

2012-09-01

The purpose of this article is to assess the value of the anaerobic threshold for use in clinical populations with the intent to improve exercise adaptations and outcomes. The anaerobic threshold is generally poorly understood, improperly used, and poorly measured. It is rarely used in clinical settings and often reserved for athletic performance testing. Increased exercise participation within both clinical and other less healthy populations has increased our attention to optimizing exercise outcomes. Of particular interest is the optimization of lipid metabolism during exercise in order to improve numerous conditions such as blood lipid profile, insulin sensitivity and secretion, and weight loss. Numerous authors report on the benefits of appropriate exercise intensity in optimizing outcomes even though regulation of intensity has proved difficult for many. Despite limited use, selected exercise physiology markers have considerable merit in exercise-intensity regulation. The anaerobic threshold, and other markers such as heart rate, may well provide a simple and valuable mechanism for regulating exercising intensity. The use of the anaerobic threshold and accurate target heart rate to regulate exercise intensity is a valuable approach that is under-utilized across populations. The measurement of the anaerobic threshold can be simplified to allow clients to use nonlaboratory measures, for example heart rate, in order to self-regulate exercise intensity and improve outcomes.

Electrochemical treatment of domestic wastewater using boron-doped diamond and nanostructured amorphous carbon electrodes.

PubMed

Daghrir, Rimeh; Drogui, Patrick; Tshibangu, Joel; Delegan, Nazar; El Khakani, My Ali

2014-05-01

The performance of the electrochemical oxidation process for efficient treatment of domestic wastewater loaded with organic matter was studied. The process was firstly evaluated in terms of its capability of producing an oxidant agent (H2O2) using amorphous carbon (or carbon felt) as cathode, whereas Ti/BDD electrode was used as anode. Relatively high concentrations of H2O2 (0.064 mM) was produced after 90 min of electrolysis time, at 4.0 A of current intensity and using amorphous carbon at the cathode. Factorial design and central composite design methodologies were successively used to define the optimal operating conditions to reach maximum removal of chemical oxygen demand (COD) and color. Current intensity and electrolysis time were found to influence the removal of COD and color. The contribution of current intensity on the removal of COD and color was around 59.1 and 58.8%, respectively, whereas the contribution of treatment time on the removal of COD and color was around 23.2 and 22.9%, respectively. The electrochemical treatment applied under 3.0 A of current intensity, during 120 min of electrolysis time and using Ti/BDD as anode, was found to be the optimal operating condition in terms of cost/effectiveness. Under these optimal conditions, the average removal rates of COD and color were 78.9 ± 2 and 85.5 ± 2 %, whereas 70% of total organic carbon removal was achieved.

Incorporating geometric ray tracing to generate initial conditions for intensity modulated arc therapy optimization

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

Oliver, Mike; Gladwish, Adam; Craig, Jeff

2008-07-15

Purpose and background: Intensity modulated arc therapy (IMAT) is a rotational variant of Intensity modulated radiation therapy (IMRT) that is achieved by allowing the multileaf collimator (MLC) positions to vary as the gantry rotates around the patient. This work describes a method to generate an IMAT plan through the use of a fast ray tracing technique based on dosimetric and geometric information for setting initial MLC leaf positions prior to final IMAT optimization. Methods and materials: Three steps were used to generate an IMAT plan. The first step was to generate arcs based on anatomical contours. The second step wasmore » to generate ray importance factor (RIF) maps by ray tracing the dose distribution inside the planning target volume (PTV) to modify the MLC leaf positions of the anatomical arcs to reduce the maximum dose inside the PTV. The RIF maps were also segmented to create a new set of arcs to improve the dose to low dose voxels within the PTV. In the third step, the MLC leaf positions from all arcs were put through a leaf position optimization (LPO) algorithm and brought into a fast Monte Carlo dose calculation engine for a final dose calculation. The method was applied to two phantom cases, a clinical prostate case and the Radiological Physics Center (RPC)'s head and neck phantom. The authors assessed the plan improvements achieved by each step and compared plans with and without using RIF. They also compared the IMAT plan with an IMRT plan for the RPC phantom. Results: All plans that incorporated RIF and LPO had lower objective function values than those that incorporated LPO only. The objective function value was reduced by about 15% after the generation of RIF arcs and 52% after generation of RIF arcs and leaf position optimization. The IMAT plan for the RPC phantom had similar dose coverage for PTV1 and PTV2 (the same dose volume histogram curves), however, slightly lower dose to the normal tissues compared to a six-field IMRT plan. Conclusion: The use of a ray importance factor can generate initial IMAT arcs efficiently for further MLC leaf position optimization to obtain more favorable IMAT plan.« less

Severe influenza in children: incidence and risk factors.

PubMed

Principi, Nicola; Esposito, Susanna

2016-10-01

The identification of factors that can predispose to the development of severe influenza is essential to enable the implementation of optimal prevention and control measures for vulnerable populations. Unfortunately, data in the pediatric age group remain difficult to interpret. However, epidemiological data seem to suggest that the most severe influenza cases, those who are hospitalized, those who are admitted to the intensive care unit, and those who died, occur in children in the first 2 years of life and in school age patients. Expert commentary: Immaturity of the immune system, and in particular of the mechanisms that usually recognize influenza viruses and activate cytokine and chemokine responses to reduce viral replication, might explain the high hospitalization rate observed in the youngest patients. Some underlying chronic conditions favour the development of the severe cases, sometime leading to death, although both admission to the intensive care unit and death can occur in otherwise healthy subjects.

Microwave-assisted inorganic salt pretreatment of sugarcane leaf waste: Effect on physiochemical structure and enzymatic saccharification.

PubMed

Moodley, Preshanthan; Kana, E B Gueguim

2017-07-01

This paper presents a method to pretreat sugarcane leaf waste using microwave-assisted (MA) inorganic salt to enhance enzymatic saccharification. The effects of process parameters of salt concentration, microwave power intensity and pretreatment time on reducing sugar yield from sugarcane leaf waste were investigated. Pretreatment models based on MA-NaCl, MA-ZnCl 2 and MA-FeCl 3 were developed with high coefficients of determination (R 2 >0.8) and optimized. Maximum reducing sugar yield of 0.406g/g was obtained with 2M FeCl 3 at 700W for 3.5min. Scanning electron microscopy (SEM), Fourier Transform Infrared analysis (FTIR) and X-ray diffraction (XRD) showed major changes in lignocellulosic structure after MA-FeCl 3 pretreatment with 71.5% hemicellulose solubilization. This regime was further assessed on sorghum leaves and Napier grass under optimal MA-FeCl 3 conditions. A 2-fold and 3.1-fold increase in sugar yield respectively were observed compared to previous reports. This pretreatment was highly effective for enhancing enzymatic saccharification of lignocellulosic biomass. Copyright © 2017. Published by Elsevier Ltd.

Establishing a Regional Nitrogen Management Approach to Mitigate Greenhouse Gas Emission Intensity from Intensive Smallholder Maize Production

PubMed Central

Wu, Liang; Chen, Xinping; Cui, Zhenling; Zhang, Weifeng; Zhang, Fusuo

2014-01-01

The overuse of Nitrogen (N) fertilizers on smallholder farms in rapidly developing countries has increased greenhouse gas (GHG) emissions and accelerated global N consumption over the past 20 years. In this study, a regional N management approach was developed based on the cost of the agricultural response to N application rates from 1,726 on-farm experiments to optimize N management across 12 agroecological subregions in the intensive Chinese smallholder maize belt. The grain yield and GHG emission intensity of this regional N management approach was investigated and compared to field-specific N management and farmers' practices. The regional N rate ranged from 150 to 219 kg N ha−1 for the 12 agroecological subregions. Grain yields and GHG emission intensities were consistent with this regional N management approach compared to field-specific N management, which indicated that this regional N rate was close to the economically optimal N application. This regional N management approach, if widely adopted in China, could reduce N fertilizer use by more than 1.4 MT per year, increase maize production by 31.9 MT annually, and reduce annual GHG emissions by 18.6 MT. This regional N management approach can minimize net N losses and reduce GHG emission intensity from over- and underapplications, and therefore can also be used as a reference point for regional agricultural extension employees where soil and/or plant N monitoring is lacking. PMID:24875747

Effect of various conditions on inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in fresh-cut lettuce using ultraviolet radiation.

PubMed

Kim, Yoon-Hee; Jeong, Seul-Gi; Back, Kyeong-Hwan; Park, Ki-Hwan; Chung, Myung-Sub; Kang, Dong-Hyun

2013-09-16

The effect of various conditions on inactivation of foodborne pathogens and quality of fresh-cut lettuce during ultraviolet (254 nm, UVC) radiation was investigated. Lettuce was inoculated with a cocktail of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes and treated at different temperatures (4 and 25 °C), distances between sample and lamp (10 and 50 cm), type of exposure (illuminated from one or two sides), UV intensities (1.36 to 6.80 mW/cm²), and exposure times (0.5 to 10 min), sequentially. UV treatment at 25 °C for 1 min achieved 1.45-, 1.35-, and 2.12-log reductions in surface-inoculated E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, whereas the reduction of these pathogens at 4 °C was 0.31, 0.57, and 1.16 log, respectively. UV radiation was most effective when distance from UV lamp to the sample was minimal (10 cm) and radiation area was maximal (two-sided exposure). All UV intensities significantly (P<0.05) reduced the three pathogens after 10 min exposure, but the effect of treatment was correlated with UV intensity and exposure time. Color values and texture parameters of lettuce subjected to UV treatment under the optimum conditions (25 °C, 10 cm between sample and lamp, two-sided exposure, 6.80 mW/cm²) were not significantly (P>0.05) different from those of nontreated samples up to 5 min exposure. However, these qualities significantly (P<0.05) changed at prolonged treatment time. These results suggest that UV radiation under optimized conditions could reduce foodborne pathogens without adversely affecting color quality properties of fresh-cut lettuce. © 2013 Elsevier B.V. All rights reserved.

Mounting evidence favoring single-family room neonatal intensive care.

PubMed

Stevens, D; Thompson, P; Helseth, C; Pottala, J

2015-01-01

Controversy regarding the optimal design for neonatal intensive care has existed for more than 20 years. Recent evidence confirms that in comparison with the traditional open-bay design, the single-room facility provides for improved control of excessive noise and light, improved staff and parental satisfaction with care and equal, or possibly reduced, cost of care. Single-room care was not associated with any increase in adverse outcomes. To optimize long term developmental outcomes, single-room care must be augmented with appropriate developmental therapy and programs to actively support parental involvement.

Debiasing comparative optimism and increasing worry for health outcomes.

PubMed

Rose, Jason P

2012-11-01

Comparative optimism - feeling at less personal risk for negative outcomes than one's peers - has been linked to reduced prevention efforts. This study examined a novel debiasing technique aimed at simultaneously reducing both indirectly and directly measured comparative optimism. Before providing direct comparative estimates, participants provided absolute self and peer estimates in a joint format (same computer screen) or a separate format (different computer screens). Relative to the separate format condition, participants in the joint format condition showed (1) lower comparative optimism in absolute/indirect measures, (2) lower direct comparative optimism, and (3) heightened worry. Implications for risk perception screening are discussed.

Removal of copper in leachate from mining residues using electrochemical technology.

PubMed

Lambert, Andréa; Drogui, Patrick; Daghrir, Rimeh; Zaviska, François; Benzaazoua, Mostafa

2014-01-15

This research is related to a laboratory study on the performance of a successive mining residues leaching and electrochemical copper recovery process. To clearly define the experimental region for response surface methodology (RSM), a preliminary study was performed by applying a current intensity varying from 0.5 A to 4.0 A for 60 min. By decreasing the current intensity from 4.0 A to 0.5 A, a good adhesion and a very smooth and continuous interface of copper was formed and deposited on the cathode electrode. However, the removal rate of Cu decreased from 83.7% to 37.9% when the current intensity passed from 4.0 A to 0.5 A, respectively. Subsequently, the factorial design and central composite design methodologies were successively employed to define the optimal operating conditions for copper removal in the mining residues leachate. Using a 2(3) factorial matrix, the best performance for copper removal (97.7%) was obtained at a current intensity of 2.0 A during 100 min. The current intensity and electrolysis time were found to be the most influent parameters. The contribution of current intensity and electrolysis time was around 65.8% and 33.9%, respectively. The treatment using copper electrode and current intensity of 1.3 A during 80 min was found to be the optimal conditions in terms of cost/effectiveness. Under these conditions, 86% of copper can be recovered for a total cost of 0.56 $ per cubic meter of treated mining residues leachate. Copyright © 2013 Elsevier Ltd. All rights reserved.

Field Performance versus Standard Test Condition Efficiency of Tandem Solar Cells and the Singular Case of Perovskites/Silicon Devices.

PubMed

Dupré, Olivier; Niesen, Bjoern; De Wolf, Stefaan; Ballif, Christophe

2018-01-18

Multijunction cells may offer a cost-effective route to boost the efficiency of industrial photovoltaics. For any technology to be deployed in the field, its performance under actual operating conditions is extremely important. In this perspective, we evaluate the impact of spectrum, light intensity, and module temperature variations on the efficiency of tandem devices with crystalline silicon bottom cells with a particular focus on perovskite top cells. We consider devices with different efficiencies and calculate their energy yields using field data from Denver. We find that annual losses due to differences between operating conditions and standard test conditions are similar for single-junction and four-terminal tandem devices. The additional loss for the two-terminal tandem configuration caused by current mismatch reduces its performance ratio by only 1.7% when an optimal top cell bandgap is used. Additionally, the unusual bandgap temperature dependence of perovskites is shown to have a positive, compensating effect on current mismatch.

Impact of aerobic exercise intensity on craving and reactivity to smoking cues.

PubMed

Janse Van Rensburg, Kate; Elibero, Andrea; Kilpatrick, Marcus; Drobes, David J

2013-06-01

Aerobic exercise can acutely reduce cigarette cravings during periods of nicotine deprivation. The primary aim of this study was to assess the differential effects of light and vigorous intensity aerobic exercise on cigarette cravings, subjective and physiological reactivity to smoking cues, and affect after overnight nicotine deprivation. A secondary aim was to examine cortisol change as a mediator of the effects of exercise on smoking motivation. 162 (55 female, 107 male) overnight nicotine-deprived smokers were randomized to one of three exercise conditions: light intensity, vigorous intensity, or a passive control condition. After each condition, participants engaged in a standardized cue reactivity assessment. Self-reported urges to smoke, affect, and salivary cortisol were assessed at baseline (i.e., before each condition), immediately after each condition, and after the cue reactivity assessment. Light and vigorous exercise significantly decreased urges to smoke and increased positive affect, relative to the control condition. In addition, those in the vigorous exercise condition demonstrated suppressed appetitive reactivity to smoking cues, as indexed by the startle eyeblink reflex. Although exercise intensity was associated with expected changes in cortisol concentration, these effects were not related to changes in craving or cue reactivity. Both light and vigorous exercise can reduce general cravings to smoke, whereas vigorous exercise appears especially well-suited for reducing appetitive reactions to cues that may precede smoking. Results did not support exercise-induced cortisol release as a mechanism for these effects. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Computational Process Modeling for Additive Manufacturing

NASA Technical Reports Server (NTRS)

Bagg, Stacey; Zhang, Wei

2014-01-01

Computational Process and Material Modeling of Powder Bed additive manufacturing of IN 718. Optimize material build parameters with reduced time and cost through modeling. Increase understanding of build properties. Increase reliability of builds. Decrease time to adoption of process for critical hardware. Potential to decrease post-build heat treatments. Conduct single-track and coupon builds at various build parameters. Record build parameter information and QM Meltpool data. Refine Applied Optimization powder bed AM process model using data. Report thermal modeling results. Conduct metallography of build samples. Calibrate STK models using metallography findings. Run STK models using AO thermal profiles and report STK modeling results. Validate modeling with additional build. Photodiode Intensity measurements highly linear with power input. Melt Pool Intensity highly correlated to Melt Pool Size. Melt Pool size and intensity increase with power. Applied Optimization will use data to develop powder bed additive manufacturing process model.

Temporal behavior of RHEED intensity oscillations during molecular beam epitaxial growth of GaAs and AlGaAs on (111)B GaAs substrates

NASA Astrophysics Data System (ADS)

Yen, Ming Y.; Haas, T. W.

1990-10-01

We present the temporal behavior of intensity oscillations in reflection high-energy electron diffraction (RHEED) during molecular beam epitaxial (MBE) growth of GaAs and A1GaAs on (1 1 1)B GaAs substrates. The RHEED intensity oscillations were examined as a function of growth parameters in order to provide the insight into the dynamic characteristics and to identify the optimal condition for the two-dimensional layer-by-layer growth. The most intense RHEED oscillation was found to occur within a very narrow temperature range which seems to optimize the surface migration kinetics of the arriving group III elements and the molecular dissodiative reaction of the group V elements. The appearance of an initial transient of the intensity upon commencement of the growth and its implications are described.

Multi-images deconvolution improves signal-to-noise ratio on gated stimulated emission depletion microscopy

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

Castello, Marco; DIBRIS, University of Genoa, Via Opera Pia 13, Genoa 16145; Diaspro, Alberto

2014-12-08

Time-gated detection, namely, only collecting the fluorescence photons after a time-delay from the excitation events, reduces complexity, cost, and illumination intensity of a stimulated emission depletion (STED) microscope. In the gated continuous-wave- (CW-) STED implementation, the spatial resolution improves with increased time-delay, but the signal-to-noise ratio (SNR) reduces. Thus, in sub-optimal conditions, such as a low photon-budget regime, the SNR reduction can cancel-out the expected gain in resolution. Here, we propose a method which does not discard photons, but instead collects all the photons in different time-gates and recombines them through a multi-image deconvolution. Our results, obtained on simulated andmore » experimental data, show that the SNR of the restored image improves relative to the gated image, thereby improving the effective resolution.« less

Reciprocal Space Mapping of Macromolecular Crystals in the Home Laboratory

NASA Technical Reports Server (NTRS)

Snell, Edward H.; Fewster, P. F.; Andrew, Norman; Boggon, T. J.; Judge, Russell A.; Pusey, Marc A.

1999-01-01

Reciprocal space mapping techniques are used widely by the materials science community to provide physical information about their crystal samples. We have used similar methods at synchrotron sources to look at the quality of macromolecular crystals produced both on the ground and under microgravity conditions. The limited nature of synchrotron time has led us to explore the use of a high resolution materials research diffractometer to perform similar measurements in the home laboratory. Although the available intensity is much reduced due to the beam conditioning necessary for high reciprocal space resolution, lower resolution data can be collected in the same detail as the synchrotron source. Experiments can be optimized at home to make most benefit from the synchrotron time available. Preliminary results including information on the mosaicity and the internal strains from reciprocal space maps will be presented.

Multi-objective Optimization Design of Gear Reducer Based on Adaptive Genetic Algorithms

NASA Astrophysics Data System (ADS)

Li, Rui; Chang, Tian; Wang, Jianwei; Wei, Xiaopeng; Wang, Jinming

2008-11-01

An adaptive Genetic Algorithm (GA) is introduced to solve the multi-objective optimized design of the reducer. Firstly, according to the structure, strength, etc. in a reducer, a multi-objective optimized model of the helical gear reducer is established. And then an adaptive GA based on a fuzzy controller is introduced, aiming at the characteristics of multi-objective, multi-parameter, multi-constraint conditions. Finally, a numerical example is illustrated to show the advantages of this approach and the effectiveness of an adaptive genetic algorithm used in optimized design of a reducer.

Enhanced therapeutic anti-inflammatory effect of betamethasone on topical administration with low-frequency, low-intensity (20 kHz, 100 mW/cm(2)) ultrasound exposure on carrageenan-induced arthritis in a mouse model.

PubMed

Cohen, Gadi; Natsheh, Hiba; Sunny, Youhan; Bawiec, Christopher R; Touitou, Elka; Lerman, Melissa A; Lazarovici, Philip; Lewin, Peter A

2015-09-01

The purpose of this work was to investigate whether low-frequency, low-intensity (20 kHz, <100 mW/cm(2), spatial-peak, temporal-peak intensity) ultrasound, delivered with a lightweight (<100 g), tether-free, fully wearable, battery-powered applicator, is capable of reducing inflammation in a mouse model of rheumatoid arthritis. The therapeutic, acute, anti-inflammatory effect was estimated from the relative swelling induced in mice hindlimb paws. In an independent, indirect approach, the inflammation was bio-imaged by measuring glycolytic activity with near-infrared labeled 2-deoxyglucose. The outcome of the experiments indicated that the combination of ultrasound exposure and topical application of 0.1% (w/w) betamethasone gel resulted in statistically significantly (p < 0.05) enhanced anti-inflammatory activity in comparison with drug or ultrasound treatment alone. The present study underscores the potential benefits of low-frequency, low-intensity ultrasound-assisted drug delivery. However, the proof of concept presented indicates the need for additional experiments to systematically evaluate and optimize the potential of, and the conditions for, tolerable low-frequency, low-intensity ultrasound-promoted non-invasive drug delivery. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Study on low intensity aeration oxygenation model and optimization for shallow water

NASA Astrophysics Data System (ADS)

Chen, Xiao; Ding, Zhibin; Ding, Jian; Wang, Yi

2018-02-01

Aeration/oxygenation is an effective measure to improve self-purification capacity in shallow water treatment while high energy consumption, high noise and expensive management refrain the development and the application of this process. Based on two-film theory, the theoretical model of the three-dimensional partial differential equation of aeration in shallow water is established. In order to simplify the equation, the basic assumptions of gas-liquid mass transfer in vertical direction and concentration diffusion in horizontal direction are proposed based on engineering practice and are tested by the simulation results of gas holdup which are obtained by simulating the gas-liquid two-phase flow in aeration tank under low-intensity condition. Based on the basic assumptions and the theory of shallow permeability, the model of three-dimensional partial differential equations is simplified and the calculation model of low-intensity aeration oxygenation is obtained. The model is verified through comparing the aeration experiment. Conclusions as follows: (1)The calculation model of gas-liquid mass transfer in vertical direction and concentration diffusion in horizontal direction can reflect the process of aeration well; (2) Under low-intensity conditions, the long-term aeration and oxygenation is theoretically feasible to enhance the self-purification capacity of water bodies; (3) In the case of the same total aeration intensity, the effect of multipoint distributed aeration on the diffusion of oxygen concentration in the horizontal direction is obvious; (4) In the shallow water treatment, reducing the volume of aeration equipment with the methods of miniaturization, array, low-intensity, mobilization to overcome the high energy consumption, large size, noise and other problems can provide a good reference.

Dependence of optimal initial density on laser parameters for multi-keV x-ray radiators generated by nanosecond laser-produced underdense plasma

NASA Astrophysics Data System (ADS)

Tu, Shao-yong; Yuan, Yong-teng; Hu, Guang-yue; Miao, Wen-yong; Zhao, Bin; Zheng, Jian; Jiang, Shao-en; Ding, Yong-kun

2016-01-01

Efficient multi-keV x-ray sources can be produced using nanosecond laser pulse-heated middle-Z underdense plasmas generated using gas or foam. Previous experimental results show that an optimal initial target density exists for efficient multi-keV x-ray emission at which the laser ionization wave is supersonic. Here we explore the influence of the laser intensity and the pulse duration on this optimal initial target density via a one-dimensional radiation hydrodynamic simulation. The simulation shows that the optimal initial density is sensitive to both the laser intensity and the pulse duration. However, the speed of the supersonic ionization wave at the end of the laser irradiation is always maintained at 1.5 to 1.7 times that of the ion acoustic wave under the optimal initial density conditions.

Ultrasound assisted enzyme catalyzed hydrolysis of waste cooking oil under solvent free condition.

PubMed

Waghmare, Govind V; Rathod, Virendra K

2016-09-01

The present work demonstrates the hydrolysis of waste cooking oil (WCO) under solvent free condition using commercial available immobilized lipase (Novozyme 435) under the influence of ultrasound irradiation. The process parameters were optimized using a sequence of experimental protocol to evaluate the effects of temperature, molar ratios of substrates, enzyme loading, duty cycle and ultrasound intensity. It has been observed that ultrasound-assisted lipase-catalyzed hydrolysis of WCO would be a promising alternative for conventional methods. A maximum conversion of 75.19% was obtained at mild operating parameters: molar ratio of oil to water (buffer pH 7) 3:1, catalyst loading of 1.25% (w/w), lower ultrasound power 100W (ultrasound intensity - 7356.68Wm(-2)), duty cycle 50% and temperature (50°C) in a relatively short reaction time (2h). The activation energy and thermodynamic study shows that the hydrolysis reaction is more feasible when ultrasound is combined with mechanical agitation as compared with the ultrasound alone and simple conventional stirring technique. Application of ultrasound considerably reduced the reaction time as compared to conventional reaction. The successive use of the catalyst for repetitive cycles under the optimum experimental conditions resulted in a loss of enzymatic activity and also minimized the product conversion. Copyright © 2016. Published by Elsevier B.V.

Hopelessness is associated with decreased heart rate variability during championship chess games.

PubMed

Schwarz, Alfons M; Schächinger, Hartmut; Adler, Rolf H; Goetz, Stefan M

2003-01-01

Clinical observations suggest that negative affects such as helplessness/hopelessness (HE/HO) may induce autonomic duration; affects were assessed for every move after reconstruction of the games. In all games compiled, 18 situation of intense confidence/optimism and 20 of intense helplessness/hopelessness were observed. Intense affects of HE/HO were associated with decreasing HF-HRV (Fisher exact test, p =.003), increasing "nervousness" (p =.0005), decreasing "optimism" (p =.0005), and decreasing "calmness" (p =.0005). Investigation of championship chess game players with an ELO strength > or = 2300 in a natural field setting revealed increasing HE/HO being associated with reduced HF-HRV suggestive of vagal withdrawal. Thus, our data may help link negative mood states, autonomic nervous system disturbances, and cardiac events.

Optimal Control of Malaria Transmission using Insecticide Treated Nets and Spraying

NASA Astrophysics Data System (ADS)

Athina, D.; Bakhtiar, T.; Jaharuddin

2017-03-01

In this paper, we consider a model of the transmission of malaria which was developed by Silva and Torres equipped with two control variables, namely the use of insecticide treated nets (ITN) to reduce the number of human beings infected and spraying to reduce the number of mosquitoes. Pontryagin maximum principle was applied to derive the differential equation system as optimality conditions which must be satisfied by optimal control variables. The Mangasarian sufficiency theorem shows that Pontryagin maximum principle is necessary as well as sufficient conditions for optimization problem. The 4th-order Runge Kutta method was then performed to solve the differential equations system. The numerical results show that both controls given at once can reduce the number of infected individuals as well as the number of mosquitoes which reduce the impact of malaria transmission.

Beam orientation optimization for intensity-modulated radiation therapy using mixed integer programming

NASA Astrophysics Data System (ADS)

Yang, Ruijie; Dai, Jianrong; Yang, Yong; Hu, Yimin

2006-08-01

The purpose of this study is to extend an algorithm proposed for beam orientation optimization in classical conformal radiotherapy to intensity-modulated radiation therapy (IMRT) and to evaluate the algorithm's performance in IMRT scenarios. In addition, the effect of the candidate pool of beam orientations, in terms of beam orientation resolution and starting orientation, on the optimized beam configuration, plan quality and optimization time is also explored. The algorithm is based on the technique of mixed integer linear programming in which binary and positive float variables are employed to represent candidates for beam orientation and beamlet weights in beam intensity maps. Both beam orientations and beam intensity maps are simultaneously optimized in the algorithm with a deterministic method. Several different clinical cases were used to test the algorithm and the results show that both target coverage and critical structures sparing were significantly improved for the plans with optimized beam orientations compared to those with equi-spaced beam orientations. The calculation time was less than an hour for the cases with 36 binary variables on a PC with a Pentium IV 2.66 GHz processor. It is also found that decreasing beam orientation resolution to 10° greatly reduced the size of the candidate pool of beam orientations without significant influence on the optimized beam configuration and plan quality, while selecting different starting orientations had large influence. Our study demonstrates that the algorithm can be applied to IMRT scenarios, and better beam orientation configurations can be obtained using this algorithm. Furthermore, the optimization efficiency can be greatly increased through proper selection of beam orientation resolution and starting beam orientation while guaranteeing the optimized beam configurations and plan quality.

Optimal field-splitting algorithm in intensity-modulated radiotherapy: Evaluations using head-and-neck and female pelvic IMRT cases

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

Dou, Xin; Kim, Yusung, E-mail: yusung-kim@uiowa.edu; Bayouth, John E.

2013-04-01

To develop an optimal field-splitting algorithm of minimal complexity and verify the algorithm using head-and-neck (H and N) and female pelvic intensity-modulated radiotherapy (IMRT) cases. An optimal field-splitting algorithm was developed in which a large intensity map (IM) was split into multiple sub-IMs (≥2). The algorithm reduced the total complexity by minimizing the monitor units (MU) delivered and segment number of each sub-IM. The algorithm was verified through comparison studies with the algorithm as used in a commercial treatment planning system. Seven IMRT, H and N, and female pelvic cancer cases (54 IMs) were analyzed by MU, segment numbers, andmore » dose distributions. The optimal field-splitting algorithm was found to reduce both total MU and the total number of segments. We found on average a 7.9 ± 11.8% and 9.6 ± 18.2% reduction in MU and segment numbers for H and N IMRT cases with an 11.9 ± 17.4% and 11.1 ± 13.7% reduction for female pelvic cases. The overall percent (absolute) reduction in the numbers of MU and segments were found to be on average −9.7 ± 14.6% (−15 ± 25 MU) and −10.3 ± 16.3% (−3 ± 5), respectively. In addition, all dose distributions from the optimal field-splitting method showed improved dose distributions. The optimal field-splitting algorithm shows considerable improvements in both total MU and total segment number. The algorithm is expected to be beneficial for the radiotherapy treatment of large-field IMRT.« less

[Hygienic optimization of the use of chemical protective means on railway transport].

PubMed

Kaptsov, V A; Pankova, V B; Elizarov, B B; Mezentsev, A P; Komleva, E A

2004-01-01

The paper presents data characterizing the working conditions of railway workers. It shows that there is the greatest levels of noise and vibration, the burden and intensity of work. The worst working conditions are noted in energy supply, car, locomotive services and track facilities. The working conditions determine a significant industrial risk of railway workers since the prevention of health abnormalities by using chemical protective means is a topical problem. The priority lines of hygienic rationale for optimization the choice and use of chemical protective means for workers exposed to occupational hazards are determined.

Statistical optimization of ultraviolet irradiate conditions for vitamin D₂ synthesis in oyster mushrooms (Pleurotus ostreatus) using response surface methodology.

PubMed

Wu, Wei-Jie; Ahn, Byung-Yong

2014-01-01

Response surface methodology (RSM) was used to determine the optimum vitamin D2 synthesis conditions in oyster mushrooms (Pleurotus ostreatus). Ultraviolet B (UV-B) was selected as the most efficient irradiation source for the preliminary experiment, in addition to the levels of three independent variables, which included ambient temperature (25-45°C), exposure time (40-120 min), and irradiation intensity (0.6-1.2 W/m2). The statistical analysis indicated that, for the range which was studied, irradiation intensity was the most critical factor that affected vitamin D2 synthesis in oyster mushrooms. Under optimal conditions (ambient temperature of 28.16°C, UV-B intensity of 1.14 W/m2, and exposure time of 94.28 min), the experimental vitamin D2 content of 239.67 µg/g (dry weight) was in very good agreement with the predicted value of 245.49 µg/g, which verified the practicability of this strategy. Compared to fresh mushrooms, the lyophilized mushroom powder can synthesize remarkably higher level of vitamin D2 (498.10 µg/g) within much shorter UV-B exposure time (10 min), and thus should receive attention from the food processing industry.

Optimizing Cardiovascular Benefits of Exercise: A Review of Rodent Models

PubMed Central

Davis, Brittany; Moriguchi, Takeshi; Sumpio, Bauer

2013-01-01

Although research unanimously maintains that exercise can ward off cardiovascular disease (CVD), the optimal type, duration, intensity, and combination of forms are yet not clear. In our review of existing rodent-based studies on exercise and cardiovascular health, we attempt to find the optimal forms, intensities, and durations of exercise. Using Scopus and Medline, a literature review of English language comparative journal studies of cardiovascular benefits and exercise was performed. This review examines the existing literature on rodent models of aerobic, anaerobic, and power exercise and compares the benefits of various training forms, intensities, and durations. The rodent studies reviewed in this article correlate with reports on human subjects that suggest regular aerobic exercise can improve cardiac and vascular structure and function, as well as lipid profiles, and reduce the risk of CVD. Findings demonstrate an abundance of rodent-based aerobic studies, but a lack of anaerobic and power forms of exercise, as well as comparisons of these three components of exercise. Thus, further studies must be conducted to determine a truly optimal regimen for cardiovascular health. PMID:24436579

A Fast Synthetic Aperture Radar Raw Data Simulation Using Cloud Computing.

PubMed

Li, Zhixin; Su, Dandan; Zhu, Haijiang; Li, Wei; Zhang, Fan; Li, Ruirui

2017-01-08

Synthetic Aperture Radar (SAR) raw data simulation is a fundamental problem in radar system design and imaging algorithm research. The growth of surveying swath and resolution results in a significant increase in data volume and simulation period, which can be considered to be a comprehensive data intensive and computing intensive issue. Although several high performance computing (HPC) methods have demonstrated their potential for accelerating simulation, the input/output (I/O) bottleneck of huge raw data has not been eased. In this paper, we propose a cloud computing based SAR raw data simulation algorithm, which employs the MapReduce model to accelerate the raw data computing and the Hadoop distributed file system (HDFS) for fast I/O access. The MapReduce model is designed for the irregular parallel accumulation of raw data simulation, which greatly reduces the parallel efficiency of graphics processing unit (GPU) based simulation methods. In addition, three kinds of optimization strategies are put forward from the aspects of programming model, HDFS configuration and scheduling. The experimental results show that the cloud computing based algorithm achieves 4_ speedup over the baseline serial approach in an 8-node cloud environment, and each optimization strategy can improve about 20%. This work proves that the proposed cloud algorithm is capable of solving the computing intensive and data intensive issues in SAR raw data simulation, and is easily extended to large scale computing to achieve higher acceleration.

Gold in the hills: patterns of placer gold accumulation under dynamic tectonic and climatic conditions

NASA Astrophysics Data System (ADS)

Roy, Sam; Upton, Phaedra; Craw, Dave

2018-01-01

Formation of placer accumulations in fluvial environments requires 103-106 or even greater times concentration of heavy minerals. For this to occur, regular sediment supply from erosion of adjacent topography is required, the river should remain within a single course for an extended period of time and the material must be reworked such that a high proportion of the sediment is removed while a high proportion of the heavy minerals remains. We use numerical modeling, constrained by observations of circum-Pacific placer gold deposits, to explore processes occurring in evolving river systems in dynamic tectonic environments. A fluvial erosion/transport model is used to determine the mobility of placer gold under variable uplift rate, storm intensity, and rock mass strength conditions. Gold concentration is calculated from hydraulic and bedload grain size conditions. Model results suggest that optimal gold concentration occurs in river channels that frequently approach a threshold between detachment-limited and transport-limited hydraulic conditions. Such a condition enables the accumulation of gold particles within the framework of a residual gravel lag. An increase in transport capacity, which can be triggered by faster uplift rates, more resistant bedrock, or higher intensity storm events, will strip all bedload from the channel. Conversely, a reduction in transport capacity, triggered by a reduction in uplift rate, bedrock resistance, or storm intensity, will lead to a greater accumulation of a majority of sediments and a net decrease in gold concentration. For our model parameter range, the optimal conditions for placer gold concentration are met by 103 times difference in strength between bedrock and fault, uplift rates between 1 and 5 mm a-1, and moderate storm intensities. Fault damage networks are shown to be a critical factor for high Au concentrations and should be a target for exploration.

Conditions for NIR fluorescence-guided tumor resectioning in preclinical lung cancer model (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kim, Minji; Quan, Yuhua; Choi, Byeong Hyun; Choi, Yeonho; Kim, Hyun Koo; Kim, Beop-Min

2016-03-01

Pulmonary nodule could be identified by intraoperative fluorescence imaging system from systemic injection of indocyanine green (ICG) which achieves enhanced permeability and retention (EPR) effects. This study was performed to evaluate optimal injection time of ICG for detecting cancer during surgery in rabbit lung cancer model. VX2 carcinoma cell was injected in rabbit lung under fluoroscopic computed tomography-guidance. Solitary lung cancer was confirmed on positron emitting tomography with CT (PET/CT) 2 weeks after inoculation. ICG was administered intravenously and fluorescent intensity of lung tumor was measured using the custom-built intraoperative color and fluorescence merged imaging system (ICFIS) for 15 hours. Solitary lung cancer was resected through thoracoscopic version of ICFIS. ICG was observed in all animals. Because Lung has fast blood pulmonary circulation, Fluorescent signal showed maximum intensity earlier than previous studies in other organs. Fluorescent intensity showed maximum intensity within 6-9 hours in rabbit lung cancer. Overall, Fluorescent intensity decreased with increasing time, however, all tumors were detectable using fluorescent images until 12 hours. In conclusion, while there had been studies in other organs showed that optimal injection time was at least 24 hours before operation, this study showed shorter optimal injection time at lung cancer. Since fluorescent signal showed the maximum intensity within 6-9 hours, cancer resection could be performed during this time. This data informed us that optimal injection time of ICG should be evaluated in each different solid organ tumor for fluorescent image guided surgery.

Combined oxidative leaching and electrowinning process for mercury recovery from spent fluorescent lamps.

PubMed

Ozgur, Cihan; Coskun, Sezen; Akcil, Ata; Beyhan, Mehmet; Üncü, Ismail Serkan; Civelekoglu, Gokhan

2016-11-01

In this paper, oxidative leaching and electrowinnig processes were performed to recovery of mercury from spent tubular fluorescent lamps. Hypochlorite was found to be effectively used for the leaching of mercury to the solution. Mercury could be leached with an efficiency of 96% using 0.5M/0.2M NaOCl/NaCl reagents at 50°C and pH 7.5 for 2-h. Electrowinning process was conducted on the filtered leaching solutions and over the 81% of mercury was recovered at the graphite electrode using citric acid as a reducing agent. The optimal process conditions were observed as a 6A current intensity, 30g/L of reducing agent concentration, 120min. electrolysis time and pH of 7 at the room temperature. It was found that current intensity and citric acid amount had positive effect for mercury reduction. Recovery of mercury in its elemental form was confirmed by SEM/EDX. Oxidative leaching with NaOCl/NaCl reagent was followed by electrowinning process can be effectively used for the recovery of mercury from spent fluorescent lamps. Copyright © 2016 Elsevier Ltd. All rights reserved.

Controlling Gas-Phase Reactions for Efficient Charge Reduction Electrospray Mass Spectrometry of Intact Proteins

PubMed Central

Frey, Brian L.; Lin, Yuan; Westphall, Michael S.; Smith, Lloyd M.

2006-01-01

Charge reduction electrospray mass spectrometry (CREMS) reduces the charge states of electrospray-generated ions, which concentrates the ions from a protein into fewer peaks spread over a larger m/z range, thereby increasing peak separation and decreasing spectral congestion. An optimized design for a CREMS source is described that provides an order-of-magnitude increase in sensitivity compared to previous designs and provides control over the extent of charge reduction. Either a corona discharge or an α-particle source was employed to generate anions that abstract protons from electrosprayed protein cations. These desired ion/ion proton transfer reactions predominated, but some oxidation and ion-attachment reactions also occurred leading to new peaks or mass-shifted broader peaks while decreasing signal intensity. The species producing these deleterious side-reactions were identified, and conditions were found that prevented their formation. Spectrometer m/z biases were examined because of their effect upon the signal intensity of higher m/z charge-reduced protein ions. The utility of this atmospheric pressure CREMS was demonstrated using a cell lysate fraction from E. coli. The spectral simplification afforded by CREMS reveals more proteins than are observed without charge reduction. PMID:16198118

Moderating influence of dominant attentional style and exercise intensity on responses to asynchronous music.

PubMed

Hutchinson, Jasmin C; Karageorghis, Costas I

2013-12-01

We examined independent and combined influences of asynchronous music and dominant attentional style (DAS) on psychological and psychophysical variables during exercise using mixed methods. Participants (N = 34) were grouped according to DAS and completed treadmill runs at three intensities (low, moderate, high) crossed with three music conditions (motivational, oudeterous, no-music control). State attentional focus shifted from dissociative to associative with increasing intensity and was most aligned with DAS during moderate-intensity exercise. Both music conditions facilitated dissociation at low-to-moderate intensities. At high exercise intensity, both music conditions were associated with reduced RPE among participants with an associative DAS. Dissociators reported higher RPE overall during moderate and high intensities. Psychological responses were most positive in the motivational condition, followed by oudeterous and control. Findings illustrate the relevance of individual differences in DAS as well as task intensity and duration when selecting music for exercise.

Effect of cell culture medium components on color of formulated monoclonal antibody drug substance.

PubMed

Vijayasankaran, Natarajan; Varma, Sharat; Yang, Yi; Mun, Melissa; Arevalo, Silvana; Gawlitzek, Martin; Swartz, Trevor; Lim, Amy; Li, Feng; Zhang, Boyan; Meier, Steve; Kiss, Robert

2013-01-01

As the industry moves toward subcutaneous delivery as a preferred route of drug administration, high drug substance concentrations are becoming the norm for monoclonal antibodies. At such high concentrations, the drug substance may display a more intense color than at the historically lower concentrations. The effect of process conditions and/or changes on color is more readily observed in the higher color, high concentration formulations. Since color is a product quality attribute that needs to be controlled, it is useful to study the impact of process conditions and/or modifications on color. This manuscript summarizes cell culture experiments and reports on findings regarding the effect of various media components that contribute to drug substance color for a specific monoclonal antibody. In this work, lower drug substance color was achieved via optimization of the cell culture medium. Specifically, lowering the concentrations of B-vitamins in the cell culture medium has the effect of reducing color intensity by as much as 25%. In addition, decreasing concentration of iron was also directly correlated color intensity decrease of as much as 37%. It was also shown that the color of the drug substance directly correlates with increased acidic variants, especially when increased iron levels cause increased color. Potential mechanisms that could lead to antibody coloration are briefly discussed. © 2013 American Institute of Chemical Engineers.

Microalgal cultivation in wastewater from the fermentation effluent in Riboflavin (B2) manufacturing for biodiesel production.

PubMed

Sun, Xuefei; Wang, Cunwen; Li, Zihao; Wang, Weiguo; Tong, Yanjie; Wei, Jiang

2013-09-01

In this work, the acclimation of Chlorella pyrenoidosa in diluted wastewater was studied to produce biomass and remove chemical oxygen demand (COD), ammonia-N and phosphorous. The results indicated that the optimal conditions (the volume ratio of wastewater, light intensity, culture temperature, CO2 concentration in feeding gas) which could influence the wastewater treatment efficiency were 0.05, 250 photons m(-2) s(-1), 28 °C and 5%, respectively. Under these conditions, the removal efficiency of COD reached up to 89.2%, while the total nitrogen and total phosphorous decreased by 64.52% and 82.20%, respectively. With the second treatment, COD in the wastewater was further reduced to less than 100 mg/L while it was only reduced to 542.9 mg/L after the first treatment. The treated wastewater could be discharged directly or subjected to for further treatment for recycling. In addition, 1.25 g/L of the biomass and 38.27% (dry basis, w%) of lipid content were reached after microalgal cultivation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Optimization of High Solids Dilute Acid Hydrolysis of Spent Coffee Ground at Mild Temperature for Enzymatic Saccharification and Microbial Oil Fermentation.

PubMed

Wang, Hui-Min David; Cheng, Yu-Shen; Huang, Chi-Hao; Huang, Chia-Wei

2016-10-01

Soluble coffee, being one of the world's most popular consuming drinks, produces a considerable amount of spent coffee ground (SCG) along with its production. The SCG could function as a potential lignocellulosic feedstock for production of bioproducts. The objective of this study is to investigate the possible optimal condition of dilute acid hydrolysis (DAH) at high solids and mild temperature condition to release the reducing sugars from SCG. The optimal condition was found to be 5.3 % (w/w) sulfuric acid concentration and 118 min reaction time. Under the optimal condition, the mean yield of reducing sugars from enzymatic saccharification of defatted SCG acid hydrolysate was 563 mg/g. The SCG hydrolysate was then successfully applied to culture Lipomyces starkeyi for microbial oil fermentation without showing any inhibition. The results suggested that dilute acid hydrolysis followed by enzymatic saccharification has the great potential to convert SCG carbohydrates to reducing sugars. This study is useful for the further developing of biorefinery using SCG as feedstock at a large scale.

Turbine blade tip clearance measurement using a skewed dual-beam fiber optic sensor

NASA Astrophysics Data System (ADS)

Ye, De-chao; Duan, Fa-jie; Guo, Hao-tian; Li, Yangzong; Wang, Kai

2012-08-01

Optimization and active control of the tip clearance of turbine blades has been identified as a key to improve fuel efficiency, reduce emission, and increase service life of the engine. However, reliable and real-time tip clearance measurement is difficult due to the adverse environmental conditions that are typically found in a turbine. We describe a dual-beam fiber optic measurement system that can measure the tip timing and tip clearance simultaneously. Because the tip timing information is used to calculate the tip clearance, the method is insensitive to the signal intensity variation caused by fluctuations in environmental conditions such as light source instability, contamination, and blade tip imperfection. The system was calibrated and tested using experimental rotors. The test results indicated a high resolution of 4.5 μm and measurement accuracy of ±20 μm over the rotation speed range of 2000 to 10,000 rpm.

A method to incorporate leakage and head scatter corrections into a tomotherapy inverse treatment planning algorithm

NASA Astrophysics Data System (ADS)

Holmes, Timothy W.

2001-01-01

A detailed tomotherapy inverse treatment planning method is described which incorporates leakage and head scatter corrections during each iteration of the optimization process, allowing these effects to be directly accounted for in the optimized dose distribution. It is shown that the conventional inverse planning method for optimizing incident intensity can be extended to include a `concurrent' leaf sequencing operation from which the leakage and head scatter corrections are determined. The method is demonstrated using the steepest-descent optimization technique with constant step size and a least-squared error objective. The method was implemented using the MATLAB scientific programming environment and its feasibility demonstrated for 2D test cases simulating treatment delivery using a single coplanar rotation. The results indicate that this modification does not significantly affect convergence of the intensity optimization method when exposure times of individual leaves are stratified to a large number of levels (>100) during leaf sequencing. In general, the addition of aperture dependent corrections, especially `head scatter', reduces incident fluence in local regions of the modulated fan beam, resulting in increased exposure times for individual collimator leaves. These local variations can result in 5% or greater local variation in the optimized dose distribution compared to the uncorrected case. The overall efficiency of the modified intensity optimization algorithm is comparable to that of the original unmodified case.

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

Li, Heng, E-mail: hengli@mdanderson.org; Zhu, X. Ronald; Zhang, Xiaodong

Purpose: To develop and validate a novel delivery strategy for reducing the respiratory motion–induced dose uncertainty of spot-scanning proton therapy. Methods and Materials: The spot delivery sequence was optimized to reduce dose uncertainty. The effectiveness of the delivery sequence optimization was evaluated using measurements and patient simulation. One hundred ninety-one 2-dimensional measurements using different delivery sequences of a single-layer uniform pattern were obtained with a detector array on a 1-dimensional moving platform. Intensity modulated proton therapy plans were generated for 10 lung cancer patients, and dose uncertainties for different delivery sequences were evaluated by simulation. Results: Without delivery sequence optimization,more » the maximum absolute dose error can be up to 97.2% in a single measurement, whereas the optimized delivery sequence results in a maximum absolute dose error of ≤11.8%. In patient simulation, the optimized delivery sequence reduces the mean of fractional maximum absolute dose error compared with the regular delivery sequence by 3.3% to 10.6% (32.5-68.0% relative reduction) for different patients. Conclusions: Optimizing the delivery sequence can reduce dose uncertainty due to respiratory motion in spot-scanning proton therapy, assuming the 4-dimensional CT is a true representation of the patients' breathing patterns.« less

Determination of cadmium in seawater by chelate vapor generation atomic fluorescence spectrometry

NASA Astrophysics Data System (ADS)

Sun, Rui; Ma, Guopeng; Duan, Xuchuan; Sun, Jinsheng

2018-03-01

A method for the determination of cadmium in seawater by chelate vapor generation (Che-VG) atomic fluorescence spectrometry is described. Several commercially available chelating agents, including ammonium pyrrolidine dithiocarbamate (APDC), sodium dimethyl dithiocarbamate (DMDTC), ammonium dibutyl dithiophosphate (DBDTP) and sodium O,O-diethyl dithiophosphate (DEDTP), are compared with sodium diethyldithiocarbamate (DDTC) for the Che-VG of cadmium, and results showed that DDTC and DEDTP had very good cadmium signal intensity. The effect of the conditions of Che-VG with DDTC on the intensity of cadmium signal was investigated. Under the optimal conditions, 85 ± 3% Che-VG efficiency is obtained for cadmium. The detection limit (3σ) obtained in the optimal conditions was 0.19 ng ml- 1. The relative standard deviation (RSD, %) for ten replicate determinations at 2 ng ml- 1 Cd was 3.42%. The proposed method was successfully applied to the ultratrace determination of cadmium in seawater samples by the standard addition method.

Impact of ultrasound on solid-liquid extraction of phenolic compounds from maritime pine sawdust waste. Kinetics, optimization and large scale experiments.

PubMed

Meullemiestre, A; Petitcolas, E; Maache-Rezzoug, Z; Chemat, F; Rezzoug, S A

2016-01-01

Maritime pine sawdust, a by-product from industry of wood transformation, has been investigated as a potential source of polyphenols which were extracted by ultrasound-assisted maceration (UAM). UAM was optimized for enhancing extraction efficiency of polyphenols and reducing time-consuming. In a first time, a preliminary study was carried out to optimize the solid/liquid ratio (6g of dry material per mL) and the particle size (0.26 cm(2)) by conventional maceration (CVM). Under these conditions, the optimum conditions for polyphenols extraction by UAM, obtained by response surface methodology, were 0.67 W/cm(2) for the ultrasonic intensity (UI), 40°C for the processing temperature (T) and 43 min for the sonication time (t). UAM was compared with CVM, the results showed that the quantity of polyphenols was improved by 40% (342.4 and 233.5mg of catechin equivalent per 100g of dry basis, respectively for UAM and CVM). A multistage cross-current extraction procedure allowed evaluating the real impact of UAM on the solid-liquid extraction enhancement. The potential industrialization of this procedure was implemented through a transition from a lab sonicated reactor (3 L) to a large scale one with 30 L volume. Copyright © 2015 Elsevier B.V. All rights reserved.

LED lighting – modification of growth, metabolism, yield and flour composition in wheat by spectral quality and intensity

USDA-ARS?s Scientific Manuscript database

The use of light-emitting diode (LED) technology for plant cultivation under controlled environmental conditions can result in significant reductions in energy consumption. However, there is still a lack of detailed information on the lighting conditions required for optimal growth of different plan...

Extraction of bioactives from Orthosiphon stamineus using microwave and ultrasound-assisted techniques: Process optimization and scale up.

PubMed

Chan, Chung-Hung; See, Tiam-You; Yusoff, Rozita; Ngoh, Gek-Cheng; Kow, Kien-Woh

2017-04-15

This work demonstrated the optimization and scale up of microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE) of bioactive compounds from Orthosiphon stamineus using energy-based parameters such as absorbed power density and absorbed energy density (APD-AED) and response surface methodology (RSM). The intensive optimum conditions of MAE obtained at 80% EtOH, 50mL/g, APD of 0.35W/mL, AED of 250J/mL can be used to determine the optimum conditions of the scale-dependent parameters i.e. microwave power and treatment time at various extraction scales (100-300mL solvent loading). The yields of the up scaled conditions were consistent with less than 8% discrepancy and they were about 91-98% of the Soxhlet extraction yield. By adapting APD-AED method in the case of UAE, the intensive optimum conditions of the extraction, i.e. 70% EtOH, 30mL/g, APD of 0.22W/mL, AED of 450J/mL are able to achieve similar scale up results. Copyright © 2016 Elsevier Ltd. All rights reserved.

Umbilical Cord Blood Transplantation Corrects Very Early-Onset Inflammatory Bowel Disease in Chinese Patients With IL10RA-Associated Immune Deficiency.

PubMed

Peng, Kaiyue; Qian, Xiaowen; Huang, Zhiheng; Lu, Junping; Wang, Yuhuan; Zhou, Ying; Wang, Huijun; Wu, Bingbing; Wang, Ying; Chen, Lingli; Zhai, Xiaowen; Huang, Ying

2018-05-18

Hematopoietic stem cell transplantation is considered the only curative therapy for very early-onset inflammatory bowel disease with specific immune defects, such as interleukin-10 receptor deficiency. We performed reduced-intensity conditioning before umbilical cord blood transplantation in patients with interleukin-10 receptor-A deficiency. We enrolled 9 very early-onset inflammatory bowel disease patients with typical manifestations. We diagnosed the patients with interleukin-10 receptor-A deficiency by whole-exome sequencing. Umbilical cord blood transplantation was performed in all 9 patients. Eight patients received the reduced-intensity conditioning regimen, and 1 patient received the myeloablative conditioning regimen. All 9 patients received transplantation between the ages of 6 months to 43 months (average, 16.8 months) with body weights ranging from 3 to 10.4 kg (average, 6.6 kg). The patients displayed complete chimerism at 2-8 weeks after transplantation; 6 patients achieved complete remission without evidence of graft-vs-host disease or infections; 1 patient died of chronic lung graft-vs-host disease at 6 months post-transplantation; and the other 2 patients died of sepsis post-transplantation because of unsuccessful engraftments. Severe malnutrition and growth retardation associated with interleukin-10 receptor-A deficiency were significantly improved post-transplantation. We recommend umbilical cord blood transplantation as a potential treatment for very early-onset inflammatory bowel disease with a defined monogenic immunodeficiency, and we suggest that reduced-intensity conditioning chemotherapy is more suitable than myeloablative conditioning for patients with severe malnutrition and bowel disease. We have demonstrated success with reduced-intensity conditioning for interleukin-10 receptor-A deficiency in pediatric patients with severe clinical conditions. 10.1093/ibd/izy028_video1izy028.video15786489183001.

Clinical impact of NK-cell reconstitution after reduced intensity conditioned unrelated cord blood transplantation in patients with acute myeloid leukemia: analysis of a prospective phase II multicenter trial on behalf of the Société Française de Greffe de Moelle Osseuse et Thérapie Cellulaire and Eurocord.

PubMed

Nguyen, S; Achour, A; Souchet, L; Vigouroux, S; Chevallier, P; Furst, S; Sirvent, A; Bay, J-O; Socié, G; Ceballos, P; Huynh, A; Cornillon, J; Francois, S; Legrand, F; Yakoub-Agha, I; Michel, G; Maillard, N; Margueritte, G; Maury, S; Uzunov, M; Bulabois, C-E; Michallet, M; Clement, L; Dauriac, C; Bilger, K; Lejeune, J; Béziat, V; Rocha, V; Rio, B; Chevret, S; Vieillard, V

2017-10-01

Unrelated cord blood transplantation (UCBT) after a reduced intensity conditioning regimen (RIC) has extended the use of UCB in elderly patients and those with co-morbidities without an HLA-identical donor, although post-transplant relapse remains a concern in high-risk acute myeloid leukemia (AML) patients. HLA incompatibilities between donor and recipient might enhance the alloreactivity of natural killer (NK) cells after allogeneic hematopoietic stem-cell transplantation (HSCT). We studied the reconstitution of NK cells and KIR-L mismatch in 54 patients who underwent a RIC-UCBT for AML in CR in a prospective phase II clinical trial. After RIC-UCBT, NK cells displayed phenotypic features of both activation and immaturity. Restoration of their polyfunctional capacities depended on the timing of their acquisition of phenotypic markers of maturity. The incidence of treatment-related mortality (TRM) was correlated with low CD16 expression (P=0.043) and high HLA-DR expression (P=0.0008), whereas overall survival was associated with increased frequency of NK-cell degranulation (P=0.001). These features reflect a general impairment of the NK licensing process in HLA-mismatched HSCT and may aid the development of future strategies for selecting optimal UCB units and enhancing immune recovery.

Using an artificial neural network to predict the optimal conditions for enzymatic hydrolysis of apple pomace.

PubMed

Gama, Repson; Van Dyk, J Susan; Burton, Mike H; Pletschke, Brett I

2017-06-01

The enzymatic degradation of lignocellulosic biomass such as apple pomace is a complex process influenced by a number of hydrolysis conditions. Predicting optimal conditions, including enzyme and substrate concentration, temperature and pH can improve conversion efficiency. In this study, the production of sugar monomers from apple pomace using commercial enzyme preparations, Celluclast 1.5L, Viscozyme L and Novozyme 188 was investigated. A limited number of experiments were carried out and then analysed using an artificial neural network (ANN) to model the enzymatic hydrolysis process. The ANN was used to simulate the enzymatic hydrolysis process for a range of input variables and the optimal conditions were successfully selected as was indicated by the R 2 value of 0.99 and a small MSE value. The inputs for the ANN were substrate loading, enzyme loading, temperature, initial pH and a combination of these parameters, while release profiles of glucose and reducing sugars were the outputs. Enzyme loadings of 0.5 and 0.2 mg/g substrate and a substrate loading of 30% were optimal for glucose and reducing sugar release from apple pomace, respectively, resulting in concentrations of 6.5 g/L glucose and 28.9 g/L reducing sugars. Apple pomace hydrolysis can be successfully carried out based on the predicted optimal conditions from the ANN.

Algorithms and analyses for stochastic optimization for turbofan noise reduction using parallel reduced-order modeling

NASA Astrophysics Data System (ADS)

Yang, Huanhuan; Gunzburger, Max

2017-06-01

Simulation-based optimization of acoustic liner design in a turbofan engine nacelle for noise reduction purposes can dramatically reduce the cost and time needed for experimental designs. Because uncertainties are inevitable in the design process, a stochastic optimization algorithm is posed based on the conditional value-at-risk measure so that an ideal acoustic liner impedance is determined that is robust in the presence of uncertainties. A parallel reduced-order modeling framework is developed that dramatically improves the computational efficiency of the stochastic optimization solver for a realistic nacelle geometry. The reduced stochastic optimization solver takes less than 500 seconds to execute. In addition, well-posedness and finite element error analyses of the state system and optimization problem are provided.

Optimizing Interactive Development of Data-Intensive Applications

PubMed Central

Interlandi, Matteo; Tetali, Sai Deep; Gulzar, Muhammad Ali; Noor, Joseph; Condie, Tyson; Kim, Miryung; Millstein, Todd

2017-01-01

Modern Data-Intensive Scalable Computing (DISC) systems are designed to process data through batch jobs that execute programs (e.g., queries) compiled from a high-level language. These programs are often developed interactively by posing ad-hoc queries over the base data until a desired result is generated. We observe that there can be significant overlap in the structure of these queries used to derive the final program. Yet, each successive execution of a slightly modified query is performed anew, which can significantly increase the development cycle. Vega is an Apache Spark framework that we have implemented for optimizing a series of similar Spark programs, likely originating from a development or exploratory data analysis session. Spark developers (e.g., data scientists) can leverage Vega to significantly reduce the amount of time it takes to re-execute a modified Spark program, reducing the overall time to market for their Big Data applications. PMID:28405637

Optimizing the 391-nm lasing intensity from ionized nitrogen molecules in 800-nm femtosecond laser fields

NASA Astrophysics Data System (ADS)

Zhong, Xunqi; Miao, Zhiming; Zhang, Linlin; Jiang, Hongbing; Liu, Yunquan; Gong, Qihuang; Wu, Chengyin

2018-03-01

We investigate the 391-nm lasing dynamics from ionized nitrogen molecules in 800-nm femtosecond laser fields. By comparing the radiation intensity, spectrum shape, and temporal profile of the 391-nm lasing at various experimental conditions, we conclude that the lasing dynamics contains not only the generation and the decay of ionized nitrogen molecules, but also the seed-built coherence among emitters as well as the propagation effect in the plasma filamentation. These results provide reliable guidance for optimizing the 391-nm lasing from ionized nitrogen molecules in 800-nm femtosecond laser fields, which have potential applications for remote sensing in the atmosphere.

Control strategies for wind farm power optimization: LES study

NASA Astrophysics Data System (ADS)

Ciri, Umberto; Rotea, Mario; Leonardi, Stefano

2017-11-01

Turbines in wind farms operate in off-design conditions as wake interactions occur for particular wind directions. Advanced wind farm control strategies aim at coordinating and adjusting turbine operations to mitigate power losses in such conditions. Coordination is achieved by controlling on upstream turbines either the wake intensity, through the blade pitch angle or the generator torque, or the wake direction, through yaw misalignment. Downstream turbines can be adapted to work in waked conditions and limit power losses, using the blade pitch angle or the generator torque. As wind conditions in wind farm operations may change significantly, it is difficult to determine and parameterize the variations of the coordinated optimal settings. An alternative is model-free control and optimization of wind farms, which does not require any parameterization and can track the optimal settings as conditions vary. In this work, we employ a model-free optimization algorithm, extremum-seeking control, to find the optimal set-points of generator torque, blade pitch and yaw angle for a three-turbine configuration. Large-Eddy Simulations are used to provide a virtual environment to evaluate the performance of the control strategies under realistic, unsteady incoming wind. This work was supported by the National Science Foundation, Grants No. 1243482 (the WINDINSPIRE project) and IIP 1362033 (I/UCRC WindSTAR). TACC is acknowledged for providing computational time.

Sun/shade conditions affect recruitment and local adaptation of a columnar cactus in dry forests.

PubMed

Miranda-Jácome, Antonio; Montaña, Carlos; Fornoni, Juan

2013-02-01

Facilitation among plants in water-limited environments (i.e. where evapotranspiration overcomes the availability of water during the growing season) has been considered a local adaptation to water and light conditions. Among cacti, early life-history stages can benefit from the facilitative effects of nurse plants that reduce solar radiation and water stress. However, whether light condition itself acts as an agent of selection through facilitation remains untested. The aim of this study was to determine (1) whether light conditions affect seedling recruitment, (2) whether the positive effect of shade on seedling recruitment is more intense under more stressful conditions and (3) whether shade condition (facilitation) reduces the magnitude of local adaptation on seedling recruitment relative to full sunlight conditions. A reciprocal transplant experiment, coupled with the artificial manipulation of sun/shade conditions, was performed to test for the effects of local adaptation on germination, seedling survival and growth, using two demes of the columnar cactus Pilosocereus leucocephalus, representing different intensities of stressful conditions. Full sunlight conditions reduced recruitment success and supported the expectation of lower recruitment in more stressful environments. Significant local adaptation was mainly detected under full sunlight conditions, indicating that this environmental factor acts as an agent of selection at both sites. The results supported the expectation that the magnitude of local adaptation, driven by the effects of facilitative nurse plants, is less intense under reduced stressful conditions. This study is the first to demonstrate that sun/shade conditions act as a selective agent accounting for local adaptation in water-limited environments, and that facilitation provided by nurse plants in these environments can attenuate the patterns of local adaptation among plants benefiting from the nurse effect.

Sun/shade conditions affect recruitment and local adaptation of a columnar cactus in dry forests

PubMed Central

Miranda-Jácome, Antonio; Montaña, Carlos; Fornoni, Juan

2013-01-01

Background and Aims Facilitation among plants in water-limited environments (i.e. where evapotranspiration overcomes the availability of water during the growing season) has been considered a local adaptation to water and light conditions. Among cacti, early life-history stages can benefit from the facilitative effects of nurse plants that reduce solar radiation and water stress. However, whether light condition itself acts as an agent of selection through facilitation remains untested. The aim of this study was to determine (1) whether light conditions affect seedling recruitment, (2) whether the positive effect of shade on seedling recruitment is more intense under more stressful conditions and (3) whether shade condition (facilitation) reduces the magnitude of local adaptation on seedling recruitment relative to full sunlight conditions. Methods A reciprocal transplant experiment, coupled with the artificial manipulation of sun/shade conditions, was performed to test for the effects of local adaptation on germination, seedling survival and growth, using two demes of the columnar cactus Pilosocereus leucocephalus, representing different intensities of stressful conditions. Key Results Full sunlight conditions reduced recruitment success and supported the expectation of lower recruitment in more stressful environments. Significant local adaptation was mainly detected under full sunlight conditions, indicating that this environmental factor acts as an agent of selection at both sites. Conclusions The results supported the expectation that the magnitude of local adaptation, driven by the effects of facilitative nurse plants, is less intense under reduced stressful conditions. This study is the first to demonstrate that sun/shade conditions act as a selective agent accounting for local adaptation in water-limited environments, and that facilitation provided by nurse plants in these environments can attenuate the patterns of local adaptation among plants benefiting from the nurse effect. PMID:23223204

Betacaryophyllene - A phytocannabinoid as potential therapeutic modality for human sepsis?

PubMed

Meza, Angel; Lehmann, Christian

2018-01-01

Sepsis is a clinical condition resulting from a dysregulated immune response to an infection that leads to organ dysfunction. Despite numerous efforts to optimize treatment, sepsis remains to be the main cause of death in most intensive care units. The endogenous cannabinoid system (ECS) plays an important role in inflammation. Cannabinoid receptor 2 (CB2R) activation is immunosuppressive, which might be beneficial during the hyper-inflammatory phase of sepsis. Beta-caryophyllene (BCP) is a non-psychoactive natural cannabinoid (phytocannabinoid) found in Cannabis sativa and in essential oils of spices and food plants, that acts as a selective agonist of CB2R. We propose BCP administration as novel treatment to reduce hyper-inflammation in human sepsis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimized extraction of polysaccharides from corn silk by pulsed electric field and response surface quadratic design.

PubMed

Zhao, Wenzhu; Yu, Zhipeng; Liu, Jingbo; Yu, Yiding; Yin, Yongguang; Lin, Songyi; Chen, Feng

2011-09-01

Corn silk is a traditional Chinese herbal medicine, which has been widely used for treatment of some diseases. In this study the effects of pulsed electric field on the extraction of polysaccharides from corn silk were investigated. Polysaccharides in corn silk were extracted by pulsed electric field and optimized by response surface methodology (RSM), based on a Box-Behnken design (BBD). Three independent variables, including electric field intensity (kV cm(-1) ), ratio of liquid to raw material and pulse duration (µs), were investigated. The experimental data were fitted to a second-order polynomial equation and also profiled into the corresponding 3-D contour plots. Optimal extraction conditions were as follows: electric field intensity 30 kV cm(-1) , ratio of liquid to raw material 50, and pulse duration 6 µs. Under these condition, the experimental yield of extracted polysaccharides was 7.31% ± 0.15%, matching well with the predicted value. The results showed that a pulsed electric field could be applied to extract value-added products from foods and/or agricultural matrix. Copyright © 2011 Society of Chemical Industry.

Effect of pulsed electric fields on the activity of neutral trehalase from beer yeast and RSM analysis.

PubMed

Ye, Haiqing; Jin, Yan; Lin, Songyi; Liu, Mingyuan; Yang, Yi; Zhang, Meishuo; Zhao, Ping; Jones, Gregory

2012-06-01

The trehalase activity plays an important role in extraction of trehalose from beer yeast. In this study, the effect of pulsed electric field processing on neutral trehalase activity in beer yeast was investigated. In order to develop and optimize a pulsed electric field (PEF) mathematical model for activating the neutral trehalase, we have investigated three variables, including electric field intensity (10-50 kV/cm), pulse duration (2-10 μs) and liquid-solid ratio (20-50 ml/g) and subsequently optimized them by response surface methodology (RSM). The experimental data were fitted to a second-order polynomial equation and profiled into the corresponding contour plots. Optimal condition obtained by RSM is as follows: electric field intensity 42.13 kV/cm, liquid-solid ratio 30.12 ml/g and pulse duration 5.46 μs. Under these conditions, with the trehalose decreased 8.879 mg/L, the PEF treatment had great effect on activating neutral trehalase in beer yeast cells. Copyright © 2012 Elsevier B.V. All rights reserved.

A Fast Synthetic Aperture Radar Raw Data Simulation Using Cloud Computing

PubMed Central

Li, Zhixin; Su, Dandan; Zhu, Haijiang; Li, Wei; Zhang, Fan; Li, Ruirui

2017-01-01

Synthetic Aperture Radar (SAR) raw data simulation is a fundamental problem in radar system design and imaging algorithm research. The growth of surveying swath and resolution results in a significant increase in data volume and simulation period, which can be considered to be a comprehensive data intensive and computing intensive issue. Although several high performance computing (HPC) methods have demonstrated their potential for accelerating simulation, the input/output (I/O) bottleneck of huge raw data has not been eased. In this paper, we propose a cloud computing based SAR raw data simulation algorithm, which employs the MapReduce model to accelerate the raw data computing and the Hadoop distributed file system (HDFS) for fast I/O access. The MapReduce model is designed for the irregular parallel accumulation of raw data simulation, which greatly reduces the parallel efficiency of graphics processing unit (GPU) based simulation methods. In addition, three kinds of optimization strategies are put forward from the aspects of programming model, HDFS configuration and scheduling. The experimental results show that the cloud computing based algorithm achieves 4× speedup over the baseline serial approach in an 8-node cloud environment, and each optimization strategy can improve about 20%. This work proves that the proposed cloud algorithm is capable of solving the computing intensive and data intensive issues in SAR raw data simulation, and is easily extended to large scale computing to achieve higher acceleration. PMID:28075343

Optimizing a positive psychology intervention to promote health behaviors following an acute coronary syndrome: The Positive Emotions after Acute Coronary Events-III (PEACE-III) randomized factorial trial.

PubMed

Celano, Christopher M; Albanese, Ariana M; Millstein, Rachel A; Mastromauro, Carol A; Chung, Wei-Jean; Campbell, Kirsti A; Legler, Sean R; Park, Elyse R; Healy, Brian C; Collins, Linda M; Januzzi, James L; Huffman, Jeff C

2018-04-05

Despite the clear benefits of physical activity and related behaviors on prognosis, most patients suffering an acute coronary syndrome (ACS) remain nonadherent to these behaviors. Deficits in positive psychological constructs (e.g., optimism) are linked to reduced participation in health behaviors, supporting the potential utility of a positive psychology (PP)-based intervention in post-ACS patients. Accordingly, we aimed to identify optimal components of a PP-based intervention to promote post-ACS physical activity. As part of a multiphase optimization strategy, we completed a randomized factorial trial with eight conditions in 128 post-ACS patients to efficiently identify best-performing intervention components. All participants received a PP-based intervention, with conditions varying in duration (presence/absence of booster sessions), intensity (weekly/daily PP exercises), and content (PP alone or combined with motivational interviewing [MI]), allowing three concurrent comparisons within the trial. Study aims included assessments of the overall feasibility, acceptability, and impact of the intervention, along with the primary aim of determining which components were associated with objectively-measured physical activity and self-reported health behavior adherence at 16 weeks, assessed using longitudinal models. The intervention was well-accepted and associated with substantial improvements in behavioral and psychological outcomes. Booster sessions were associated with greater activity to a nearly significant degree (β=8.58, 95% confidence interval= -0.49-17.65, effect size difference=.43; p=.064), MI was associated with overall adherence (β=0.95, 95% confidence interval=0.02-1.87, effect size difference=.39; p=.044), and weekly exercise completion was generally superior to daily. These findings will enable optimization of the PP-based intervention in preparation for a well-powered controlled trial. ClinicalTrials.gov identifier: NCT02754895.

A case series of CAEBV of children and young adults treated with reduced-intensity conditioning and allogeneic bone marrow transplantation: a single-center study.

PubMed

Watanabe, Yuko; Sasahara, Yoji; Satoh, Miki; Looi, Chung Yeng; Katayama, Saori; Suzuki, Tasuku; Suzuki, Nobu; Ouchi, Meri; Horino, Satoshi; Moriya, Kunihiko; Nanjyo, Yuka; Onuma, Masaei; Kitazawa, Hiroshi; Irie, Masahiro; Niizuma, Hidetaka; Uchiyama, Toru; Rikiishi, Takeshi; Kumaki, Satoru; Minegishi, Masayoshi; Wada, Taizo; Yachie, Akihiro; Tsuchiya, Shigeru; Kure, Shigeo

2013-09-01

Epstein-Barr virus (EBV)-infected T or NK cells cause chronic active EBV infection (CAEBV). Allogeneic hematopoietic stem cell transplantation (HSCT) is curative treatment for CAEBV patients. However, chemotherapy prior to HSCT and optimal conditioning regimen for allogeneic HSCT are still controversial. We retrospectively analyzed five patients with CAEBV treated with reduced-intensity conditioning (RIC) consisted of fludarabine, cyclophosphamide, and low-dose total-body irradiation followed by allogeneic bone marrow transplantation in a single institute. Only one of five patients received chemotherapy prior to transplantation. We analyzed EBV-infected cells in a patient whose EBV load increased after HSCT by T-cell repertoire assay, separation of T-cell subpopulations, in situ hybridization and microsatellite analysis. All five patients achieved engraftment, complete chimera, and eradication of EBV load. All patients have been alive without any serious regimen-related toxicity for more than 16 months following HSCT. However, one patient transplanted from HLA-matched sibling donor developed clonal proliferation of CD4+ Vβ3+ T cells caused by monoclonal EBV infection on day 99 after transplantation. Further analysis revealed that the CD4+ Vβ3+ T cells selectively harbored EBV genome, and these infected cells were derived from donor T cells. Allogeneic HSCT with RIC is a safe and effective treatment for better overall survival and less regimen-related toxicity in patients with CAEBV. Our first pediatric case reported in the literature suggests that we should consider the possibility of persistent EBV infection in donor T cells as well as the relapse in recipient cells if EBV load increases after allogeneic HSCT. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Reduced Order Adaptive Controllers for Distributed Parameter Systems

DTIC Science & Technology

2005-09-01

pitch moment [J313. Neural Network adaptive output feedback control for intensive care unit sedation and intraop- erative anesthesia . Neural network...depth of anesthesia for noncardiac surgery [C3, J15]. These results present an extension of [C8, J9, J10]. Modelling and vibration control of...for Intensive Care Unit Sedation and Operating Room Hypnosis , Submitted to 6 Special Issue of SIAM Journal of Control and Optimization on Control

Speed and convergence properties of gradient algorithms for optimization of IMRT.

PubMed

Zhang, Xiaodong; Liu, Helen; Wang, Xiaochun; Dong, Lei; Wu, Qiuwen; Mohan, Radhe

2004-05-01

Gradient algorithms are the most commonly employed search methods in the routine optimization of IMRT plans. It is well known that local minima can exist for dose-volume-based and biology-based objective functions. The purpose of this paper is to compare the relative speed of different gradient algorithms, to investigate the strategies for accelerating the optimization process, to assess the validity of these strategies, and to study the convergence properties of these algorithms for dose-volume and biological objective functions. With these aims in mind, we implemented Newton's, conjugate gradient (CG), and the steepest decent (SD) algorithms for dose-volume- and EUD-based objective functions. Our implementation of Newton's algorithm approximates the second derivative matrix (Hessian) by its diagonal. The standard SD algorithm and the CG algorithm with "line minimization" were also implemented. In addition, we investigated the use of a variation of the CG algorithm, called the "scaled conjugate gradient" (SCG) algorithm. To accelerate the optimization process, we investigated the validity of the use of a "hybrid optimization" strategy, in which approximations to calculated dose distributions are used during most of the iterations. Published studies have indicated that getting trapped in local minima is not a significant problem. To investigate this issue further, we first obtained, by trial and error, and starting with uniform intensity distributions, the parameters of the dose-volume- or EUD-based objective functions which produced IMRT plans that satisfied the clinical requirements. Using the resulting optimized intensity distributions as the initial guess, we investigated the possibility of getting trapped in a local minimum. For most of the results presented, we used a lung cancer case. To illustrate the generality of our methods, the results for a prostate case are also presented. For both dose-volume and EUD based objective functions, Newton's method far outperforms other algorithms in terms of speed. The SCG algorithm, which avoids expensive "line minimization," can speed up the standard CG algorithm by at least a factor of 2. For the same initial conditions, all algorithms converge essentially to the same plan. However, we demonstrate that for any of the algorithms studied, starting with previously optimized intensity distributions as the initial guess but for different objective function parameters, the solution frequently gets trapped in local minima. We found that the initial intensity distribution obtained from IMRT optimization utilizing objective function parameters, which favor a specific anatomic structure, would lead to a local minimum corresponding to that structure. Our results indicate that from among the gradient algorithms tested, Newton's method appears to be the fastest by far. Different gradient algorithms have the same convergence properties for dose-volume- and EUD-based objective functions. The hybrid dose calculation strategy is valid and can significantly accelerate the optimization process. The degree of acceleration achieved depends on the type of optimization problem being addressed (e.g., IMRT optimization, intensity modulated beam configuration optimization, or objective function parameter optimization). Under special conditions, gradient algorithms will get trapped in local minima, and reoptimization, starting with the results of previous optimization, will lead to solutions that are generally not significantly different from the local minimum.

Improving multi-objective reservoir operation optimization with sensitivity-informed dimension reduction

NASA Astrophysics Data System (ADS)

Chu, J.; Zhang, C.; Fu, G.; Li, Y.; Zhou, H.

2015-08-01

This study investigates the effectiveness of a sensitivity-informed method for multi-objective operation of reservoir systems, which uses global sensitivity analysis as a screening tool to reduce computational demands. Sobol's method is used to screen insensitive decision variables and guide the formulation of the optimization problems with a significantly reduced number of decision variables. This sensitivity-informed method dramatically reduces the computational demands required for attaining high-quality approximations of optimal trade-off relationships between conflicting design objectives. The search results obtained from the reduced complexity multi-objective reservoir operation problems are then used to pre-condition the full search of the original optimization problem. In two case studies, the Dahuofang reservoir and the inter-basin multi-reservoir system in Liaoning province, China, sensitivity analysis results show that reservoir performance is strongly controlled by a small proportion of decision variables. Sensitivity-informed dimension reduction and pre-conditioning are evaluated in their ability to improve the efficiency and effectiveness of multi-objective evolutionary optimization. Overall, this study illustrates the efficiency and effectiveness of the sensitivity-informed method and the use of global sensitivity analysis to inform dimension reduction of optimization problems when solving complex multi-objective reservoir operation problems.

Derivative-free generation and interpolation of convex Pareto optimal IMRT plans

NASA Astrophysics Data System (ADS)

Hoffmann, Aswin L.; Siem, Alex Y. D.; den Hertog, Dick; Kaanders, Johannes H. A. M.; Huizenga, Henk

2006-12-01

In inverse treatment planning for intensity-modulated radiation therapy (IMRT), beamlet intensity levels in fluence maps of high-energy photon beams are optimized. Treatment plan evaluation criteria are used as objective functions to steer the optimization process. Fluence map optimization can be considered a multi-objective optimization problem, for which a set of Pareto optimal solutions exists: the Pareto efficient frontier (PEF). In this paper, a constrained optimization method is pursued to iteratively estimate the PEF up to some predefined error. We use the property that the PEF is convex for a convex optimization problem to construct piecewise-linear upper and lower bounds to approximate the PEF from a small initial set of Pareto optimal plans. A derivative-free Sandwich algorithm is presented in which these bounds are used with three strategies to determine the location of the next Pareto optimal solution such that the uncertainty in the estimated PEF is maximally reduced. We show that an intelligent initial solution for a new Pareto optimal plan can be obtained by interpolation of fluence maps from neighbouring Pareto optimal plans. The method has been applied to a simplified clinical test case using two convex objective functions to map the trade-off between tumour dose heterogeneity and critical organ sparing. All three strategies produce representative estimates of the PEF. The new algorithm is particularly suitable for dynamic generation of Pareto optimal plans in interactive treatment planning.

Signal-to-noise enhancement techniques for quantum cascade absorption spectrometers employing optimal filtering and other approaches

NASA Astrophysics Data System (ADS)

Disselkamp, R. S.; Kelly, J. F.; Sams, R. L.; Anderson, G. A.

Optical feedback to the laser source in tunable diode laser spectroscopy (TDLS) is known to create intensity modulation noise due to elatoning and optical feedback (i.e. multiplicative technical noise) that usually limits spectral signal-to-noise (S/N). The large technical noise often limits absorption spectroscopy to noise floors 100-fold greater than the Poisson shot noise limit due to fluctuations in the laser intensity. The high output powers generated from quantum cascade (QC) lasers, along with their high gain, makes these injection laser systems especially susceptible to technical noise. In this article we discuss a method of using optimal filtering to reduce technical noise. We have observed S/N enhancements ranging from 20% to a factor of 50. The degree to which optimal filtering enhances S/N depends on the similarity between the Fourier components of the technical noise and those of the signal, with lower S/N enhancements observed for more similar Fourier decompositions of the signal and technical noise. We also examine the linearity of optimal filtered spectra in both time and intensity. This was accomplished by creating a synthetic spectrum for the species being studied (CH4, N2O, CO2 and H2O in ambient air) utilizing line positions and linewidths with an assumed Voigt profile from a commercial database (HITRAN). Agreement better than 0.036% in wavenumber and 1.64% in intensity (up to a 260-fold intensity ratio employed) was observed. Our results suggest that rapid ex post facto digital optimal filtering can be used to enhance S/N for routine trace gas detection.

Biventricular pacemaker optimization guided by comprehensive echocardiography-preliminary observations regarding the effects on systolic and diastolic ventricular function and third heart sound.

PubMed

Taha, Nima; Zhang, Jing; Ranjan, Rupesh; Daneshvar, Samuel; Castillo, Edilzar; Guillen, Elizabeth; Montoya, Martha C; Velasquez, Giovanna; Naqvi, Tasneem Z

2010-08-01

Doppler echocardiography of mitral inflow or aortic outflow or both has been validated and advocated to guide biventricular (Biv) pacemaker optimization. A comprehensive and tailored Doppler echocardiographic evaluation may be required in patients with heart failure to assist with Biv pacemaker optimization. The third heart sound (S(3)), an acoustic cardiographic parameter, has been demonstrated to be a highly specific finding for hemodynamic evaluation in patients with heart failure. The aims of this study were to evaluate the use of comprehensive Doppler echocardiography as a guide during Biv pacemaker optimization in patients after cardiac resynchronization therapy and to evaluate the feasibility of S(3) intensity to be a cost-efficient parameter for Biv pacemaker optimization compared with Doppler echocardiography. Comprehensive Doppler echocardiographic evaluations were performed during Biv pacemaker optimization in 44 patients referred for pacemaker optimization (mean age, 71 + or - 12 years; mean left ventricular ejection fraction, 34 + or - 11%). Blinded assessment of S(3) intensity was performed simultaneously using acoustic cardiography. The correlation and improvement in cardiac hemodynamics were analyzed between the methods. Echocardiographically guided optimization resulted in significant improvements in the left ventricular outflow velocity-time integral (15.92 + or - 4.77 to 18.51 + or - 5.19 cm, P < .001), ejection time (278 + or - 40 to 293 + or - 40 ms, P < .001), myocardial performance index (0.57 + or - 0.19 to 0.44 + or - 0.14, P < .002), and peak pulmonary artery systolic pressure (42 + or - 13 to 36 + or - 11 mm Hg, P < .04) and decreased S(3) intensity from 4.81 + or - 1.84 at baseline to 3.96 + or - 1.22 after optimization (P < .02) for the overall study group and from 6.63 + or - 1.37 to 4.85 + or - 1.13 (P < .001) in the 18 patients with baseline S(3) intensity > 5.0. The correlation between echocardiographic and acoustic cardiographic S(3) intensity for optimal atrioventricular delay was 0.86 (P < .001) and for optimal interventricular delay was 0.64 (P < .001). Optimal atrioventricular delay was identical by echocardiographic and acoustic cardiographic S(3) intensity in 56%, and optimal interventricular delay was identical in 75% of patients. Pacemakers were permanently programmed on the basis of echocardiographic evaluation. In 35 patients available for follow up, the mean New York Heart Association class reduced from 2.55 + or - 0.81 to 1.77 + or - 0.90 (P < .001) and the mean quality-of-life score as assessed by Minnesota Living With Heart Failure Questionnaire improved from 45 + or - 28 to 32 + or - 28 (P = .08) at 2.5 + or - 2.1 months. Comprehensive echocardiographically guided Biv pacemaker optimization produces significant improvement in Doppler echocardiographic hemodynamics, a reduction in S(3) intensity, and an improvement in functional class in patients after cardiac resynchronization therapy. Copyright 2010 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

Start-Stop Moment Optimization of Range Extender and Control Strategy Design for Extended -Range Electric Vehicle

NASA Astrophysics Data System (ADS)

Zhao, Jing-bo; Han, Bing-yuan; Bei, Shao-yi

2017-10-01

Range extender is the core component of E-REV, its start-stop control determines the operation modes of vehicle. This paper based on a certain type of E-REV, researched constant power control strategy of range extender in extended-range model, to target range as constraint condition, combined with different driving cycle conditions, by correcting battery SOC for range extender start-stop moment, optimized the control strategy of range extender, and established the vehicle and range extender start-stop control simulation model. Selected NEDC and UDDS conditions simulation results show that: under certain target mileage, the range extender running time reduced by 37.2% and 28.2% in the NEDC condition, and running time UDDS conditions were reduced by 40.6% and 33.5% in the UDDS condition, reached the purpose of meeting the vehicle mileage and reducing consumption and emission.

A comprehensive formulation for volumetric modulated arc therapy planning

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

Nguyen, Dan; Lyu, Qihui; Ruan, Dan

2016-07-15

Purpose: Volumetric modulated arc therapy (VMAT) is a widely employed radiation therapy technique, showing comparable dosimetry to static beam intensity modulated radiation therapy (IMRT) with reduced monitor units and treatment time. However, the current VMAT optimization has various greedy heuristics employed for an empirical solution, which jeopardizes plan consistency and quality. The authors introduce a novel direct aperture optimization method for VMAT to overcome these limitations. Methods: The comprehensive VMAT (comVMAT) planning was formulated as an optimization problem with an L2-norm fidelity term to penalize the difference between the optimized dose and the prescribed dose, as well as an anisotropicmore » total variation term to promote piecewise continuity in the fluence maps, preparing it for direct aperture optimization. A level set function was used to describe the aperture shapes and the difference between aperture shapes at adjacent angles was penalized to control MLC motion range. A proximal-class optimization solver was adopted to solve the large scale optimization problem, and an alternating optimization strategy was implemented to solve the fluence intensity and aperture shapes simultaneously. Single arc comVMAT plans, utilizing 180 beams with 2° angular resolution, were generated for a glioblastoma multiforme case, a lung (LNG) case, and two head and neck cases—one with three PTVs (H&N{sub 3PTV}) and one with foue PTVs (H&N{sub 4PTV})—to test the efficacy. The plans were optimized using an alternating optimization strategy. The plans were compared against the clinical VMAT (clnVMAT) plans utilizing two overlapping coplanar arcs for treatment. Results: The optimization of the comVMAT plans had converged within 600 iterations of the block minimization algorithm. comVMAT plans were able to consistently reduce the dose to all organs-at-risk (OARs) as compared to the clnVMAT plans. On average, comVMAT plans reduced the max and mean OAR dose by 6.59% and 7.45%, respectively, of the prescription dose. Reductions in max dose and mean dose were as high as 14.5 Gy in the LNG case and 15.3 Gy in the H&N{sub 3PTV} case. PTV coverages measured by D95, D98, and D99 were within 0.25% of the prescription dose. By comprehensively optimizing all beams, the comVMAT optimizer gained the freedom to allow some selected beams to deliver higher intensities, yielding a dose distribution that resembles a static beam IMRT plan with beam orientation optimization. Conclusions: The novel nongreedy VMAT approach simultaneously optimizes all beams in an arc and then directly generates deliverable apertures. The single arc VMAT approach thus fully utilizes the digital Linac’s capability in dose rate and gantry rotation speed modulation. In practice, the new single VMAT algorithm generates plans superior to existing VMAT algorithms utilizing two arcs.« less

Malaria transmission potential could be reduced with current and future climate change.

PubMed

Murdock, C C; Sternberg, E D; Thomas, M B

2016-06-21

Several studies suggest the potential for climate change to increase malaria incidence in cooler, marginal transmission environments. However, the effect of increasing temperature in warmer regions where conditions currently support endemic transmission has received less attention. We investigate how increases in temperature from optimal conditions (27 °C to 30 °C and 33 °C) interact with realistic diurnal temperature ranges (DTR: ± 0 °C, 3 °C, and 4.5 °C) to affect the ability of key vector species from Africa and Asia (Anopheles gambiae and An. stephensi) to transmit the human malaria parasite, Plasmodium falciparum. The effects of increasing temperature and DTR on parasite prevalence, parasite intensity, and mosquito mortality decreased overall vectorial capacity for both mosquito species. Increases of 3 °C from 27 °C reduced vectorial capacity by 51-89% depending on species and DTR, with increases in DTR alone potentially halving transmission. At 33 °C, transmission potential was further reduced for An. stephensi and blocked completely in An. gambiae. These results suggest that small shifts in temperature could play a substantial role in malaria transmission dynamics, yet few empirical or modeling studies consider such effects. They further suggest that rather than increase risk, current and future warming could reduce transmission potential in existing high transmission settings.

Editor's Choice - Acute Cardiovascular Care Association Position Paper on Intensive Cardiovascular Care Units: An update on their definition, structure, organisation and function.

PubMed

Bonnefoy-Cudraz, Eric; Bueno, Hector; Casella, Gianni; De Maria, Elia; Fitzsimons, Donna; Halvorsen, Sigrun; Hassager, Christian; Iakobishvili, Zaza; Magdy, Ahmed; Marandi, Toomas; Mimoso, Jorge; Parkhomenko, Alexander; Price, Susana; Rokyta, Richard; Roubille, Francois; Serpytis, Pranas; Shimony, Avi; Stepinska, Janina; Tint, Diana; Trendafilova, Elina; Tubaro, Marco; Vrints, Christiaan; Walker, David; Zahger, Doron; Zima, Endre; Zukermann, Robert; Lettino, Maddalena

2018-02-01

Acute cardiovascular care has progressed considerably since the last position paper was published 10 years ago. It is now a well-defined, complex field with demanding multidisciplinary teamworking. The Acute Cardiovascular Care Association has provided this update of the 2005 position paper on acute cardiovascular care organisation, using a multinational working group. The patient population has changed, and intensive cardiovascular care units now manage a large range of conditions from those simply requiring specialised monitoring, to critical cardiovascular diseases with associated multi-organ failure. To describe better intensive cardiovascular care units case mix, acuity of care has been divided into three levels, and then defining intensive cardiovascular care unit functional organisation. For each level of intensive cardiovascular care unit, this document presents the aims of the units, the recommended management structure, the optimal number of staff, the need for specially trained cardiologists and cardiovascular nurses, the desired equipment and architecture, and the interaction with other departments in the hospital and other intensive cardiovascular care units in the region/area. This update emphasises cardiologist training, referring to the recently updated Acute Cardiovascular Care Association core curriculum on acute cardiovascular care. The training of nurses in acute cardiovascular care is additionally addressed. Intensive cardiovascular care unit expertise is not limited to within the unit's geographical boundaries, extending to different specialties and subspecialties of cardiology and other specialties in order to optimally manage the wide scope of acute cardiovascular conditions in frequently highly complex patients. This position paper therefore addresses the need for the inclusion of acute cardiac care and intensive cardiovascular care units within a hospital network, linking university medical centres, large community hospitals, and smaller hospitals with more limited capabilities.

A new Monte Carlo-based treatment plan optimization approach for intensity modulated radiation therapy.

PubMed

Li, Yongbao; Tian, Zhen; Shi, Feng; Song, Ting; Wu, Zhaoxia; Liu, Yaqiang; Jiang, Steve; Jia, Xun

2015-04-07

Intensity-modulated radiation treatment (IMRT) plan optimization needs beamlet dose distributions. Pencil-beam or superposition/convolution type algorithms are typically used because of their high computational speed. However, inaccurate beamlet dose distributions may mislead the optimization process and hinder the resulting plan quality. To solve this problem, the Monte Carlo (MC) simulation method has been used to compute all beamlet doses prior to the optimization step. The conventional approach samples the same number of particles from each beamlet. Yet this is not the optimal use of MC in this problem. In fact, there are beamlets that have very small intensities after solving the plan optimization problem. For those beamlets, it may be possible to use fewer particles in dose calculations to increase efficiency. Based on this idea, we have developed a new MC-based IMRT plan optimization framework that iteratively performs MC dose calculation and plan optimization. At each dose calculation step, the particle numbers for beamlets were adjusted based on the beamlet intensities obtained through solving the plan optimization problem in the last iteration step. We modified a GPU-based MC dose engine to allow simultaneous computations of a large number of beamlet doses. To test the accuracy of our modified dose engine, we compared the dose from a broad beam and the summed beamlet doses in this beam in an inhomogeneous phantom. Agreement within 1% for the maximum difference and 0.55% for the average difference was observed. We then validated the proposed MC-based optimization schemes in one lung IMRT case. It was found that the conventional scheme required 10(6) particles from each beamlet to achieve an optimization result that was 3% difference in fluence map and 1% difference in dose from the ground truth. In contrast, the proposed scheme achieved the same level of accuracy with on average 1.2 × 10(5) particles per beamlet. Correspondingly, the computation time including both MC dose calculations and plan optimizations was reduced by a factor of 4.4, from 494 to 113 s, using only one GPU card.

Enhanced laser conditioning using temporally shaped pulses

DOE PAGES

Kafka, K. R. P.; Papernov, S.; Demos, S. G.

2018-03-06

Laser conditioning was investigated as a function of the temporal shape and duration of 351-nm, nanosecond pulses for fused-silica substrates polished via magnetorheological finishing. Here, the aim is to advance our understanding of the dynamics involved to enable improved control of the interaction of laser light with the material to optimize laser conditioning. Gaussian pulses that are temporally truncated at the intensity peak are observed to enhance laser conditioning, in comparison to a Gaussian pulse shape.

Enhanced laser conditioning using temporally shaped pulses.

PubMed

Kafka, K R P; Papernov, S; Demos, S G

2018-03-15

Laser conditioning was investigated as a function of the temporal shape and duration of 351 nm nanosecond pulses for fused-silica substrates polished via magnetorheological finishing. The aim is to advance our understanding of the dynamics involved to enable improved control of the interaction of laser light with the material to optimize laser conditioning. Gaussian pulses that are temporally truncated at the intensity peak are observed to enhance laser conditioning, in comparison to a Gaussian pulse shape.

Enhanced laser conditioning using temporally shaped pulses

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

Kafka, K. R. P.; Papernov, S.; Demos, S. G.

Laser conditioning was investigated as a function of the temporal shape and duration of 351-nm, nanosecond pulses for fused-silica substrates polished via magnetorheological finishing. Here, the aim is to advance our understanding of the dynamics involved to enable improved control of the interaction of laser light with the material to optimize laser conditioning. Gaussian pulses that are temporally truncated at the intensity peak are observed to enhance laser conditioning, in comparison to a Gaussian pulse shape.

Optimal design of photoreceptor mosaics: why we do not see color at night.

PubMed

Manning, Jeremy R; Brainard, David H

2009-01-01

While color vision mediated by rod photoreceptors in dim light is possible (Kelber & Roth, 2006), most animals, including humans, do not see in color at night. This is because their retinas contain only a single class of rod photoreceptors. Many of these same animals have daylight color vision, mediated by multiple classes of cone photoreceptors. We develop a general formulation, based on Bayesian decision theory, to evaluate the efficacy of various retinal photoreceptor mosaics. The formulation evaluates each mosaic under the assumption that its output is processed to optimally estimate the image. It also explicitly takes into account the statistics of the environmental image ensemble. Using the general formulation, we consider the trade-off between monochromatic and dichromatic retinal designs as a function of overall illuminant intensity. We are able to demonstrate a set of assumptions under which the prevalent biological pattern represents optimal processing. These assumptions include an image ensemble characterized by high correlations between image intensities at nearby locations, as well as high correlations between intensities in different wavelength bands. They also include a constraint on receptor photopigment biophysics and/or the information carried by different wavelengths that produces an asymmetry in the signal-to-noise ratio of the output of different receptor classes. Our results thus provide an optimality explanation for the evolution of color vision for daylight conditions and monochromatic vision for nighttime conditions. An additional result from our calculations is that regular spatial interleaving of two receptor classes in a dichromatic retina yields performance superior to that of a retina where receptors of the same class are clumped together.

Optimizing chemical conditioning for odour removal of undigested sewage sludge in drying processes.

PubMed

Vega, Esther; Monclús, Hèctor; Gonzalez-Olmos, Rafael; Martin, Maria J

2015-03-01

Emission of odours during the thermal drying in sludge handling processes is one of the main sources of odour problems in wastewater treatment plants. The objective of this work was to assess the use of the response surface methodology as a technique to optimize the chemical conditioning process of undigested sewage sludges, in order to improve the dewaterability, and to reduce the odour emissions during the thermal drying of the sludge. Synergistic effects between inorganic conditioners (iron chloride and calcium oxide) were observed in terms of sulphur emissions and odour reduction. The developed quadratic models indicated that optimizing the conditioners dosage is possible to increase a 70% the dewaterability, reducing a 50% and 54% the emission of odour and volatile sulphur compounds respectively. The optimization of the conditioning process was validated experimentally. Copyright © 2014 Elsevier Ltd. All rights reserved.

Signal one and two blockade are both critical for non-myeloablative murine HSCT across a major histocompatibility complex barrier.

PubMed

Langford-Smith, Kia J; Sandiford, Zara; Langford-Smith, Alex; Wilkinson, Fiona L; Jones, Simon A; Wraith, J Ed; Wynn, Robert F; Bigger, Brian W

2013-01-01

Non-myeloablative allogeneic haematopoietic stem cell transplantation (HSCT) is rarely achievable clinically, except where donor cells have selective advantages. Murine non-myeloablative conditioning regimens have limited clinical success, partly through use of clinically unachievable cell doses or strain combinations permitting allograft acceptance using immunosuppression alone. We found that reducing busulfan conditioning in murine syngeneic HSCT, increases bone marrow (BM):blood SDF-1 ratio and total donor cells homing to BM, but reduces the proportion of donor cells engrafting. Despite this, syngeneic engraftment is achievable with non-myeloablative busulfan (25 mg/kg) and higher cell doses induce increased chimerism. Therefore we investigated regimens promoting initial donor cell engraftment in the major histocompatibility complex barrier mismatched CBA to C57BL/6 allo-transplant model. This requires full myeloablation and immunosuppression with non-depleting anti-CD4/CD8 blocking antibodies to achieve engraftment of low cell doses, and rejects with reduced intensity conditioning (≤75 mg/kg busulfan). We compared increased antibody treatment, G-CSF, niche disruption and high cell dose, using reduced intensity busulfan and CD4/8 blockade in this model. Most treatments increased initial donor engraftment, but only addition of co-stimulatory blockade permitted long-term engraftment with reduced intensity or non-myeloablative conditioning, suggesting that signal 1 and 2 T-cell blockade is more important than early BM niche engraftment for transplant success.

The effect of statistical noise on IMRT plan quality and convergence for MC-based and MC-correction-based optimized treatment plans.

PubMed

Siebers, Jeffrey V

2008-04-04

Monte Carlo (MC) is rarely used for IMRT plan optimization outside of research centres due to the extensive computational resources or long computation times required to complete the process. Time can be reduced by degrading the statistical precision of the MC dose calculation used within the optimization loop. However, this eventually introduces optimization convergence errors (OCEs). This study determines the statistical noise levels tolerated during MC-IMRT optimization under the condition that the optimized plan has OCEs <100 cGy (1.5% of the prescription dose) for MC-optimized IMRT treatment plans.Seven-field prostate IMRT treatment plans for 10 prostate patients are used in this study. Pre-optimization is performed for deliverable beams with a pencil-beam (PB) dose algorithm. Further deliverable-based optimization proceeds using: (1) MC-based optimization, where dose is recomputed with MC after each intensity update or (2) a once-corrected (OC) MC-hybrid optimization, where a MC dose computation defines beam-by-beam dose correction matrices that are used during a PB-based optimization. Optimizations are performed with nominal per beam MC statistical precisions of 2, 5, 8, 10, 15, and 20%. Following optimizer convergence, beams are re-computed with MC using 2% per beam nominal statistical precision and the 2 PTV and 10 OAR dose indices used in the optimization objective function are tallied. For both the MC-optimization and OC-optimization methods, statistical equivalence tests found that OCEs are less than 1.5% of the prescription dose for plans optimized with nominal statistical uncertainties of up to 10% per beam. The achieved statistical uncertainty in the patient for the 10% per beam simulations from the combination of the 7 beams is ~3% with respect to maximum dose for voxels with D>0.5D(max). The MC dose computation time for the OC-optimization is only 6.2 minutes on a single 3 Ghz processor with results clinically equivalent to high precision MC computations.

A method for the preparation of curcumin by ultrasonic-assisted ammonium sulfate/ethanol aqueous two phase extraction.

PubMed

Xu, Guangkuan; Hao, Changchun; Tian, Suyang; Gao, Feng; Sun, Wenyuan; Sun, Runguang

2017-01-15

This study investigated a new and easy-to-industrialized extracting method for curcumin from Curcuma longa rhizomes using ultrasonic extraction technology combined with ammonium sulfate/ethanol aqueous two-phase system (ATPS), and the preparation of curcumin using the semi-preparative HPLC. The single-factor experiments and response surface methodology (RSM) were utilized to determine the optimal material-solvent ratio, ultrasonic intensity (UI) and ultrasonic time. The optimum extraction conditions were finally determined to be material-solvent rate of 3.29:100, ultrasonic intensity of 33.63W/cm 2 and ultrasonic time of 17min. At these optimum conditions, the extraction yield could reach 46.91mg/g. And the extraction yields of curcumin remained stable in the case of amplification, which indicated that scale-up extraction was feasible and efficient. Afterwards, the semi-preparative HPLC experiment was carried out, in which optimal preparation conditions were elected according to the single factor experiment. The prepared curcumin was obtained and the purity could up to 85.58% by the semi-preparative HPLC. Copyright © 2016 Elsevier B.V. All rights reserved.

Dosimetric advantages of IMPT over IMRT for laser-accelerated proton beams

NASA Astrophysics Data System (ADS)

Luo, W.; Li, J.; Fourkal, E.; Fan, J.; Xu, X.; Chen, Z.; Jin, L.; Price, R.; Ma, C.-M.

2008-12-01

As a clinical application of an exciting scientific breakthrough, a compact and cost-efficient proton therapy unit using high-power laser acceleration is being developed at Fox Chase Cancer Center. The significance of this application depends on whether or not it can yield dosimetric superiority over intensity-modulated radiation therapy (IMRT). The goal of this study is to show how laser-accelerated proton beams with broad energy spreads can be optimally used for proton therapy including intensity-modulated proton therapy (IMPT) and achieve dosimetric superiority over IMRT for prostate cancer. Desired energies and spreads with a varying δE/E were selected with the particle selection device and used to generate spread-out Bragg peaks (SOBPs). Proton plans were generated on an in-house Monte Carlo-based inverse-planning system. Fifteen prostate IMRT plans previously used for patient treatment have been included for comparison. Identical dose prescriptions, beam arrangement and consistent dose constrains were used for IMRT and IMPT plans to show the dosimetric differences that were caused only by the different physical characteristics of proton and photon beams. Different optimization constrains and beam arrangements were also used to find optimal IMPT. The results show that conventional proton therapy (CPT) plans without intensity modulation were not superior to IMRT, but IMPT can generate better proton plans if appropriate beam setup and optimization are used. Compared to IMRT, IMPT can reduce the target dose heterogeneity ((D5-D95)/D95) by up to 56%. The volume receiving 65 Gy and higher (V65) for the bladder and the rectum can be reduced by up to 45% and 88%, respectively, while the volume receiving 40 Gy and higher (V40) for the bladder and the rectum can be reduced by up to 49% and 68%, respectively. IMPT can also reduce the whole body non-target tissue dose by up to 61% or a factor 2.5. This study has shown that the laser accelerator under development has a potential to generate high-quality proton beams for cancer treatment. Significant improvement in target dose uniformity and normal tissue sparing as well as in reduction of whole body dose can be achieved by IMPT with appropriate optimization and beam setup.

Optimized endoscopic autofluorescence spectroscopy for the identification of premalignant lesions in Barrett's oesophagus.

PubMed

Holz, Jasmin A; Boerwinkel, David F; Meijer, Sybren L; Visser, Mike; van Leeuwen, Ton G; Aalders, Maurice C G; Bergman, Jacques J G H M

2013-12-01

Fluorescence spectroscopy has the potential to detect early cellular changes in Barrett's oesophagus before these become visible. As the technique is based on varying concentrations of intrinsic fluorophores, each with its own optimal excitation wavelength, it is important to assess the optimal excitation wavelength(s) for identification of premalignant lesions in patients with Barrett's oesophagus. The endoscopic spectroscopy system used contained five (ultra)violet light sources (λexc=369-416 nm) to generate autofluorescence during routine endoscopic surveillance. Autofluorescence spectroscopy was followed by a biopsy for histological assessment and spectra correlation. Three intensity ratios (r1, r2, r3) were calculated by dividing the area, A, under the spectral curve of selected emission wavelength ranges for each spectrum generated by each excitation wavelength λexc as follows (Equation is included in full-text article.). Double intensity ratios were calculated using two excitation wavelengths. Fifty-eight tissue areas from 22 patients were used for autofluorescence spectra analysis. Excitation with 395, 405 or 410 nm showed a significant (P≤0.0006) differentiation between intestinal metaplasia and grouped high-grade dysplasia/early carcinoma for intensity ratios r2 and r3. A sensitivity of 80.0% and specificity of 89.5% with an area under the ROC curve of 0.85 was achieved using 395 nm excitation and intensity ratio r3. Double excitation showed no additional value over single excitation. The combination of 395 nm excitation and intensity ratio r3 showed optimal conditions to discriminate nondysplastic from early neoplasia in Barrett's oesophagus.

Photoplethysmography Signal Analysis for Optimal Region-of-Interest Determination in Video Imaging on a Built-In Smartphone under Different Conditions.

PubMed

Nam, Yunyoung; Nam, Yun-Cheol

2017-10-19

Smartphones and tablets are widely used in medical fields, which can improve healthcare and reduce healthcare costs. Many medical applications for smartphones and tablets have already been developed and widely used by both health professionals and patients. Specifically, video recordings of fingertips made using a smartphone camera contain a pulsatile component caused by the cardiac pulse equivalent to that present in a photoplethysmographic signal. By performing peak detection on the pulsatile signal, it is possible to estimate a continuous heart rate and a respiratory rate. To estimate the heart rate and respiratory rate accurately, which pixel regions of the color bands give the most optimal signal quality should be investigated. In this paper, we investigate signal quality to determine the best signal quality by the largest amplitude values for three different smartphones under different conditions. We conducted several experiments to obtain reliable PPG signals and compared the PPG signal strength in the three color bands when the flashlight was both on and off. We also evaluated the intensity changes of PPG signals obtained from the smartphones with motion artifacts and fingertip pressure force. Furthermore, we have compared the PSNR of PPG signals of the full-size images with that of the region of interests (ROIs).

On the improvement of signal repeatability in laser-induced air plasmas

NASA Astrophysics Data System (ADS)

Zhang, Shuai; Sheta, Sahar; Hou, Zong-Yu; Wang, Zhe

2018-04-01

The relatively low repeatability of laser-induced breakdown spectroscopy (LIBS) severely hinders its wide commercialization. In the present work, we investigate the optimization of LIBS system for repeatability improvement for both signal generation (plasma evolution) and signal collection. Timeintegrated spectra and images were obtained under different laser energies and focal lengths to investigate the optimum configuration for stable plasmas and repeatable signals. Using our experimental setup, the optimum conditions were found to be a laser energy of 250 mJ and a focus length of 100 mm. A stable and homogeneous plasma with the largest hot core area in the optimum condition yielded the most stable LIBS signal. Time-resolved images showed that the rebounding processes through the air plasma evolution caused the relative standard deviation (RSD) to increase with laser energies of > 250 mJ. In addition, the emission collection was improved by using a concave spherical mirror. The line intensities doubled as their RSDs decreased by approximately 25%. When the signal generation and collection were optimized simultaneously, the pulse-to-pulse RSDs were reduced to approximately 3% for O(I), N(I), and H(I) lines, which are better than the RSDs reported for solid samples and showed great potential for LIBS quantitative analysis by gasifying the solid or liquid samples.

Tolerance of chufa (Cyperus esculentus) as a vegetation unit's representative of bioregenerative life support systems to elevated temperatures

NASA Astrophysics Data System (ADS)

Shklavtsova, Ekaterina; Ushakova, Sofya; Shikhov, Valentin; Kudenko, Yurii

Plants inclusion in the photosynthesizing unit of bioregenerative life support systems (BLSS) expects knowledge of both production characteristics of plants cultivated under optimal condi-tions and their tolerance to stress-factors' effect caused by contingency origination in a system. The work was aimed at investigation of chufa (Cyperus esculentus) tolerance to the effect of super optimal air temperature of 44 subject to PAR intensity and exposure duration. Chufa was grown in light culture conditions by hydroponics method on expanded clay aggregate. The Knop solution was used as nutrition medium. Up to 30 days the plants were cultivated at the intensity of 690 micromole*m-2*s*-1 and air temperature of 25. Heat shock was employed at the age of 30 days under the air temperature of 44 during 7, 20 and 44 hours at two different PAR intensities of 690 and 1150 micromole*m-2*s*-1. Chufa heat tolerance was estimated by intensity of external 2 gas exchange and by state of leaves' photosynthetic apparatus (PSA). Effect of disturbing temperature during 44 hours at PAR intensity of 690 micromole*m-2*s*-1 resulted in frozen-in damage of PSA-leaves' die-off. Chufa plants exposed to heat stress at PAR intensity of 690 micromole*m-2*s*-1 during both 7 and 20-hours demonstrated respiration dominance over photosynthesis; and 2 emission was observed by light. Functional activity of photosynthetic apparatus estimated with respect to parameters of pulse-amplitude-modulated chlorophyll fluorescence of photosystem 2 (PS 2) decreased on 40

Enhancing the auto-flocculation of photosynthetic bacteria to realize biomass recovery in brewery wastewater treatment.

PubMed

Lu, Haifeng; Dong, Shan; Zhang, Guangming; Han, Ting; Zhang, Yuanhui; Li, Baoming

2018-02-15

Photosynthetic bacteria (PSB) wastewater treatment technology can simultaneously realize wastewater purification and biomass production. The produced biomass contains high value-added products, which can be used in medical and agricultural industry. However, because of the small size and high electronegativity, PSB are hard to be collected from wastewater, which hampers the commercialization of PSB-based industrial processes. Auto-flocculation is a low cost, energy saving, non-toxic biomass collection method for microbiology. In this work, the influence factors with their optimal levels and mechanism for enhancing the auto-flocculation of PSB were investigated in pure cultivation medium. Then PSB auto-flocculation performance in real brewery wastewater was probed. Results showed that Na + concentration, pH and light intensity were three crucial factors except the initial inoculum sizes and temperature. In the pure medium cultivation system, the optimal condition for PSB auto-flocculation was as follows: pH was 9.5, inoculum size was 420 mg l -1 , Na + concentration was 0.067 mol l -1 , light intensity was 5000 lux, temperature was 30°C. Under the optimal condition, the auto-flocculation ratio and biomass recovery reached 85.0% and 1488 mg l -1 , which improved by 1.67-fold and 2.14-fold compared with the PSB enrichment cultivation conditions, respectively. Mechanism analysis showed that the protein/polysaccharides ratio and absolute Zeta potential value had a liner relationship. For the brewery wastewater treatment, under the above optimal condition, the chemical oxygen demand removal reached 94.3% with the auto-flocculation ratio and biomass recovery of 89.6% and 1510 mg l -1 , which increased 2.75-fold and 2.77-fold, respectively.

Improving multi-objective reservoir operation optimization with sensitivity-informed problem decomposition

NASA Astrophysics Data System (ADS)

Chu, J. G.; Zhang, C.; Fu, G. T.; Li, Y.; Zhou, H. C.

2015-04-01

This study investigates the effectiveness of a sensitivity-informed method for multi-objective operation of reservoir systems, which uses global sensitivity analysis as a screening tool to reduce the computational demands. Sobol's method is used to screen insensitive decision variables and guide the formulation of the optimization problems with a significantly reduced number of decision variables. This sensitivity-informed problem decomposition dramatically reduces the computational demands required for attaining high quality approximations of optimal tradeoff relationships between conflicting design objectives. The search results obtained from the reduced complexity multi-objective reservoir operation problems are then used to pre-condition the full search of the original optimization problem. In two case studies, the Dahuofang reservoir and the inter-basin multi-reservoir system in Liaoning province, China, sensitivity analysis results show that reservoir performance is strongly controlled by a small proportion of decision variables. Sensitivity-informed problem decomposition and pre-conditioning are evaluated in their ability to improve the efficiency and effectiveness of multi-objective evolutionary optimization. Overall, this study illustrates the efficiency and effectiveness of the sensitivity-informed method and the use of global sensitivity analysis to inform problem decomposition when solving the complex multi-objective reservoir operation problems.

Quantifying the effect of forests on frequency and intensity of rockfalls

NASA Astrophysics Data System (ADS)

Moos, Christine; Dorren, Luuk; Stoffel, Markus

2017-02-01

Forests serve as a natural means of protection against small rockfalls. Due to their barrier effect, they reduce the intensity and the propagation probability of falling rocks and thus reduce the occurrence frequency of a rockfall event for a given element at risk. However, despite established knowledge on the protective effect of forests, they are generally neglected in quantitative rockfall risk analyses. Their inclusion in quantitative rockfall risk assessment would, however, be necessary to express their efficiency in monetary terms and to allow comparison of forests with other protective measures, such as nets and dams. The goal of this study is to quantify the effect of forests on the occurrence frequency and intensity of rockfalls. We therefore defined an onset frequency of blocks based on a power-law magnitude-frequency distribution and determined their propagation probabilities on a virtual slope based on rockfall simulations. Simulations were run for different forest and non-forest scenarios under varying forest stand and terrain conditions. We analysed rockfall frequencies and intensities at five different distances from the release area. Based on two multivariate statistical prediction models, we investigated which of the terrain and forest characteristics predominantly drive the role of forest in reducing rockfall occurrence frequency and intensity and whether they are able to predict the effect of forest on rockfall risk. The rockfall occurrence frequency below forested slopes is reduced between approximately 10 and 90 % compared to non-forested slope conditions; whereas rockfall intensity is reduced by 10 to 70 %. This reduction increases with increasing slope length and decreases with decreasing tree density, tree diameter and increasing rock volume, as well as in cases of clustered or gappy forest structures. The statistical prediction models reveal that the cumulative basal area of trees, block volume and horizontal forest structure represent key variables for the prediction of the protective effect of forests. In order to validate these results, models have to be tested on real slopes with a wide variation of terrain and forest conditions.

[Functions of participatory ergonomics programs in reducing work-related musculoskeletal disorders].

PubMed

Guo, M J; Liu, J J; Yao, H Y

2016-08-10

Work-related musculoskeletal disorders (MSDs) are most commonly seen in all the occupational non-fatal injuries and illnesses for workers, especially those who are involved in labor-intensive industries. Participatory ergonomics is frequently used to prevent musculoskeletal disorders. This paper gives an overview of a historical perspective on the use of participatory ergonomics approach in reducing the health effects of labor-intensive industries. Progress, barriers and facilitators on the organization, implementation and evaluation of participatory ergonomics programs are studied. Participatory ergonomics seems a successful method to develop, prioritize measures to prevent MSDs. Participatory ergonomics can help industries reduce musculoskeletal injuries and disorders, improve workplace condition and promote health conditions of the workers.

Simplex optimization of the variables influencing the determination of pefloxacin by time-resolved chemiluminescence

NASA Astrophysics Data System (ADS)

Murillo Pulgarín, José A.; Alañón Molina, Aurelia; Jiménez García, Elisa

2018-03-01

A new chemiluminescence (CL) detection system combined with flow injection analysis (FIA) for the determination of Pefloxacin is proposed. The determination is based on an energy transfer from Pefloxacin to terbium (III). The metal ion enhances the weak CL signal produced by the KMnO4/H2SO3/Pefloxacin system. A modified simplex method was used to optimize chemical and instrumental variables. The influence of the interaction of the permanganate, Tb (III), sodium sulphite and sulphuric acid concentrations, flow rate and injected sample volume was thoroughly investigated by using a modified simplex optimization procedure. The results revealed a strong direct relationship between flow rate and CL intensity throughout the studied range that was confirmed by a gamma test. The response factor for the CL emission intensity was used to assess performance in order to identify the optimum conditions for maximization of the response. Under such conditions, the CL response was proportional to the Pefloxacin concentration over a wide range. The detection limit as calculated according to Clayton's criterion 13.7 μg L- 1. The analyte was successfully determined in milk samples with an average recovery of 100.6 ± 9.8%.

Application of growth-phase based light-feeding strategies to simultaneously enhance Chlorella vulgaris growth and lipid accumulation.

PubMed

Sun, Yahui; Liao, Qiang; Huang, Yun; Xia, Ao; Fu, Qian; Zhu, Xun; Fu, Jingwei; Li, Jun

2018-05-01

Considering the variations of optimal light intensity required by microalgae cells along with growth phases, growth-phase light-feeding strategies were proposed and verified in this paper, aiming at boosting microalgae lipid productivity from the perspective of light conditions optimization. Experimental results demonstrate that under an identical time-averaged light intensity, the light-feeding strategies characterized by stepwise incremental light intensities showed a positive effect on biomass and lipid accumulation. The lipid productivity (235.49 mg L -1  d -1 ) attained under light-feeding strategy V (time-averaged light intensity: 225 μmol m -2  s -1 ) was 52.38% higher over that obtained under a constant light intensity of 225 μmol m -2  s -1 . Subsequently, based on light-feeding strategy V, microalgae lipid productivity was further elevated to 312.92 mg L -1  d -1 employing a two-stage based light-feeding strategy V 560 (time-averaged light intensity: 360 μmol m -2  s -1 ), which was 79.63% higher relative to that achieved under a constant light intensity of 360 μmol m -2  s -1 . Copyright © 2018 Elsevier Ltd. All rights reserved.

Optimization of the Nano-Dust Analyzer (NDA) for operation under solar UV illumination

NASA Astrophysics Data System (ADS)

O`Brien, L.; Grün, E.; Sternovsky, Z.

2015-12-01

The performance of the Nano-Dust Analyzer (NDA) instrument is analyzed for close pointing to the Sun, finding the optimal field-of-view (FOV), arrangement of internal baffles and measurement requirements. The laboratory version of the NDA instrument was recently developed (O'Brien et al., 2014) for the detection and elemental composition analysis of nano-dust particles. These particles are generated near the Sun by the collisional breakup of interplanetary dust particles (IDP), and delivered to Earth's orbit through interaction with the magnetic field of the expanding solar wind plasma. NDA is operating on the basis of impact ionization of the particle and collecting the generated ions in a time-of-flight fashion. The challenge in the measurement is that nano-dust particles arrive from a direction close to that of the Sun and thus the instrument is exposed to intense ultraviolet (UV) radiation. The performed optical ray-tracing analysis shows that it is possible to suppress the number of UV photons scattering into NDA's ion detector to levels that allow both high signal-to-noise ratio measurements, and long-term instrument operation. Analysis results show that by avoiding direct illumination of the target, the photon flux reaching the detector is reduced by a factor of about 103. Furthermore, by avoiding the target and also implementing a low-reflective coating, as well as an optimized instrument geometry consisting of an internal baffle system and a conical detector housing, the photon flux can be reduced by a factor of 106, bringing it well below the operation requirement. The instrument's FOV is optimized for the detection of nano-dust particles, while excluding the Sun. With the Sun in the FOV, the instrument can operate with reduced sensitivity and for a limited duration. The NDA instrument is suitable for future space missions to provide the unambiguous detection of nano-dust particles, to understand the conditions in the inner heliosphere and its temporal variability, and to constrain the chemical differentiation and processing of IDPs.

With a little help from my kin: barn swallow nestlings modulate solicitation of parental care according to nestmates' need.

PubMed

Romano, Andrea; Caprioli, M; Boncoraglio, G; Saino, N; Rubolini, D

2012-09-01

In altricial species, offspring competing for access to limiting parental resources (e.g. food) are selected to achieve an optimal balance between the costs of scrambling for food, the benefits of being fed and the indirect costs of subtracting food to relatives. As the marginal benefits of acquiring additional food decrease with decreasing levels of need, satiated offspring should be prone to favour access to food by their needy kin, thus enhancing their own indirect fitness, while concomitantly reducing costs of harsh competition with hungry broodmates. We tested this prediction in feeding trials of barn swallow (Hirundo rustica) nestlings by comparing begging behaviour and food intake of two similar-sized nestmates, one of which was food-deprived (FD). Non-food-deprived (NFD) offspring modulated begging intensity depending on their nestmate's need: when competing with FD nestmates, NFD nestlings reduced both the intensity and frequency of begging displays compared to themselves in the control trial before food deprivation. Hence, NFD nestlings reduced their competitiveness to the advantage of FD nestmates, which obtained more feedings and showed a threefold larger increase in body mass. Moderation of individual selfishness can therefore be adaptive in the presence of a needier kin, because the indirect fitness benefits of promoting its condition can outweigh the costs of forgoing being fed, and because it limits the cost of begging escalation against a vigorous competitor. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

Intensive Education: How It Affects Teachers' and Students' Work Conditions.

ERIC Educational Resources Information Center

Fallon, Karin

This qualitative study of a high school using intensive education shows how teaching and learning were improved when teachers taught and students attended one class daily for 6 weeks. Intensive education is an alternative scheduling and organizational format that reduces class size and extends class length by having teachers and students in one…

High-Intensity Interval Training Versus Moderate-Intensity Continuous Training in the Prevention/Management of Cardiovascular Disease.

PubMed

Hussain, Syed R; Macaluso, Andrea; Pearson, Stephen J

Moderate-intensity continuous training (MICT) has long been considered the most effective exercise treatment modality for the prevention and management of cardiovascular disease (CVD), but more recently high-intensity interval training (HIIT) has been viewed as a potential alternative to MICT in accruing such benefits. HIIT was initially found to induce significant improvements in numerous physiological and health-related indices, to a similar if not superior extent to MICT. Since then, many studies have attempted to explore the potential clinical utility of HIIT, relative to MICT, with respect to treating numerous cardiovascular conditions, such as coronary artery disease, heart failure, stroke, and hypertension. Despite this, however, the efficacy of HIIT in reversing the specific symptoms and risk factors of these cardiovascular pathologies is not well understood. HIIT is often perceived as very strenuous, which could render it unsafe for those at risk of or afflicted with CVD, but these issues are also yet to be reviewed. Furthermore, the optimal HIIT protocol for each of the CVD cohorts has not been established. Thus, the purpose of this review article is to (1) evaluate the efficacy of HIIT relative to MICT in the prevention and management of cardiovascular conditions, and (2) explore any potential safety issues surrounding the suitability and/or tolerability of HIIT for patients with CVD, and the potential optimal prescriptive variables of HIIT for application in the clinical environment.

Customized Noise-Stimulation Intensity for Bipedal Stability and Unipedal Balance Deficits Associated With Functional Ankle Instability

PubMed Central

Ross, Scott E.; Linens, Shelley W.; Wright, Cynthia J.; Arnold, Brent L.

2013-01-01

Context: Stochastic resonance stimulation (SRS) administered at an optimal intensity could maximize the effects of treatment on balance. Objective: To determine if a customized optimal SRS intensity is better than a traditional SRS protocol (applying the same percentage sensory threshold intensity for all participants) for improving double- and single-legged balance in participants with or without functional ankle instability (FAI). Design: Case-control study with an embedded crossover design. Setting: Laboratory. Patients or Other Participants: Twelve healthy participants (6 men, 6 women; age = 22 ± 2 years, height = 170 ± 7 cm, mass = 64 ± 10 kg) and 12 participants (6 men, 6 women; age = 23 ± 3 years, height = 174 ± 8 cm, mass = 69 ± 10 kg) with FAI. Intervention(s): The SRS optimal intensity level was determined by finding the intensity from 4 experimental intensities at the percentage sensory threshold (25% [SRS25], 50% [SRS50], 75% [SRS75], 90% [SRS90]) that produced the greatest improvement in resultant center-of-pressure velocity (R-COPV) over a control condition (SRS0) during double-legged balance. We examined double- and single-legged balance tests, comparing optimal SRS (SRSopt1) and SRS0 using a battery of center-of-pressure measures in the frontal and sagittal planes. Main Outcome Measure(s): Anterior-posterior (A-P) and medial-lateral (M-L) center-of-pressure velocity (COPV) and center-of-pressure excursion (COPE), R-COPV, and 95th percentile center-of-pressure area ellipse (COPA-95). Results: Data were organized into bins that represented optimal (SRSopt1), second (SRSopt2), third (SRSopt3), and fourth (SRSopt4) improvement over SRS0. The SRSopt1 enhanced R-COPV (P ≤ .05) over SRS0 and other SRS conditions (SRS0 = 0.94 ± 0.32 cm/s, SRSopt1 = 0.80 ± 0.19 cm/s, SRSopt2 = 0.88 ± 0.24 cm/s, SRSopt3 = 0.94 ± 0.25 cm/s, SRSopt4 = 1.00 ± 0.28 cm/s). However, SRS did not improve R-COPV over SRS0 when data were categorized by sensory threshold. Furthermore, SRSopt1 improved double-legged balance over SRS0 from 11% to 25% in all participants for the center-of-pressure frontal- and sagittal-plane assessments (P ≤ .05). The SRSopt1 also improved single-legged balance over SRS0 from 10% to 17% in participants with FAI for the center-of-pressure frontal- and sagittal-plane assessments (P ≤ .05). The SRSopt1 did not improve single-legged balance in participants with stable ankles. Conclusions: The SRSopt1 improved double-legged balance and transfers to enhancing single-legged balance deficits associated with FAI. PMID:23724774

The Effect of Cycling Intensity on Cycling Economy During Seated and Standing Cycling.

PubMed

Arkesteijn, Marco; Jobson, Simon; Hopker, James; Passfield, Louis

2016-10-01

Previous research has shown that cycling in a standing position reduces cycling economy compared with seated cycling. It is unknown whether the cycling intensity moderates the reduction in cycling economy while standing. The aim was to determine whether the negative effect of standing on cycling economy would be decreased at a higher intensity. Ten cyclists cycled in 8 different conditions. Each condition was either at an intensity of 50% or 70% of maximal aerobic power at a gradient of 4% or 8% and in the seated or standing cycling position. Cycling economy and muscle activation level of 8 leg muscles were recorded. There was an interaction between cycling intensity and position for cycling economy (P = .03), the overall activation of the leg muscles (P = .02), and the activation of the lower leg muscles (P = .05). The interaction showed decreased cycling economy when standing compared with seated cycling, but the difference was reduced at higher intensity. The overall activation of the leg muscles and the lower leg muscles, respectively, increased and decreased, but the differences between standing and seated cycling were reduced at higher intensity. Cycling economy was lower during standing cycling than seated cycling, but the difference in economy diminishes when cycling intensity increases. Activation of the lower leg muscles did not explain the lower cycling economy while standing. The increased overall activation, therefore, suggests that increased activation of the upper leg muscles explains part of the lower cycling economy while standing.

Optimizing ion channel models using a parallel genetic algorithm on graphical processors.

PubMed

Ben-Shalom, Roy; Aviv, Amit; Razon, Benjamin; Korngreen, Alon

2012-01-01

We have recently shown that we can semi-automatically constrain models of voltage-gated ion channels by combining a stochastic search algorithm with ionic currents measured using multiple voltage-clamp protocols. Although numerically successful, this approach is highly demanding computationally, with optimization on a high performance Linux cluster typically lasting several days. To solve this computational bottleneck we converted our optimization algorithm for work on a graphical processing unit (GPU) using NVIDIA's CUDA. Parallelizing the process on a Fermi graphic computing engine from NVIDIA increased the speed ∼180 times over an application running on an 80 node Linux cluster, considerably reducing simulation times. This application allows users to optimize models for ion channel kinetics on a single, inexpensive, desktop "super computer," greatly reducing the time and cost of building models relevant to neuronal physiology. We also demonstrate that the point of algorithm parallelization is crucial to its performance. We substantially reduced computing time by solving the ODEs (Ordinary Differential Equations) so as to massively reduce memory transfers to and from the GPU. This approach may be applied to speed up other data intensive applications requiring iterative solutions of ODEs. Copyright © 2012 Elsevier B.V. All rights reserved.

Development of sustainable stormwater management using simulation-optimization approach under climate change

NASA Astrophysics Data System (ADS)

Huang, Yu-ru; Tung, Ching-pin

2015-04-01

Climate change had altered the hydrological processes globally with result that the extreme events have an increase in both the magnitude and the frequency. In particular, the high intensity rainfall cause the severe flooding had significantly impacted on human life and property in recently year. The traditional facility to handle runoff is the drainage system which is designed in accordance with the intensity-duration-frequency (IDF) curve. However, the flooding occurs once the drainage capacity is overwhelmed by excess stormwater. Thus the general solution are that expanding and upgrading the existing drainage system or increasing the design return period for new development areas to reduce flooding. Besides, another technique which is low impact development(LID) is regarded as more sustainable solution for stormwater management. The concept of LID is to control stormwater at the source by decentralized practices and mimic the predevelopment hydrologic conditions including storage, retention and high rate of infiltration. In contrast to conventional drainage system aims to move runoff away as quickly as possible, the LID approach attempts to keep runoff on site to reduce peak and volume of flow. The purpose of this research is to identify the most cost-effective measures for stormwater management after the analysis of the strategies combining drainage system and LID on various land use planning. The case study is a rural community in Hsinchu in Taiwan, and having residential areas, farms and pond. It is assumed that two land use layout are planned and drainage system are designed for 2-,and 5-year return period events. On the other hand, three LID technologies, namely green roof, porous pavement and rain barrel, are selected to place in the scenario of the drainage system for 2-year return period event, and the minimal peak flow is target to optimize LID placement by simulated annealing algorithm. Moreover, the design storm under climate change are derived from the revised IDF curve. After that the storm water management model (SWMM) is used to simulate these strategies for a spectrum of design storms, the cost and the benefit can be analyzed to provide government an advice in developing stormwater management under uncertain conditions of climate change.

TU-EF-304-07: Monte Carlo-Based Inverse Treatment Plan Optimization for Intensity Modulated Proton Therapy

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

Li, Y; UT Southwestern Medical Center, Dallas, TX; Tian, Z

2015-06-15

Purpose: Intensity-modulated proton therapy (IMPT) is increasingly used in proton therapy. For IMPT optimization, Monte Carlo (MC) is desired for spots dose calculations because of its high accuracy, especially in cases with a high level of heterogeneity. It is also preferred in biological optimization problems due to the capability of computing quantities related to biological effects. However, MC simulation is typically too slow to be used for this purpose. Although GPU-based MC engines have become available, the achieved efficiency is still not ideal. The purpose of this work is to develop a new optimization scheme to include GPU-based MC intomore » IMPT. Methods: A conventional approach using MC in IMPT simply calls the MC dose engine repeatedly for each spot dose calculations. However, this is not the optimal approach, because of the unnecessary computations on some spots that turned out to have very small weights after solving the optimization problem. GPU-memory writing conflict occurring at a small beam size also reduces computational efficiency. To solve these problems, we developed a new framework that iteratively performs MC dose calculations and plan optimizations. At each dose calculation step, the particles were sampled from different spots altogether with Metropolis algorithm, such that the particle number is proportional to the latest optimized spot intensity. Simultaneously transporting particles from multiple spots also mitigated the memory writing conflict problem. Results: We have validated the proposed MC-based optimization schemes in one prostate case. The total computation time of our method was ∼5–6 min on one NVIDIA GPU card, including both spot dose calculation and plan optimization, whereas a conventional method naively using the same GPU-based MC engine were ∼3 times slower. Conclusion: A fast GPU-based MC dose calculation method along with a novel optimization workflow is developed. The high efficiency makes it attractive for clinical usages.« less

[Admission, discharge and triage guidelines for paediatric intensive care units in Spain].

PubMed

de la Oliva, Pedro; Cambra-Lasaosa, Francisco José; Quintana-Díaz, Manuel; Rey-Galán, Corsino; Sánchez-Díaz, Juan Ignacio; Martín-Delgado, María Cruz; de Carlos-Vicente, Juan Carlos; Hernández-Rastrollo, Ramón; Holanda-Peña, María Soledad; Pilar-Orive, Francisco Javier; Ocete-Hita, Esther; Rodríguez-Núñez, Antonio; Serrano-González, Ana; Blanch, Luis

2018-05-01

A paediatric intensive care unit (PICU) is a separate physical facility or unit specifically designed for the treatment of paediatric patients who, because of the severity of illness or other life-threatening conditions, require comprehensive and continuous inten-sive care by a medical team with special skills in paediatric intensive care medicine. Timely and personal intervention in intensive care reduces mortality, reduces length of stay, and decreases cost of care. With the aim of defending the right of the child to receive the highest attainable standard of health and the facilities for the treatment of illness and rehabilitation, as well as ensuring the quality of care and the safety of critically ill paediatric patients, the Spanish Association of Paediatrics (AEP), Spanish Society of Paediatric Intensive Care (SECIP) and Spanish Society of Critical Care (SEMICYUC) have approved the guidelines for the admission, discharge and triage for Spanish PICUs. By using these guidelines, the performance of Spanish paediatric intensive care units can be optimised and paediatric patients can receive the appropriate level of care for their clinical condition. Copyright © 2017 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

Admission, discharge and triage guidelines for paediatric intensive care units in Spain.

PubMed

de la Oliva, Pedro; Cambra-Lasaosa, Francisco José; Quintana-Díaz, Manuel; Rey-Galán, Corsino; Sánchez-Díaz, Juan Ignacio; Martín-Delgado, María Cruz; de Carlos-Vicente, Juan Carlos; Hernández-Rastrollo, Ramón; Holanda-Peña, María Soledad; Pilar-Orive, Francisco Javier; Ocete-Hita, Esther; Rodríguez-Núñez, Antonio; Serrano-González, Ana; Blanch, Luis

2018-05-01

A paediatric intensive care unit (PICU) is a separate physical facility or unit specifically designed for the treatment of paediatric patients who, because of the severity of illness or other life-threatening conditions, require comprehensive and continuous inten-sive care by a medical team with special skills in paediatric intensive care medicine. Timely and personal intervention in intensive care reduces mortality, reduces length of stay, and decreases cost of care. With the aim of defending the right of the child to receive the highest attainable standard of health and the facilities for the treatment of illness and rehabilitation, as well as ensuring the quality of care and the safety of critically ill paediatric patients, the Spanish Association of Paediatrics (AEP), Spanish Society of Paediatric Intensive Care (SECIP) and Spanish Society of Critical Care (SEMICYUC) have approved the guidelines for the admission, discharge and triage for Spanish PICUs. By using these guidelines, the performance of Spanish paediatric intensive care units can be optimised and paediatric patients can receive the appropriate level of care for their clinical condition. Copyright © 2017. Publicado por Elsevier España, S.L.U.

The effects of climate change associated abiotic stresses on maize phytochemical defenses

USDA-ARS?s Scientific Manuscript database

Reliable large-scale maize production is an essential component of global food security; however, sustained efforts are needed to ensure optimized resilience under diverse crop stress conditions. Climate changes are expected to increase the frequency and intensity of both abiotic and biotic stress. ...

Optimize Flue Gas Settings to Promote Microalgae Growth in Photobioreactors via Computer Simulations

PubMed Central

He, Lian; Chen, Amelia B; Yu, Yi; Kucera, Leah; Tang, Yinjie

2013-01-01

Flue gas from power plants can promote algal cultivation and reduce greenhouse gas emissions1. Microalgae not only capture solar energy more efficiently than plants3, but also synthesize advanced biofuels2-4. Generally, atmospheric CO2 is not a sufficient source for supporting maximal algal growth5. On the other hand, the high concentrations of CO2 in industrial exhaust gases have adverse effects on algal physiology. Consequently, both cultivation conditions (such as nutrients and light) and the control of the flue gas flow into the photo-bioreactors are important to develop an efficient “flue gas to algae” system. Researchers have proposed different photobioreactor configurations4,6 and cultivation strategies7,8 with flue gas. Here, we present a protocol that demonstrates how to use models to predict the microalgal growth in response to flue gas settings. We perform both experimental illustration and model simulations to determine the favorable conditions for algal growth with flue gas. We develop a Monod-based model coupled with mass transfer and light intensity equations to simulate the microalgal growth in a homogenous photo-bioreactor. The model simulation compares algal growth and flue gas consumptions under different flue-gas settings. The model illustrates: 1) how algal growth is influenced by different volumetric mass transfer coefficients of CO2; 2) how we can find optimal CO2 concentration for algal growth via the dynamic optimization approach (DOA); 3) how we can design a rectangular on-off flue gas pulse to promote algal biomass growth and to reduce the usage of flue gas. On the experimental side, we present a protocol for growing Chlorella under the flue gas (generated by natural gas combustion). The experimental results qualitatively validate the model predictions that the high frequency flue gas pulses can significantly improve algal cultivation. PMID:24121788

Fuel consumption optimization for smart hybrid electric vehicle during a car-following process

NASA Astrophysics Data System (ADS)

Li, Liang; Wang, Xiangyu; Song, Jian

2017-03-01

Hybrid electric vehicles (HEVs) provide large potential to save energy and reduce emission, and smart vehicles bring out great convenience and safety for drivers. By combining these two technologies, vehicles may achieve excellent performances in terms of dynamic, economy, environmental friendliness, safety, and comfort. Hence, a smart hybrid electric vehicle (s-HEV) is selected as a platform in this paper to study a car-following process with optimizing the fuel consumption. The whole process is a multi-objective optimal problem, whose optimal solution is not just adding an energy management strategy (EMS) to an adaptive cruise control (ACC), but a deep fusion of these two methods. The problem has more restricted conditions, optimal objectives, and system states, which may result in larger computing burden. Therefore, a novel fuel consumption optimization algorithm based on model predictive control (MPC) is proposed and some search skills are adopted in receding horizon optimization to reduce computing burden. Simulations are carried out and the results indicate that the fuel consumption of proposed method is lower than that of the ACC+EMS method on the condition of ensuring car-following performances.

HPLC-MS/MS method for dexmedetomidine quantification with Design of Experiments approach: application to pediatric pharmacokinetic study.

PubMed

Szerkus, Oliwia; Struck-Lewicka, Wiktoria; Kordalewska, Marta; Bartosińska, Ewa; Bujak, Renata; Borsuk, Agnieszka; Bienert, Agnieszka; Bartkowska-Śniatkowska, Alicja; Warzybok, Justyna; Wiczling, Paweł; Nasal, Antoni; Kaliszan, Roman; Markuszewski, Michał Jan; Siluk, Danuta

2017-02-01

The purpose of this work was to develop and validate a rapid and robust LC-MS/MS method for the determination of dexmedetomidine (DEX) in plasma, suitable for analysis of a large number of samples. Systematic approach, Design of Experiments, was applied to optimize ESI source parameters and to evaluate method robustness, therefore, a rapid, stable and cost-effective assay was developed. The method was validated according to US FDA guidelines. LLOQ was determined at 5 pg/ml. The assay was linear over the examined concentration range (5-2500 pg/ml), Results: Experimental design approach was applied for optimization of ESI source parameters and evaluation of method robustness. The method was validated according to the US FDA guidelines. LLOQ was determined at 5 pg/ml. The assay was linear over the examined concentration range (R 2 > 0.98). The accuracies, intra- and interday precisions were less than 15%. The stability data confirmed reliable behavior of DEX under tested conditions. Application of Design of Experiments approach allowed for fast and efficient analytical method development and validation as well as for reduced usage of chemicals necessary for regular method optimization. The proposed technique was applied to determination of DEX pharmacokinetics in pediatric patients undergoing long-term sedation in the intensive care unit.

Energy consumption of agitators in activated sludge tanks - actual state and optimization potential.

PubMed

Füreder, K; Svardal, K; Frey, W; Kroiss, H; Krampe, J

2018-02-01

Depending on design capacity, agitators consume about 5 to 20% of the total energy consumption of a wastewater treatment plant. Based on inhabitant-specific energy consumption (kWh PE 120 -1 a -1 ; PE 120 is population equivalent, assuming 120 g chemical oxygen demand per PE per day), power density (W m -3 ) and volume-specific energy consumption (Wh m -3 d -1 ) as evaluation indicators, this paper provides a sound contribution to understanding energy consumption and energy optimization potentials of agitators. Basically, there are two ways to optimize agitator operation: the reduction of the power density and the reduction of the daily operating time. Energy saving options range from continuous mixing with low power densities of 1 W m -3 to mixing by means of short, intense energy pulses (impulse aeration, impulse stirring). However, the following correlation applies: the shorter the duration of energy input, the higher the power density on the respective volume-specific energy consumption isoline. Under favourable conditions with respect to tank volume, tank geometry, aeration and agitator position, mixing energy can be reduced to 24 Wh m -3 d -1 and below. Additionally, it could be verified that power density of agitators stands in inverse relation to tank volume.

Fluid-Dynamic Optimal Design of Helical Vascular Graft for Stenotic Disturbed Flow

PubMed Central

Ha, Hojin; Hwang, Dongha; Choi, Woo-Rak; Baek, Jehyun; Lee, Sang Joon

2014-01-01

Although a helical configuration of a prosthetic vascular graft appears to be clinically beneficial in suppressing thrombosis and intimal hyperplasia, an optimization of a helical design has yet to be achieved because of the lack of a detailed understanding on hemodynamic features in helical grafts and their fluid dynamic influences. In the present study, the swirling flow in a helical graft was hypothesized to have beneficial influences on a disturbed flow structure such as stenotic flow. The characteristics of swirling flows generated by helical tubes with various helical pitches and curvatures were investigated to prove the hypothesis. The fluid dynamic influences of these helical tubes on stenotic flow were quantitatively analysed by using a particle image velocimetry technique. Results showed that the swirling intensity and helicity of the swirling flow have a linear relation with a modified Germano number (Gn*) of the helical pipe. In addition, the swirling flow generated a beneficial flow structure at the stenosis by reducing the size of the recirculation flow under steady and pulsatile flow conditions. Therefore, the beneficial effects of a helical graft on the flow field can be estimated by using the magnitude of Gn*. Finally, an optimized helical design with a maximum Gn* was suggested for the future design of a vascular graft. PMID:25360705

Optimization of equivalent uniform dose using the L-curve criterion.

PubMed

Chvetsov, Alexei V; Dempsey, James F; Palta, Jatinder R

2007-10-07

Optimization of equivalent uniform dose (EUD) in inverse planning for intensity-modulated radiation therapy (IMRT) prevents variation in radiobiological effect between different radiotherapy treatment plans, which is due to variation in the pattern of dose nonuniformity. For instance, the survival fraction of clonogens would be consistent with the prescription when the optimized EUD is equal to the prescribed EUD. One of the problems in the practical implementation of this approach is that the spatial dose distribution in EUD-based inverse planning would be underdetermined because an unlimited number of nonuniform dose distributions can be computed for a prescribed value of EUD. Together with ill-posedness of the underlying integral equation, this may significantly increase the dose nonuniformity. To optimize EUD and keep dose nonuniformity within reasonable limits, we implemented into an EUD-based objective function an additional criterion which ensures the smoothness of beam intensity functions. This approach is similar to the variational regularization technique which was previously studied for the dose-based least-squares optimization. We show that the variational regularization together with the L-curve criterion for the regularization parameter can significantly reduce dose nonuniformity in EUD-based inverse planning.

Priority interventions to reduce HIV transmission in sex work settings in sub-Saharan Africa and delivery of these services.

PubMed

Chersich, Matthew F; Luchters, Stanley; Ntaganira, Innocent; Gerbase, Antonio; Lo, Ying-Ru; Scorgie, Fiona; Steen, Richard

2013-03-04

Virtually no African country provides HIV prevention services in sex work settings with an adequate scale and intensity. Uncertainty remains about the optimal set of interventions and mode of delivery. We systematically reviewed studies reporting interventions for reducing HIV transmission among female sex workers in sub-Saharan Africa between January 2000 and July 2011. Medline (PubMed) and non-indexed journals were searched for studies with quantitative study outcomes. We located 26 studies, including seven randomized trials. Evidence supports implementation of the following interventions to reduce unprotected sex among female sex workers: peer-mediated condom promotion, risk-reduction counselling and skills-building for safer sex. One study found that interventions to counter hazardous alcohol-use lowered unprotected sex. Data also show effectiveness of screening for sexually transmitted infections (STIs) and syndromic STI treatment, but experience with periodic presumptive treatment is limited. HIV testing and counselling is essential for facilitating sex workers' access to care and antiretroviral treatment (ART), but testing models for sex workers and indeed for ART access are little studied, as are structural interventions, which create conditions conducive for risk reduction. With the exception of Senegal, persistent criminalization of sex work across Africa reduces sex workers' control over working conditions and impedes their access to health services. It also obstructs health-service provision and legal protection. There is sufficient evidence of effectiveness of targeted interventions with female sex workers in Africa to inform delivery of services for this population. With improved planning and political will, services - including peer interventions, condom promotion and STI screening - would act at multiple levels to reduce HIV exposure and transmission efficiency among sex workers. Initiatives are required to enhance access to HIV testing and ART for sex workers, using current CD4 thresholds, or possibly earlier for prevention. Services implemented at sufficient scale and intensity also serve as a platform for subsequent community mobilization and sex worker empowerment, and alleviate a major source of incident infection sustaining even generalized HIV epidemics. Ultimately, structural and legal changes that align public health and human rights are needed to ensure that sex workers on the continent are adequately protected from HIV.

Lower light intensity reduces larval aggression in matrinxã, Brycon amazonicus.

PubMed

Lopes, Ana Caroliny C; Villacorta-Correa, Marle Angélica; Carvalho, Thaís B

2018-06-01

Brycon amazonicus shows a high frequency of aggressive behavior, which can be a limiting factor in intensive farming systems. Environmental changes can modulate the social interactions of fish and reduce aggression during the different stages of production. Groups of three larvae at 12 h after hatching (HAH) were subjected to different levels of light intensity: low (17 ± 3 lx), intermediate (204 ± 12.17 lx) and high (1,613.33 ± 499.03 lx), with eight replicates for each level. The lower light intensity reduced the frequency of aggressive interactions and locomotor activity exhibited by the animals. Based on these results, light intensity modulates aggression in B. amazonicus larvae. Manipulation of this factor could improve the social conditions of this species during farming and contribute to the development of new production technologies. Copyright © 2018 Elsevier B.V. All rights reserved.

Low-intensity vibrations normalize adipogenesis-induced morphological and molecular changes of adult mesenchymal stem cells.

PubMed

Baskan, Oznur; Mese, Gulistan; Ozcivici, Engin

2017-02-01

Bone marrow mesenchymal stem cells that are committed to adipogenesis were exposed daily to high-frequency low-intensity mechanical vibrations to understand molecular, morphological and ultrastructural adaptations to mechanical signals during adipogenesis. D1-ORL-UVA mouse bone marrow mesenchymal stem cells were cultured with either growth or adipogenic medium for 1 week. Low-intensity vibration signals (15 min/day, 90 Hz, 0.1 g) were applied to one group of adipogenic cells, while the other adipogenic group served as a sham control. Cellular viability, lipid accumulation, ultrastructure and morphology were determined with MTT, Oil-Red-O staining, phalloidin staining and atomic force microscopy. Semiquantitative reverse transcription polymerase chain reaction showed expression profile of the genes responsible for adipogenesis and ultrastructure of cells. Low-intensity vibration signals increased viability of the cells in adipogenic culture that was reduced significantly compared to quiescent controls. Low-intensity vibration signals also normalized the effects of adipogenic condition on cell morphology, including area, perimeter, circularization and actin cytoskeleton. Furthermore, low-intensity vibration signals reduced the expression of some adipogenic markers significantly. Mesenchymal stem cells are sensitive and responsive to mechanical loads, but debilitating conditions such as aging or obesity may steer mesenchymal stem cells toward adipogenesis. Here, daily application of low-intensity vibration signals partially neutralized the effects of adipogenic induction on mesenchymal stem cells, suggesting that these signals may provide an alternative and/or complementary option to reduce fat deposition.

Will musculoskeletal and visual stress change when Visual Display Unit (VDU) operators move from small offices to an ergonomically optimized office landscape?

PubMed

Helland, Magne; Horgen, Gunnar; Kvikstad, Tor Martin; Garthus, Tore; Aarås, Arne

2011-11-01

This study investigated the effect of moving from small offices to a landscape environment for 19 Visual Display Unit (VDU) operators at Alcatel Denmark AS. The operators reported significantly improved lighting condition and glare situation. Further, visual discomfort was also significantly reduced on a Visual Analogue Scale (VAS). There was no significant correlation between lighting condition and visual discomfort neither in the small offices nor in the office landscape. However, visual discomfort correlated significantly with glare in small offices i.e. more glare is related to more visual discomfort. This correlation disappeared after the lighting system in the office landscape had been improved. There was also a significant correlation between glare and itching of the eyes as well as blurred vision in the small offices, i.e. more glare more visual symptoms. Experience of pain was found to reduce the subjective assessment of work capacity during VDU tasks. There was a significant correlation between visual discomfort and reduced work capacity in small offices and in the office landscape. When moving from the small offices to the office landscape, there was a significant reduction in headache as well as back pain. No significant changes in pain intensity in the neck, shoulder, forearm, and wrist/hand were observed. The pain levels in different body areas were significantly correlated with subjective assessment of reduced work capacity in small offices and in the office landscape. By careful design and construction of an office landscape with regard to lighting and visual conditions, transfer from small offices may be acceptable from a visual-ergonomic point of view. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Use of information technologies when designing multilayered plates and covers with filler of various types

NASA Astrophysics Data System (ADS)

Golova, T. A.; Magerramova, I. A.; Ivanov, S. A.

2018-05-01

Calculation of multilayered plates and covers does not consider anisotropic properties of a construction. Calculation comes down to uniform isotropic covers and definition of one of intense and deformation conditions of constructions. The existing techniques consider work of multilayered designs by means of various coefficients. The article describes the optimized algorithm of operations when designing multilayered plates and covers with filler of various types on the basis of the conducted researches. It is dealt with a development engineering algorithm of calculation of multi-layer constructions of walls. Software is created which allows one to carry out assessment of intense and deformation conditions of constructions of walls.

Power requirements reducing of FBG based all-optical switching

NASA Astrophysics Data System (ADS)

Scholtz, Ľubomír.; Solanská, Michaela; Ladányi, Libor; Müllerová, Jarmila

2017-12-01

Although Fiber Bragg gratings (FBGs) are well known devices, their using as all-optical switching elements has been still examined. Current research is focused on optimization of their properties for their using in future all-optical networks. The main problem are high switching intensities needed for achieving the changes of the transmission state. Over several years switching intensities have been reduced from hundreds of GW/cm2 to tens of MW/cm2 by selecting appropriate gratings and signal parameters or using suitable materials. Two principal nonlinear effects with similar power requirements can result in the bistable transmission/reflection of an input optical pulse. In the self-phase modulation (SPM) regime switching is achieved by the intense probe pulse itself. Using cross-phase modulation (XPM) a strong pump alters the FBG refractive index experienced by a weak probe pulse. As a result of this the detuning of the probe pulse from the center of the photonic band gap occurs. Using of XPM the effect of modulation instability is reduced. Modulation instability which is the main SPM degradation mechanism. We focused on nonlinear FBGs based on chalcogenide glasses which are very often used in various applications. Thanks to high nonlinear parameters chalcogenide glasses are suitable candidates for reducing switching intensities of nonlinear FBGs.

Organically Modified Nanoclay-Reinforced Rigid Polyurethane Films

NASA Astrophysics Data System (ADS)

Park, Yong Tae; Qian, Yuqiang; Lindsay, Chris; Stein, Andreas; Macosko, Christopher

2012-02-01

The nanodispersion of vermiculite in polyurethanes was investigated to produce organoclay-reinforced rigid gas barrier films. Reducing gas transport can improve the insulation performance of closed cell polyurethane foam. In a previous study, the dispersion of vermiculite in polyurethanes without organic modification was not sufficient due to the non-uniform dispersion morphology. When vermiculite was modified by cation exchange with long-chain quaternary ammonium cations, the dispersion in methylene diphenyl diisocyanate (MDI) was significantly improved. Dispersion was improved by combining high intensity dispersive mixing with efficient distributive mixing. Polymerization conditions were also optimized in order to provide a high state of nanodispersion in the polyurethane nanocomposite. The dispersions were characterized using rheological, microscopic and scattering/diffraction techniques. The final nanocomposites showed enhancement of mechanical properties and reduction in permeability to carbon dioxide at low clay concentration (around 2 wt percent).

A new microscope optics for laser dark-field illumination applied to high precision two dimensional measurement of specimen displacement.

PubMed

Noda, Naoki; Kamimura, Shinji

2008-02-01

With conventional light microscopy, precision in the measurement of the displacement of a specimen depends on the signal-to-noise ratio when we measure the light intensity of magnified images. This implies that, for the improvement of precision, getting brighter images and reducing background light noise are both inevitably required. For this purpose, we developed a new optics for laser dark-field illumination. For the microscopy, we used a laser beam and a pair of axicons (conical lenses) to get an optimal condition for dark-field observations. The optics was applied to measuring two dimensional microbead displacements with subnanometer precision. The bandwidth of our detection system overall was 10 kHz. Over most of this bandwidth, the observed noise level was as small as 0.1 nm/radicalHz.

Enhancing Self-Efficacy for Optimized Patient Outcomes through the Theory of Symptom Self-Management

PubMed Central

Hoffman, Amy J.

2012-01-01

Background In today’s world, greater patient empowerment is imperative since 90 million Americans live with one or more chronic conditions such as cancer. Evidence reveals that healthy behaviors such as effective symptom self-management can prevent or reduce much of the suffering from cancer. Oncology nurses play a pivotal role in developing a symptom self-management plan that is critical to optimizing a patient’s symptom self-management behaviors. Objective This article uses exemplars to describe how oncology nurses can apply a tested middle-range theory, the Theory of Symptom Self-Management, to clinical practice by incorporating interventions to increase a patient’s perceived self-efficacy to optimize patient outcomes. Methods The Theory of Symptom Self-Management provides a means to understand the dynamic aspects of symptom self-management and provides a tested framework for the development of efficacy enhancing interventions for use by oncology nurses in clinical practice. Results Exemplars based on the Theory of Symptom Self-Management that depict how oncology nursing can use perceived self-efficacy enhancing symptom self-management interventions to improve the functional status and quality of life of their patients. Conclusion Guided by a theoretical approach, oncology nurses can have a significant positive impact on the lives of their patients by reducing the symptom burden associated with cancer and its treatment. Implications for Practice Oncology nurses can partner with their patients to design tailored approaches to symptom self-management. These tailored approaches provide the ability to implement patient specific behaviors that recognize, prevent, relieve, or decrease the timing, intensity, distress, concurrence, and unpleasant quality of symptoms. PMID:22495550

Automated electrotransformation of Escherichia coli on a digital microfluidic platform using bioactivated magnetic beads.

PubMed

Moore, J A; Nemat-Gorgani, M; Madison, A C; Sandahl, M A; Punnamaraju, S; Eckhardt, A E; Pollack, M G; Vigneault, F; Church, G M; Fair, R B; Horowitz, M A; Griffin, P B

2017-01-01

This paper reports on the use of a digital microfluidic platform to perform multiplex automated genetic engineering (MAGE) cycles on droplets containing Escherichia coli cells. Bioactivated magnetic beads were employed for cell binding, washing, and media exchange in the preparation of electrocompetent cells in the electrowetting-on-dieletric (EWoD) platform. On-cartridge electroporation was used to deliver oligonucleotides into the cells. In addition to the optimization of a magnetic bead-based benchtop protocol for generating and transforming electrocompetent E. coli cells, we report on the implementation of this protocol in a fully automated digital microfluidic platform. Bead-based media exchange and electroporation pulse conditions were optimized on benchtop for transformation frequency to provide initial parameters for microfluidic device trials. Benchtop experiments comparing electrotransformation of free and bead-bound cells are presented. Our results suggest that dielectric shielding intrinsic to bead-bound cells significantly reduces electroporation field exposure efficiency. However, high transformation frequency can be maintained in the presence of magnetic beads through the application of more intense electroporation pulses. As a proof of concept, MAGE cycles were successfully performed on a commercial EWoD cartridge using variations of the optimal magnetic bead-based preparation procedure and pulse conditions determined by the benchtop results. Transformation frequencies up to 22% were achieved on benchtop; this frequency was matched within 1% (21%) by MAGE cycles on the microfluidic device. However, typical frequencies on the device remain lower, averaging 9% with a standard deviation of 9%. The presented results demonstrate the potential of digital microfluidics to perform complex and automated genetic engineering protocols.

Automated electrotransformation of Escherichia coli on a digital microfluidic platform using bioactivated magnetic beads

PubMed Central

Moore, J. A.; Nemat-Gorgani, M.; Madison, A. C.; Punnamaraju, S.; Eckhardt, A. E.; Pollack, M. G.; Church, G. M.; Fair, R. B.; Horowitz, M. A.; Griffin, P. B.

2017-01-01

This paper reports on the use of a digital microfluidic platform to perform multiplex automated genetic engineering (MAGE) cycles on droplets containing Escherichia coli cells. Bioactivated magnetic beads were employed for cell binding, washing, and media exchange in the preparation of electrocompetent cells in the electrowetting-on-dieletric (EWoD) platform. On-cartridge electroporation was used to deliver oligonucleotides into the cells. In addition to the optimization of a magnetic bead-based benchtop protocol for generating and transforming electrocompetent E. coli cells, we report on the implementation of this protocol in a fully automated digital microfluidic platform. Bead-based media exchange and electroporation pulse conditions were optimized on benchtop for transformation frequency to provide initial parameters for microfluidic device trials. Benchtop experiments comparing electrotransformation of free and bead-bound cells are presented. Our results suggest that dielectric shielding intrinsic to bead-bound cells significantly reduces electroporation field exposure efficiency. However, high transformation frequency can be maintained in the presence of magnetic beads through the application of more intense electroporation pulses. As a proof of concept, MAGE cycles were successfully performed on a commercial EWoD cartridge using variations of the optimal magnetic bead-based preparation procedure and pulse conditions determined by the benchtop results. Transformation frequencies up to 22% were achieved on benchtop; this frequency was matched within 1% (21%) by MAGE cycles on the microfluidic device. However, typical frequencies on the device remain lower, averaging 9% with a standard deviation of 9%. The presented results demonstrate the potential of digital microfluidics to perform complex and automated genetic engineering protocols. PMID:28191268

LED Lighting – Modification of Growth, Metabolism, Yield and Flour Composition in Wheat by Spectral Quality and Intensity

PubMed Central

Monostori, István; Heilmann, Márk; Kocsy, Gábor; Rakszegi, Marianna; Ahres, Mohamed; Altenbach, Susan B.; Szalai, Gabriella; Pál, Magda; Toldi, Dávid; Simon-Sarkadi, Livia; Harnos, Noémi; Galiba, Gábor; Darko, Éva

2018-01-01

The use of light-emitting diode (LED) technology for plant cultivation under controlled environmental conditions can result in significant reductions in energy consumption. However, there is still a lack of detailed information on the lighting conditions required for optimal growth of different plant species and the effects of light intensity and spectral composition on plant metabolism and nutritional quality. In the present study, wheat plants were grown under six regimens designed to compare the effects of LED and conventional fluorescent lights on growth and development, leaf photosynthesis, thiol and amino acid metabolism as well as grain yield and flour quality of wheat. Benefits of LED light sources over fluorescent lighting were manifested in both yield and quality of wheat. Elevated light intensities made possible with LEDs increased photosynthetic activity, the number of tillers, biomass and yield. At lower light intensities, blue, green and far-red light operated antagonistically during the stem elongation period. High photosynthetic activity was achieved when at least 50% of red light was applied during cultivation. A high proportion of blue light prolonged the juvenile phase, while the shortest flowering time was achieved when the blue to red ratio was around one. Blue and far-red light affected the glutathione- and proline-dependent redox environment in leaves. LEDs, especially in Blue, Pink and Red Low Light (RedLL) regimens improved flour quality by modifying starch and protein content, dough strength and extensibility as demonstrated by the ratios of high to low molecular weight glutenins, ratios of glutenins to gliadins and gluten spread values. These results clearly show that LEDs are efficient for experimental wheat cultivation, and make it possible to optimize the growth conditions and to manipulate metabolism, yield and quality through modification of light quality and quantity. PMID:29780400

LED Lighting - Modification of Growth, Metabolism, Yield and Flour Composition in Wheat by Spectral Quality and Intensity.

PubMed

Monostori, István; Heilmann, Márk; Kocsy, Gábor; Rakszegi, Marianna; Ahres, Mohamed; Altenbach, Susan B; Szalai, Gabriella; Pál, Magda; Toldi, Dávid; Simon-Sarkadi, Livia; Harnos, Noémi; Galiba, Gábor; Darko, Éva

2018-01-01

The use of light-emitting diode (LED) technology for plant cultivation under controlled environmental conditions can result in significant reductions in energy consumption. However, there is still a lack of detailed information on the lighting conditions required for optimal growth of different plant species and the effects of light intensity and spectral composition on plant metabolism and nutritional quality. In the present study, wheat plants were grown under six regimens designed to compare the effects of LED and conventional fluorescent lights on growth and development, leaf photosynthesis, thiol and amino acid metabolism as well as grain yield and flour quality of wheat. Benefits of LED light sources over fluorescent lighting were manifested in both yield and quality of wheat. Elevated light intensities made possible with LEDs increased photosynthetic activity, the number of tillers, biomass and yield. At lower light intensities, blue, green and far-red light operated antagonistically during the stem elongation period. High photosynthetic activity was achieved when at least 50% of red light was applied during cultivation. A high proportion of blue light prolonged the juvenile phase, while the shortest flowering time was achieved when the blue to red ratio was around one. Blue and far-red light affected the glutathione- and proline-dependent redox environment in leaves. LEDs, especially in Blue, Pink and Red Low Light (RedLL) regimens improved flour quality by modifying starch and protein content, dough strength and extensibility as demonstrated by the ratios of high to low molecular weight glutenins, ratios of glutenins to gliadins and gluten spread values. These results clearly show that LEDs are efficient for experimental wheat cultivation, and make it possible to optimize the growth conditions and to manipulate metabolism, yield and quality through modification of light quality and quantity.

ENDURANCE TRAINING IN FASTING CONDITIONS: BIOLOGICAL ADAPTATIONS AND BODY WEIGHT MANAGEMENT.

PubMed

Vicente-Salar, Néstor; Urdampilleta Otegui, Aritz; Roche Collado, Enrique

2015-12-01

in the majority of sports the athlete is required to achieve optimal conditions both at a muscular and metabolic level as well as in body composition, increasing the lean body mass and maintaining a low body fat mass. In this context, different training protocols have been proposed in order to reduce body fat content, by maximizing fat use instead of glycogen. to verify if the training while fasting favours the use of fatty acids due to the low glycogen levels, allowing an improvement in the performance ant the control of body weight. protocols have been published, differing in time periods and exercise intensity. In addition, several markers ranging from gene expression analysis to determination of circulating parameters have been assessed in order to interpret the results. Discusion: at low intensities of endurance-based exercises, adipose tissue lipolysis and muscle fat oxidation rate seem to be higher in fasting than in fed state. On the other hand, glucose metabolism is adapted in order to save glycogen stores, possibly through gluconeogenesis activation. Finally, it has been observed that protein degradation is mainly downregulated. Only one study analyses changes in body composition after fasting during long periods, thus further work is necessary to demonstrate that this is the best method to control body fat. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Intelligent Space Tube Optimization for speeding ground water remedial design.

PubMed

Kalwij, Ineke M; Peralta, Richard C

2008-01-01

An innovative Intelligent Space Tube Optimization (ISTO) two-stage approach facilitates solving complex nonlinear flow and contaminant transport management problems. It reduces computational effort of designing optimal ground water remediation systems and strategies for an assumed set of wells. ISTO's stage 1 defines an adaptive mobile space tube that lengthens toward the optimal solution. The space tube has overlapping multidimensional subspaces. Stage 1 generates several strategies within the space tube, trains neural surrogate simulators (NSS) using the limited space tube data, and optimizes using an advanced genetic algorithm (AGA) with NSS. Stage 1 speeds evaluating assumed well locations and combinations. For a large complex plume of solvents and explosives, ISTO stage 1 reaches within 10% of the optimal solution 25% faster than an efficient AGA coupled with comprehensive tabu search (AGCT) does by itself. ISTO input parameters include space tube radius and number of strategies used to train NSS per cycle. Larger radii can speed convergence to optimality for optimizations that achieve it but might increase the number of optimizations reaching it. ISTO stage 2 automatically refines the NSS-AGA stage 1 optimal strategy using heuristic optimization (we used AGCT), without using NSS surrogates. Stage 2 explores the entire solution space. ISTO is applicable for many heuristic optimization settings in which the numerical simulator is computationally intensive, and one would like to reduce that burden.

Decolorization of distillery spent wash effluent by electro oxidation (EC and EF) and Fenton processes: A comparative study.

PubMed

David, Charles; Arivazhagan, M; Tuvakara, Fazaludeen

2015-11-01

In this study, laboratory scale experiments were performed to degrade highly concentrated organic matter in the form of color in the distillery spent wash through batch oxidative methods such as electrocoagulation (EC), electrofenton (EF) and Fenton process. The effect of corresponding operating parameters, namely initial pH: 2-10; current intensity: 1-5A; electrolysis time: 0.5-4h; agitation speed: 100-500rpm; inter-electrode distance: 0.5-4cm and Fenton's reagent dosage: 5-40mg/L was employed for optimizing the process of spent wash color removal. The performance of all the three processes was compared and assessed in terms of percentage color removal. For EC, 79% color removal was achieved using iron electrodes arranged with 0.5cm of inter-electrode space and at optimum conditions of pH 7, 5A current intensity, 300rpm agitation speed and in 2h of electrolysis time. In EF, 44% spent wash decolorization was observed using carbon (graphite) electrodes with an optimum conditions of 0.5cm inter-electrode distance, pH 3, 4A current intensity, 20mg/L FeSO4 and agitation speed of 400rpm for 3h of electrolysis time. By Fenton process, 66% decolorization was attained by Fenton process at optimized conditions of pH 3, 40mg/L of Fenton's reagent and at 500rpm of agitation speed for 4h of treatment time. Copyright © 2015 Elsevier Inc. All rights reserved.

Attentional bias to emotional stimuli is altered during moderate- but not high-intensity exercise.

PubMed

Tian, Qu; Smith, J Carson

2011-12-01

Little is known regarding how attention to emotional stimuli is affected during simultaneously performed exercise. Attentional biases to emotional face stimuli were assessed in 34 college students (17 women) using the dot-probe task during counterbalanced conditions of moderate- (heart rate at 45% peak oxygen consumption) and high-intensity exercise (heart rate at 80% peak oxygen consumption) compared with seated rest. The dot-probe task consisted of 1 emotional face (pleasant or unpleasant) paired with a neutral face for 1,000 ms; 256 trials (128 trials for each valence) were presented during each condition. Each condition lasted approximately 10 min. Participants were instructed to perform each trial of the dot-probe task as quickly and accurately as possible during the exercise and rest conditions. During moderate-intensity exercise, participants exhibited significantly greater attentional bias scores to pleasant compared with unpleasant faces (p < .01), whereas attentional bias scores to emotional faces did not differ at rest or during high-intensity exercise (p > .05). In addition, the attentional bias to unpleasant faces was significantly reduced during moderate-intensity exercise compared with that during rest (p < .05). These results provide behavioral evidence that during exercise at a moderate intensity, there is a shift in attention allocation toward pleasant emotional stimuli and away from unpleasant emotional stimuli. Future work is needed to determine whether acute exercise may be an effective treatment approach to reduce negative bias or enhance positive bias in individuals diagnosed with mood or anxiety disorders, or whether attentional bias during exercise predicts adherence to exercise. (c) 2011 APA, all rights reserved.

42 CFR 410.49 - Cardiac rehabilitation program and intensive cardiac rehabilitation program: Conditions of coverage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... patients' cardiovascular disease through specific outcome measurements described in paragraph (c) of this... heart disease. (ii) Reduced the need for coronary bypass surgery. (iii) Reduced the need for...

Autologous or Reduced-Intensity Conditioning Allogeneic Hematopoietic Cell Transplantation for Chemotherapy-Sensitive Mantle-Cell Lymphoma: Analysis of Transplantation Timing and Modality

PubMed Central

Fenske, Timothy S.; Zhang, Mei-Jie; Carreras, Jeanette; Ayala, Ernesto; Burns, Linda J.; Cashen, Amanda; Costa, Luciano J.; Freytes, César O.; Gale, Robert P.; Hamadani, Mehdi; Holmberg, Leona A.; Inwards, David J.; Lazarus, Hillard M.; Maziarz, Richard T.; Munker, Reinhold; Perales, Miguel-Angel; Rizzieri, David A.; Schouten, Harry C.; Smith, Sonali M.; Waller, Edmund K.; Wirk, Baldeep M.; Laport, Ginna G.; Maloney, David G.; Montoto, Silvia; Hari, Parameswaran N.

2014-01-01

Purpose To examine the outcomes of patients with chemotherapy-sensitive mantle-cell lymphoma (MCL) following a first hematopoietic stem-cell transplantation (HCT), comparing outcomes with autologous (auto) versus reduced-intensity conditioning allogeneic (RIC allo) HCT and with transplantation applied at different times in the disease course. Patients and Methods In all, 519 patients who received transplantations between 1996 and 2007 and were reported to the Center for International Blood and Marrow Transplant Research were analyzed. The early transplantation cohort was defined as those patients in first partial or complete remission with no more than two lines of chemotherapy. The late transplantation cohort was defined as all the remaining patients. Results Auto-HCT and RIC allo-HCT resulted in similar overall survival from transplantation for both the early (at 5 years: 61% auto-HCT v 62% RIC allo-HCT; P = .951) and late cohorts (at 5 years: 44% auto-HCT v 31% RIC allo-HCT; P = .202). In both early and late transplantation cohorts, progression/relapse was lower and nonrelapse mortality was higher in the allo-HCT group. Overall survival and progression-free survival were highest in patients who underwent auto-HCT in first complete response. Multivariate analysis of survival from diagnosis identified a survival benefit favoring early HCT for both auto-HCT and RIC allo-HCT. Conclusion For patients with chemotherapy-sensitive MCL, the optimal timing for HCT is early in the disease course. Outcomes are particularly favorable for patients undergoing auto-HCT in first complete remission. For those unable to achieve complete remission after two lines of chemotherapy or those with relapsed disease, either auto-HCT or RIC allo-HCT may be effective, although the chance for long-term remission and survival is lower. PMID:24344210

Autologous or reduced-intensity conditioning allogeneic hematopoietic cell transplantation for chemotherapy-sensitive mantle-cell lymphoma: analysis of transplantation timing and modality.

PubMed

Fenske, Timothy S; Zhang, Mei-Jie; Carreras, Jeanette; Ayala, Ernesto; Burns, Linda J; Cashen, Amanda; Costa, Luciano J; Freytes, César O; Gale, Robert P; Hamadani, Mehdi; Holmberg, Leona A; Inwards, David J; Lazarus, Hillard M; Maziarz, Richard T; Munker, Reinhold; Perales, Miguel-Angel; Rizzieri, David A; Schouten, Harry C; Smith, Sonali M; Waller, Edmund K; Wirk, Baldeep M; Laport, Ginna G; Maloney, David G; Montoto, Silvia; Hari, Parameswaran N

2014-02-01

To examine the outcomes of patients with chemotherapy-sensitive mantle-cell lymphoma (MCL) following a first hematopoietic stem-cell transplantation (HCT), comparing outcomes with autologous (auto) versus reduced-intensity conditioning allogeneic (RIC allo) HCT and with transplantation applied at different times in the disease course. In all, 519 patients who received transplantations between 1996 and 2007 and were reported to the Center for International Blood and Marrow Transplant Research were analyzed. The early transplantation cohort was defined as those patients in first partial or complete remission with no more than two lines of chemotherapy. The late transplantation cohort was defined as all the remaining patients. Auto-HCT and RIC allo-HCT resulted in similar overall survival from transplantation for both the early (at 5 years: 61% auto-HCT v 62% RIC allo-HCT; P = .951) and late cohorts (at 5 years: 44% auto-HCT v 31% RIC allo-HCT; P = .202). In both early and late transplantation cohorts, progression/relapse was lower and nonrelapse mortality was higher in the allo-HCT group. Overall survival and progression-free survival were highest in patients who underwent auto-HCT in first complete response. Multivariate analysis of survival from diagnosis identified a survival benefit favoring early HCT for both auto-HCT and RIC allo-HCT. For patients with chemotherapy-sensitive MCL, the optimal timing for HCT is early in the disease course. Outcomes are particularly favorable for patients undergoing auto-HCT in first complete remission. For those unable to achieve complete remission after two lines of chemotherapy or those with relapsed disease, either auto-HCT or RIC allo-HCT may be effective, although the chance for long-term remission and survival is lower.

[Simultaneous desulfurization and denitrification by TiO2/ACF under different irradiation].

PubMed

Han, Jing; Zhao, Yi

2009-04-15

The supported TiO2 photocatalysts were prepared in laboratory, and the experiments of simultaneous desulfurization and denitrification were carried out by self-designed photocatalysis reactor. The optimal experimental conditions were achieved, and the efficiencies of simultaneous desulfurization and denitrification under two different light sources were compared. The results show that the oxygen content of flue gas, reaction temperature, flue gas humidity and irradiation intensity are most essential factors to photocatalysis. For TiO2/ACF, the removal efficiencies of 99.7% for SO2 and 64.3% for NO are obtained respectively at optimal experimental conditions under UV irradiation. For TiO2/ACF, the removal efficiencies of 97.5% for SO2 and 49.6% for NO are achieved respectively at optimal experimental conditions under the visible light irradiation. The results of five times parallel experiments indicate standard deviation S of parallel data is little. The mechanism of removal for SO2 and NO is proposed under two light sources by ion chromatography analysis of the absorption liquid.

Optimization of laser-induced breakdown spectroscopy for coal powder analysis with different particle flow diameters

NASA Astrophysics Data System (ADS)

Yao, Shunchun; Xu, Jialong; Dong, Xuan; Zhang, Bo; Zheng, Jianping; Lu, Jidong

2015-08-01

The on-line measurement of coal is extremely useful for emission control and combustion process optimization in coal-fired plant. Laser-induced breakdown spectroscopy was employed to directly analyze coal particle flow. A set of tapered tubes were proposed for beam-focusing the coal particle flow to different diameters. For optimizing the measurement of coal particle flow, the characteristics of laser-induced plasma, including optical breakdown, the relative standard deviation of repeated measurement, partial breakdown spectra ratio and line intensity, were carefully analyzed. The comparison of the plasma characteristics among coal particle flow with different diameters showed that air breakdown and the random change in plasma position relative to the collection optics could significantly influence on the line intensity and the reproducibility of measurement. It is demonstrated that the tapered tube with a diameter of 5.5 mm was particularly useful to enrich the coal particles in laser focus spot as well as to reduce the influence of air breakdown and random changes of plasma in the experiment.

Enhanced ion acceleration in transition from opaque to transparent plasmas

NASA Astrophysics Data System (ADS)

Mishra, R.; Fiuza, F.; Glenzer, S.

2018-04-01

Using particle-in-cell simulations, we investigate ion acceleration in the interaction of high intensity lasers with plasmas which transition from opaque to transparent during the interaction process. We show that the highest ion energies are achieved when the laser traverses the target around the peak intensity and re-heats the electron population responsible for the plasma expansion, enhancing the corresponding sheath electric field. This process can lead to an increase of up to 2x in ion energy when compared with the standard Target Normal Sheath Acceleration in opaque targets under the same laser conditions. A theoretical model is developed to predict the optimal target areal density as a function of laser intensity and pulse duration. A systematic parametric scan for a wide range of target densities and thicknesses is performed in 1D, 2D and 3D and shown consistent with the theory and with recent experimental results. These results open the way for a better optimization of the ion energy in future laser–solid experiments.

Closing the yield gap could reduce projected greenhouse gas emissions: a case study of maize production in China.

PubMed

Cui, Zhenling; Yue, Shanchao; Wang, Guiliang; Meng, Qingfeng; Wu, Liang; Yang, Zhiping; Zhang, Qiang; Li, Shiqing; Zhang, Fusuo; Chen, Xinping

2013-08-01

Although the goal of doubling food demand while simultaneously reducing agricultural environmental damage has become widely accepted, the dominant agricultural paradigm still considers high yields and reduced greenhouse gas (GHG) intensity to be in conflict with one another. Here, we achieved an increase in maize yield of 70% in on-farm experiments by closing the yield gap and evaluated the trade-off between grain yield, nitrogen (N) fertilizer use, and GHG emissions. Based on two groups of N application experiments in six locations for 16 on-farm site-years, an integrated soil-crop system (HY) approach achieved 93% of the yield potential and averaged 14.8 Mg ha(-1) maize grain yield at 15.5% moisture. This is 70% higher than current crop (CC) management. More importantly, the optimal N rate for the HY system was 250 kg N ha(-1) , which is only 38% more N fertilizer input than that applied in the CC system. Both the N2 O emission intensity and GHG intensity increased exponentially as the N application rate increased, and the response curve for the CC system was always higher than that for the HY system. Although the N application rate increased by 38%, N2 O emission intensity and the GHG intensity of the HY system were reduced by 12% and 19%, respectively. These on-farm observations indicate that closing the yield gap alongside efficient N management should therefore be prominent among a portfolio of strategies to meet food demand while reducing GHG intensity at the same time. © 2013 John Wiley & Sons Ltd.

Effect of exercise intensity on postprandial lipemia, markers of oxidative stress, and endothelial function after a high-fat meal.

PubMed

Lopes Krüger, Renata; Costa Teixeira, Bruno; Boufleur Farinha, Juliano; Cauduro Oliveira Macedo, Rodrigo; Pinto Boeno, Francesco; Rech, Anderson; Lopez, Pedro; Silveira Pinto, Ronei; Reischak-Oliveira, Alvaro

2016-12-01

The aim of this study was to compare the effects of 2 different exercise intensities on postprandial lipemia, oxidative stress markers, and endothelial function after a high-fat meal (HFM). Eleven young men completed 2-day trials in 3 conditions: rest, moderate-intensity exercise (MI-Exercise) and heavy-intensity exercise (HI-Exercise). Subjects performed an exercise bout or no exercise (Rest) on the evening of day 1. On the morning of day 2, an HFM was provided. Blood was sampled at fasting (0 h) and every hour from 1 to 5 h during the postprandial period for triacylglycerol (TAG), thiobarbituric acid reactive substance (TBARS), and nitrite/nitrate (NOx) concentrations. Flow-mediated dilatation (FMD) was also analyzed. TAG concentrations were reduced in exercise conditions compared with Rest during the postprandial period (P < 0.004). TAG incremental area under the curve (iAUC) was smaller after HI-Exercise compared with Rest (P = 0.012). TBARS concentrations were reduced in MI-Exercise compared with Rest (P < 0.041). FMD was higher in exercise conditions than Rest at 0 h (P < 0.02) and NOx concentrations were enhanced in MI-Exercise compared with Rest at 0 h (P < 0.01). These results suggest that acute exercise can reduce lipemia after an HFM. However, HI-Exercise showed to be more effective in reducing iAUC TAG, which might suggest higher protection against postprandial TAG enhancement. Conversely, MI-Exercise can be beneficial to attenuate the susceptibility of oxidative damage induced by an HFM and to increase endothelial function in the fasted state compared with Rest.

Growth kinetics of Chlorococcum humicola - A potential feedstock for biomass with biofuel properties.

PubMed

Thomas, Jibu; Jayachithra, E V

2015-11-01

Economically viable production facilities for microalgae depend on the optimization of growth parameters with regard to nutrient requirements. Using microalgae to treat industrial effluents containing heavy metals presents an alternative to the current practice of using physical and chemical methods. Present work focuses on the statistical optimization of growth of Chlorococcum humicola to ascertain the maximum production of biomass. Plackett Burman design was carried out to screen the significant variables influencing biomass production. Further, Response Surface Methodology was employed to optimize the effect of inoculum, light intensity and pH on net biomass yield. Optimum conditions for maximum biomass yield were identified to be inoculum at 15%, light intensity to be 1500lx and pH 8.5. Theoretical and predicted values were in agreement and thus the model was found to be significant. Gas chromatography analyses of the FAME derivatives showed a high percentage of saturated fatty acids thereby confirming the biofuel properties of the oil derived from algal biomass. Copyright © 2015 Elsevier Inc. All rights reserved.

Reduced-intensity conditioning for alternative donor hematopoietic stem cell transplantation in patients with dyskeratosis congenita.

PubMed

Nishio, Nobuhiro; Takahashi, Yoshiyuki; Ohashi, Haruhiko; Doisaki, Sayoko; Muramatsu, Hideki; Hama, Asahito; Shimada, Akira; Yagasaki, Hiroshi; Kojima, Seiji

2011-03-01

DC is an inherited bone marrow failure syndrome mainly characterized by nail dystrophy, abnormal skin pigmentation, and oral leukoplakia. Bone marrow failure is the most common cause of death in patients with DC. Because previous results of HSCT with a myeloablative regimen were disappointing, we used a reduced-intensity conditioning regimen for two patients with classic DC, and one patient with cryptic DC who harbored the TERT mutation. Graft sources included two mismatched-related bone marrow (BM) donors and one unrelated BM donor. Successful engraftment was achieved with few regimen-related toxicities in all patients. They were alive 10, 66, and 72 months after transplantation, respectively. Long-term follow-up is crucial to determine the late effects of our conditioning regimen. © 2010 John Wiley & Sons A/S.

Peak-Seeking Optimization of Trim for Reduced Fuel Consumption: Flight-Test Results

NASA Technical Reports Server (NTRS)

Brown, Nelson Andrew; Schaefer, Jacob Robert

2013-01-01

A peak-seeking control algorithm for real-time trim optimization for reduced fuel consumption has been developed by researchers at the National Aeronautics and Space Administration (NASA) Dryden Flight Research Center to address the goals of the NASA Environmentally Responsible Aviation project to reduce fuel burn and emissions. The peak-seeking control algorithm is based on a steepest-descent algorithm using a time-varying Kalman filter to estimate the gradient of a performance function of fuel flow versus control surface positions. In real-time operation, deflections of symmetric ailerons, trailing-edge flaps, and leading-edge flaps of an F/A-18 airplane (McDonnell Douglas, now The Boeing Company, Chicago, Illinois) are used for optimization of fuel flow. Results from six research flights are presented herein. The optimization algorithm found a trim configuration that required approximately 3 percent less fuel flow than the baseline trim at the same flight condition. The algorithm consistently rediscovered the solution from several initial conditions. These results show that the algorithm has good performance in a relevant environment.

Peak-Seeking Optimization of Trim for Reduced Fuel Consumption: Flight-test Results

NASA Technical Reports Server (NTRS)

Brown, Nelson Andrew; Schaefer, Jacob Robert

2013-01-01

A peak-seeking control algorithm for real-time trim optimization for reduced fuel consumption has been developed by researchers at the National Aeronautics and Space Administration (NASA) Dryden Flight Research Center to address the goals of the NASA Environmentally Responsible Aviation project to reduce fuel burn and emissions. The peak-seeking control algorithm is based on a steepest-descent algorithm using a time-varying Kalman filter to estimate the gradient of a performance function of fuel flow versus control surface positions. In real-time operation, deflections of symmetric ailerons, trailing-edge flaps, and leading-edge flaps of an F/A-18 airplane (McDonnell Douglas, now The Boeing Company, Chicago, Illinois) are used for optimization of fuel flow. Results from six research flights are presented herein. The optimization algorithm found a trim configuration that required approximately 3 percent less fuel flow than the baseline trim at the same flight condition. The algorithm consistently rediscovered the solution from several initial conditions. These results show that the algorithm has good performance in a relevant environment.

Incorporating Flexibility in the Design of Repairable Systems - Design of Microgrids

DTIC Science & Technology

2014-01-01

MICROGRIDS Vijitashwa Pandey1 Annette Skowronska1,2...optimization of complex systems such as a microgrid is however, computationally intensive. The problem is exacerbated if we must incorporate...flexibility in terms of allowing the microgrid architecture and its running protocol to change with time. To reduce the computational effort, this paper

Low-cost production of 6G-fructofuranosidase with high value-added astaxanthin by Xanthophyllomyces dendrorhous.

PubMed

Ning, Yawei; Li, Qiang; Chen, Feng; Yang, Na; Jin, Zhengyu; Xu, Xueming

2012-01-01

The effects of medium composition and culture conditions on the production of (6)G-fructofuranosidase with value-added astaxanthin were investigated to reduce the capital cost of neo-fructooligosaccharides (neo-FOS) production by Xanthophyllomyces dendrorhous. The sucrose and corn steep liquor (CSL) were found to be the optimal carbon source and nitrogen source, respectively. CSL and initial pH were selected as the critical factors using Plackett-Burman design. Maximum (6)G-fructofuranosidase 242.57 U/mL with 5.23 mg/L value-added astaxanthin was obtained at CSL 52.5 mL/L and pH 7.89 by central composite design. Neo-FOS yield could reach 238.12 g/L under the optimized medium conditions. Cost analysis suggested 66.3% of substrate cost was reduced compared with that before optimization. These results demonstrated that the optimized medium and culture conditions could significantly enhance the production of (6)G-fructofuranosidase with value-added astaxanthin and remarkably decrease the substrate cost, which opened up possibilities to produce neo-FOS industrially. Copyright © 2011 Elsevier Ltd. All rights reserved.

Peak Seeking Control for Reduced Fuel Consumption with Preliminary Flight Test Results

NASA Technical Reports Server (NTRS)

Brown, Nelson

2012-01-01

The Environmentally Responsible Aviation project seeks to accomplish the simultaneous reduction of fuel burn, noise, and emissions. A project at NASA Dryden Flight Research Center is contributing to ERAs goals by exploring the practical application of real-time trim configuration optimization for enhanced performance and reduced fuel consumption. This peak-seeking control approach is based on Newton-Raphson algorithm using a time-varying Kalman filter to estimate the gradient of the performance function. In real-time operation, deflection of symmetric ailerons, trailing-edge flaps, and leading-edge flaps of a modified F-18 are directly optimized, and the horizontal stabilators and angle of attack are indirectly optimized. Preliminary results from three research flights are presented herein. The optimization system found a trim configuration that required approximately 3.5% less fuel flow than the baseline trim at the given flight condition. The algorithm consistently rediscovered the solution from several initial conditions. These preliminary results show the algorithm has good performance and is expected to show similar results at other flight conditions and aircraft configurations.

The intensity of knock in an internal combustion engine: An experimental and modeling study

NASA Astrophysics Data System (ADS)

Cowart, J. S.; Haghooie, M.; Newman, C. E.; Davis, G. C.; Pitz, W. J.; Westbrook, C. K.

1992-09-01

Experimental data have been obtained that characterize knock occurrence times and knock intensities in a spark ignition engine operating on indolene and 91 primary reference fuel, as spark timing and inlet temperature were varied. Individual, in-cylinder pressure histories measured under knocking conditions were conditioned and averaged to obtain representative pressure traces. These averaged pressure histories were used as input to a reduced and detailed chemical kinetic model. The time derivative of CO concentration and temperature were correlated with the measured knock intensity and percent cycles knocking. The goal was to evaluate the potential of using homogeneous, chemical kinetic models as predictive tools for knock intensity.

Generalization of conditioned fear along a dimension of increasing fear intensity

PubMed Central

Dunsmoor, Joseph E.; Mitroff, Stephen R.; LaBar, Kevin S.

2009-01-01

The present study investigated the extent to which fear generalization in humans is determined by the amount of fear intensity in nonconditioned stimuli relative to a perceptually similar conditioned stimulus. Stimuli consisted of graded emotionally expressive faces of the same identity morphed between neutral and fearful endpoints. Two experimental groups underwent discriminative fear conditioning between a face stimulus of 55% fear intensity (conditioned stimulus, CS+), reinforced with an electric shock, and a second stimulus that was unreinforced (CS−). In Experiment 1 the CS− was a relatively neutral face stimulus, while in Experiment 2 the CS− was the most fear-intense stimulus. Before and following fear conditioning, skin conductance responses (SCR) were recorded to different morph values along the neutral-to-fear dimension. Both experimental groups showed gradients of generalization following fear conditioning that increased with the fear intensity of the stimulus. In Experiment 1 a peak shift in SCRs extended to the most fear-intense stimulus. In contrast, generalization to the most fear-intense stimulus was reduced in Experiment 2, suggesting that discriminative fear learning procedures can attenuate fear generalization. Together, the findings indicate that fear generalization is broadly tuned and sensitive to the amount of fear intensity in nonconditioned stimuli, but that fear generalization can come under stimulus control. These results reveal a novel form of fear generalization in humans that is not merely based on physical similarity to a conditioned exemplar, and may have implications for understanding generalization processes in anxiety disorders characterized by heightened sensitivity to nonthreatening stimuli. PMID:19553384

Optimization and phase matching of fiber-laser-driven high-order harmonic generation at high repetition rate.

PubMed

Cabasse, Amélie; Machinet, Guillaume; Dubrouil, Antoine; Cormier, Eric; Constant, Eric

2012-11-15

High-repetition-rate sources are very attractive for high-order harmonic generation (HHG). However, due to their pulse characteristics (low energy, long duration), those systems require a tight focusing geometry to achieve the necessary intensity to generate harmonics. In this Letter, we investigate theoretically and experimentally the optimization of HHG in this geometry, to maximize the extreme UV (XUV) photon flux and improve the conversion efficiency. We analyze the influence of atomic gas media (Ar, Kr, or Xe), gas pressure, and interaction geometries (a gas jet and a finite and a semi-infinite gas cell). Numerical simulations allow us to define optimal conditions for HHG in this tight focusing regime and to observe the signature of on-axis phase matching. These conditions are implemented experimentally using a high-repetition-rate Yb-doped fiber laser system. We achieve optimization of emission with a recorded XUV photon flux of 4.5×10(12) photons/s generated in Xe at 100 kHz repetition rate.

Maximizing the probability of satisfying the clinical goals in radiation therapy treatment planning under setup uncertainty

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

Fredriksson, Albin, E-mail: albin.fredriksson@raysearchlabs.com; Hårdemark, Björn; Forsgren, Anders

2015-07-15

Purpose: This paper introduces a method that maximizes the probability of satisfying the clinical goals in intensity-modulated radiation therapy treatments subject to setup uncertainty. Methods: The authors perform robust optimization in which the clinical goals are constrained to be satisfied whenever the setup error falls within an uncertainty set. The shape of the uncertainty set is included as a variable in the optimization. The goal of the optimization is to modify the shape of the uncertainty set in order to maximize the probability that the setup error will fall within the modified set. Because the constraints enforce the clinical goalsmore » to be satisfied under all setup errors within the uncertainty set, this is equivalent to maximizing the probability of satisfying the clinical goals. This type of robust optimization is studied with respect to photon and proton therapy applied to a prostate case and compared to robust optimization using an a priori defined uncertainty set. Results: Slight reductions of the uncertainty sets resulted in plans that satisfied a larger number of clinical goals than optimization with respect to a priori defined uncertainty sets, both within the reduced uncertainty sets and within the a priori, nonreduced, uncertainty sets. For the prostate case, the plans taking reduced uncertainty sets into account satisfied 1.4 (photons) and 1.5 (protons) times as many clinical goals over the scenarios as the method taking a priori uncertainty sets into account. Conclusions: Reducing the uncertainty sets enabled the optimization to find better solutions with respect to the errors within the reduced as well as the nonreduced uncertainty sets and thereby achieve higher probability of satisfying the clinical goals. This shows that asking for a little less in the optimization sometimes leads to better overall plan quality.« less

Parametric optimization of optical signal detectors employing the direct photodetection scheme

NASA Astrophysics Data System (ADS)

Kirakosiants, V. E.; Loginov, V. A.

1984-08-01

The problem of optimization of the optical signal detection scheme parameters is addressed using the concept of a receiver with direct photodetection. An expression is derived which accurately approximates the field of view (FOV) values obtained by a direct computer minimization of the probability of missing a signal; optimum values of the receiver FOV were found for different atmospheric conditions characterized by the number of coherence spots and the intensity fluctuations of a plane wave. It is further pointed out that the criterion presented can be possibly used for parametric optimization of detectors operating in accordance with the Neumann-Pearson criterion.

Multi Response Optimization of Laser Micro Marking Process:A Grey- Fuzzy Approach

NASA Astrophysics Data System (ADS)

Shivakoti, I.; Das, P. P.; Kibria, G.; Pradhan, B. B.; Mustafa, Z.; Ghadai, R. K.

2017-07-01

The selection of optimal parametric combination for efficient machining has always become a challenging issue for the manufacturing researcher. The optimal parametric combination always provides a better machining which improves the productivity, product quality and subsequently reduces the production cost and time. The paper presents the hybrid approach of Grey relational analysis and Fuzzy logic to obtain the optimal parametric combination for better laser beam micro marking on the Gallium Nitride (GaN) work material. The response surface methodology has been implemented for design of experiment considering three parameters with their five levels. The parameter such as current, frequency and scanning speed has been considered and the mark width, mark depth and mark intensity has been considered as the process response.

Management of sepsis in neutropenic patients: 2014 updated guidelines from the Infectious Diseases Working Party of the German Society of Hematology and Medical Oncology (AGIHO).

PubMed

Penack, Olaf; Becker, Carolin; Buchheidt, Dieter; Christopeit, Maximilian; Kiehl, Michael; von Lilienfeld-Toal, Marie; Hentrich, Marcus; Reinwald, Marc; Salwender, Hans; Schalk, Enrico; Schmidt-Hieber, Martin; Weber, Thomas; Ostermann, Helmut

2014-07-01

Sepsis is a major cause of mortality during the neutropenic phase after intensive cytotoxic therapies for malignancies. Improved management of sepsis during neutropenia may reduce the mortality of cancer therapies. Clinical guidelines on sepsis treatment have been published by others. However, optimal management may differ between neutropenic and non-neutropenic patients. Our aim is to give evidence-based recommendations for haematologist, oncologists and intensive care physicians on how to manage adult patients with neutropenia and sepsis.

Developmental and Interprofessional Care of the Preterm Infant: Neonatal Intensive Care Unit Through High-Risk Infant Follow-up.

PubMed

Lipner, Hildy S; Huron, Randye F

2018-02-01

Practices in the neonatal intensive care unit (NICU) that reduce infant stress and respond to behavioral cues positively influence developmental outcomes. Proactive developmental surveillance and timely introduction of early intervention services improve outcomes for premature infants. A model that emphasizes infant development and a continuum of care beginning in the NICU with transition to outpatient monitoring and provision of early intervention services is hypothesized to support the most optimal outcomes for premature infants. Copyright © 2017 Elsevier Inc. All rights reserved.

Fabrication of highly efficient ZnO nanoscintillators

NASA Astrophysics Data System (ADS)

Procházková, Lenka; Gbur, Tomáš; Čuba, Václav; Jarý, Vítězslav; Nikl, Martin

2015-09-01

Photo-induced synthesis of high-efficiency ultrafast nanoparticle scintillators of ZnO was demonstrated. Controlled doping with Ga(III) and La(III) ions together with the optimized method of ZnO synthesis and subsequent two-step annealing in air and under reducing atmosphere allow to achieve very high intensity of UV exciton luminescence, up to 750% of BGO intensity magnitude. Fabricated nanoparticles feature extremely short sub-nanosecond photoluminescence decay times. Temperature dependence of the photoluminescence spectrum within 8-340 K range was investigated and shows the absence of visible defect-related emission within all temperature intervals.

Combinatorial Partial Hydrogenation Reactions of 4-Nitroacetophenone: An Undergraduate Organic Laboratory

ERIC Educational Resources Information Center

Kittredge, Kevin W.; Marine, Susan S.; Taylor, Richard T.

2004-01-01

A molecule possessing other functional groups that could be hydrogenerated is examined, where a variety of metal catalysts are evaluated under similar reaction conditions. Optimizing organic reactions is both time and labor intensive, and the use of a combinatorial parallel synthesis reactor was great time saving device, as per summary.

[Work and health status of workers of shoe manufacturing industries].

PubMed

Mironov, A I; Kirillov, V F; Bul'bulian, M A; Golubeva, A P; Kraeva, G K; Kuznetsova, A I; Nikolaeva, G M

2001-01-01

According to work conditions, severity and intensity, the main shoe-making occupations are assigned to III class of I-II jeopardy grade. If new technology applied, the work is assigned to I-II jeopardy class, being optimal--allowable. Increased mortality with liver cancer and lympholeucosis was revealed among workers contacting chloroprene.

Electrochemical degradation and mineralization of glyphosate herbicide.

PubMed

Tran, Nam; Drogui, Patrick; Doan, Tuan Linh; Le, Thanh Son; Nguyen, Hoai Chau

2017-12-01

The presence of herbicide is a concern for both human and ecological health. Glyphosate is occasionally detected as water contaminants in agriculture areas where the herbicide is used extensively. The removal of glyphosate in synthetic solution using advanced oxidation process is a possible approach for remediation of contaminated waters. The ability of electrochemical oxidation for the degradation and mineralization of glyphosate herbicide was investigated using Ti/PbO 2 anode. The current intensity, treatment time, initial concentration and pH of solution are the influent parameters on the degradation efficiency. An experimental design methodology was applied to determine the optimal condition (in terms of cost/effectiveness) based on response surface methodology. Glyphosate concentration (C 0  = 16.9 mg L -1 ) decreased up to 0.6 mg L -1 when the optimal conditions were imposed (current intensity of 4.77 A and treatment time of 173 min). The removal efficiencies of glyphosate and total organic carbon were 95 ± 16% and 90.31%, respectively. This work demonstrates that electrochemical oxidation is a promising process for degradation and mineralization of glyphosate.

Intermittent micro-aeration control of methane emissions from an integrated vertical-flow constructed wetland during agricultural domestic wastewater treatment.

PubMed

Liu, Xiaoling; Zhang, Ke; Fan, Liangqian; Luo, Hongbing; Jiang, Mingshu; Anderson, Bruce C; Li, Mei; Huang, Bo; Yu, Lijuan; He, Guozhu; Wang, Jingting; Pu, Aiping

2018-06-16

It is very important to control methane emissions to mitigate global warming. An intermittent micro-aeration control system was used to control methane emissions from an integrated vertical-flow constructed wetland (IVCW) to treat agricultural domestic wastewater pollution in this study. The optimized intermittent micro-aeration conditions were a 20-min aeration time and 340-min non-aeration time, 3.9 m 3  h -1 aeration intensity, evenly distributed micro-aeration diffusers at the tank bottom, and an aeration period of every 6 h. Methane flux emission by intermittent micro-aeration was decreased by 60.7% under the optimized conditions. The average oxygen transfer efficiency was 26.73%. The control of CH 4 emission from IVCWs was most strongly influenced by the intermittent micro-aeration diffuser distribution, followed by aeration intensity, aeration time, and water depth. Scaling up of IVCWs is feasible in rural areas by using intermittent micro-aeration control as a mitigation measure for methane gas emissions for climate change.

A new paradigm for producing astaxanthin from the unicellular green alga Haematococcus pluvialis.

PubMed

Zhang, Zhen; Wang, Baobei; Hu, Qiang; Sommerfeld, Milton; Li, Yuanguang; Han, Danxiang

2016-10-01

The unicellular green alga Haematococcus pluvialis has been exploited as a cell factory to produce the high-value antioxidant astaxanthin for over two decades, due to its superior ability to synthesize astaxanthin under adverse culture conditions. However, slow vegetative growth under favorable culture conditions and cell deterioration or death under stress conditions (e.g., high light, nitrogen starvation) has limited the astaxanthin production. In this study, a new paradigm that integrated heterotrophic cultivation, acclimation of heterotrophically grown cells to specific light/nutrient regimes, followed by induction of astaxanthin accumulation under photoautotrophic conditions was developed. First, the environmental conditions such as pH, carbon source, nitrogen regime, and light intensity, were optimized to induce astaxanthin accumulation in the dark-grown cells. Although moderate astaxanthin content (e.g., 1% of dry weight) and astaxanthin productivity (2.5 mg L(-1)  day(-1) ) were obtained under the optimized conditions, a considerable number of cells died off when subjected to stress for astaxanthin induction. To minimize the susceptibility of dark-grown cells to light stress, the algal cells were acclimated, prior to light induction of astaxanthin biosynthesis, under moderate illumination in the presence of nitrogen. Introduction of this strategy significantly reduced the cell mortality rate under high-light and resulted in increased cellular astaxanthin content and astaxanthin productivity. The productivity of astaxanthin was further improved to 10.5 mg L(-1)  day(-1) by implementation of such a strategy in a bubbling column photobioreactor. Biochemical and physiological analyses suggested that rebuilding of photosynthetic apparatus including D1 protein and PsbO, and recovery of PSII activities, are essential for acclimation of dark-grown cells under photo-induction conditions. Biotechnol. Bioeng. 2016;113: 2088-2099. © 2016 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. © 2016 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

A new paradigm for producing astaxanthin from the unicellular green alga Haematococcus pluvialis

PubMed Central

Zhang, Zhen; Wang, Baobei; Hu, Qiang; Sommerfeld, Milton

2016-01-01

ABSTRACT The unicellular green alga Haematococcus pluvialis has been exploited as a cell factory to produce the high‐value antioxidant astaxanthin for over two decades, due to its superior ability to synthesize astaxanthin under adverse culture conditions. However, slow vegetative growth under favorable culture conditions and cell deterioration or death under stress conditions (e.g., high light, nitrogen starvation) has limited the astaxanthin production. In this study, a new paradigm that integrated heterotrophic cultivation, acclimation of heterotrophically grown cells to specific light/nutrient regimes, followed by induction of astaxanthin accumulation under photoautotrophic conditions was developed. First, the environmental conditions such as pH, carbon source, nitrogen regime, and light intensity, were optimized to induce astaxanthin accumulation in the dark‐grown cells. Although moderate astaxanthin content (e.g., 1% of dry weight) and astaxanthin productivity (2.5 mg L−1 day−1) were obtained under the optimized conditions, a considerable number of cells died off when subjected to stress for astaxanthin induction. To minimize the susceptibility of dark‐grown cells to light stress, the algal cells were acclimated, prior to light induction of astaxanthin biosynthesis, under moderate illumination in the presence of nitrogen. Introduction of this strategy significantly reduced the cell mortality rate under high‐light and resulted in increased cellular astaxanthin content and astaxanthin productivity. The productivity of astaxanthin was further improved to 10.5 mg L−1 day−1 by implementation of such a strategy in a bubbling column photobioreactor. Biochemical and physiological analyses suggested that rebuilding of photosynthetic apparatus including D1 protein and PsbO, and recovery of PSII activities, are essential for acclimation of dark‐grown cells under photo‐induction conditions. Biotechnol. Bioeng. 2016;113: 2088–2099. © 2016 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. PMID:27563850

Method and Process Development of Advanced Atmospheric Plasma Spraying for Thermal Barrier Coatings

NASA Astrophysics Data System (ADS)

Mihm, Sebastian; Duda, Thomas; Gruner, Heiko; Thomas, Georg; Dzur, Birger

2012-06-01

Over the last few years, global economic growth has triggered a dramatic increase in the demand for resources, resulting in steady rise in prices for energy and raw materials. In the gas turbine manufacturing sector, process optimizations of cost-intensive production steps involve a heightened potential of savings and form the basis for securing future competitive advantages in the market. In this context, the atmospheric plasma spraying (APS) process for thermal barrier coatings (TBC) has been optimized. A constraint for the optimization of the APS coating process is the use of the existing coating equipment. Furthermore, the current coating quality and characteristics must not change so as to avoid new qualification and testing. Using experience in APS and empirically gained data, the process optimization plan included the variation of e.g. the plasma gas composition and flow-rate, the electrical power, the arrangement and angle of the powder injectors in relation to the plasma jet, the grain size distribution of the spray powder and the plasma torch movement procedures such as spray distance, offset and iteration. In particular, plasma properties (enthalpy, velocity and temperature), powder injection conditions (injection point, injection speed, grain size and distribution) and the coating lamination (coating pattern and spraying distance) are examined. The optimized process and resulting coating were compared to the current situation using several diagnostic methods. The improved process significantly reduces costs and achieves the requirement of comparable coating quality. Furthermore, a contribution was made towards better comprehension of the APS of ceramics and the definition of a better method for future process developments.

First report of the production of a potent biosurfactant with α,β-trehalose by Fusarium fujikuroi under optimized conditions of submerged fermentation.

PubMed

Reis, Cristiane Bianchi Loureiro Dos; Morandini, Liziane Maria Barassuol; Bevilacqua, Caroline Borges; Bublitz, Fabricio; Ugalde, Gustavo; Mazutti, Marcio Antonio; Jacques, Rodrigo Josemar Seminoti

2018-04-24

Biosurfactants have many advantages over synthetic surfactants but have higher production costs. Identifying microorganisms with high production capacities for these molecules and optimizing their growth conditions can reduce cost. The present work aimed to isolate and identify a fungus with high biosurfactant production capacity, optimize its growth conditions in a low cost culture medium, and characterize the chemical structure of the biosurfactant molecule. The fungal strain UFSM-BAS-01 was isolated from soil contaminated with hydrocarbons and identified as Fusarium fujikuroi. To optimize biosurfactant production, a Plackett-Burman design and a central composite rotational design were used. The variables evaluated were pH, incubation period, temperature, agitation and amount of inoculum in a liquid medium containing glucose. The partial structure of the biosurfactant molecule was identified by nuclear magnetic resonance spectrometry. F. fujikuroi reduced surface tension from 72 to 20mNm -1 under the optimized conditions of pH 5.0, 37°C and 7 days of incubation with 190rpm agitation. The partial identification of the structure of the biosurfactant demonstrated the presence of an α,β-trehalose. The present study is the first report of the biosynthesis of this compound by F. fujikuroi, suggesting that the biosurfactant produced belongs to the class of trehalolipids. Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Numerical study on wake characteristics of high-speed trains

NASA Astrophysics Data System (ADS)

Yao, Shuan-Bao; Sun, Zhen-Xu; Guo, Di-Long; Chen, Da-Wei; Yang, Guo-Wei

2013-12-01

Intensive turbulence exists in the wakes of high speed trains, and the aerodynamic performance of the trailing car could deteriorate rapidly due to complicated features of the vortices in the wake zone. As a result, the safety and amenity of high speed trains would face a great challenge. This paper considers mainly the mechanism of vortex formation and evolution in the train flow field. A real CRH2 model is studied, with a leading car, a middle car and a trailing car included. Different running speeds and cross wind conditions are considered, and the approaches of unsteady Reynold-averaged Navier-Stokes (URANS) and detached eddy simulation (DES) are utilized, respectively. Results reveal that DES has better capability of capturing small eddies compared to URANS. However, for large eddies, the effects of two approaches are almost the same. In conditions without cross winds, two large vortex streets stretch from the train nose and interact strongly with each other in the wake zone. With the reinforcement of the ground, a complicated wake vortex system generates and becomes strengthened as the running speed increases. However, the locations of flow separations on the train surface and the separation mechanism keep unchanged. In conditions with cross winds, three large vortices develop along the leeward side of the train, among which the weakest one has no obvious influence on the wake flow while the other two stretch to the tail of the train and combine with the helical vortices in the train wake. Thus, optimization of the aerodynamic performance of the trailing car should be aiming at reducing the intensity of the wake vortex system.

Effects of Introduced Grasses, Grazing and Fire on Regional Biogeochemistry in Hawaii

NASA Astrophysics Data System (ADS)

Elmore, A. J.; Asner, G. P.

2003-12-01

African grasses introduced for grazing have expanded in geographic extent in mesic tropical systems of Hawaii and other regions of the world. Grassland expansion leads to increases in fire frequency, speeding woodland and forest destruction at greater geographic scales than occurs with grazing alone. At Pu'uwa'awa'a Ranch, Hawaii, restoration of the native woodland habitat has become a critical objective following the introduction and dominance of the African grass species Pennisetum clandestinum and P. setaceum. Grazing and grass-fueled fires have destroyed over 60% of the original forest. To stabilize these communities, managers must balance the combined effects of grazing and fire. Grazing reduces the recruitment success of native tropical trees, but grazing also reduces fire risk by moderating grass fuel conditions and restricting the extent and density of the most flammable grass species. Our study focuses on two questions: (1) What grazing intensity is necessary to change the fire conditions of a region given in situ soil and precipitation conditions? (2) Have long-term grazing conditions altered soil carbon and nitrogen stocks? We used high resolution imaging spectrometer data to measure photosynthetic and non-photosynthetic vegetation cover, analysis of soil carbon and nitrogen stocks, and measurements of plant community composition along gradients in grazing intensity. P. setaceum, the more flammable alien grass, was dominant where grazing intensity was low and at lower elevations where precipitation is low. The less flammable grass, P. clandestinum, occurred in regions of high grazing intensity and higher precipitation. Grazing influenced the dominance of P. setaceum and P. clandestinum only where precipitation and soil characteristics were suitable for both grasses to occur. At suitable sites, grazing reduced fire conditions through a species sift towards P. clandestinum. Soil carbon and nitrogen stocks decreased with grazing intensity, which was correlated with the fractional cover of P. setaceum. Soil carbon also increased with precipitation. These results show how grazing impacts fire conditions and soil chemistry through changes in species composition, and not through removal of carbon inputs (direct removal of biomass).

Intensive motivational interviewing for women with concurrent alcohol problems and methamphetamine dependence.

PubMed

Korcha, Rachael A; Polcin, Douglas L; Evans, Kristy; Bond, Jason C; Galloway, Gantt P

2014-02-01

Motivational interviewing (MI) for the treatment of alcohol and drug problems is typically conducted over 1 to 3 sessions. The current work evaluates an intensive 9-session version of MI (Intensive MI) compared to a standard single MI session (Standard MI) using 163 methamphetamine (MA) dependent individuals. The primary purpose of this paper is to report the unexpected finding that women with co-occurring alcohol problems in the Intensive MI condition reduced the severity of their alcohol problems significantly more than women in the Standard MI condition at the 6-month follow-up. Stronger perceived alliance with the therapist was inversely associated with alcohol problem severity scores. Findings indicate that Intensive MI is a beneficial treatment for alcohol problems among women with MA dependence. © 2013.

Center for Technology for Advanced Scientific Componet Software (TASCS)

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

Govindaraju, Madhusudhan

Advanced Scientific Computing Research Computer Science FY 2010Report Center for Technology for Advanced Scientific Component Software: Distributed CCA State University of New York, Binghamton, NY, 13902 Summary The overall objective of Binghamton's involvement is to work on enhancements of the CCA environment, motivated by the applications and research initiatives discussed in the proposal. This year we are working on re-focusing our design and development efforts to develop proof-of-concept implementations that have the potential to significantly impact scientific components. We worked on developing parallel implementations for non-hydrostatic code and worked on a model coupling interface for biogeochemical computations coded in MATLAB.more » We also worked on the design and implementation modules that will be required for the emerging MapReduce model to be effective for scientific applications. Finally, we focused on optimizing the processing of scientific datasets on multi-core processors. Research Details We worked on the following research projects that we are working on applying to CCA-based scientific applications. 1. Non-Hydrostatic Hydrodynamics: Non-static hydrodynamics are significantly more accurate at modeling internal waves that may be important in lake ecosystems. Non-hydrostatic codes, however, are significantly more computationally expensive, often prohibitively so. We have worked with Chin Wu at the University of Wisconsin to parallelize non-hydrostatic code. We have obtained a speed up of about 26 times maximum. Although this is significant progress, we hope to improve the performance further, such that it becomes a practical alternative to hydrostatic codes. 2. Model-coupling for water-based ecosystems: To answer pressing questions about water resources requires that physical models (hydrodynamics) be coupled with biological and chemical models. Most hydrodynamics codes are written in Fortran, however, while most ecologists work in MATLAB. This disconnect creates a great barrier. To address this, we are working on a model coupling interface that will allow biogeochemical computations written in MATLAB to couple with Fortran codes. This will greatly improve the productivity of ecosystem scientists. 2. Low overhead and Elastic MapReduce Implementation Optimized for Memory and CPU-Intensive Applications: Since its inception, MapReduce has frequently been associated with Hadoop and large-scale datasets. Its deployment at Amazon in the cloud, and its applications at Yahoo! for large-scale distributed document indexing and database building, among other tasks, have thrust MapReduce to the forefront of the data processing application domain. The applicability of the paradigm however extends far beyond its use with data intensive applications and diskbased systems, and can also be brought to bear in processing small but CPU intensive distributed applications. MapReduce however carries its own burdens. Through experiments using Hadoop in the context of diverse applications, we uncovered latencies and delay conditions potentially inhibiting the expected performance of a parallel execution in CPU-intensive applications. Furthermore, as it currently stands, MapReduce is favored for data-centric applications, and as such tends to be solely applied to disk-based applications. The paradigm, falls short in bringing its novelty to diskless systems dedicated to in-memory applications, and compute intensive programs processing much smaller data, but requiring intensive computations. In this project, we focused both on the performance of processing large-scale hierarchical data in distributed scientific applications, as well as the processing of smaller but demanding input sizes primarily used in diskless, and memory resident I/O systems. We designed LEMO-MR [1], a Low overhead, elastic, configurable for in- memory applications, and on-demand fault tolerance, an optimized implementation of MapReduce, for both on disk and in memory applications. We conducted experiments to identify not only the necessary components of this model, but also trade offs and factors to be considered. We have initial results to show the efficacy of our implementation in terms of potential speedup that can be achieved for representative data sets used by cloud applications. We have quantified the performance gains exhibited by our MapReduce implementation over Apache Hadoop in a compute intensive environment. 3. Cache Performance Optimization for Processing XML and HDF-based Application Data on Multi-core Processors: It is important to design and develop scientific middleware libraries to harness the opportunities presented by emerging multi-core processors. Implementations of scientific middleware and applications that do not adapt to the programming paradigm when executing on emerging processors can severely impact the overall performance. In this project, we focused on the utilization of the L2 cache, which is a critical shared resource on chip multiprocessors (CMP). The access pattern of the shared L2 cache, which is dependent on how the application schedules and assigns processing work to each thread, can either enhance or hurt the ability to hide memory latency on a multi-core processor. Therefore, while processing scientific datasets such as HDF5, it is essential to conduct fine-grained analysis of cache utilization, to inform scheduling decisions in multi-threaded programming. In this project, using the TAU toolkit for performance feedback from dual- and quad-core machines, we conducted performance analysis and recommendations on how processing threads can be scheduled on multi-core nodes to enhance the performance of a class of scientific applications that requires processing of HDF5 data. In particular, we quantified the gains associated with the use of the adaptations we have made to the Cache-Affinity and Balanced-Set scheduling algorithms to improve L2 cache performance, and hence the overall application execution time [2]. References: 1. Zacharia Fadika, Madhusudhan Govindaraju, ``MapReduce Implementation for Memory-Based and Processing Intensive Applications'', accepted in 2nd IEEE International Conference on Cloud Computing Technology and Science, Indianapolis, USA, Nov 30 - Dec 3, 2010. 2. Rajdeep Bhowmik, Madhusudhan Govindaraju, ``Cache Performance Optimization for Processing XML-based Application Data on Multi-core Processors'', in proceedings of The 10th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing, May 17-20, 2010, Melbourne, Victoria, Australia. Contact Information: Madhusudhan Govindaraju Binghamton University State University of New York (SUNY) mgovinda@cs.binghamton.edu Phone: 607-777-4904« less

Optimization of headspace solid phase micro-extraction of volatile compounds from papaya fruit assisted by GC-olfactometry.

PubMed

da Rocha, Renier Felinto Julião; da Silva Araújo, Ídila Maria; de Freitas, Sílvia Maria; Dos Santos Garruti, Deborah

2017-11-01

Optimization of the extraction conditions to investigate the volatile composition of papaya fruit involving headspace solid phase micro-extraction was carried out using multivariate strategies such as factorial design and response surface methodology. The performance of different combinations of time for reaching the equilibrium in the headspace and time for maximum extraction of volatiles was evaluated by GC-olfactometry of the extract (intensity of papaya characteristic aroma), number of peaks and total area in the chromatogram. Thirty-two compounds were identified by GC-MS under the optimized extraction conditions, the majority of which were aldehydes, both in number of compounds and area. Major compounds were δ-octalactone, β-citral, benzaldehyde, heptanal, benzyl isothiocyanate, isoamyl acetate, γ-octalactone, (E)-linalool oxide and benzyl alcohol. Seven aldehydes and two other compounds are reported for the first time in papaya's volatile profile.

Successful reduced-intensity stem cell transplantation with cord blood for a poor-prognosis adult with refractory chronic active epstein-barr virus infection.

PubMed

Nakagawa, Masao; Hashino, Satoshi; Takahata, Mutsumi; Kawamura, Takahito; Fujisawa, Fumie; Kahata, Kaoru; Kondo, Takeshi; Imamura, Masahiro; Ando, Sachiko; Asaka, Masahiro

2007-06-01

A 56-year-old woman with a poor-prognosis chronic active Epstein-Barr virus (CAEBV) infection underwent reduced-intensity stem cell transplantation (RIST) using cryopreserved cord blood (CB). Administration of EBV-seronegative CB cells following a reduced-intensity conditioning regimen was effective and well tolerated. Complete remission with no symptoms, low titers of EBV-related antibodies, and an undetectable level of EBV DNA in peripheral blood mononuclear cells continued for 16 months after RIST. This report is the first of successful RIST with CB for an adult with CAEBV infection. The results also show that a graft-versus-CAEBV effect can be achieved in an allogeneic hematopoietic stem cell transplantation setting.

Inhibition of brain tumor cell proliferation by alternating electric fields

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

Jeong, Hyesun; Oh, Seung-ick; Hong, Sunghoi, E-mail: shong21@korea.ac.kr, E-mail: radioyoon@korea.ac.kr

2014-11-17

This study was designed to investigate the mechanism by which electric fields affect cell function, and to determine the optimal conditions for electric field inhibition of cancer cell proliferation. Low-intensity (<2 V/cm) and intermediate-frequency (100–300 kHz) alternating electric fields were applied to glioblastoma cell lines. These electric fields inhibited cell proliferation by inducing cell cycle arrest and abnormal mitosis due to the malformation of microtubules. These effects were significantly dependent on the intensity and frequency of applied electric fields.

Effects of various LED light wavelengths and intensities on microalgae-based simultaneous biogas upgrading and digestate nutrient reduction process.

PubMed

Zhao, Yongjun; Wang, Juan; Zhang, Hui; Yan, Cheng; Zhang, Yuejin

2013-05-01

Biogas is a well-known, primary renewable energy source, but its utilizations are possible only after upgrading. The microalgae-based bag photo-bioreactor utilized in this research could effectively upgrade biogas and simultaneously reduce the nutrient content in digestate. Red light was determined as the optimal light wavelength for microalgae growth, biogas upgrading, and digestate nutrient reduction. In the range of moderate light intensities (i.e., 800, 1200, 1600, and 2000 μmol m(-2) s(-1)), higher light intensities achieved higher biogas upgrade and larger digestate nutrient reduction. Methane content attained the highest value of 92.74±3.56% (v/v). The highest chemical oxygen demand, total nitrogen, and total phosphorus reduction efficiency of digestate were 85.35±1.04%, 77.98±1.84%, and 73.03±2.14%, respectively. Considering the reduction and economic efficiencies of the carbon dioxide content of biogas and digestate nutrient as well as the biogas upgrading standard, the optimal light intensity range was determined to be from 1200 to 1600 μmol m(-2) s(-1). Copyright © 2013 Elsevier Ltd. All rights reserved.

PRECISE - pregabalin in addition to usual care for sciatica: study protocol for a randomised controlled trial

PubMed Central

2013-01-01

Background Sciatica is a type of neuropathic pain that is characterised by pain radiating into the leg. It is often accompanied by low back pain and neurological deficits in the lower limb. While this condition may cause significant suffering for the individual, the lack of evidence supporting effective treatments for sciatica makes clinical management difficult. Our objectives are to determine the efficacy of pregabalin on reducing leg pain intensity and its cost-effectiveness in patients with sciatica. Methods/Design PRECISE is a prospectively registered, double-blind, randomised placebo-controlled trial of pregabalin compared to placebo, in addition to usual care. Inclusion criteria include moderate to severe leg pain below the knee with evidence of nerve root/spinal nerve involvement. Participants will be randomised to receive either pregabalin with usual care (n = 102) or placebo with usual care (n = 102) for 8 weeks. The medicine dosage will be titrated up to the participant’s optimal dose, to a maximum 600 mg per day. Follow up consultations will monitor individual progress, tolerability and adverse events. Usual care, if deemed appropriate by the study doctor, may include a referral for physical or manual therapy and/or prescription of analgesic medication. Participants, doctors and researchers collecting participant data will be blinded to treatment allocation. Participants will be assessed at baseline and at weeks 2, 4, 8, 12, 26 and 52. The primary outcome will determine the efficacy of pregabalin in reducing leg pain intensity. Secondary outcomes will include back pain intensity, disability and quality of life. Data analysis will be blinded and by intention-to-treat. A parallel economic evaluation will be conducted from health sector and societal perspectives. Discussion This study will establish the efficacy of pregabalin in reducing leg pain intensity in patients with sciatica and provide important information regarding the effect of pregabalin treatment on disability and quality of life. The impact of this research may allow the future development of a cost-effective conservative treatment strategy for patients with sciatica. Trial registration ClinicalTrial.gov, ACTRN 12613000530729 PMID:23845078

PRECISE - pregabalin in addition to usual care for sciatica: study protocol for a randomised controlled trial.

PubMed

Mathieson, Stephanie; Maher, Christopher G; McLachlan, Andrew J; Latimer, Jane; Koes, Bart W; Hancock, Mark J; Harris, Ian; Day, Richard O; Pik, Justin; Jan, Stephen; Billot, Laurent; Lin, Chung-Wei Christine

2013-07-11

Sciatica is a type of neuropathic pain that is characterised by pain radiating into the leg. It is often accompanied by low back pain and neurological deficits in the lower limb. While this condition may cause significant suffering for the individual, the lack of evidence supporting effective treatments for sciatica makes clinical management difficult. Our objectives are to determine the efficacy of pregabalin on reducing leg pain intensity and its cost-effectiveness in patients with sciatica. PRECISE is a prospectively registered, double-blind, randomised placebo-controlled trial of pregabalin compared to placebo, in addition to usual care. Inclusion criteria include moderate to severe leg pain below the knee with evidence of nerve root/spinal nerve involvement. Participants will be randomised to receive either pregabalin with usual care (n = 102) or placebo with usual care (n = 102) for 8 weeks. The medicine dosage will be titrated up to the participant's optimal dose, to a maximum 600 mg per day. Follow up consultations will monitor individual progress, tolerability and adverse events. Usual care, if deemed appropriate by the study doctor, may include a referral for physical or manual therapy and/or prescription of analgesic medication. Participants, doctors and researchers collecting participant data will be blinded to treatment allocation. Participants will be assessed at baseline and at weeks 2, 4, 8, 12, 26 and 52. The primary outcome will determine the efficacy of pregabalin in reducing leg pain intensity. Secondary outcomes will include back pain intensity, disability and quality of life. Data analysis will be blinded and by intention-to-treat. A parallel economic evaluation will be conducted from health sector and societal perspectives. This study will establish the efficacy of pregabalin in reducing leg pain intensity in patients with sciatica and provide important information regarding the effect of pregabalin treatment on disability and quality of life. The impact of this research may allow the future development of a cost-effective conservative treatment strategy for patients with sciatica. ClinicalTrial.gov, ACTRN 12613000530729.

Recent decrease in typhoon destructive potential and global warming implications.

PubMed

Lin, I-I; Chan, Johnny C L

2015-05-20

Typhoons (tropical cyclones) severely impact the half-billion population of the Asian Pacific. Intriguingly, during the recent decade, typhoon destructive potential (Power Dissipation Index, PDI) has decreased considerably (by ∼ 35%). This decrease, paradoxically, has occurred despite the increase in typhoon intensity and ocean warming. Using the method proposed by Emanuel (in 2007), we show that the stronger negative contributions from typhoon frequency and duration, decrease to cancel the positive contribution from the increasing intensity, controlling the PDI. Examining the typhoons' environmental conditions, we find that although the ocean condition became more favourable (warming) in the recent decade, the atmospheric condition 'worsened' at the same time. The 'worsened' atmospheric condition appears to effectively overpower the 'better' ocean conditions to suppress PDI. This stronger negative contribution from reduced typhoon frequency over the increased intensity is also present under the global warming scenario, based on analysis of the simulated typhoon data from high-resolution modelling.

The choice of optimal antireflux procedure after laparoscopic cardiomyotomy: two decades of clinical experience in one center

PubMed Central

Kiudelis, Mindaugas; Sakalys, Egidijus; Jonaitis, Laimas; Mickevicius, Antanas; Endzinas, Zilvinas

2017-01-01

Introduction Two types of partial wrap are commonly performed in achalasia patients after Heller myotomy: the posterior 270° fundoplication (Toupet) and the anterior 180° fundoplication (Dor). The optimal type of fundoplication (posterior vs. anterior) is still debated. Aim To compare the long-term rates of dysphagia, reflux symptoms and patient satisfaction with current postoperative condition between two fundoplication groups in achalasia treatment. Material and methods Our retrospective study included 97 consecutive patients with achalasia: 37 patients underwent laparoscopic posterior Toupet (270°) fundoplication followed by Heller myotomy (group I); 60 patients underwent laparoscopic anterior partial Dor fundoplication followed by Heller myotomy (group II). Long-term follow-up results included evaluation of dysphagia symptoms, intensity of heartburn and patient satisfaction with current condition. Results Patients in these two groups did not differ according to age, weight, height, postoperative stay or follow-up period. Laparoscopic myotomy with posterior Toupet fundoplication was effective in 89% of patients, while laparoscopic myotomy with anterior Dor was effective in 93% of patients (p > 0.05). 11% of patients after posterior Toupet fundoplication had clinically significant heartburn vs. 35% of patients after anterior Dor fundoplication (p < 0.05). Overall patient satisfaction with current condition was 88%, with no significant difference between the groups. Conclusions According to our study results, the two laparoscopic techniques were similarly effective in reducing achalasia symptoms, but postoperative clinical manifestation of heartburn is significantly more frequent after anterior Dor fundoplication (35% vs. 11%). The majority of patients (88%) were satisfied with operation outcomes. PMID:29062443

Synthesis of silver nanoparticles by solar irradiation of cell-free Bacillus amyloliquefaciens extracts and AgNO3.

PubMed

Wei, Xuetuan; Luo, Mingfang; Li, Wei; Yang, Liangrong; Liang, Xiangfeng; Xu, Lin; Kong, Peng; Liu, Huizhou

2012-01-01

Silver nanoparticles (AgNPs) were obtained by solar irradiation of cell-free extracts of Bacillusamyloliquefaciens and AgNO3. Light intensity, extract concentration, and NaCl addition influenced the synthesis of AgNPs. Under optimized conditions (solar intensity 70,000 lx, extract concentration 3 mg/mL, and NaCl content 2 mM), 98.23±0.06% of the Ag+ (1 mM) was reduced to AgNPs within 80 min, and the ζ-potential of AgNPs reached -70.84±0.66 mV. TEM (Transmission electron microscopy) and XRD (X-ray diffraction) analysis confirmed that circular and triangular crystalline AgNPs with mean diameter of 14.6 nm were synthesized. Since heat-inactivated extracts also mediated the formation of AgNPs, enzymatic reactions are likely not involved in AgNPs formation. A high absolute ζ-potential value of the AgNPs, possibly caused by interaction with proteins likely explains the high stability of AgNPs suspensions. AgNPs showed antimicrobial activity against Bacillussubtilis and Escherichiacoli in liquid and solid medium. Copyright © 2011 Elsevier Ltd. All rights reserved.

Towards dosimetry for photodynamic diagnosis with the low-level dose of photosensitizer.

PubMed

Buzalewicz, Igor; Hołowacz, Iwona; Ulatowska-Jarża, Agnieszka; Podbielska, Halina

2017-08-01

Contemporary medicine does not concern the issue of dosimetry in photodynamic diagnosis (PDD) but follows the photosensitizer (PS) producers recommendation. Most preclinical and clinical PDD studies indicate a considerable variation in the possibility of visualization and treatment, as e.g. in case of cervix lesions. Although some of these variations can be caused by the different histological subtypes or various tumor geometries, the issue of varying PS concentration in the tumor tissue volume is definitely an important factor. Therefore, there is a need to establish the objective and systematic PDD dosimetry protocol regarding doses of light and photosensitizers. Four different irradiation sources investigated in PDD (literature) were used for PS excitation. The PS luminescence was examined by means of the non-imaging (spectroscopic) and imaging (wide- and narrow-field of view) techniques. The methodology for low-level intensity photoluminescence (PL) characterization and dedicated image processing algorithm for PS luminescence images analysis were proposed. Further, HeLa cells' cultures penetration by PS was studied by a confocal microscopy. Reducing the PS dose with the choice of proper photoexcitation conditions decreases the PDD procedure costs and the side effects, not affecting the diagnostic efficiency. We determined in vitro the minimum incubation time and photosensitizer concentration of Photolon for diagnostic purposes, for which the Photolon PL can still be observed. It was demonstrated that quantification of PS concentration, choice of proper photoexcitation source, appropriate adjustment of light dose and PS penetration of cancer cells may improve the low-level luminescence photodynamic diagnostics performance. Practical effectiveness of the PDD strongly depends on irradiation source parameters (bandwidth, maximum intensity, half-width) and their optimization is the main conditioning factor for low-level intensity and low-cost PDD. Copyright © 2017 Elsevier B.V. All rights reserved.

Improved luminescence properties of MoS2 monolayers grown via MOCVD: role of pre-treatment and growth parameters

NASA Astrophysics Data System (ADS)

Andrzejewski, D.; Marx, M.; Grundmann, A.; Pfingsten, O.; Kalisch, H.; Vescan, A.; Heuken, M.; Kümmell, T.; Bacher, G.

2018-07-01

Fabrication of transition metal dichalcogenides (TMDCs) via metalorganic chemical vapor deposition (MOCVD) represents one of the most attractive routes to large-scale 2D material layers. Although good homogeneity and electrical conductance have been reported recently, the relation between growth parameters and photoluminescence (PL) intensity—one of the most important parameters for optoelectronic applications—has not yet been discussed for MOCVD TMDCs. In this work, MoS2 is grown via MOCVD on sapphire (0001) substrates using molybdenum hexacarbonyl (Mo(CO)6, MCO) and di-tert-butyl sulphide as precursor materials. A prebake step under H2 atmosphere combined with a reduced MCO precursor flow increases the crystal grain size by one order of magnitude and strongly enhances PL intensity with a clear correlation to the grain size. A decrease of the linewidth of both Raman resonances and PL spectra down to full width at half maxima of 3.2 cm‑1 for the E 2g Raman mode and 60 meV for the overall PL spectrum indicate a reduced defect density at optimized growth conditions.

Capillary electrophoresis with gold nanoparticles enhanced electrochemiluminescence for the detection of roxithromycin.

PubMed

Wang, Jingwu; Yang, Zhiming; Wang, Xiaoxia; Yang, Nianjun

2008-06-30

Tris(2,2'-bipyridyl) ruthenium(II) (Ru(bpy)(3)(2+))-roxithromycin based electrochemiluminescence (ECL) was enhanced greatly by gold nanoparticles 10 nm in diameter. Capillary electrophoresis (CE) was coupled with the resultant ECL system as a detector for roxithromycin. This ECL emission is explained by the coreactant mechanism where roxithromycin behaves as a coreactant to generate strong reducing species and gold nanoparticles act as "floating nanoelectrodes". The reaction of Ru(bpy)(3)(3+) with the generated strong reducing species on the Pt working electrode as well as on "floating nanoelectrodes" releases Ru(bpy)(3)(2+*), resulting in enhancement of ECL emission. The selectivity of this detection system towards roxithromycin was examined by CE. Under the optimized conditions, the intensity of ECL emission varies linearly with the concentration of roxithromycin from 24 nM to 0.24 mM. The detection limit is 8.4 nM, while without adding gold nanoparticles it is only 84 nM. The detection of roxithromycin in pharmaceutical and urine samples was also performed by the proposed CE-ECL method.

INTEGRATION OF COST MODELS AND PROCESS SIMULATION TOOLS FOR OPTIMUM COMPOSITE MANUFACTURING PROCESS

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

Pack, Seongchan; Wilson, Daniel; Aitharaju, Venkat

Manufacturing cost of resin transfer molded composite parts is significantly influenced by the cycle time, which is strongly related to the time for both filling and curing of the resin in the mold. The time for filling can be optimized by various injection strategies, and by suitably reducing the length of the resin flow distance during the injection. The curing time can be reduced by the usage of faster curing resins, but it requires a high pressure injection equipment, which is capital intensive. Predictive manufacturing simulation tools that are being developed recently for composite materials are able to provide variousmore » scenarios of processing conditions virtually well in advance of manufacturing the parts. In the present study, we integrate the cost models with process simulation tools to study the influence of various parameters such as injection strategies, injection pressure, compression control to minimize high pressure injection, resin curing rate, and demold time on the manufacturing cost as affected by the annual part volume. A representative automotive component was selected for the study and the results are presented in this paper« less

Joint subchannel pairing and power control for cognitive radio networks with amplify-and-forward relaying.

PubMed

Shen, Yanyan; Wang, Shuqiang; Wei, Zhiming

2014-01-01

Dynamic spectrum sharing has drawn intensive attention in cognitive radio networks. The secondary users are allowed to use the available spectrum to transmit data if the interference to the primary users is maintained at a low level. Cooperative transmission for secondary users can reduce the transmission power and thus improve the performance further. We study the joint subchannel pairing and power allocation problem in relay-based cognitive radio networks. The objective is to maximize the sum rate of the secondary user that is helped by an amplify-and-forward relay. The individual power constraints at the source and the relay, the subchannel pairing constraints, and the interference power constraints are considered. The problem under consideration is formulated as a mixed integer programming problem. By the dual decomposition method, a joint optimal subchannel pairing and power allocation algorithm is proposed. To reduce the computational complexity, two suboptimal algorithms are developed. Simulations have been conducted to verify the performance of the proposed algorithms in terms of sum rate and average running time under different conditions.

SU-E-T-368: Evaluating Dosimetric Outcome of Modulated Photon Radiotherapy (XMRT) Optimization for Head and Neck Patients

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

McGeachy, P; Villarreal-Barajas, JE; Khan, R

2015-06-15

Purpose: The dosimetric outcome of optimized treatment plans obtained by modulating the photon beamlet energy and fluence on a small cohort of four Head and Neck (H and N) patients was investigated. This novel optimization technique is denoted XMRT for modulated photon radiotherapy. The dosimetric plans from XMRT for H and N treatment were compared to conventional, 6 MV intensity modulated radiotherapy (IMRT) optimization plans. Methods: An arrangement of two non-coplanar and five coplanar beams was used for all four H and N patients. Both XMRT and IMRT were subject to the same optimization algorithm, with XMRT optimization allowing bothmore » 6 and 18 MV beamlets while IMRT was restricted to 6 MV only. The optimization algorithm was based on a linear programming approach with partial-volume constraints implemented via the conditional value-at-risk method. H and N constraints were based off of those mentioned in the Radiation Therapy Oncology Group 1016 protocol. XMRT and IMRT solutions were assessed using metrics suggested by International Commission on Radiation Units and Measurements report 83. The Gurobi solver was used in conjunction with the CVX package to solve each optimization problem. Dose calculations and analysis were done in CERR using Monte Carlo dose calculation with VMC{sub ++}. Results: Both XMRT and IMRT solutions met all clinical criteria. Trade-offs were observed between improved dose uniformity to the primary target volume (PTV1) and increased dose to some of the surrounding healthy organs for XMRT compared to IMRT. On average, IMRT improved dose to the contralateral parotid gland and spinal cord while XMRT improved dose to the brainstem and mandible. Conclusion: Bi-energy XMRT optimization for H and N patients provides benefits in terms of improved dose uniformity to the primary target and reduced dose to some healthy structures, at the expense of increased dose to other healthy structures when compared with IMRT.« less

Remediation System Design Optimization: Field Demonstration at the Umatilla Army Deport

NASA Astrophysics Data System (ADS)

Zheng, C.; Wang, P. P.

2002-05-01

Since the early 1980s, many researchers have shown that the simulation-optimization (S/O) approach is superior to the traditional trial-and-error method for designing cost-effective groundwater pump-and-treat systems. However, the application of the S/O approach to real field problems has remained limited. This paper describes the application of a new general simulation-optimization code to optimize an existing pump-and-treat system at the Umatilla Army Depot in Oregon, as part of a field demonstration project supported by the Environmental Security Technology Certification Program (ESTCP). Two optimization formulations were developed to minimize the total capital and operational costs under the current and possibly expanded treatment plant capacities. A third formulation was developed to minimize the total contaminant mass of RDX and TNT remaining in the shallow aquifer by the end of the project duration. For the first two formulations, this study produced an optimal pumping strategy that would achieve the cleanup goal in 4 years with a total cost of 1.66 million US dollars in net present value. For comparison, the existing design in operation was calculated to require 17 years for cleanup with a total cost of 3.83 million US dollars in net present value. Thus, the optimal pumping strategy represents a reduction of 13 years in cleanup time and a reduction of 56.6 percent in the expected total expenditure. For the third formulation, this study identified an optimal dynamic pumping strategy that would reduce the total mass remaining in the shallow aquifer by 89.5 percent compared with that calculated for the existing design. In spite of their intensive computational requirements, this study shows that the global optimization techniques including tabu search and genetic algorithms can be applied successfully to large-scale field problems involving multiple contaminants and complex hydrogeological conditions.

A homotopy algorithm for digital optimal projection control GASD-HADOC

NASA Technical Reports Server (NTRS)

Collins, Emmanuel G., Jr.; Richter, Stephen; Davis, Lawrence D.

1993-01-01

The linear-quadratic-gaussian (LQG) compensator was developed to facilitate the design of control laws for multi-input, multi-output (MIMO) systems. The compensator is computed by solving two algebraic equations for which standard closed-loop solutions exist. Unfortunately, the minimal dimension of an LQG compensator is almost always equal to the dimension of the plant and can thus often violate practical implementation constraints on controller order. This deficiency is especially highlighted when considering control-design for high-order systems such as flexible space structures. This deficiency motivated the development of techniques that enable the design of optimal controllers whose dimension is less than that of the design plant. A homotopy approach based on the optimal projection equations that characterize the necessary conditions for optimal reduced-order control. Homotopy algorithms have global convergence properties and hence do not require that the initializing reduced-order controller be close to the optimal reduced-order controller to guarantee convergence. However, the homotopy algorithm previously developed for solving the optimal projection equations has sublinear convergence properties and the convergence slows at higher authority levels and may fail. A new homotopy algorithm for synthesizing optimal reduced-order controllers for discrete-time systems is described. Unlike the previous homotopy approach, the new algorithm is a gradient-based, parameter optimization formulation and was implemented in MATLAB. The results reported may offer the foundation for a reliable approach to optimal, reduced-order controller design.

High-intensity interval exercise and cerebrovascular health: curiosity, cause, and consequence

PubMed Central

Lucas, Samuel J E; Cotter, James D; Brassard, Patrice; Bailey, Damian M

2015-01-01

Exercise is a uniquely effective and pluripotent medicine against several noncommunicable diseases of westernised lifestyles, including protection against neurodegenerative disorders. High-intensity interval exercise training (HIT) is emerging as an effective alternative to current health-related exercise guidelines. Compared with traditional moderate-intensity continuous exercise training, HIT confers equivalent if not indeed superior metabolic, cardiac, and systemic vascular adaptation. Consequently, HIT is being promoted as a more time-efficient and practical approach to optimize health thereby reducing the burden of disease associated with physical inactivity. However, no studies to date have examined the impact of HIT on the cerebrovasculature and corresponding implications for cognitive function. This review critiques the implications of HIT for cerebrovascular function, with a focus on the mechanisms and translational impact for patient health and well-being. It also introduces similarly novel interventions currently under investigation as alternative means of accelerating exercise-induced cerebrovascular adaptation. We highlight a need for studies of the mechanisms and thereby also the optimal dose-response strategies to guide exercise prescription, and for studies to explore alternative approaches to optimize exercise outcomes in brain-related health and disease prevention. From a clinical perspective, interventions that selectively target the aging brain have the potential to prevent stroke and associated neurovascular diseases. PMID:25833341

High-intensity interval exercise and cerebrovascular health: curiosity, cause, and consequence.

PubMed

Lucas, Samuel J E; Cotter, James D; Brassard, Patrice; Bailey, Damian M

2015-06-01

Exercise is a uniquely effective and pluripotent medicine against several noncommunicable diseases of westernised lifestyles, including protection against neurodegenerative disorders. High-intensity interval exercise training (HIT) is emerging as an effective alternative to current health-related exercise guidelines. Compared with traditional moderate-intensity continuous exercise training, HIT confers equivalent if not indeed superior metabolic, cardiac, and systemic vascular adaptation. Consequently, HIT is being promoted as a more time-efficient and practical approach to optimize health thereby reducing the burden of disease associated with physical inactivity. However, no studies to date have examined the impact of HIT on the cerebrovasculature and corresponding implications for cognitive function. This review critiques the implications of HIT for cerebrovascular function, with a focus on the mechanisms and translational impact for patient health and well-being. It also introduces similarly novel interventions currently under investigation as alternative means of accelerating exercise-induced cerebrovascular adaptation. We highlight a need for studies of the mechanisms and thereby also the optimal dose-response strategies to guide exercise prescription, and for studies to explore alternative approaches to optimize exercise outcomes in brain-related health and disease prevention. From a clinical perspective, interventions that selectively target the aging brain have the potential to prevent stroke and associated neurovascular diseases.

Structural impact detection with vibro-haptic interfaces

NASA Astrophysics Data System (ADS)

Jung, Hwee-Kwon; Park, Gyuhae; Todd, Michael D.

2016-07-01

This paper presents a new sensing paradigm for structural impact detection using vibro-haptic interfaces. The goal of this study is to allow humans to ‘feel’ structural responses (impact, shape changes, and damage) and eventually determine health conditions of a structure. The target applications for this study are aerospace structures, in particular, airplane wings. Both hardware and software components are developed to realize the vibro-haptic-based impact detection system. First, L-shape piezoelectric sensor arrays are deployed to measure the acoustic emission data generated by impacts on a wing. Unique haptic signals are then generated by processing the measured acoustic emission data. These haptic signals are wirelessly transmitted to human arms, and with vibro-haptic interface, human pilots could identify impact location, intensity and possibility of subsequent damage initiation. With the haptic interface, the experimental results demonstrate that human could correctly identify such events, while reducing false indications on structural conditions by capitalizing on human’s classification capability. Several important aspects of this study, including development of haptic interfaces, design of optimal human training strategies, and extension of the haptic capability into structural impact detection are summarized in this paper.

Preliminary Estimates of the Possibilities for Developing a Deployable Greenhouse for a Planetary Surface (Mars)

NASA Technical Reports Server (NTRS)

Rygalov, V. Y.; Bucklin, R. A.; Fowler, P. A.; Wheeler, R. M.

2000-01-01

Two of the main conditions for plant growth and development on the Martian surface are irradiation (optimal range from 80 W/sq m to 180 W/sq m of photosynthetically active radiation) and temperature (optimal range from 20 C to 27 C). The only known natural source of energy on Mars is sunlight, with a general intensity of 589 +/- 142 W/sq m (Martian Solar Constant). Comparisons of plant growth requirements with conditions on the Martian surface are presented in Table 1, while some basic considerations for implementing plant growth in a Martian DG are presented in Table 2. The general scenario and approximate schedule of startup and development of operations in DG are shown in Table 3.

Optimization of Training Sets For Neural-Net Processing of Characteristic Patterns From Vibrating Solids

NASA Technical Reports Server (NTRS)

Decker, Arthur J. (Inventor)

2006-01-01

An artificial neural network is disclosed that processes holography generated characteristic pattern of vibrating structures along with finite-element models. The present invention provides for a folding operation for conditioning training sets for optimally training forward-neural networks to process characteristic fringe pattern. The folding pattern increases the sensitivity of the feed-forward network for detecting changes in the characteristic pattern The folding routine manipulates input pixels so as to be scaled according to the location in an intensity range rather than the position in the characteristic pattern.

[Dynamics of tooth decay prevalence in children receiving long-term preventive program in school dental facilities].

PubMed

Avraamova, O G; Kulazhenko, T V; Gabitova, K F

2016-01-01

The paper presents the assessment of tooth decay prevalence in clinically homogenous groups of children receiving long-term preventive program (PP) in school dental facilities. Five-years PP were introduced in clinical practice in 2 Moscow schools. Preventive treatment was performed by dental hygienist. The results show that systematic preventive treatment in school dental offices starting from elementary school allows reducing dental caries incidence 46-53% and stabilize the incidence of caries complications. It should be mentioned though that analysis of individualized outcomes proves heterogeneity of study results despite of equal conditions of PP. Potentially significant hence is early diagnostics and treatment of initial caries forms as demineralization foci, especially in children with intensive tooth decay. Optimization of pediatric dentist and dental hygienist activity in school dental facilities is the main factor of caries prevention efficiency.

Data parallel sorting for particle simulation

NASA Technical Reports Server (NTRS)

Dagum, Leonardo

1992-01-01

Sorting on a parallel architecture is a communications intensive event which can incur a high penalty in applications where it is required. In the case of particle simulation, only integer sorting is necessary, and sequential implementations easily attain the minimum performance bound of O (N) for N particles. Parallel implementations, however, have to cope with the parallel sorting problem which, in addition to incurring a heavy communications cost, can make the minimun performance bound difficult to attain. This paper demonstrates how the sorting problem in a particle simulation can be reduced to a merging problem, and describes an efficient data parallel algorithm to solve this merging problem in a particle simulation. The new algorithm is shown to be optimal under conditions usual for particle simulation, and its fieldwise implementation on the Connection Machine is analyzed in detail. The new algorithm is about four times faster than a fieldwise implementation of radix sort on the Connection Machine.

Parameter-induced stochastic resonance with a periodic signal

NASA Astrophysics Data System (ADS)

Li, Jian-Long; Xu, Bo-Hou

2006-12-01

In this paper conventional stochastic resonance (CSR) is realized by adding the noise intensity. This demonstrates that tuning the system parameters with fixed noise can make the noise play a constructive role and realize parameter-induced stochastic resonance (PSR). PSR can be interpreted as changing the intrinsic characteristic of the dynamical system to yield the cooperative effect between the stochastic-subjected nonlinear system and the external periodic force. This can be realized at any noise intensity, which greatly differs from CSR that is realized under the condition of the initial noise intensity not greater than the resonance level. Moreover, it is proved that PSR is different from the optimization of system parameters.

Profit intensity and cases of non-compliance with the law of demand/supply

NASA Astrophysics Data System (ADS)

Makowski, Marcin; Piotrowski, Edward W.; Sładkowski, Jan; Syska, Jacek

2017-05-01

We consider properties of the measurement intensity ρ of a random variable for which the probability density function represented by the corresponding Wigner function attains negative values on a part of the domain. We consider a simple economic interpretation of this problem. This model is used to present the applicability of the method to the analysis of the negative probability on markets where there are anomalies in the law of supply and demand (e.g. Giffen's goods). It turns out that the new conditions to optimize the intensity ρ require a new strategy. We propose a strategy (so-called à rebours strategy) based on the fixed point method and explore its effectiveness.

Application of low-mixing energy input for the coagulation process.

PubMed

Vadasarukkai, Yamuna S; Gagnon, Graham A

2015-11-01

Rapid-mixing tanks with mechanical mixers are a common design used in treatment plants. Yet, the role of such rapid-mixing systems on the effectiveness of the coagulation performance is unclear. This study looked at optimizing the direct energy used in the coagulation process for removal of natural dissolved organic matter (DOM). The role of coagulation mixing intensity (G-value) on total organic carbon (TOC) and turbidity removal was examined for the water types with high organic content, with a specific ultraviolet absorbance (SUVA) of at least 2-2.5 units of m(-1) of absorbance per mg/L. A standard jar test using ferric sulfate coagulant was performed to optimize the chemical condition in coagulation for removal of dissolved organics as well as particles. The jar test analysis at an acidic pH (4.5 ± 0.3) required an iron dose <0.3 mM to arrive at an optimal coagulant concentration and resulted in above 75% of TOC removal. The influence of coagulation mixing on TOC and turbidity removal was evaluated at G varying from 0 to 1500 s(-1) at the optimized coagulant dose and pH conditions for enhanced coagulation. In this study, a combined effective removal of TOC and turbidity was achieved at a low-mixing intensity range of 110 s(-1) < G < 450 s(-1). Coagulation operated at G greater than 450 s(-1) showed negligible improvement in TOC removal. Minimizing energy consumption in enhanced coagulation is feasible at the proposed mixing intensity range (i.e., 110 s(-1) < G < 450 s(-1)), without sacrificing the effectiveness of DOM removal by coagulation. These findings represent an opportunity for energy savings for the water industry without sacrificing quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of soil and climate heterogeneity on the performance of economic instruments for reducing nitrate leaching from agriculture.

PubMed

Peña-Haro, Salvador; García-Prats, Alberto; Pulido-Velazquez, Manuel

2014-11-15

Economic instruments can be used to control groundwater nitrate pollution due to the intensive use of fertilizers in agriculture. In order to test their efficiency on the reduction of nitrate leaching, we propose an approach based on the combined use of production and pollution functions to derive the impacts on the expected farmer response of these instruments. Some of the most important factors influencing nitrate leaching and crop yield are the type of soil and the climatic conditions. Crop yield and nitrate leaching responses to different soil and climatic conditions were classified by means of a cluster analysis, and crops located in different areas but with similar response were grouped for the analysis. We use a spatial economic optimization model to evaluate the potential of taxes on nitrogen fertilizers, water prices, and taxes on nitrate emissions to reduce nitrate pollution, as well as their economic impact in terms of social welfare and farmers' net benefits. The method was applied to the Mancha Oriental System (MOS) in Spain, a large area with different soil types and climatic conditions. We divided the study area into zones of homogeneous crop production and nitrate leaching properties. Results show spatially different responses of crop growth and nitrate leaching, proving how the cost-effectiveness of pollution control instruments is contingent upon the spatial heterogeneities of the problem. Copyright © 2014 Elsevier B.V. All rights reserved.

The influence of light intensity and photoperiod on duckweed biomass and starch accumulation for bioethanol production.

PubMed

Yin, Yehu; Yu, Changjiang; Yu, Li; Zhao, Jinshan; Sun, Changjiang; Ma, Yubin; Zhou, Gongke

2015-01-01

Duckweed has been considered as a valuable feedstock for bioethanol production due to its high biomass and starch production. To investigate the effects of light conditions on duckweed biomass and starch production, Lemna aequinoctialis 6000 was cultivated at different photoperiods (12:12, 16:8 and 24:0h) and light intensities (20, 50, 80, 110, 200 and 400μmolm(-2)s(-1)). The results showed that the duckweed biomass and starch production was increased with increasing light intensity and photoperiod except at 200 and 400μmolm(-2)s(-1). Considering the light cost, 110μmolm(-2)s(-1) was optimum light condition for starch accumulation with the highest maximum growth rate, biomass and starch production of 8.90gm(-2)day(-1), 233.25gm(-2) and 98.70gm(-2), respectively. Moreover, the results suggested that high light induction was a promising method for duckweed starch accumulation. This study provides optimized light conditions for future industrial large-scale duckweed cultivation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improving Empirical Magnetic Field Models by Fitting to In Situ Data Using an Optimized Parameter Approach

DOE PAGES

Brito, Thiago V.; Morley, Steven K.

2017-10-25

A method for comparing and optimizing the accuracy of empirical magnetic field models using in situ magnetic field measurements is presented in this paper. The optimization method minimizes a cost function—τ—that explicitly includes both a magnitude and an angular term. A time span of 21 days, including periods of mild and intense geomagnetic activity, was used for this analysis. A comparison between five magnetic field models (T96, T01S, T02, TS04, and TS07) widely used by the community demonstrated that the T02 model was, on average, the most accurate when driven by the standard model input parameters. The optimization procedure, performedmore » in all models except TS07, generally improved the results when compared to unoptimized versions of the models. Additionally, using more satellites in the optimization procedure produces more accurate results. This procedure reduces the number of large errors in the model, that is, it reduces the number of outliers in the error distribution. The TS04 model shows the most accurate results after the optimization in terms of both the magnitude and direction, when using at least six satellites in the fitting. It gave a smaller error than its unoptimized counterpart 57.3% of the time and outperformed the best unoptimized model (T02) 56.2% of the time. Its median percentage error in |B| was reduced from 4.54% to 3.84%. Finally, the difference among the models analyzed, when compared in terms of the median of the error distributions, is not very large. However, the unoptimized models can have very large errors, which are much reduced after the optimization.« less

Improving Empirical Magnetic Field Models by Fitting to In Situ Data Using an Optimized Parameter Approach

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

Brito, Thiago V.; Morley, Steven K.

A method for comparing and optimizing the accuracy of empirical magnetic field models using in situ magnetic field measurements is presented in this paper. The optimization method minimizes a cost function—τ—that explicitly includes both a magnitude and an angular term. A time span of 21 days, including periods of mild and intense geomagnetic activity, was used for this analysis. A comparison between five magnetic field models (T96, T01S, T02, TS04, and TS07) widely used by the community demonstrated that the T02 model was, on average, the most accurate when driven by the standard model input parameters. The optimization procedure, performedmore » in all models except TS07, generally improved the results when compared to unoptimized versions of the models. Additionally, using more satellites in the optimization procedure produces more accurate results. This procedure reduces the number of large errors in the model, that is, it reduces the number of outliers in the error distribution. The TS04 model shows the most accurate results after the optimization in terms of both the magnitude and direction, when using at least six satellites in the fitting. It gave a smaller error than its unoptimized counterpart 57.3% of the time and outperformed the best unoptimized model (T02) 56.2% of the time. Its median percentage error in |B| was reduced from 4.54% to 3.84%. Finally, the difference among the models analyzed, when compared in terms of the median of the error distributions, is not very large. However, the unoptimized models can have very large errors, which are much reduced after the optimization.« less

Development of an inverse distance weighted active infrared stealth scheme using the repulsive particle swarm optimization algorithm.

PubMed

Han, Kuk-Il; Kim, Do-Hwi; Choi, Jun-Hyuk; Kim, Tae-Kuk

2018-04-20

Treatments for detection by infrared (IR) signals are higher than for other signals such as radar or sonar because an object detected by the IR sensor cannot easily recognize its detection status. Recently, research for actively reducing IR signal has been conducted to control the IR signal by adjusting the surface temperature of the object. In this paper, we propose an active IR stealth algorithm to synchronize IR signals from the object and the background around the object. The proposed method includes the repulsive particle swarm optimization statistical optimization algorithm to estimate the IR stealth surface temperature, which will result in a synchronization between the IR signals from the object and the surrounding background by setting the inverse distance weighted contrast radiant intensity (CRI) equal to zero. We tested the IR stealth performance in mid wavelength infrared (MWIR) and long wavelength infrared (LWIR) bands for a test plate located at three different positions on a forest scene to verify the proposed method. Our results show that the inverse distance weighted active IR stealth technique proposed in this study is proved to be an effective method for reducing the contrast radiant intensity between the object and background up to 32% as compared to the previous method using the CRI determined as the simple signal difference between the object and the background.

Effectiveness of an acoustical product in reducing high-frequency sound within unoccupied incubators.

PubMed

Kellam, Barbara; Bhatia, Jatinder

2009-08-01

Few noise measurement studies in the neonatal intensive care unit have reported sound frequencies within incubators. Sound frequencies within incubators are markedly different from sound frequencies within the gravid uterus. This article reports the results of sound spectral analysis (SSA) within unoccupied incubators under control and treatment conditions. SSA indicated that acoustical foam panels (treatment condition) markedly reduced sound frequencies > or =500 Hz when compared with the control condition. The main findings of this study (a) illustrate the need to monitor high-frequency sound within incubators and (b) indicate one method to reduce atypical sound exposure within incubators.

[Fluorescence Determination of Trace Se with the Hydride-K13-Rhodamine 6G System].

PubMed

Liang, Ai-hui; Li, Yuan; Huang, Shan-shan; Luo, Yang-he; Wen, Gui-qing; Jiang, Zhi-liang

2015-05-01

Se is a necessary trace element for human and animals, but the excess intake of Se caused poison. Thus, it is very important to determination of Se in foods and water. The target of this study is development of a new, sensitive and selective hydride generation-molecular fluorescence method for the determination of Se. In 0. 36 mol . L-1 sulfuric acid, NaBH4 as reducing agent, Se (IV) is reduced to H2 Se. Usin3-g I solution as absorption liquid3, I- is reduced to I- by H2Se. When adding rhodamine 6G, Rhodamine 6G and I3- form association particles, which lead to the fluorescence intensity decreased. When Se(IV) existing, Rhodamine 6G and I3- bind less, And the remaining amount of Rhodamine 6G increase. So the fluorescence intensity is enhanced. The analytical conditions were optimized, a 0. 36 ml . L-1 H2SO4, 21. 6.g . L-1 NaBH4, 23.3 µm . L-1 rhodamine 6G, and 50 µmol . L-1 KI3 were chosen for use. When the excitation wavelength is at 480nm, the Rayleigh scattering peak does not affect the fluorescence recording, and was selected for determination of Se. Under the selected conditions, Se(IV) concentration in the 0. 02~0. 60 µg . mL-1 range and the increase value of the fluorescence intensity (ΔF) at 562 nm linear relationship. The linear regression equation is ΔF562 nm =12. 6c + 20. 9. The detecton limit was 0.01 µ.g . L-1. The influence of coexistence substances on the hydride generatin-molecular fluorescence determination of 5. 07 X10(-6) mol . L-1 Se(IV) was considered in details. Results showed that this new fluorescence method is of high selectivity, that is, 0. 5 mmol. L-1 Ba2+, Ca2+, Zn2+ and Fe3+, 0. 25 mmol . L-1 . Mg2+, 0. 05 mmol . L-1 K+, 0. 2 mmol . L-1 Al3+, 0. 025 mmol . L-1 Te(VI) do not interfere with the determination. The influence of Hg2+, CD2+ and Cu2+ that precipitate with Se(IV), can be eliminated by addition of complex reagent. This hydride generation-molecular fluorescence method has been applied to determination of trace Se in water samples,

Trajectory optimization for dynamic couch rotation during volumetric modulated arc radiotherapy

NASA Astrophysics Data System (ADS)

Smyth, Gregory; Bamber, Jeffrey C.; Evans, Philip M.; Bedford, James L.

2013-11-01

Non-coplanar radiation beams are often used in three-dimensional conformal and intensity modulated radiotherapy to reduce dose to organs at risk (OAR) by geometric avoidance. In volumetric modulated arc radiotherapy (VMAT) non-coplanar geometries are generally achieved by applying patient couch rotations to single or multiple full or partial arcs. This paper presents a trajectory optimization method for a non-coplanar technique, dynamic couch rotation during VMAT (DCR-VMAT), which combines ray tracing with a graph search algorithm. Four clinical test cases (partial breast, brain, prostate only, and prostate and pelvic nodes) were used to evaluate the potential OAR sparing for trajectory-optimized DCR-VMAT plans, compared with standard coplanar VMAT. In each case, ray tracing was performed and a cost map reflecting the number of OAR voxels intersected for each potential source position was generated. The least-cost path through the cost map, corresponding to an optimal DCR-VMAT trajectory, was determined using Dijkstra’s algorithm. Results show that trajectory optimization can reduce dose to specified OARs for plans otherwise comparable to conventional coplanar VMAT techniques. For the partial breast case, the mean heart dose was reduced by 53%. In the brain case, the maximum lens doses were reduced by 61% (left) and 77% (right) and the globes by 37% (left) and 40% (right). Bowel mean dose was reduced by 15% in the prostate only case. For the prostate and pelvic nodes case, the bowel V50 Gy and V60 Gy were reduced by 9% and 45% respectively. Future work will involve further development of the algorithm and assessment of its performance over a larger number of cases in site-specific cohorts.

Recent optimization of the beam-optical characteristics of the 6 MV van de Graaff accelerator for high brightness beams at the iThemba LABS NMP facility

NASA Astrophysics Data System (ADS)

Conradie, J. L.; Eisa, M. E. M.; Celliers, P. J.; Delsink, J. L. G.; Fourie, D. T.; de Villiers, J. G.; Maine, P. M.; Springhorn, K. A.; Pineda-Vargas, C. A.

2005-04-01

With the aim of improving the reliability and stability of the beams delivered to the nuclear microprobe at iThemba LABS, as well as optimization of the beam characteristics along the van de Graaff accelerator beamlines in general, relevant modifications were implemented since the beginning of 2003. The design and layout of the beamlines were revised. The beam-optical characteristics through the accelerator, from the ion source up to the analysing magnet directly after the accelerator, were calculated and the design optimised, using the computer codes TRANSPORT, IGUN and TOSCA. The ion source characteristics and optimal operating conditions were determined on an ion source test bench. The measured optimal emittance for 90% of the beam intensity was about 50π mm mrad for an extraction voltage of 6 kV. These changes allow operation of the Nuclear Microprobe at proton energies in the range 1 MeV-4 MeV with beam intensities of tenths of a pA at the target surface. The capabilities of the nuclear microprobe facility were evaluated in the improved beamline, with particular emphasis to bio-medical samples.

Developing and validating trace fear conditioning protocols in C57BL/6 mice.

PubMed

Burman, Michael A; Simmons, Cassandra A; Hughes, Miles; Lei, Lei

2014-01-30

Classical fear conditioning is commonly used to study the biology of fear, anxiety and memory. Previous research demonstrated that delay conditioning requires a neural circuit involving the amygdala, but not usually the hippocampus. Trace and contextual fear conditioning require the amygdala and hippocampus. While these paradigms were developed primarily using rat models, they are increasingly being used in mice. The current studies develop trace fear conditioning and control paradigms to allow for the assessment of trace and delay fear conditioning in C57BL/6N mice. Our initial protocol yielded clear delay and contextual conditioning. However, trace conditioning failed to differentiate from an unpaired group and was not hippocampus-dependent. These results suggested that the protocol needed to be modified to specifically accommodate trace conditioning the mice. In order to reduce unconditioned freezing and increase learning, the final protocol was developed by decreasing the intensity of the tone and by increasing the inter-trial interval. Our final protocol produced trace conditioned freezing that was significantly greater than that followed unpaired stimulus exposure and was disrupted by hippocampus lesions. A review of the literature produced 90 articles using trace conditioning in mice. Few of those articles used any kind of behavioral control group, which is required to rule out non-associative factors causing fearful behavior. Fewer used unpaired groups involving tones and shocks within a session, which is the optimal control group. Our final trace conditioning protocol can be used in future studies examining genetically modified C57BL/6N mice. Copyright © 2013 Elsevier B.V. All rights reserved.

Developing and Validating Trace Fear Conditioning Protocols in C57BL/6 Mice

PubMed Central

Burman, Michael A; Simmons, Cassandra A; Hughes, Miles; Lei, Lei

2013-01-01

Background Classical fear conditioning is commonly used to study the biology of fear, anxiety and memory. Previous research demonstrated that delay conditioning requires a neural circuit involving the amygdala, but not usually the hippocampus. Trace and contextual fear conditioning require the amygdala and hippocampus. While these paradigms were developed primarily using rat models, they are increasingly being used in mice. New Method The current studies develop trace fear conditioning and control paradigms to allow for the assessment of trace and delay fear conditioning in C57BL/6N mice. Our initial protocol yielded clear delay and contextual conditioning. However, trace conditioning failed to differentiate from an unpaired group and was not hippocampus-dependent. These results suggested that the protocol needed to be modified to specifically accommodate trace conditioning the mice. In order to reduce unconditioned freezing and increase learning, the final protocol was developed by decreasing the intensity of the tone and by increasing the inter-trial interval. Results Our final protocol produced trace conditioned freezing that was significantly greater than that followed unpaired stimulus exposure and was disrupted by hippocampus lesions. Comparison with Existing Methods A review of the literature produced 90 articles using trace conditioning in mice. Few of those articles used any kind of behavioral control group, which is required to rule out non-associative factors causing fearful behavior. Fewer used unpaired groups involving tones and shocks within a session, which is the optimal control group. Conclusions Our final trace conditioning protocol can be used in future studies examining genetically modified C57BL/6N mice. PMID:24269252

Optimizing parameter of particle damping based on Leidenfrost effect of particle flows

NASA Astrophysics Data System (ADS)

Lei, Xiaofei; Wu, Chengjun; Chen, Peng

2018-05-01

Particle damping (PD) has strongly nonlinearity. With sufficiently vigorous vibration conditions, it always plays excellent damping performance and the particles which are filled into cavity are on Leidenfrost state considered in particle flow theory. For investigating the interesting phenomenon, the damping effect of PD on this state is discussed by the developed numerical model which is established based on principle of gas and solid. Furtherly, the numerical model is reformed and applied to study the relationship of Leidenfrost velocity with characteristic parameters of PD such as particle density, diameter, mass packing ratio and diameter-length ratio. The results indicate that particle density and mass packing ratio can drastically improve the damping performance as opposed as particle diameter and diameter-length ratio, mass packing ratio and diameter-length ratio can low the excited intensity for Leidenfrost state. For discussing the application of the phenomenon in engineering, bound optimization by quadratic approximation (BOBYQA) method is employed to optimize mass packing ratio of PD for minimize maximum amplitude (MMA) and minimize total vibration level (MTVL). It is noted that the particle damping can drastically reduce the vibrating amplitude for MMA as Leidenfrost velocity equal to the vibrating velocity relative to maximum vibration amplitude. For MTVL, larger mass packing ratio is best option because particles at relatively wide frequency range is adjacent to Leidenfrost state.

SU-E-T-07: 4DCT Robust Optimization for Esophageal Cancer Using Intensity Modulated Proton Therapy

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

Liao, L; Department of Industrial Engineering, University of Houston, Houston, TX; Yu, J

2015-06-15

Purpose: To develop a 4DCT robust optimization method to reduce the dosimetric impact from respiratory motion in intensity modulated proton therapy (IMPT) for esophageal cancer. Methods: Four esophageal cancer patients were selected for this study. The different phases of CT from a set of 4DCT were incorporated into the worst-case dose distribution robust optimization algorithm. 4DCT robust treatment plans were designed and compared with the conventional non-robust plans. Result doses were calculated on the average and maximum inhale/exhale phases of 4DCT. Dose volume histogram (DVH) band graphic and ΔD95%, ΔD98%, ΔD5%, ΔD2% of CTV between different phases were used tomore » evaluate the robustness of the plans. Results: Compare to the IMPT plans optimized using conventional methods, the 4DCT robust IMPT plans can achieve the same quality in nominal cases, while yield a better robustness to breathing motion. The mean ΔD95%, ΔD98%, ΔD5% and ΔD2% of CTV are 6%, 3.2%, 0.9% and 1% for the robustly optimized plans vs. 16.2%, 11.8%, 1.6% and 3.3% from the conventional non-robust plans. Conclusion: A 4DCT robust optimization method was proposed for esophageal cancer using IMPT. We demonstrate that the 4DCT robust optimization can mitigate the dose deviation caused by the diaphragm motion.« less

Electrochemical removal of carbamazepine in water with Ti/PbO2 cylindrical mesh anode.

PubMed

García-Espinoza, J D; Gortáres-Moroyoqui, P; Orta-Ledesma, M T; Drogui, P; Mijaylova-Nacheva, P

2016-01-01

Carbamazepine (CBZ) is one of the most frequently detected organic compounds in the aquatic environment. Due to its bio-persistence and toxicity for humans and the environment its removal has become an important issue. The performance of the electrochemical oxidation process and in situ production of reactive oxygen species (ROS), such as O3 and H2O2, for CBZ removal have been studied using Ti/PbO2 cylindrical mesh anode in the presence of Na2SO4 as supporting electrolyte in a batch electrochemical reactor. In this integrated process, direct oxidation at anode and indirect oxidation by in situ electrogenerated ROS can occur simultaneously. The effect of several factors such as electrolysis time, current intensity, initial pH and oxygen flux was investigated by means of an experimental design methodology, using a 2(4) factorial matrix. CBZ removal of 83.93% was obtained and the most influential parameters turned out to be electrolysis time, current intensity and oxygen flux. Later, the optimal experimental values for CBZ degradation were obtained by means of a central composite design. The best operating conditions, analyzed by Design Expert(®) software, are the following: 110 min of electrolysis at 3.0 A, pH = 7.05 and 2.8 L O2/min. Under these optimal conditions, the model prediction (82.44%) fits very well with the experimental response (83.90 ± 0.8%). Furthermore, chemical oxygen demand decrease was quantified. Our results illustrated significant removal efficiency for the CBZ in optimized condition with second order kinetic reaction.

CO2 Removal from Biogas by Cyanobacterium Leptolyngbya sp. CChF1 Isolated from the Lake Chapala, Mexico: Optimization of the Temperature and Light Intensity.

PubMed

Choix, Francisco J; Snell-Castro, Raúl; Arreola-Vargas, Jorge; Carbajal-López, Alberto; Méndez-Acosta, Hugo O

2017-12-01

In the present study, the capacity of the cyanobacterium Leptolyngbya sp. CChF1 to remove CO 2 from real and synthetic biogas was evaluated. The identification of the cyanobacterium, isolated from the lake Chapala, was carried out by means of morphological and molecular analyses, while its potential for CO 2 removal from biogas streams was evaluated by kinetic experiments and optimized by a central composite design coupled to a response surface methodology. Results demonstrated that Leptolyngbya sp. CChF1 is able to remove CO 2 and grow indistinctly in real or synthetic biogas streams, showing tolerance to high concentrations of CO 2 and CH 4 , 25 and 75%, respectively. The characterization of the biomass composition at the end of the kinetic assays revealed that the main accumulated by-products under both biogas streams were lipids, followed by proteins and carbohydrates. Regarding the optimization experiments, light intensity and temperature were the studied variables, while synthetic biogas was the carbon source. Results showed that light intensity was significant for CO 2 capture efficiency (p = 0.0290), while temperature was significant for biomass production (p = 0.0024). The predicted CO 2 capture efficiency under optimal conditions (27.1 °C and 920 lx) was 93.48%. Overall, the results of the present study suggest that Leptolyngbya sp. CChF1 is a suitable candidate for biogas upgrading.

Simple and effective label-free capillary electrophoretic analysis of sugars by complexation using quinoline boronic acids.

PubMed

Kubo, Takuya; Kanemori, Koichi; Kusumoto, Risa; Kawai, Takayuki; Sueyoshi, Kenji; Naito, Toyohiro; Otsuka, Koji

2015-01-01

An effective separation and detection procedure for sugars by capillary electrophoresis (CE) using a complexation between quinolineboronic acid (QBA) and multiple hydroxyl structure of sugar alcohol is reported. We investigated the variation of fluorescence spectra of a variety of QBAs with sorbitol at a wide range of pH conditions and then found that 5-isoQBA strongly enhanced the fluorescence intensity by the complexation at basic pH conditions. The other sugar alcohols having multiple hydroxyls also revealed the enhancement of the fluorescence intensity with 5-isoQBA, whereas the alternation of the intensity was not found in the sugars such as glucose. After optimization of the 5-isoQBA concentration and pH of the buffered solution in CE analysis, 6 sugar alcohols were successfully separated in the order based on the formation constants with 5-isoQBA, which were calculated from the variation of the fluorescence intensity with each sugar alcohol and 5-isoQBA. Furthermore, the limits of detection for sorbitol and xylitol by the CE method were estimated at 15 and 27 μM, respectively.

Optimization of typical diffuse herbicide pollution control by soil amendment configurations under four levels of rainfall intensities.

PubMed

Ouyang, Wei; Huang, Weijia; Wei, Peng; Hao, Fanghua; Yu, Yongyong

2016-06-15

Herbicides are a main source of agricultural diffuse pollution due to their wide application in tillage practices. The aim of this study is to optimize the control efficiency of the herbicide atrazine with the aid of modified soil amendments. The soil amendments were composed of a combination of biochar and gravel. The biochar was created from corn straw with a catalytic pyrolysis of ammonium dihydrogen phosphate. The leaching experiments under four rainfall conditions were measured for the following designs: raw soil, soil amended with gravel, biochar individually and together with gravel. The control efficiency of each design was also identified. With the designed equipment, the atrazine content in the contaminant load layer, gravel substrate layer, biochar amendment layer and soil layer was measured under four types of rainfall intensities (1.25 mm/h, 2.50 mm/h, 5.00 mm/h and 10.00 mm/h). Furthermore, the vertical distribution of atrazine in the soil sections was also monitored. The results showed that the herbicide leaching load increased under the highest rainfall intensity in all designs. The soil with the combination of gravel and biochar provided the highest control efficiency of 87.85% on atrazine when the additional proportion of biochar was 3.0%. The performance assessment under the four kinds of rainfall intensity conditions provided the guideline for the soil amendment configuration. The combination of gravel and biochar is recommended as an efficient method for controlling diffuse herbicide pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Noise sensitivity of portfolio selection in constant conditional correlation GARCH models

NASA Astrophysics Data System (ADS)

Varga-Haszonits, I.; Kondor, I.

2007-11-01

This paper investigates the efficiency of minimum variance portfolio optimization for stock price movements following the Constant Conditional Correlation GARCH process proposed by Bollerslev. Simulations show that the quality of portfolio selection can be improved substantially by computing optimal portfolio weights from conditional covariances instead of unconditional ones. Measurement noise can be further reduced by applying some filtering method on the conditional correlation matrix (such as Random Matrix Theory based filtering). As an empirical support for the simulation results, the analysis is also carried out for a time series of S&P500 stock prices.

Sodium hydroxide pretreatment and enzymatic hydrolysis of coastal Bermuda grass.

PubMed

Wang, Ziyu; Keshwani, Deepak R; Redding, Arthur P; Cheng, Jay J

2010-05-01

Coastal Bermuda grass was pretreated with NaOH at concentrations from 0.5% to 3% (w/v) for a residence time from 15 to 90min at 121 degrees C. The pretreatments were evaluated based on total lignin removal and production of total reducing sugars, glucose and xylose from enzymatic hydrolysis of the pretreated biomass. Up to 86% lignin removal was observed. The optimal NaOH pretreatment conditions at 121 degrees C for total reducing sugars production as well as glucose and xylose yields are 15min and 0.75% NaOH. Under these optimal pretreatment conditions, total reducing sugars yield was about 71% of the theoretical maximum, and the overall conversion efficiencies for glucan and xylan were 90.43% and 65.11%, respectively. Copyright 2009 Elsevier Ltd. All rights reserved.

[Optimization of prokaryotic expression conditions of Leptospira interrogans trigeminy genus-specific protein antigen based on surface response analysis].

PubMed

Wang, Jiang; Luo, Dongjiao; Sun, Aihua; Yan, Jie

2008-07-01

Lipoproteins LipL32 and LipL21 and transmembrane protein OMPL1 have been confirmed as the superficial genus-specific antigens of Leptospira interrogans, which can be used as antigens for developing a universal genetic engineering vaccine. In order to obtain high expression of an artificial fusion gene lipL32/1-lipL21-ompL1/2, we optimized prokaryotic expression conditions. We used surface response analysis based on the central composite design to optimize culture conditions of a new antigen protein by recombinant Escherichia coli DE3.The culture conditions included initial pH, induction start time, post-induction time, Isopropyl beta-D-thiogalactopyranoside (IPTG) concentration, and temperature. The maximal production of antigen protein was 37.78 mg/l. The optimal culture conditions for high recombinant fusion protein was determined: initial pH 7.9, induction start time 2.5 h, a post-induction time of 5.38 h, 0.20 mM IPTG, and a post-induction temperature of 31 degrees C. Surface response analysis based on CCD increased the target production. This statistical method reduced the number of experiments required for optimization and enabled rapid identification and integration of the key culture condition parameters for optimizing recombinant protein expression.

Maintaining reduced noise levels in a resource-constrained neonatal intensive care unit by operant conditioning.

PubMed

Ramesh, A; Denzil, S B; Linda, R; Josephine, P K; Nagapoornima, M; Suman Rao, P N; Swarna Rekha, A

2013-03-01

To evaluate the efficacy of operant conditioning in sustaining reduced noise levels in the neonatal intensive care unit (NICU). Quasi-experimental study on quality of care. Level III NICU of a teaching hospital in south India. 26 staff employed in the NICU. (7 Doctors, 13 Nursing staff and 6 Nursing assistants). Operant conditioning of staff activity for 6 months. This method involves positive and negative reinforcement to condition the staff to modify noise generating activities. Comparing noise levels in decibel: A weighted [dB (A)] before conditioning with levels at 18 and 24 months after conditioning. Decibel: A weighted accounts for noise that is audible to human ears. Operant conditioning for 6 months sustains the reduced noise levels to within 62 dB in ventilator room 95% CI: 60.4 - 62.2 and isolation room (95% CI: 55.8 - 61.5). In the preterm room, noise can be maintained within 52 dB (95% CI: 50.8 - 52.6). This effect is statistically significant in all the rooms at 18 months (P = 0.001). At 24 months post conditioning there is a significant rebound of noise levels by 8.6, 6.7 and 9.9 dB in the ventilator, isolation and preterm room, respectively (P =0.001). Operant conditioning for 6 months was effective in sustaining reduced noise levels. At 18 months post conditioning, the noise levels were maintained within 62 dB (A), 60 dB (A) and 52 dB (A) in the ventilator, isolation and pre-term room, respectively. Conditioning needs to be repeated at 12 months in the ventilator room and at 18 months in the other rooms.

Optimization of a vacuum chamber for vibration measurements.

PubMed

Danyluk, Mike; Dhingra, Anoop

2011-10-01

A 200 °C high vacuum chamber has been built to improve vibration measurement sensitivity. The optimized design addresses two significant issues: (i) vibration measurements under high vacuum conditions and (ii) use of design optimization tools to reduce operating costs. A test rig consisting of a cylindrical vessel with one access port has been constructed with a welded-bellows assembly used to seal the vessel and enable vibration measurements in high vacuum that are comparable with measurements in air. The welded-bellows assembly provides a force transmissibility of 0.1 or better at 15 Hz excitation under high vacuum conditions. Numerical results based on design optimization of a larger diameter chamber are presented. The general constraints on the new design include material yield stress, chamber first natural frequency, vibration isolation performance, and forced convection heat transfer capabilities over the exterior of the vessel access ports. Operating costs of the new chamber are reduced by 50% compared to a preexisting chamber of similar size and function.

A theoretical investigation of single-molecule fluorescence detection on thin metallic layers.

PubMed

Enderlein, J

2000-04-01

In the present paper, the excitation and detection of single-molecule fluorescence over thin metallic films is studied theoretically within the framework of classical electrodynamics. The model takes into account the specific conditions of surface plasmon-assisted optical excitation, fluorescence quenching by the metal film, and detection geometry. Extensive numerical results are presented for gold, silver, and aluminum films, showing the detectable fluorescence intensities and their dependence on film thickness and the fluorescent molecule's position under optimal excitation conditions.

Autonomic Closure for Turbulent Flows Using Approximate Bayesian Computation

NASA Astrophysics Data System (ADS)

Doronina, Olga; Christopher, Jason; Hamlington, Peter; Dahm, Werner

2017-11-01

Autonomic closure is a new technique for achieving fully adaptive and physically accurate closure of coarse-grained turbulent flow governing equations, such as those solved in large eddy simulations (LES). Although autonomic closure has been shown in recent a priori tests to more accurately represent unclosed terms than do dynamic versions of traditional LES models, the computational cost of the approach makes it challenging to implement for simulations of practical turbulent flows at realistically high Reynolds numbers. The optimization step used in the approach introduces large matrices that must be inverted and is highly memory intensive. In order to reduce memory requirements, here we propose to use approximate Bayesian computation (ABC) in place of the optimization step, thereby yielding a computationally-efficient implementation of autonomic closure that trades memory-intensive for processor-intensive computations. The latter challenge can be overcome as co-processors such as general purpose graphical processing units become increasingly available on current generation petascale and exascale supercomputers. In this work, we outline the formulation of ABC-enabled autonomic closure and present initial results demonstrating the accuracy and computational cost of the approach.

Shape Optimization for Additive Manufacturing of Removable Partial Dentures - A New Paradigm for Prosthetic CAD/CAM

PubMed Central

2015-01-01

With ever-growing aging population and demand for denture treatments, pressure-induced mucosa lesion and residual ridge resorption remain main sources of clinical complications. Conventional denture design and fabrication are challenged for its labor and experience intensity, urgently necessitating an automatic procedure. This study aims to develop a fully automatic procedure enabling shape optimization and additive manufacturing of removable partial dentures (RPD), to maximize the uniformity of contact pressure distribution on the mucosa, thereby reducing associated clinical complications. A 3D heterogeneous finite element (FE) model was constructed from CT scan, and the critical tissue of mucosa was modeled as a hyperelastic material from in vivo clinical data. A contact shape optimization algorithm was developed based on the bi-directional evolutionary structural optimization (BESO) technique. Both initial and optimized dentures were prototyped by 3D printing technology and evaluated with in vitro tests. Through the optimization, the peak contact pressure was reduced by 70%, and the uniformity was improved by 63%. In vitro tests verified the effectiveness of this procedure, and the hydrostatic pressure induced in the mucosa is well below clinical pressure-pain thresholds (PPT), potentially lessening risk of residual ridge resorption. This proposed computational optimization and additive fabrication procedure provides a novel method for fast denture design and adjustment at low cost, with quantitative guidelines and computer aided design and manufacturing (CAD/CAM) for a specific patient. The integration of digitalized modeling, computational optimization, and free-form fabrication enables more efficient clinical adaptation. The customized optimal denture design is expected to minimize pain/discomfort and potentially reduce long-term residual ridge resorption. PMID:26161878

ACOG Committee Opinion No. 650: Physical Activity and Exercise During Pregnancy and the Postpartum Period.

PubMed

2015-12-01

Physical activity in all stages of life maintains and improves cardiorespiratory fitness, reduces the risk of obesity and associated comorbidities, and results in greater longevity. Physical activity in pregnancy has minimal risks and has been shown to benefit most women, although some modification to exercise routines may be necessary because of normal anatomic and physiologic changes and fetal requirements. Women with uncomplicated pregnancies should be encouraged to engage in aerobic and strength-conditioning exercises before, during, and after pregnancy. Obstetrician-gynecologists and other obstetric care providers should carefully evaluate women with medical or obstetric complications before making recommendations on physical activity participation during pregnancy. Although frequently prescribed, bed rest is only rarely indicated and, in most cases, allowing ambulation should be considered. Regular physical activity during pregnancy improves or maintains physical fitness, helps with weight management, reduces the risk of gestational diabetes in obese women, and enhances psychologic well-being. An exercise program that leads to an eventual goal of moderate-intensity exercise for at least 20-30 minutes per day on most or all days of the week should be developed with the patient and adjusted as medically indicated. Additional research is needed to study the effects of exercise on pregnancy-specific outcomes and to clarify the most effective behavioral counseling methods, and the optimal intensity and frequency of exercise. Similar work is needed to create an improved evidence base concerning the effects of occupational physical activity on maternal-fetal health.

Developing a vacuum cooking equipment prototype to produce strawberry jam and optimization of vacuum cooking conditions.

PubMed

Okut, Dilara; Devseren, Esra; Koç, Mehmet; Ocak, Özgül Özdestan; Karataş, Haluk; Kaymak-Ertekin, Figen

2018-01-01

Purpose of this study was to develop prototype cooking equipment that can work at reduced pressure and to evaluate its performance for production of strawberry jam. The effect of vacuum cooking conditions on color soluble solid content, reducing sugars total sugars HMF and sensory properties were investigated. Also, the optimum vacuum cooking conditions for strawberry jam were optimized for Composite Rotatable Design. The optimum cooking temperature and time were determined targeting maximum soluble solid content and sensory attributes (consistency) and minimum Hue value and HMF content. The optimum vacuum cooking conditions determined were 74.4 °C temperature and 19.8 time. The soluble solid content strawberry jam made by vacuum process were similar to those prepared by traditional method. HMF contents of jams produced with vacuum cooking method were well within limit of standards.

Computational methods for aerodynamic design using numerical optimization

NASA Technical Reports Server (NTRS)

Peeters, M. F.

1983-01-01

Five methods to increase the computational efficiency of aerodynamic design using numerical optimization, by reducing the computer time required to perform gradient calculations, are examined. The most promising method consists of drastically reducing the size of the computational domain on which aerodynamic calculations are made during gradient calculations. Since a gradient calculation requires the solution of the flow about an airfoil whose geometry was slightly perturbed from a base airfoil, the flow about the base airfoil is used to determine boundary conditions on the reduced computational domain. This method worked well in subcritical flow.

Three dimensional intensity modulated brachytherapy (IMBT): dosimetry algorithm and inverse treatment planning.

PubMed

Shi, Chengyu; Guo, Bingqi; Cheng, Chih-Yao; Esquivel, Carlos; Eng, Tony; Papanikolaou, Niko

2010-07-01

The feasibility of intensity modulated brachytherapy (IMBT) to improve dose conformity for irregularly shaped targets has been previously investigated by researchers by means of using partially shielded sources. However, partial shielding does not fully explore the potential of IMBT. The goal of this study is to introduce the concept of three dimensional (3D) intensity modulated brachytherapy and solve two fundamental issues regarding the application of 3D IMBT treatment planning: The dose calculation algorithm and the inverse treatment planning method. A 3D IMBT treatment planning system prototype was developed using the MATLAB platform. This system consists of three major components: (1) A comprehensive IMBT source calibration method with dosimetric inputs from Monte Carlo (EGSnrc) simulations; (2) a "modified TG-43" (mTG-43) dose calculation formalism for IMBT dosimetry; and (3) a physical constraint based inverse IMBT treatment planning platform utilizing a simulated annealing optimization algorithm. The model S700 Axxent electronic brachytherapy source developed by Xoft, Inc. (Fremont, CA), was simulated in this application. Ten intracavitary accelerated partial breast irradiation (APBI) cases were studied. For each case, an "isotropic plan" with only optimized source dwell time and a fully optimized IMBT plan were generated and compared to the original plan in various dosimetric aspects, such as the plan quality, planning, and delivery time. The issue of the mechanical complexity of the IMBT applicator is not addressed in this study. IMBT approaches showed superior plan quality compared to the original plans and tht isotropic plans to different extents in all studied cases. An extremely difficult case with a small breast and a small distance to the ribs and skin, the IMBT plan minimized the high dose volume V200 by 16.1% and 4.8%, respectively, compared to the original and the isotropic plans. The conformity index for the target was increased by 0.13 and 0.04, respectively. The maximum dose to the skin was reduced by 56 and 28 cGy, respectively, per fraction. Also, the maximum dose to the ribs was reduced by 104 and 96 cGy, respectively, per fraction. The mean dose to the ipsilateral and contralateral breasts and lungs were also slightly reduced by the IMBT plan. The limitations of IMBT are the longer planning and delivery time. The IMBT plan took around 2 h to optimize, while the isotropic plan optimization could reach the global minimum within 5 min. The delivery time for the IMBT plan is typically four to six times longer than the corresponding isotropic plan. In this study, a dosimetry method for IMBT sources was proposed and an inverse treatment planning system prototype for IMBT was developed. The improvement of plan quality by 3D IMBT was demonstrated using ten APBI case studies. Faster computers and higher output of the source can further reduce plan optimization and delivery time, respectively.

Comparing model-based predictions of a wind turbine wake to LiDAR measurements in complex terrain

NASA Astrophysics Data System (ADS)

Kay, Andrew; Jones, Paddy; Boyce, Dean; Bowman, Neil

2013-04-01

The application of remote sensing techniques to the measurement of wind characteristics offers great potential to accurately predict the atmospheric boundary layer flow (ABL) and its interactions with wind turbines. An understanding of these interactions is important for optimizing turbine siting in wind farms and improving the power performance and lifetime of individual machines. In particular, Doppler wind Light Detection and Ranging (LiDAR) can be used to remotely measure the wind characteristics (speed, direction and turbulence intensity) approaching a rotor. This information can be utilised to improve turbine lifetime (advanced detection of incoming wind shear, wind veer and extreme wind conditions, such as gusts) and optimise power production (improved yaw, pitch and speed control). LiDAR can also make detailed measurements of the disturbed wind profile in the wake, which can damage surrounding turbines and reduce efficiency. These observational techniques can help engineers better understand and model wakes to optimize turbine spacing in large wind farms, improving efficiency and reducing the cost of energy. NEL is currently undertaking research to measure the disturbed wind profile in the wake of a 950 kW wind turbine using a ZephIR Dual Mode LiDAR at its Myres Hill wind turbine test site located near Glasgow, Scotland. Myres Hill is moderately complex terrain comprising deep peat, low lying grass and heathers, localised slopes and nearby forest, approximately 2 km away. Measurements have been obtained by vertically scanning at 10 recorded heights across and above the rotor plane to determine the wind speed, wind direction and turbulence intensity profiles. Measurement stations located at various rotor diameters downstream of the turbine were selected in an attempt to capture the development of the wake and its recovery towards free stream conditions. Results of the measurement campaign will also highlight how the wake behaves as a result of sudden gusts or rapid changes in wind direction. NEL has carried out simulations to model the wake of the turbine using Computational Fluid Dynamics (CFD) software provided by ANSYS Inc. The model incorporates a simple actuator disk concept to model the turbine and its wake, typical of that used in many commercial wind farm optimization tools. The surrounding terrain, including the forestry is modelled allowing an investigation of the wake-terrain interactions occurring across the site. The overall aim is to compare the LiDAR measurements with simulated data to assess the quality of the model and its sensitivity to variables such as mesh size and turbulence/forestry modelling techniques. Knowledge acquired from the study will help to define techniques for combining LiDAR measurements with CFD modelling to improve predictions of wake losses in large wind farms and hence, energy production. In addition, the impact of transient wind conditions on the results of predictions based on idealised, steady state models has been examined.

Myeloablative Versus Reduced-Intensity Hematopoietic Cell Transplantation for Acute Myeloid Leukemia and Myelodysplastic Syndromes

PubMed Central

Pasquini, Marcelo C.; Logan, Brent R.; Wu, Juan; Devine, Steven M.; Porter, David L.; Maziarz, Richard T.; Warlick, Erica D.; Fernandez, Hugo F.; Alyea, Edwin P.; Hamadani, Mehdi; Bashey, Asad; Giralt, Sergio; Geller, Nancy L.; Leifer, Eric; Le-Rademacher, Jennifer; Mendizabal, Adam M.; Horowitz, Mary M.; Deeg, H. Joachim; Horwitz, Mitchell E.

2017-01-01

Purpose The optimal regimen intensity before allogeneic hematopoietic cell transplantation (HCT) is unknown. We hypothesized that lower treatment-related mortality (TRM) with reduced-intensity conditioning (RIC) would result in improved overall survival (OS) compared with myeloablative conditioning (MAC). To test this hypothesis, we performed a phase III randomized trial comparing MAC with RIC in patients with acute myeloid leukemia or myelodysplastic syndromes. Patients and Methods Patients age 18 to 65 years with HCT comorbidity index ≤ 4 and < 5% marrow myeloblasts pre-HCT were randomly assigned to receive MAC (n = 135) or RIC (n = 137) followed by HCT from HLA-matched related or unrelated donors. The primary end point was OS 18 months post–random assignment based on an intent-to-treat analysis. Secondary end points included relapse-free survival (RFS) and TRM. Results Planned enrollment was 356 patients; accrual ceased at 272 because of high relapse incidence with RIC versus MAC (48.3%; 95% CI, 39.6% to 56.4% and 13.5%; 95% CI, 8.3% to 19.8%, respectively; P < .001). At 18 months, OS for patients in the RIC arm was 67.7% (95% CI, 59.1% to 74.9%) versus 77.5% (95% CI, 69.4% to 83.7%) for those in the MAC arm (difference, 9.8%; 95% CI, −0.8% to 20.3%; P = .07). TRM with RIC was 4.4% (95% CI, 1.8% to 8.9%) versus 15.8% (95% CI, 10.2% to 22.5%) with MAC (P = .002). RFS with RIC was 47.3% (95% CI, 38.7% to 55.4%) versus 67.8% (95% CI, 59.1% to 75%) with MAC (P < .01). Conclusion OS was higher with MAC, but this was not statistically significant. RIC resulted in lower TRM but higher relapse rates compared with MAC, with a statistically significant advantage in RFS with MAC. These data support the use of MAC as the standard of care for fit patients with acute myeloid leukemia or myelodysplastic syndromes. PMID:28380315

Adaptive optimization of reference intensity for optical coherence imaging using galvanometric mirror tilting method

NASA Astrophysics Data System (ADS)

Kim, Ji-hyun; Han, Jae-Ho; Jeong, Jichai

2015-09-01

Integration time and reference intensity are important factors for achieving high signal-to-noise ratio (SNR) and sensitivity in optical coherence tomography (OCT). In this context, we present an adaptive optimization method of reference intensity for OCT setup. The reference intensity is automatically controlled by tilting a beam position using a Galvanometric scanning mirror system. Before sample scanning, the OCT system acquires two dimensional intensity map with normalized intensity and variables in color spaces using false-color mapping. Then, the system increases or decreases reference intensity following the map data for optimization with a given algorithm. In our experiments, the proposed method successfully corrected the reference intensity with maintaining spectral shape, enabled to change integration time without manual calibration of the reference intensity, and prevented image degradation due to over-saturation and insufficient reference intensity. Also, SNR and sensitivity could be improved by increasing integration time with automatic adjustment of the reference intensity. We believe that our findings can significantly aid in the optimization of SNR and sensitivity for optical coherence tomography systems.

Optimization methods and silicon solar cell numerical models

NASA Technical Reports Server (NTRS)

Girardini, K.

1986-01-01

The goal of this project is the development of an optimization algorithm for use with a solar cell model. It is possible to simultaneously vary design variables such as impurity concentrations, front junction depth, back junctions depth, and cell thickness to maximize the predicted cell efficiency. An optimization algorithm has been developed and interfaced with the Solar Cell Analysis Program in 1 Dimension (SCAPID). SCAPID uses finite difference methods to solve the differential equations which, along with several relations from the physics of semiconductors, describe mathematically the operation of a solar cell. A major obstacle is that the numerical methods used in SCAPID require a significant amount of computer time, and during an optimization the model is called iteratively until the design variables converge to the value associated with the maximum efficiency. This problem has been alleviated by designing an optimization code specifically for use with numerically intensive simulations, to reduce the number of times the efficiency has to be calculated to achieve convergence to the optimal solution. Adapting SCAPID so that it could be called iteratively by the optimization code provided another means of reducing the cpu time required to complete an optimization. Instead of calculating the entire I-V curve, as is usually done in SCAPID, only the efficiency is calculated (maximum power voltage and current) and the solution from previous calculations is used to initiate the next solution.

Carbohydrate-Restriction with High-Intensity Interval Training: An Optimal Combination for Treating Metabolic Diseases?

PubMed

Francois, Monique E; Gillen, Jenna B; Little, Jonathan P

2017-01-01

Lifestyle interventions incorporating both diet and exercise strategies remain cornerstone therapies for treating metabolic disease. Carbohydrate-restriction and high-intensity interval training (HIIT) have independently been shown to improve cardiovascular and metabolic health. Carbohydrate-restriction reduces postprandial hyperglycemia, thereby limiting potential deleterious metabolic and cardiovascular consequences of excessive glucose excursions. Additionally, carbohydrate-restriction has been shown to improve body composition and blood lipids. The benefits of exercise for improving insulin sensitivity are well known. In this regard, HIIT has been shown to rapidly improve glucose control, endothelial function, and cardiorespiratory fitness. Here, we report the available evidence for each strategy and speculate that the combination of carbohydrate-restriction and HIIT will synergistically maximize the benefits of both approaches. We hypothesize that this lifestyle strategy represents an optimal intervention to treat metabolic disease; however, further research is warranted in order to harness the potential benefits of carbohydrate-restriction and HIIT for improving cardiometabolic health.

Efficient monoenergetic proton beam from ultra-fast laser interaction with nanostructured targets

NASA Astrophysics Data System (ADS)

Fazeli, R.

2018-03-01

The broad energy spectrum of laser-accelerated proton beams is the most important difficulty associated with such particle sources on the way to future applications such as medical therapy, proton imaging, inertial fusion, and high-energy physics. The generation of proton beams with enhanced monoenergetic features through an ultra-intense laser interaction with optimized nanostructured targets is reported. Targets were irradiated by 40 fs laser pulses of intensity 5.5 ×1020 W c m -2 and wavelength 1 μm. The results of multi-parametric Particle-in-Cell calculations showed that proton beams with considerably reduced energy spread can be obtained by using the proposed nanostructured target. At optimized target dimensions, the proton spectrum was found to exhibit a narrow peak at about 63 MeV with a relative energy spread of ΔE /Epeak˜ 5 % which is efficiently lower than what is expected for unstructured double layer targets (˜70%).

Relaxed damage threshold intensity conditions and nonlinear increase in the conversion efficiency of an optical parametric oscillator using a bi-directional pump geometry.

PubMed

Norris, G; McConnell, G

2010-03-01

A novel bi-directional pump geometry that nonlinearly increases the nonlinear optical conversion efficiency of a synchronously pumped optical parametric oscillator (OPO) is reported. This bi-directional pumping method synchronizes the circulating signal pulse with two counter-propagating pump pulses within a linear OPO resonator. Through this pump scheme, an increase in nonlinear optical conversion efficiency of 22% was achieved at the signal wavelength, corresponding to a 95% overall increase in average power. Given an almost unchanged measured pulse duration of 260 fs under optimal performance conditions, this related to a signal wavelength peak power output of 18.8 kW, compared with 10 kW using the traditional single-pass geometry. In this study, a total effective peak intensity pump-field of 7.11 GW/cm(2) (corresponding to 3.55 GW/cm(2) from each pump beam) was applied to a 3 mm long periodically poled lithium niobate crystal, which had a damage threshold intensity of 4 GW/cm(2), without impairing crystal integrity. We therefore prove the application of this novel pump geometry provides opportunities for power-scaling of synchronously pumped OPO systems together with enhanced nonlinear conversion efficiency through relaxed damage threshold intensity conditions.

SU-E-T-618: Dosimetric Comparison of Manual and Beam Angle Optimization of Gantry Angles in IMRT for Cervical Cancer

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

Lin, X; Sun, T; Liu, T

2014-06-01

Purpose: To evaluate the dosimetric characteristics of intensity-modulated radiotherapy (IMRT) treatment plan with beam angle optimization. Methods: Ten post-operation patients with cervical cancer were included in this analysis. Two IMRT plans using seven beams were designed in each patient. A standard coplanar equi-space beam angles were used in the first plan (plan 1), whereas the selection of beam angle was optimized by beam angle optimization algorithm in Varian Eclipse treatment planning system for the same number of beams in the second plan (plan 2). Two plans were designed for each patient with the same dose-volume constraints and prescription dose. Allmore » plans were normalized to the mean dose to PTV. The dose distribution in the target, the dose to the organs at risk and total MU were compared. Results: For conformity and homogeneity in PTV, no statistically differences were observed in the two plans. For the mean dose in bladder, plan 2 were significantly lower than plan 1(p<0.05). No statistically significant differences were observed between two plans for the mean doses in rectum, left and right femur heads. Compared with plan1, the average monitor units reduced 16% in plan 2. Conclusion: The IMRT plan based on beam angle optimization for cervical cancer could reduce the dose delivered to bladder and also reduce MU. Therefore there were some dosimetric advantages in the IMRT plan with beam angle optimization for cervical cancer.« less

Enhanced ion acceleration in transition from opaque to transparent plasmas

DOE PAGES

Mishra, R.; Fiuza, F.; Glenzer, S.

2018-04-20

Using particle-in-cell simulations, we investigate ion acceleration in the interaction of high intensity lasers with plasmas which transition from opaque to transparent during the interaction process. We show that the highest ion energies are achieved when the laser traverses the target around the peak intensity and re-heats the electron population responsible for the plasma expansion, enhancing the corresponding sheath electric field. This process can lead to an increase of up to 2x in ion energy when compared with the standard Target Normal Sheath Acceleration in opaque targets under the same laser conditions. A theoretical model is developed to predict themore » optimal target areal density as a function of laser intensity and pulse duration. A systematic parametric scan for a wide range of target densities and thicknesses is performed in 1D, 2D and 3D and shown consistent with the theory and with recent experimental results. Thus, these results open the way for a better optimization of the ion energy in future laser–solid experiments.« less

XFEL diffraction: Developing processing methods to optimize data quality

DOE PAGES

Sauter, Nicholas K.

2015-01-29

Serial crystallography, using either femtosecond X-ray pulses from free-electron laser sources or short synchrotron-radiation exposures, has the potential to reveal metalloprotein structural details while minimizing damage processes. However, deriving a self-consistent set of Bragg intensities from numerous still-crystal exposures remains a difficult problem, with optimal protocols likely to be quite different from those well established for rotation photography. Here several data processing issues unique to serial crystallography are examined. It is found that the limiting resolution differs for each shot, an effect that is likely to be due to both the sample heterogeneity and pulse-to-pulse variation in experimental conditions. Shotsmore » with lower resolution limits produce lower-quality models for predicting Bragg spot positions during the integration step. Also, still shots by their nature record only partial measurements of the Bragg intensity. An approximate model that corrects to the full-spot equivalent (with the simplifying assumption that the X-rays are monochromatic) brings the distribution of intensities closer to that expected from an ideal crystal, and improves the sharpness of anomalous difference Fourier peaks indicating metal positions.« less

Enhanced ion acceleration in transition from opaque to transparent plasmas

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

Mishra, R.; Fiuza, F.; Glenzer, S.

Using particle-in-cell simulations, we investigate ion acceleration in the interaction of high intensity lasers with plasmas which transition from opaque to transparent during the interaction process. We show that the highest ion energies are achieved when the laser traverses the target around the peak intensity and re-heats the electron population responsible for the plasma expansion, enhancing the corresponding sheath electric field. This process can lead to an increase of up to 2x in ion energy when compared with the standard Target Normal Sheath Acceleration in opaque targets under the same laser conditions. A theoretical model is developed to predict themore » optimal target areal density as a function of laser intensity and pulse duration. A systematic parametric scan for a wide range of target densities and thicknesses is performed in 1D, 2D and 3D and shown consistent with the theory and with recent experimental results. Thus, these results open the way for a better optimization of the ion energy in future laser–solid experiments.« less

Optimization of hydrostatic pressure at varied sonication conditions--power density, intensity, very low frequency--for isothermal ultrasonic sludge treatment.

PubMed

Delmas, Henri; Le, Ngoc Tuan; Barthe, Laurie; Julcour-Lebigue, Carine

2015-07-01

This work aims at investigating for the first time the key sonication (US) parameters: power density (DUS), intensity (IUS), and frequency (FS) - down to audible range, under varied hydrostatic pressure (Ph) and low temperature isothermal conditions (to avoid any thermal effect). The selected application was activated sludge disintegration, a major industrial US process. For a rational approach all comparisons were made at same specific energy input (ES, US energy per solid weight) which is also the relevant economic criterion. The decoupling of power density and intensity was obtained by either changing the sludge volume or most often by changing probe diameter, all other characteristics being unchanged. Comprehensive results were obtained by varying the hydrostatic pressure at given power density and intensity. In all cases marked maxima of sludge disintegration appeared at optimum pressures, which values increased at increasing power intensity and density. Such optimum was expected due to opposite effects of increasing hydrostatic pressure: higher cavitation threshold then smaller and fewer bubbles, but higher temperature and pressure at the end of collapse. In addition the first attempt to lower US frequency down to audible range was very successful: at any operation condition (DUS, IUS, Ph, sludge concentration and type) higher sludge disintegration was obtained at 12 kHz than at 20 kHz. The same values of optimum pressure were observed at 12 and 20 kHz. At same energy consumption the best conditions - obtained at 12 kHz, maximum power density 720 W/L and 3.25 bar - provided about 100% improvement with respect to usual conditions (1 bar, 20 kHz). Important energy savings and equipment size reduction may then be expected. Copyright © 2014 Elsevier B.V. All rights reserved.

Development of optimized segmentation map in dual energy computed tomography

NASA Astrophysics Data System (ADS)

Yamakawa, Keisuke; Ueki, Hironori

2012-03-01

Dual energy computed tomography (DECT) has been widely used in clinical practice and has been particularly effective for tissue diagnosis. In DECT the difference of two attenuation coefficients acquired by two kinds of X-ray energy enables tissue segmentation. One problem in conventional DECT is that the segmentation deteriorates in some cases, such as bone removal. This is due to two reasons. Firstly, the segmentation map is optimized without considering the Xray condition (tube voltage and current). If we consider the tube voltage, it is possible to create an optimized map, but unfortunately we cannot consider the tube current. Secondly, the X-ray condition is not optimized. The condition can be set empirically, but this means that the optimized condition is not used correctly. To solve these problems, we have developed methods for optimizing the map (Method-1) and the condition (Method-2). In Method-1, the map is optimized to minimize segmentation errors. The distribution of the attenuation coefficient is modeled by considering the tube current. In Method-2, the optimized condition is decided to minimize segmentation errors depending on tube voltagecurrent combinations while keeping the total exposure constant. We evaluated the effectiveness of Method-1 by performing a phantom experiment under the fixed condition and of Method-2 by performing a phantom experiment under different combinations calculated from the total exposure constant. When Method-1 was followed with Method-2, the segmentation error was reduced from 37.8 to 13.5 %. These results demonstrate that our developed methods can achieve highly accurate segmentation while keeping the total exposure constant.

Poster — Thur Eve — 35: The impact of intensity- and energy-modulated photon radiotherapy (XMRT) optimization on a variety of organ geometries

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

McGeachy, P.; Villarreal-Barajas, J. E.; Khan, R.

2014-08-15

We previously reported on a novel, modulated in both energy and intensity; photon radiotherapy (XMRT) optimization technique. The purpose of this investigation was to test this XMRT optimization against conventional intensity modulated radiotherapy (IMRT) optimization on four different organ test geometries. All geometries mimicked clinically relevant scenarios. Both IMRT and XMRT were based on a linear programming approach where the objective function was the mean dose to healthy organs and organ-specific linear dose-point constraints were used. For IMRT, the beam energy was fixed to 6 MV while XMRT optimized in terms of both 6 and 18 MV beams. All plansmore » consisted of a seven beam coplanar arrangement. All organ geometries were contoured on a 25cm diameter cylindrical water phantom in open source radiotherapy research software known as CERR. Solutions for both IMRT and XMRT were obtained for each geometry using a numerical solver Gurobi. Analyzing the quality of the solutions was done by comparing dose distributions and dose volume histograms calculated using CERR. For all four geometries, IMRT and XMRT solutions were comparable in terms of target coverage. For two of the geometries, IMRT provided an advantage in terms of reduced dose to the healthy structures. XMRT showed improved dose reduction to healthy organs for one geometry and a comparable dose distribution to IMRT for the remaining geometry. The inability to exploit the benefits of using multiple energies may be attributed to limited water phantom diameter and having the majority of the organs in close proximity to the transverse axis.« less

Antibunching and unconventional photon blockade with Gaussian squeezed states

NASA Astrophysics Data System (ADS)

Lemonde, Marc-Antoine; Didier, Nicolas; Clerk, Aashish A.

2014-12-01

Photon antibunching is a quantum phenomenon typically observed in strongly nonlinear systems where photon blockade suppresses the probability of detecting two photons at the same time. Antibunching has also been reported with Gaussian states, where optimized amplitude squeezing yields classically forbidden values of the intensity correlation, g(2 )(0 ) <1 . As a consequence, observation of antibunching is not necessarily a signature of photon-photon interactions. To clarify the significance of the intensity correlations, we derive a sufficient condition for deducing whether a field is non-Gaussian based on a g(2 )(0 ) measurement. We then show that the Gaussian antibunching obtained with a degenerate parametric amplifier is close to the ideal case reached using dissipative squeezing protocols. We finally shed light on the so-called unconventional photon blockade effect predicted in a driven two-cavity setup with surprisingly weak Kerr nonlinearities, stressing that it is a particular realization of optimized Gaussian amplitude squeezing.

Optical bi-stable shutter development/improvement

NASA Astrophysics Data System (ADS)

Lizon, J. L.; Haddad, N.; Castillo, R.

2012-09-01

Two of the VLT instruments (Giraffe and VIMOS) are using the large magnetic E/150 from Prontor (with an aperture diameter of 150 mm). As we were facing an unacceptable number of failures with this component some improvement plan was discussed already in 2004. The final decision for starting this program was conditioned by the decision from the constructor to stop the production. The opportunity was taken to improve the design building a fully bi-stable mechanism in order to reduce the thermal dissipation. The project was developed in collaboration between the two main ESO sites doing the best use of the manpower and of the technical capability available at the two centers. The project took advantage of the laser Mask Manufacturing Unit and the invar sheets used to prepare the VIMOS MOS mask to fabricate the shutter petals. Our paper describes the development including the intensive and long optimization period. To conclude this optimization we proceed with a long life test on two units. These units have demonstrate a very high level of reliability (up to 100 000 cycles without failure which can be estimated to an equivalent 6 years of operation of the instrument) A new bi-stable shutter driver and controller have also been developed. Some of the highlights of this unit are the fully configurable coil driving parameters, usage of braking strategy to dump mechanical vibration and reduce mechanical wearing, configurable usage of OPEN and CLOSE sensors, non volatile storage of parameters, user friendly front panel interface.

[Just-in-time initiation of optimal dialysis].

PubMed

Cornelis, Tom; Kooman, Jeroen P; van der Sande, Frank M

2010-01-01

The IDEAL trial shows that the decision to start renal replacement treatment should not depend on GFR alone, but should be taken on the basis of clinical parameters. Quality of Life (QoL) questionnaires and bio-impedance analysis are potential tools for detecting subtle changes in the predialysis clinic. Too early an initiation of dialysis may be deleterious for the patient and the healthcare system. We are convinced that ESRD patients should be informed about intensive haemodialysis (HD), especially nocturnal (home) HD, as the best available dialysis modality. There is substantial evidence which shows that intensive HD improves clinical, biochemical and biological parameters, and may even prolong survival. We believe that 'just-in-time delivery of intensive haemodialysis' may result in optimised QoL and reduced economic burden.

Optimization of wireless sensor networks based on chicken swarm optimization algorithm

NASA Astrophysics Data System (ADS)

Wang, Qingxi; Zhu, Lihua

2017-05-01

In order to reduce the energy consumption of wireless sensor network and improve the survival time of network, the clustering routing protocol of wireless sensor networks based on chicken swarm optimization algorithm was proposed. On the basis of LEACH agreement, it was improved and perfected that the points on the cluster and the selection of cluster head using the chicken group optimization algorithm, and update the location of chicken which fall into the local optimum by Levy flight, enhance population diversity, ensure the global search capability of the algorithm. The new protocol avoided the die of partial node of intensive using by making balanced use of the network nodes, improved the survival time of wireless sensor network. The simulation experiments proved that the protocol is better than LEACH protocol on energy consumption, also is better than that of clustering routing protocol based on particle swarm optimization algorithm.

Implementation and on-sky results of an optimal wavefront controller for the MMT NGS adaptive optics system

NASA Astrophysics Data System (ADS)

Powell, Keith B.; Vaitheeswaran, Vidhya

2010-07-01

The MMT observatory has recently implemented and tested an optimal wavefront controller for the NGS adaptive optics system. Open loop atmospheric data collected at the telescope is used as the input to a MATLAB based analytical model. The model uses nonlinear constrained minimization to determine controller gains and optimize the system performance. The real-time controller performing the adaptive optics close loop operation is implemented on a dedicated high performance PC based quad core server. The controller algorithm is written in C and uses the GNU scientific library for linear algebra. Tests at the MMT confirmed the optimal controller significantly reduced the residual RMS wavefront compared with the previous controller. Significant reductions in image FWHM and increased peak intensities were obtained in J, H and K-bands. The optimal PID controller is now operating as the baseline wavefront controller for the MMT NGS-AO system.

Direct aperture optimization using an inverse form of back-projection.

PubMed

Zhu, Xiaofeng; Cullip, Timothy; Tracton, Gregg; Tang, Xiaoli; Lian, Jun; Dooley, John; Chang, Sha X

2014-03-06

Direct aperture optimization (DAO) has been used to produce high dosimetric quality intensity-modulated radiotherapy (IMRT) treatment plans with fast treatment delivery by directly modeling the multileaf collimator segment shapes and weights. To improve plan quality and reduce treatment time for our in-house treatment planning system, we implemented a new DAO approach without using a global objective function (GFO). An index concept is introduced as an inverse form of back-projection used in the CT multiplicative algebraic reconstruction technique (MART). The index, introduced for IMRT optimization in this work, is analogous to the multiplicand in MART. The index is defined as the ratio of the optima over the current. It is assigned to each voxel and beamlet to optimize the fluence map. The indices for beamlets and segments are used to optimize multileaf collimator (MLC) segment shapes and segment weights, respectively. Preliminary data show that without sacrificing dosimetric quality, the implementation of the DAO reduced average IMRT treatment time from 13 min to 8 min for the prostate, and from 15 min to 9 min for the head and neck using our in-house treatment planning system PlanUNC. The DAO approach has also shown promise in optimizing rotational IMRT with burst mode in a head and neck test case.

Integrated beam orientation and scanning-spot optimization in intensity-modulated proton therapy for brain and unilateral head and neck tumors.

PubMed

Gu, Wenbo; O'Connor, Daniel; Nguyen, Dan; Yu, Victoria Y; Ruan, Dan; Dong, Lei; Sheng, Ke

2018-04-01

Intensity-Modulated Proton Therapy (IMPT) is the state-of-the-art method of delivering proton radiotherapy. Previous research has been mainly focused on optimization of scanning spots with manually selected beam angles. Due to the computational complexity, the potential benefit of simultaneously optimizing beam orientations and spot pattern could not be realized. In this study, we developed a novel integrated beam orientation optimization (BOO) and scanning-spot optimization algorithm for intensity-modulated proton therapy (IMPT). A brain chordoma and three unilateral head-and-neck patients with a maximal target size of 112.49 cm 3 were included in this study. A total number of 1162 noncoplanar candidate beams evenly distributed across 4π steradians were included in the optimization. For each candidate beam, the pencil-beam doses of all scanning spots covering the PTV and a margin were calculated. The beam angle selection and spot intensity optimization problem was formulated to include three terms: a dose fidelity term to penalize the deviation of PTV and OAR doses from ideal dose distribution; an L1-norm sparsity term to reduce the number of active spots and improve delivery efficiency; a group sparsity term to control the number of active beams between 2 and 4. For the group sparsity term, convex L2,1-norm and nonconvex L2,1/2-norm were tested. For the dose fidelity term, both quadratic function and linearized equivalent uniform dose (LEUD) cost function were implemented. The optimization problem was solved using the Fast Iterative Shrinkage-Thresholding Algorithm (FISTA). The IMPT BOO method was tested on three head-and-neck patients and one skull base chordoma patient. The results were compared with IMPT plans created using column generation selected beams or manually selected beams. The L2,1-norm plan selected spatially aggregated beams, indicating potential degeneracy using this norm. L2,1/2-norm was able to select spatially separated beams and achieve smaller deviation from the ideal dose. In the L2,1/2-norm plans, the [mean dose, maximum dose] of OAR were reduced by an average of [2.38%, 4.24%] and[2.32%, 3.76%] of the prescription dose for the quadratic and LEUD cost function, respectively, compared with the IMPT plan using manual beam selection while maintaining the same PTV coverage. The L2,1/2 group sparsity plans were dosimetrically superior to the column generation plans as well. Besides beam orientation selection, spot sparsification was observed. Generally, with the quadratic cost function, 30%~60% spots in the selected beams remained active. With the LEUD cost function, the percentages of active spots were in the range of 35%~85%.The BOO-IMPT run time was approximately 20 min. This work shows the first IMPT approach integrating noncoplanar BOO and scanning-spot optimization in a single mathematical framework. This method is computationally efficient, dosimetrically superior and produces delivery-friendly IMPT plans. © 2018 American Association of Physicists in Medicine.

Recovery of Iron from Hematite-Rich Diasporic-Type Bauxite Ore

NASA Astrophysics Data System (ADS)

Jiang, Tao; Li, Zhuoxuan; Yang, Lin; Li, Guanghui; Zhang, Yuanbo; Zeng, Jinghua

A technique has been proposed for recovering iron from hematite-rich diasporic-type bauxite ore in this study. Direct reduction roasting followed by low intensity wet magnetic separation process was carried out. The parameters including reduction temperature and time, sodium salts, grinding conditions and magnetic field intensity for separation of iron were determined. The optimum process parameters as follows: roasting temperature of 1050 °C, time of 60 min, sodium salts involving sodium sulfate, borax, sodium carbonate with dosages of 10 wt%, 2 wt%, 35 wt% respectively, and magnetic field intensity of 1000 Gs with fineness of pulp reached 92.75% passing -0.074mm. Under the optimal conditions, an iron concentrate containing 88.17% total iron grade and iron recovery of 92.51% was obtained, 4.55% total iron grade in tailings. This novel technique provide a potential route for utilizing hematiterich diasporic bauxite ore, recovering iron resource firstly, and extracting alumina from magnetic separation tailings further.

Priority interventions to reduce HIV transmission in sex work settings in sub-Saharan Africa and delivery of these services

PubMed Central

Chersich, Matthew F; Luchters, Stanley; Ntaganira, Innocent; Gerbase, Antonio; Lo, Ying-Ru; Scorgie, Fiona; Steen, Richard

2013-01-01

Introduction Virtually no African country provides HIV prevention services in sex work settings with an adequate scale and intensity. Uncertainty remains about the optimal set of interventions and mode of delivery. Methods We systematically reviewed studies reporting interventions for reducing HIV transmission among female sex workers in sub-Saharan Africa between January 2000 and July 2011. Medline (PubMed) and non-indexed journals were searched for studies with quantitative study outcomes. Results We located 26 studies, including seven randomized trials. Evidence supports implementation of the following interventions to reduce unprotected sex among female sex workers: peer-mediated condom promotion, risk-reduction counselling and skills-building for safer sex. One study found that interventions to counter hazardous alcohol-use lowered unprotected sex. Data also show effectiveness of screening for sexually transmitted infections (STIs) and syndromic STI treatment, but experience with periodic presumptive treatment is limited. HIV testing and counselling is essential for facilitating sex workers’ access to care and antiretroviral treatment (ART), but testing models for sex workers and indeed for ART access are little studied, as are structural interventions, which create conditions conducive for risk reduction. With the exception of Senegal, persistent criminalization of sex work across Africa reduces sex workers’ control over working conditions and impedes their access to health services. It also obstructs health-service provision and legal protection. Conclusions There is sufficient evidence of effectiveness of targeted interventions with female sex workers in Africa to inform delivery of services for this population. With improved planning and political will, services – including peer interventions, condom promotion and STI screening – would act at multiple levels to reduce HIV exposure and transmission efficiency among sex workers. Initiatives are required to enhance access to HIV testing and ART for sex workers, using current CD4 thresholds, or possibly earlier for prevention. Services implemented at sufficient scale and intensity also serve as a platform for subsequent community mobilization and sex worker empowerment, and alleviate a major source of incident infection sustaining even generalized HIV epidemics. Ultimately, structural and legal changes that align public health and human rights are needed to ensure that sex workers on the continent are adequately protected from HIV. PMID:23462140

Influence of Exercise Intensity for Improving Depressed Mood in Depression: A Dose-Response Study.

PubMed

Meyer, Jacob D; Koltyn, Kelli F; Stegner, Aaron J; Kim, Jee-Seon; Cook, Dane B

2016-07-01

Exercise effectively improves mood in major depressive disorder (MDD), but the optimal exercise stimulus to improve depressed mood is unknown. To determine the dose-response relationship of acute exercise intensity with depressed mood responses to exercise in MDD. We hypothesized that the acute response to exercise would differ between light, moderate, and hard intensity exercise with higher intensities yielding more beneficial responses. Once weekly, 24 women (age: 38.6±14.0) diagnosed with MDD underwent a 30-minute session at one of three steady-state exercise intensities (light, moderate, hard; rating of perceived exertion 11, 13 or 15) or quiet rest on a stationary bicycle. Depressed mood was evaluated with the Profile of Mood States before, 10 and 30 minutes post-exercise. Exercise reduced depressed mood 10 and 30 minutes following exercise, but this effect was not influenced by exercise intensity. Participants not currently taking antidepressants (n=10) had higher baseline depression scores, but did not demonstrate a different antidepressant response to exercise compared to those taking antidepressants. To acutely improve depressed mood, exercise of any intensity significantly improved feelings of depression with no differential effect following light, moderate, or hard exercise. Pharmacological antidepressant usage did not limit the mood-enhancing effect of acute exercise. Acute exercise should be used as a symptom management tool to improve mood in depression, with even light exercise an effective recommendation. These results need to be replicated and extended to other components of exercise prescription (e.g., duration, frequency, mode) to optimize exercise guidelines for improving depression. Copyright © 2016. Published by Elsevier Ltd.

Thinning method and intensity influence long-term mortality trends in a red pine forest

Treesearch

Matthew D. Powers; Brian J. Palik; John B. Bradford; Shawn Fraver; Christopher R. Webster

2010-01-01

Tree mortality shapes forest development, but rising mortality can represent lost production or an adverse response to changing environmental conditions. Thinning represents a strategy for reducing mortality rates, but different thinning techniques and intensities could have varying impacts depending on how they alter stand structure. We analyzed trends in stand...

Scheduling fertilizer applications as a simple mitigation option for reducing N2O emission in intensively managed mown grassland systems

NASA Astrophysics Data System (ADS)

Neftel, Albrecht; Calanca, Pierluigi; Felber, Raphael; Grant, Robert; Conen, Franz

2014-05-01

A general principle in all proposed N2O mitigation options is the fertilization according to plants' requirements. Meanwhile the amount of N fertilization allowed is regulated in many countries. Due to the high pressure from food security and the need for economic efficiency the given limits are generally used up. In mown grassland systems a simple mitigation option is to optimize the timing of the fertilizer applications. Application of fertilizer, both organic manure and mineral fertilizer, is generally scheduled after each cut in a narrow time window. In practice, the delay between cut and fertilizer application is determined by weather conditions, management conditions and most important by the planning and experience of the individual farmer. Many field experiments have shown that enhanced N2O emissions tend to occur after cuts but before the application of fertilizer, especially when soils are characterized by a high WFPS. These findings suggest that the time of fertilizer application has an important implications for the N2O emission rate and that scheduling fertilization according to soil conditions might be a simple, cheap and efficient measure to mitigate N2O emissions. In this paper we report on results from a sensitivity analysis aiming at quantifying the effects of the timing of the fertilizer applications on N2O emissions from intensively managed, mown grasslands. Simulations for different time schedules were carried out with the comprehensive ecosystem model "ECOSYS" . To our knowledge this aspect has not been systematically investigated from a scientific point of view, but might have been always there within the experiences of attentive environmentally concerned farmers.

Improving the Molecular Ion Signal Intensity for In Situ Liquid SIMS Analysis

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

Zhou, Yufan; Yao, Juan; Ding, Yuanzhao

In situ liquid secondary ion mass spectrometry (SIMS) enabled by system for analysis at the liquid vacuum interface (SALVI) has proven to be a promising new tool to provide molecular information at solid–liquid and liquid–vacuum interfaces. However, the initial data showed that useful signals in positive ion spectra are too weak to be meaningful in most cases. In addition, it is difficult to obtain strong negative molecular ion signals when m/z>200. These two drawbacks have been the biggest obstacle towards practical use of this new analytical approach. In this study, we report that strong and reliable positive and negative molecularmore » signals are achievable after optimizing the SIMS experimental conditions. Four model systems, including a 1,8-diazabicycloundec-7-ene (DBU)-base switchable ionic liquid, a live Shewanella oneidensis biofilm, a hydrated mammalian epithelia cell, and an electrolyte popularly used in Li ion batteries were studied. A signal enhancement of about two orders of magnitude was obtained in comparison with non-optimized conditions. Therefore, molecular ion signal intensity has become very acceptable to use for in situ liquid SIMS to study solid–liquid and liquid–vacuum interfaces.« less

Improving the Molecular Ion Signal Intensity for In Situ Liquid SIMS Analysis.

PubMed

Zhou, Yufan; Yao, Juan; Ding, Yuanzhao; Yu, Jiachao; Hua, Xin; Evans, James E; Yu, Xiaofei; Lao, David B; Heldebrant, David J; Nune, Satish K; Cao, Bin; Bowden, Mark E; Yu, Xiao-Ying; Wang, Xue-Lin; Zhu, Zihua

2016-12-01

In situ liquid secondary ion mass spectrometry (SIMS) enabled by system for analysis at the liquid vacuum interface (SALVI) has proven to be a promising new tool to provide molecular information at solid-liquid and liquid-vacuum interfaces. However, the initial data showed that useful signals in positive ion spectra are too weak to be meaningful in most cases. In addition, it is difficult to obtain strong negative molecular ion signals when m/z>200. These two drawbacks have been the biggest obstacle towards practical use of this new analytical approach. In this study, we report that strong and reliable positive and negative molecular signals are achievable after optimizing the SIMS experimental conditions. Four model systems, including a 1,8-diazabicycloundec-7-ene (DBU)-base switchable ionic liquid, a live Shewanella oneidensis biofilm, a hydrated mammalian epithelia cell, and an electrolyte popularly used in Li ion batteries were studied. A signal enhancement of about two orders of magnitude was obtained in comparison with non-optimized conditions. Therefore, molecular ion signal intensity has become very acceptable for use of in situ liquid SIMS to study solid-liquid and liquid-vacuum interfaces. Graphical Abstract ᅟ.

Investigating the effects of PDC cutters geometry on ROP using the Taguchi technique

NASA Astrophysics Data System (ADS)

Jamaludin, A. A.; Mehat, N. M.; Kamaruddin, S.

2017-10-01

At times, the polycrystalline diamond compact (PDC) bit’s performance dropped and affects the rate of penetration (ROP). The objective of this project is to investigate the effect of PDC cutter geometry and optimize them. An intensive study in cutter geometry would further enhance the ROP performance. The relatively extended analysis was carried out and four significant geometry factors have been identified that directly improved the ROP. Cutter size, back rake angle, side rake angle and chamfer angle are the stated geometry factors. An appropriate optimization technique that effectively controls all influential geometry factors during cutters manufacturing is introduced and adopted in this project. By adopting L9 Taguchi OA, simulation experiment is conducted by using explicit dynamics finite element analysis. Through a structure Taguchi analysis, ANOVA confirms that the most significant geometry to improve ROP is cutter size (99.16% percentage contribution). The optimized cutter is expected to drill with high ROP that can reduce the rig time, which in its turn, may reduce the total drilling cost.

Randomized algorithms for high quality treatment planning in volumetric modulated arc therapy

NASA Astrophysics Data System (ADS)

Yang, Yu; Dong, Bin; Wen, Zaiwen

2017-02-01

In recent years, volumetric modulated arc therapy (VMAT) has been becoming a more and more important radiation technique widely used in clinical application for cancer treatment. One of the key problems in VMAT is treatment plan optimization, which is complicated due to the constraints imposed by the involved equipments. In this paper, we consider a model with four major constraints: the bound on the beam intensity, an upper bound on the rate of the change of the beam intensity, the moving speed of leaves of the multi-leaf collimator (MLC) and its directional-convexity. We solve the model by a two-stage algorithm: performing minimization with respect to the shapes of the aperture and the beam intensities alternatively. Specifically, the shapes of the aperture are obtained by a greedy algorithm whose performance is enhanced by random sampling in the leaf pairs with a decremental rate. The beam intensity is optimized using a gradient projection method with non-monotonic line search. We further improve the proposed algorithm by an incremental random importance sampling of the voxels to reduce the computational cost of the energy functional. Numerical simulations on two clinical cancer date sets demonstrate that our method is highly competitive to the state-of-the-art algorithms in terms of both computational time and quality of treatment planning.

Thermo-chemical pretreatment and enzymatic hydrolysis for enhancing saccharification of catalpa sawdust.

PubMed

Jin, Shuguang; Zhang, Guangming; Zhang, Panyue; Li, Fan; Fan, Shiyang; Li, Juan

2016-04-01

To improve the reducing sugar production from catalpa sawdust, thermo-chemical pretreatments were examined and the chemicals used including NaOH, Ca(OH)2, H2SO4, and HCl. The hemicellulose solubilization and cellulose crystallinity index (CrI) were significantly increased after thermo-alkaline pretreatments, and the thermo-Ca(OH)2 pretreatment showed the best improvement for reducing sugar production comparing to other three pretreatments. The conditions of thermo-Ca(OH)2 pretreatment and enzymatic hydrolysis were systematically optimized. Under the optimal conditions, the reducing sugar yield increased by 1185.7% comparing to the control. This study indicates that the thermo-Ca(OH)2 pretreatment is ideal for the saccharification of catalpa sawdust and that catalpa sawdust is a promising raw material for biofuel. Copyright © 2016 Elsevier Ltd. All rights reserved.

In vivo Selection of Autologous MGMT Gene-Modified Cells Following Reduced Intensity Conditioning with BCNU and Temozolomide in the Dog Model

PubMed Central

Gori, Jennifer L.; Beard, Brian C.; Ironside, Christina; Karponi, Garyfalia; Kiem, Hans-Peter

2012-01-01

Chemotherapy with BCNU and temozolomide (TMZ) is commonly used for the treatment of glioblastoma multiforme (GBM) and other cancers. In preparation for a clinical gene therapy study in patients with glioblastoma, we wished to study whether these reagents could be used as a reduced-intensity conditioning regimen for autologous transplantation of gene-modified cells. We used an MGMT(P140K)-expressing lentivirus vector to modify dog CD34+ cells and tested in 4 dogs whether these autologous cells engraft and provide chemoprotection after transplantation. Treatment with O6-benzylguanine (O6BG)/TMZ after transplantation resulted in gene marking levels up to 75%, without significant hematopoietic cytopenia, which is consistent with hematopoietic chemoprotection. Retrovirus integration analysis showed that multiple clones contribute to hematopoiesis. These studies demonstrate the ability to achieve stable engraftment of MGMT(P140K)-modified autologous HSCs after a novel reduced-intensity conditioning protocol using a combination of BCNU and TMZ. Furthermore, we show that MGMT(P140K)-HSC engraftment provides chemoprotection during TMZ dose escalation. Clinically, chemoconditioning with BCNU and TMZ should facilitate engraftment of MGMT(P140K)-modified cells while providing anti-tumor activity for patients with poor prognosis glioblastoma or alkylating agent sensitive tumors, thereby supporting dose-intensified chemotherapy regimens. PMID:22627392

Uremic Pruritus, Dialysis Adequacy, and Metabolic Profiles in Hemodialysis Patients: A Prospective 5-Year Cohort Study

PubMed Central

Chen, Hung-Yuan; Chiu, Yen-Ling; Hsu, Shih-Ping; Pai, Mei-Fen; Ju-YehYang; Lai, Chun-Fu; Lu, Hui-Min; Huang, Shu-Chen; Yang, Shao-Yu; Wen, Su-Yin; Chiu, Hsien-Ching; Hu, Fu-Chang; Peng, Yu-Sen; Jee, Shiou-Hwa

2013-01-01

Background Uremic pruritus is a common and intractable symptom in patients on chronic hemodialysis, but factors associated with the severity of pruritus remain unclear. This study aimed to explore the associations of metabolic factors and dialysis adequacy with the aggravation of pruritus. Methods We conducted a 5-year prospective cohort study on patients with maintenance hemodialysis. A visual analogue scale (VAS) was used to assess the intensity of pruritus. Patient demographic and clinical characteristics, laboratory parameters, dialysis adequacy (assessed by Kt/V), and pruritus intensity were recorded at baseline and follow-up. Change score analysis of the difference score of VAS between baseline and follow-up was performed using multiple linear regression models. The optimal threshold of Kt/V, which is associated with the aggravation of uremic pruritus, was determined by generalized additive models and receiver operating characteristic analysis. Results A total of 111 patients completed the study. Linear regression analysis showed that lower Kt/V and use of low-flux dialyzer were significantly associated with the aggravation of pruritus after adjusting for the baseline pruritus intensity and a variety of confounding factors. The optimal threshold value of Kt/V for pruritus was 1.5 suggested by both generalized additive models and receiver operating characteristic analysis. Conclusions Hemodialysis with the target of Kt/V ≥1.5 and use of high-flux dialyzer may reduce the intensity of pruritus in patients on chronic hemodialysis. Further clinical trials are required to determine the optimal dialysis dose and regimen for uremic pruritus. PMID:23940749

Reduced-intensity versus reduced-toxicity myeloablative fludarabine/busulfan-based conditioning regimens for allografted non-Hodgkin lymphoma adult patients: a retrospective study on behalf of the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire.

PubMed

Le Bourgeois, A; Labopin, M; Blaise, D; Ceballos, P; Vigouroux, S; Peffault de Latour, R; Marçais, A; Bulabois, C E; Bay, J O; Chantepie, S; Deconinck, E; Daguindau, E; Contentin, N; Yakoub-Agha, I; Cornillon, J; Mercier, M; Turlure, P; Charbonnier, A; Rorhlich, P S; N'Guyen, S; Maillard, N; Marchand, T; Mohty, M; Chevallier, P

2017-09-01

Fludarabine/busulfan-based conditioning regimens are widely used to perform allogeneic stem-cell transplantation (allo-SCT) in high-risk non-Hodgkin lymphoma (NHL) patients. The impact of the dose intensity of busulfan on outcomes has not been reported yet. This was a retrospective with the aim to compare the outcomes of NHL patients who received before allo-SCT a fludarabine/busulfan conditioning regimen, either of reduced intensity (FB2, 2 days of busulfan at 4 mg/kg/day oral or 3.2 mg/kg/day i.v.) (n = 277) or at a myeloablative reduced-toxicity dose (FB3/FB4, 3 or 4 days of busulfan at 4 mg/kg/day oral or 3.2 mg/kg/day i.v.) (n = 101). In univariate analysis, the 2-year overall survival (FB2 66.5% versus 60.3%, P = 0.33), lymphoma-free survival (FB2 57.9% versus 49.8%, P = 0.26), and non-relapse mortality (FB2 19% versus 21.1%, P = 0.91) were similar between both groups. Cumulative incidence of grade III-IV acute graft versus host disease (GVHD) (FB2 11.2% versus 18%, P = 0.08), extensive chronic GVHD (FB2: 17.3% versus 10.7%, P = 0.18) and 2-year GVHD free-relapse free survival (FB2: 44.4% versus 42.8%, P = 0.38) were also comparable. In multivariate analysis there was a trend for a worse outcome using FB3/FB4 regimens (overall survival: HR 1.47, 95% CI: 0.96-2.24, P = 0.08; lymphoma-free survival: HR: 1.43, 95% CI: 0.99-2.06, P = 0.05; relapse incidence: HR 1.54; 95% CI: 0.96-2.48, P = 0.07). These results were confirmed using a propensity score-matching strategy. We conclude that reduced toxicity myeloablative conditioning with fludarabine/busulfan does not improve the outcomes compared with reduced-intensity conditioning in adults receiving allo-SCT for NHL. © The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Expectations contribute to reduced pain levels during prayer in highly religious participants.

PubMed

Jegindø, Else-Marie Elmholdt; Vase, Lene; Skewes, Joshua Charles; Terkelsen, Astrid Juhl; Hansen, John; Geertz, Armin W; Roepstorff, Andreas; Jensen, Troels Staehelin

2013-08-01

Although the use of prayer as a religious coping strategy is widespread and often claimed to have positive effects on physical disorders including pain, it has never been tested in a controlled experimental setting whether prayer has a pain relieving effect. Religious beliefs and practices are complex phenomena and the use of prayer may be mediated by general psychological factors known to be related to the pain experience, such as expectations, desire for pain relief, and anxiety. Twenty religious and twenty non-religious healthy volunteers were exposed to painful electrical stimulation during internal prayer to God, a secular contrast condition, and a pain-only control condition. Subjects rated expected pain intensity levels, desire for pain relief, and anxiety before each trial and pain intensity and pain unpleasantness immediately after on mechanical visual analogue scales. Autonomic and cardiovascular measures provided continuous non-invasive objective means for assessing the potential analgesic effects of prayer. Prayer reduced pain intensity by 34 % and pain unpleasantness by 38 % for religious participants, but not for non-religious participants. For religious participants, expectancy and desire predicted 56-64 % of the variance in pain intensity scores, but for non-religious participants, only expectancy was significantly predictive of pain intensity (65-73 %). Conversely, prayer-induced reduction in pain intensity and pain unpleasantness were not followed by autonomic and cardiovascular changes.

Numerical optimization of a picosecond pulse driven Ni-like Nb x-ray laser at 20.3 nm

NASA Astrophysics Data System (ADS)

Lu, X.; Zhong, J. Y.; Li, Y. J.; Zhang, J.

2003-07-01

Detailed simulations of a Ni-like Nb x-ray laser pumped by a nanosecond prepulse followed by a picosecond main pulse are presented. The atomic physics data are obtained using the Cowan code [R. D. Cowan, The Theory of Atomic Structure and Spectra (University of California Press, Berkeley, CA, 1981)]. The optimization calculations are performed in terms of the intensity of prepulse and the time delay between the prepulse and the main pulse. A high gain over 150 cm-1 is obtained for the optimized drive pulse configuration. The ray-tracing calculations suggest that the total pump energy for a saturated x-ray laser can be reduced to less than 1 J.

Impacts of Fog Characteristics, Forward Illumination, and Warning Beacon Intensity Distribution on Roadway Hazard Visibility

PubMed Central

2016-01-01

Warning beacons are critical for the safety of transportation, construction, and utility workers. These devices need to produce sufficient luminous intensity to be visible without creating glare to drivers. Published standards for the photometric performance of warning beacons do not address their performance in conditions of reduced visibility such as fog. Under such conditions light emitted in directions other than toward approaching drivers can create scattered light that makes workers and other hazards less visible. Simulations of visibility of hazards under varying conditions of fog density, forward vehicle lighting, warning beacon luminous intensity, and intensity distribution were performed to assess their impacts on visual performance by drivers. Each of these factors can influence the ability of drivers to detect and identify workers and hazards along the roadway in work zones. Based on the results, it would be reasonable to specify maximum limits on the luminous intensity of warning beacons in directions that are unlikely to be seen by drivers along the roadway, limits which are not included in published performance specifications. PMID:27314058

Design and analysis of truck body for increasing the payload capacity

NASA Astrophysics Data System (ADS)

Vamshi Krishna, K.; Yugandhar Reddy, K.; Venugopal, K.; Ravi, K.

2017-11-01

Truck industry is a major source of transportation in India. With an average truck travelling about 300 kilometers per day [1], every kilogram of truck weight is of concern to the industry in order to get the best out of the truck. The main objective of this project is to increase the payload capacity of automotive truck body. Every kilogram of increased vehicle weight will decrease the vehicle payload capacity in turn increasing the manufacturing cost and reducing the fuel economy by increase the fuel consumption. With the intension of weight reduction, standard truck body has been designed and analyzed in ANSYS software. C-cross section beams were used instead of conventional rectangular box sections to reduce the weight of the body. Light-weight Aluminum alloy Al 6061 T6 is used to increase the payload capacity. The strength of the Truck platform is monitored in terms of deformation and stress concentration. These parameters will be obtained in structural analysis test condition environment. For reducing the stress concentration the concept of beams of uniform strength is used. Accordingly necessary modifications are done so that the optimized model has a better stress distribution and much lesser weight compared to the conventional model. The results obtained by analyzing the modified model are compared with the standard model.

Stochastic optimization for modeling physiological time series: application to the heart rate response to exercise

NASA Astrophysics Data System (ADS)

Zakynthinaki, M. S.; Stirling, J. R.

2007-01-01

Stochastic optimization is applied to the problem of optimizing the fit of a model to the time series of raw physiological (heart rate) data. The physiological response to exercise has been recently modeled as a dynamical system. Fitting the model to a set of raw physiological time series data is, however, not a trivial task. For this reason and in order to calculate the optimal values of the parameters of the model, the present study implements the powerful stochastic optimization method ALOPEX IV, an algorithm that has been proven to be fast, effective and easy to implement. The optimal parameters of the model, calculated by the optimization method for the particular athlete, are very important as they characterize the athlete's current condition. The present study applies the ALOPEX IV stochastic optimization to the modeling of a set of heart rate time series data corresponding to different exercises of constant intensity. An analysis of the optimization algorithm, together with an analytic proof of its convergence (in the absence of noise), is also presented.

[Amount and intensity of physical exercise in primary prevention].

PubMed

Smekal, G; Pokan, R; Baron, R; Tschan, H; Bachl, N

2001-01-01

Numerous epidemiological studies have demonstrated an inverse relation between physical activity and physical "fitness" on one hand and premature death and the risk of chronic disease on the other hand. However, most of these studies showed crucial methodological and statistical differences, a fact which caused a lack of consensus of dose and intensity of physical activities for "health benefits". The optimal amount of physical activity to decrease mortality is in literature stated to range between 1,000 and 3,500 motoric kcal per week. Only a few data exist concerning the optimal intensity of preventive physical activities. There is some indication that only "vigorous" but not "non-vigorous" physical activities are associated with decreased mortality. Previous investigations suggest that a "threshold-intensity" (e.g. of at least 6 MET of "conditioning physical activity") is needed to produce an adequate preventive effect. On the other hand it has been documented, that "physical fitness" (endurance capacity) is a decisive factor for a decreased mortality. Therefore it may be assumed, that physical activities are only efficient for health benefits, if they also result in increased physical fitness. Following from this assumption the quality and quantity of training in primary prevention has to be adjusted to the individual requirements (performance, age, gender, health) of men.

Inter- and Intra-individual Variability in Response to Transcranial Direct Current Stimulation (tDCS) at Varying Current Intensities.

PubMed

Chew, Taariq; Ho, Kerrie-Anne; Loo, Colleen K

2015-01-01

Translation of transcranial direct current stimulation (tDCS) from research to clinical practice is hindered by a lack of consensus on optimal stimulation parameters, significant inter-individual variability in response, and in sufficient intra-individual reliability data. Inter-individual differences in response to anodal tDCS at a range of current intensities were explored. Intra-individual reliability in response to anodal tDCS across two identical sessions was also investigated. Twenty-nine subjects participated in a crossover study. Anodal-tDCS using four different current intensities (0.2, 0.5, 1 and 2 mA), with an anode size of 16 cm2, was tested. The 0.5 mA condition was repeated to assess intra-individual variability. TMS was used to elicit 40 motor-evoked potentials (MEPs) before 10 min of tDCS, and 20 MEPs at four time-points over 30 min following tDCS. ANOVA revealed no main effect of TIME for all conditions except the first 0.5 mA condition, and no differences in response between the four current intensities. Cluster analysis identified two clusters for the 0.2 and 2 mA conditions only. Frequency distributions based on individual subject responses (excitatory, inhibitory or no response) to each condition indicate possible differential responses between individuals to different current intensities. Test-retest reliability was negligible (ICC(2,1) = -0.50). Significant inter-individual variability in response to tDCS across a range of current intensities was found. 2 mA and 0.2 mA tDCS were most effective at inducing a distinct response. Significant intra-individual variability in response to tDCS was also found. This has implications for interpreting results of single-session tDCS experiments. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Optimization of remotely delivered intensive lifestyle treatment for obesity using the Multiphase Optimization Strategy: Opt-IN study protocol.

PubMed

Pellegrini, Christine A; Hoffman, Sara A; Collins, Linda M; Spring, Bonnie

2014-07-01

Obesity-attributable medical expenditures remain high, and interventions that are both effective and cost-effective have not been adequately developed. The Opt-IN study is a theory-guided trial using the Multiphase Optimization Strategy (MOST) to develop an optimized, scalable version of a technology-supported weight loss intervention. Opt-IN aims to identify which of 5 treatment components or component levels contribute most meaningfully and cost-efficiently to the improvement of weight loss over a 6 month period. Five hundred and sixty obese adults (BMI 30-40 kg/m(2)) between 18 and 60 years old will be randomized to one of 16 conditions in a fractional factorial design involving five intervention components: treatment intensity (12 vs. 24 coaching calls), reports sent to primary care physician (No vs. Yes), text messaging (No vs. Yes), meal replacement recommendations (No vs. Yes), and training of a participant's self-selected support buddy (No vs. Yes). During the 6-month intervention, participants will monitor weight, diet, and physical activity on the Opt-IN smartphone application downloaded to their personal phone. Weight will be assessed at baseline, 3, and 6 months. The Opt-IN trial is the first study to use the MOST framework to develop a weight loss treatment that will be optimized to yield the best weight loss outcome attainable for $500 or less. Copyright © 2014 Elsevier Inc. All rights reserved.

Rapid Synthesis of Silver Nanoparticles from Fusarium oxysporum by Optimizing Physicocultural Conditions

PubMed Central

Birla, Sonal S.; Gaikwad, Swapnil C.; Gade, Aniket K.; Rai, Mahendra K.

2013-01-01

Synthesis of silver nanoparticles (SNPs) by fungi is emerging as an important branch of nanotechnology due to its ecofriendly, safe, and cost-effective nature. In order to increase the yield of biosynthesized SNPs of desired shape and size, it is necessary to control the cultural and physical parameters during the synthesis. We report optimum synthesis of SNPs on malt extract glucose yeast extract peptone (MGYP) medium at pH 9–11, 40–60°C, and 190.7 Lux and in sun light. The salt concentrations, volume of filtrate and biomass quantity were found to be directly proportional to the yield. The optimized conditions for the stable and rapid synthesis will help in large scale synthesis of monodispersed SNPs. The main aim of the present study was to optimize different media, temperature, pH, light intensity, salt concentration, volume of filtrate, and biomass quantity for the synthesis of SNPs by Fusarium oxysporum. PMID:24222751

Topology optimization analysis based on the direct coupling of the boundary element method and the level set method

NASA Astrophysics Data System (ADS)

Vitório, Paulo Cezar; Leonel, Edson Denner

2017-12-01

The structural design must ensure suitable working conditions by attending for safe and economic criteria. However, the optimal solution is not easily available, because these conditions depend on the bodies' dimensions, materials strength and structural system configuration. In this regard, topology optimization aims for achieving the optimal structural geometry, i.e. the shape that leads to the minimum requirement of material, respecting constraints related to the stress state at each material point. The present study applies an evolutionary approach for determining the optimal geometry of 2D structures using the coupling of the boundary element method (BEM) and the level set method (LSM). The proposed algorithm consists of mechanical modelling, topology optimization approach and structural reconstruction. The mechanical model is composed of singular and hyper-singular BEM algebraic equations. The topology optimization is performed through the LSM. Internal and external geometries are evolved by the LS function evaluated at its zero level. The reconstruction process concerns the remeshing. Because the structural boundary moves at each iteration, the body's geometry change and, consequently, a new mesh has to be defined. The proposed algorithm, which is based on the direct coupling of such approaches, introduces internal cavities automatically during the optimization process, according to the intensity of Von Mises stress. The developed optimization model was applied in two benchmarks available in the literature. Good agreement was observed among the results, which demonstrates its efficiency and accuracy.

Locally produced natural conditioners for dewatering of faecal sludge

PubMed Central

Gold, Moritz; Dayer, Pauline; Faye, Marie Christine Amie Sene; Clair, Guillaume; Seck, Alsane; Niang, Seydou; Morgenroth, Eberhard; Strande, Linda

2016-01-01

ABSTRACT In urban areas of low-income countries, treatment of faecal sludge (FS) is insufficient or non-existent. This results in large amounts of FS being dumped into the environment. Existing treatment technologies for FS, such as settling-thickening tanks and drying beds, are land intensive which is limiting in urban areas. Enhanced settling and dewatering by conditioning was evaluated in order to reduce the treatment footprint (or increase treatment capacity). Conventional wastewater conditioners, such as commercially available lime and polymers, are expensive, and commonly rely on complex supply chains for use in low-income countries. Therefore, the treatment performance of five conditioners which could be produced locally was evaluated: Moringa oleifera seeds and press cake, Jatropha curcas seeds, Jatropha Calotropis leaves and chitosan. M. oleifera seeds and press cake, and chitosan improved settling and dewatering and had a similar performance compared to lime and polymers. Optimal dosages were 400–500 kg M. oleifera/t TS, 300–800 kg lime/t TS and 25–50 kg polymer solution/t TS. In comparison, chitosan required 1.5–3.75 kg/t TS. These dosages are comparable to those recommended for wastewater (sludge). The results indicate that conditioning of FS can reduce total suspended solids (TSS) in the effluent of settling-thickening tanks by 22–81% and reduce dewatering time with drying beds by 59–97%. This means that the area of drying beds could be reduced by 59–97% with end-use as soil conditioner, or 9–26% as solid fuel. Least expensive options and availability will depend on the local context. In Dakar, Senegal, chitosan produced from shrimp waste appears to be most promising. PMID:26984372

Locally produced natural conditioners for dewatering of faecal sludge.

PubMed

Gold, Moritz; Dayer, Pauline; Faye, Marie Christine Amie Sene; Clair, Guillaume; Seck, Alsane; Niang, Seydou; Morgenroth, Eberhard; Strande, Linda

2016-11-01

In urban areas of low-income countries, treatment of faecal sludge (FS) is insufficient or non-existent. This results in large amounts of FS being dumped into the environment. Existing treatment technologies for FS, such as settling-thickening tanks and drying beds, are land intensive which is limiting in urban areas. Enhanced settling and dewatering by conditioning was evaluated in order to reduce the treatment footprint (or increase treatment capacity). Conventional wastewater conditioners, such as commercially available lime and polymers, are expensive, and commonly rely on complex supply chains for use in low-income countries. Therefore, the treatment performance of five conditioners which could be produced locally was evaluated: Moringa oleifera seeds and press cake, Jatropha curcas seeds, Jatropha Calotropis leaves and chitosan. M. oleifera seeds and press cake, and chitosan improved settling and dewatering and had a similar performance compared to lime and polymers. Optimal dosages were 400-500 kg M. oleifera/t TS, 300-800 kg lime/t TS and 25-50 kg polymer solution/t TS. In comparison, chitosan required 1.5-3.75 kg/t TS. These dosages are comparable to those recommended for wastewater (sludge). The results indicate that conditioning of FS can reduce total suspended solids (TSS) in the effluent of settling-thickening tanks by 22-81% and reduce dewatering time with drying beds by 59-97%. This means that the area of drying beds could be reduced by 59-97% with end-use as soil conditioner, or 9-26% as solid fuel. Least expensive options and availability will depend on the local context. In Dakar, Senegal, chitosan produced from shrimp waste appears to be most promising.

I-ImaS: intelligent imaging sensors

NASA Astrophysics Data System (ADS)

Griffiths, J.; Royle, G.; Esbrand, C.; Hall, G.; Turchetta, R.; Speller, R.

2010-08-01

Conventional x-radiography uniformly irradiates the relevant region of the patient. Across that region, however, there is likely to be significant variation in both the thickness and pathological composition of the tissues present, which means that the x-ray exposure conditions selected, and consequently the image quality achieved, are a compromise. The I-ImaS concept eliminates this compromise by intelligently scanning the patient to identify the important diagnostic features, which are then used to adaptively control the x-ray exposure conditions at each point in the patient. In this way optimal image quality is achieved throughout the region of interest whilst maintaining or reducing the dose. An I-ImaS system has been built under an EU Framework 6 project and has undergone pre-clinical testing. The system is based upon two rows of sensors controlled via an FPGA based DAQ board. Each row consists of a 160 mm × 1 mm linear array of ten scintillator coated 3T CMOS APS devices with 32 μm pixels and a readable array of 520 × 40 pixels. The first sensor row scans the patient using a fraction of the total radiation dose to produce a preview image, which is then interrogated to identify the optimal exposure conditions at each point in the image. A signal is then sent to control a beam filter mechanism to appropriately moderate x-ray beam intensity at the patient as the second row of sensors follows behind. Tests performed on breast tissue sections found that the contrast-to-noise ratio in over 70% of the images was increased by an average of 15% at an average dose reduction of 9%. The same technology is currently also being applied to baggage scanning for airport security.

Dynamical attribution of oceanic prediction uncertainty in the North Atlantic: application to the design of optimal monitoring systems

NASA Astrophysics Data System (ADS)

Sévellec, Florian; Dijkstra, Henk A.; Drijfhout, Sybren S.; Germe, Agathe

2017-11-01

In this study, the relation between two approaches to assess the ocean predictability on interannual to decadal time scales is investigated. The first pragmatic approach consists of sampling the initial condition uncertainty and assess the predictability through the divergence of this ensemble in time. The second approach is provided by a theoretical framework to determine error growth by estimating optimal linear growing modes. In this paper, it is shown that under the assumption of linearized dynamics and normal distributions of the uncertainty, the exact quantitative spread of ensemble can be determined from the theoretical framework. This spread is at least an order of magnitude less expensive to compute than the approximate solution given by the pragmatic approach. This result is applied to a state-of-the-art Ocean General Circulation Model to assess the predictability in the North Atlantic of four typical oceanic metrics: the strength of the Atlantic Meridional Overturning Circulation (AMOC), the intensity of its heat transport, the two-dimensional spatially-averaged Sea Surface Temperature (SST) over the North Atlantic, and the three-dimensional spatially-averaged temperature in the North Atlantic. For all tested metrics, except for SST, ˜ 75% of the total uncertainty on interannual time scales can be attributed to oceanic initial condition uncertainty rather than atmospheric stochastic forcing. The theoretical method also provide the sensitivity pattern to the initial condition uncertainty, allowing for targeted measurements to improve the skill of the prediction. It is suggested that a relatively small fleet of several autonomous underwater vehicles can reduce the uncertainty in AMOC strength prediction by 70% for 1-5 years lead times.

Smart LED lighting for major reductions in power and energy use for plant lighting in space

NASA Astrophysics Data System (ADS)

Poulet, Lucie

Launching or resupplying food, oxygen, and water into space for long-duration, crewed missions to distant destinations, such as Mars, is currently impossible. Bioregenerative life-support systems under development worldwide involving photoautotrophic organisms offer a solution to the food dilemma. However, using traditional Earth-based lighting methods, growth of food crops consumes copious energy, and since sunlight will not always be available at different space destinations, efficient electric lighting solutions are badly needed to reduce the Equivalent System Mass (ESM) of life-support infrastructure to be launched and transported to future space destinations with sustainable human habitats. The scope of the present study was to demonstrate that using LEDs coupled to plant detection, and optimizing spectral and irradiance parameters of LED light, the model crop lettuce (Lactuca sativa L. cv. Waldmann's Green) can be grown with significantly lower electrical energy for plant lighting than using traditional lighting sources. Initial experiments aimed at adapting and troubleshooting a first-generation "smart" plant-detection system coupled to LED arrays resulted in optimizing the detection process for plant position and size to the limits of its current design. Lettuce crops were grown hydroponically in a growth chamber, where temperature, relative humidity, and CO2 level are controlled. Optimal irradiance and red/blue ratio of LED lighting were determined for plant growth during both lag and exponential phases of crop growth. Under optimizing conditions, the efficiency of the automatic detection system was integrated with LED switching and compared to a system in which all LEDs were energized throughout a crop-production cycle. At the end of each cropping cycle, plant fresh and dry weights and leaf area were measured and correlated with the amount of electrical energy (kWh) consumed. Preliminary results indicated that lettuce plants grown under optimizing conditions with red and blue LED lighting required 12 times less energy than with a traditional high-intensity discharge lighting system. This study paves the way for refinement of the smart lighting system and further, major reductions in ESM for space life-support systems and for ground-based controlled-environment agriculture. Project supported by NASA grant number NNX09AL99G.

Odor intensity and characterization of jet exhaust and chemical analytical measurements

NASA Technical Reports Server (NTRS)

Kendall, D. A.; Levins, P. L.

1973-01-01

Odor and chemical analyses were carried out on the exhaust samples from a J-57 combustor can operated over a range of inlet conditions, and with several fuel types and nozzle modifications. The odor characteristics and total intensity of odor for each exhaust were determined over a range of dilutions to allow for a least squares determination of the intensity at 1,000 to 1 dilutions. Analytical measures included the concentration of total hydrocarbons and the concentrations of aromatic organic species and oxygenated organic species from collected samples which were taken concurrently. A correlation was found between the concentration of the odorous oxygenated fraction and the total intensity of aroma. Inlet operating conditions and nozzle modifications which increase the efficiency of combustion as measured by exhaust gas analyses reduce the odor intensity and the quantity of oxygenates in the exhaust. The type of fuel burned altered the intensity of odor in relation to the quantity of oxygenates produced and, in some instances, changed the odor character.

Effect of halideions on the surface-enhanced Raman spectroscopy of methylene blue for borohydride-reduced silver colloid

NASA Astrophysics Data System (ADS)

Dong, Xiao; Gu, Huaimin; Liu, Fang

2011-01-01

The surface enhanced Raman scattering (SERS) spectrum of methylene blue (MB) was studied when adding a range of halideions to borohydride-reduced silver colloid. The halideions such as chloride, bromide and iodide were added as aggregating agents to study the effects of halideions on SERS spectroscopy of MB and observe which halideion gives the greatest enhancement for borohydride-reduced silver colloids. The SERS spectra of MB were also detected over a wide range of concentrations of halideions to find the optimum concentration of halideions for SERS enhancement. From the results of this study, the intensity of SERS signal of MB was enhanced significantly when adding halideions to the colloid. Among the three kinds of halideions, chloride gives the greatest enhancement on SERS signal. The enhancement factors for MB with optimal concentration of chloride, bromide and iodide are 3.44×104, 2.04×104, and 1.0×104, respectively. The differences of the SERS spectra of MB when adding different kinds and concentrations of halideions to the colloid may be attributed to the both effects of extent of aggregation of the colloid and the modification of silver surface chemistry. The purpose of this study is to further investigate the effect of halideions on borohydride-reduced silver colloid and to make the experimental conditions suitable for detecting some analytes in high efficiency on rational principles.

Method of determining the optimal dilution ratio for fluorescence fingerprint of food constituents.

PubMed

Trivittayasil, Vipavee; Tsuta, Mizuki; Kokawa, Mito; Yoshimura, Masatoshi; Sugiyama, Junichi; Fujita, Kaori; Shibata, Mario

2015-01-01

Quantitative determination by fluorescence spectroscopy is possible because of the linear relationship between the intensity of emitted fluorescence and the fluorophore concentration. However, concentration quenching may cause the relationship to become nonlinear, and thus, the optimal dilution ratio has to be determined. In the case of fluorescence fingerprint (FF) measurement, fluorescence is measured under multiple wavelength conditions and a method of determining the optimal dilution ratio for multivariate data such as FFs has not been reported. In this study, the FFs of mixed solutions of tryptophan and epicatechin of different concentrations and composition ratios were measured. Principal component analysis was applied, and the resulting loading plots were found to contain useful information about each constituent. The optimal concentration ranges could be determined by identifying the linear region of the PC score plotted against total concentration.

BFL: a node and edge betweenness based fast layout algorithm for large scale networks

PubMed Central

Hashimoto, Tatsunori B; Nagasaki, Masao; Kojima, Kaname; Miyano, Satoru

2009-01-01

Background Network visualization would serve as a useful first step for analysis. However, current graph layout algorithms for biological pathways are insensitive to biologically important information, e.g. subcellular localization, biological node and graph attributes, or/and not available for large scale networks, e.g. more than 10000 elements. Results To overcome these problems, we propose the use of a biologically important graph metric, betweenness, a measure of network flow. This metric is highly correlated with many biological phenomena such as lethality and clusters. We devise a new fast parallel algorithm calculating betweenness to minimize the preprocessing cost. Using this metric, we also invent a node and edge betweenness based fast layout algorithm (BFL). BFL places the high-betweenness nodes to optimal positions and allows the low-betweenness nodes to reach suboptimal positions. Furthermore, BFL reduces the runtime by combining a sequential insertion algorim with betweenness. For a graph with n nodes, this approach reduces the expected runtime of the algorithm to O(n2) when considering edge crossings, and to O(n log n) when considering only density and edge lengths. Conclusion Our BFL algorithm is compared against fast graph layout algorithms and approaches requiring intensive optimizations. For gene networks, we show that our algorithm is faster than all layout algorithms tested while providing readability on par with intensive optimization algorithms. We achieve a 1.4 second runtime for a graph with 4000 nodes and 12000 edges on a standard desktop computer. PMID:19146673

Use of plan quality degradation to evaluate tradeoffs in delivery efficiency and clinical plan metrics arising from IMRT optimizer and sequencer compromises

PubMed Central

Wilkie, Joel R.; Matuszak, Martha M.; Feng, Mary; Moran, Jean M.; Fraass, Benedick A.

2013-01-01

Purpose: Plan degradation resulting from compromises made to enhance delivery efficiency is an important consideration for intensity modulated radiation therapy (IMRT) treatment plans. IMRT optimization and/or multileaf collimator (MLC) sequencing schemes can be modified to generate more efficient treatment delivery, but the effect those modifications have on plan quality is often difficult to quantify. In this work, the authors present a method for quantitative assessment of overall plan quality degradation due to tradeoffs between delivery efficiency and treatment plan quality, illustrated using comparisons between plans developed allowing different numbers of intensity levels in IMRT optimization and/or MLC sequencing for static segmental MLC IMRT plans. Methods: A plan quality degradation method to evaluate delivery efficiency and plan quality tradeoffs was developed and used to assess planning for 14 prostate and 12 head and neck patients treated with static IMRT. Plan quality was evaluated using a physician's predetermined “quality degradation” factors for relevant clinical plan metrics associated with the plan optimization strategy. Delivery efficiency and plan quality were assessed for a range of optimization and sequencing limitations. The “optimal” (baseline) plan for each case was derived using a clinical cost function with an unlimited number of intensity levels. These plans were sequenced with a clinical MLC leaf sequencer which uses >100 segments, assuring delivered intensities to be within 1% of the optimized intensity pattern. Each patient's optimal plan was also sequenced limiting the number of intensity levels (20, 10, and 5), and then separately optimized with these same numbers of intensity levels. Delivery time was measured for all plans, and direct evaluation of the tradeoffs between delivery time and plan degradation was performed. Results: When considering tradeoffs, the optimal number of intensity levels depends on the treatment site and on the stage in the process at which the levels are limited. The cost of improved delivery efficiency, in terms of plan quality degradation, increased as the number of intensity levels in the sequencer or optimizer decreased. The degradation was more substantial for the head and neck cases relative to the prostate cases, particularly when fewer than 20 intensity levels were used. Plan quality degradation was less severe when the number of intensity levels was limited in the optimizer rather than the sequencer. Conclusions: Analysis of plan quality degradation allows for a quantitative assessment of the compromises in clinical plan quality as delivery efficiency is improved, in order to determine the optimal delivery settings. The technique is based on physician-determined quality degradation factors and can be extended to other clinical situations where investigation of various tradeoffs is warranted. PMID:23822412

HIFU procedures at moderate intensities--effect of large blood vessels.

PubMed

Hariharan, P; Myers, M R; Banerjee, R K

2007-06-21

A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams.

Overview of field gamma spectrometries based on Si-photomultiplier

NASA Astrophysics Data System (ADS)

Denisov, Viktor; Korotaev, Valery; Titov, Aleksandr; Blokhina, Anastasia; Kleshchenok, Maksim

2017-05-01

Design of optical-electronic devices and systems involves the selection of such technical patterns that under given initial requirements and conditions are optimal according to certain criteria. The original characteristic of the OES for any purpose, defining its most important feature ability is a threshold detection. Based on this property, will be achieved the required functional quality of the device or system. Therefore, the original criteria and optimization methods have to subordinate to the idea of a better detectability. Generally reduces to the problem of optimal selection of the expected (predetermined) signals in the predetermined observation conditions. Thus the main purpose of optimization of the system when calculating its detectability is the choice of circuits and components that provide the most effective selection of a target.

Identification of optimal feedback control rules from micro-quadrotor and insect flight trajectories.

PubMed

Faruque, Imraan A; Muijres, Florian T; Macfarlane, Kenneth M; Kehlenbeck, Andrew; Humbert, J Sean

2018-06-01

This paper presents "optimal identification," a framework for using experimental data to identify the optimality conditions associated with the feedback control law implemented in the measurements. The technique compares closed loop trajectory measurements against a reduced order model of the open loop dynamics, and uses linear matrix inequalities to solve an inverse optimal control problem as a convex optimization that estimates the controller optimality conditions. In this study, the optimal identification technique is applied to two examples, that of a millimeter-scale micro-quadrotor with an engineered controller on board, and the example of a population of freely flying Drosophila hydei maneuvering about forward flight. The micro-quadrotor results show that the performance indices used to design an optimal flight control law for a micro-quadrotor may be recovered from the closed loop simulated flight trajectories, and the Drosophila results indicate that the combined effect of the insect longitudinal flight control sensing and feedback acts principally to regulate pitch rate.

Parameter study of shipping conditions for the ready-to-use application of a 3D human hemicornea construct in drug absorption studies.

PubMed

Beißner, Nicole; Zorn-Kruppa, Michaela; Reichl, Stephan

2018-01-30

In this study, a shipping protocol for our 3D human hemicornea (HC) construct should be developed to provide quality-maintaining shipping conditions and to allow its ready-to-use application in drug absorption studies. First, the effects of single and multiple parameters, such as the type of shipping container, storage temperature and CO 2 supply, were investigated under controlled laboratory conditions by assessing cell viability via MTT dye reaction and epithelial barrier properties via transepithelial electrical resistance (TEER) measurements. These investigations showed that TEER is more susceptible to shipping parameters than cell viability. Furthermore, the results were used to determine the optimal shipping conditions and critical values for subsequent overnight, real-time shipping experiments. Epithelial barrier properties were then investigated via TEER and the permeation of sodium fluorescein for shipped and not shipped HC. The results underscore that acceleration forces and changes in position may have a great impact on the epithelial barrier of 3D models. Low acceleration values and short changes in position caused only minor impairments. However, combined or intensive separate effects resulted in considerably low yields after shipping. Consequently, barrier-maintaining shipping of 3D in vitro models seems to be challenging, as mechanical forces have to be reduced to a minimum. Copyright © 2017 Elsevier B.V. All rights reserved.

Computationally efficient optimization of radiation drives

NASA Astrophysics Data System (ADS)

Zimmerman, George; Swift, Damian

2017-06-01

For many applications of pulsed radiation, the temporal pulse shape is designed to induce a desired time-history of conditions. This optimization is normally performed using multi-physics simulations of the system, adjusting the shape until the desired response is induced. These simulations may be computationally intensive, and iterative forward optimization is then expensive and slow. In principle, a simulation program could be modified to adjust the radiation drive automatically until the desired instantaneous response is achieved, but this may be impracticable in a complicated multi-physics program. However, the computational time increment is typically much shorter than the time scale of changes in the desired response, so the radiation intensity can be adjusted so that the response tends toward the desired value. This relaxed in-situ optimization method can give an adequate design for a pulse shape in a single forward simulation, giving a typical gain in computational efficiency of tens to thousands. This approach was demonstrated for the design of laser pulse shapes to induce ramp loading to high pressure in target assemblies where different components had significantly different mechanical impedance, requiring careful pulse shaping. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Wavefront sensorless adaptive optics ophthalmoscopy in the human eye

PubMed Central

Hofer, Heidi; Sredar, Nripun; Queener, Hope; Li, Chaohong; Porter, Jason

2011-01-01

Wavefront sensor noise and fidelity place a fundamental limit on achievable image quality in current adaptive optics ophthalmoscopes. Additionally, the wavefront sensor ‘beacon’ can interfere with visual experiments. We demonstrate real-time (25 Hz), wavefront sensorless adaptive optics imaging in the living human eye with image quality rivaling that of wavefront sensor based control in the same system. A stochastic parallel gradient descent algorithm directly optimized the mean intensity in retinal image frames acquired with a confocal adaptive optics scanning laser ophthalmoscope (AOSLO). When imaging through natural, undilated pupils, both control methods resulted in comparable mean image intensities. However, when imaging through dilated pupils, image intensity was generally higher following wavefront sensor-based control. Despite the typically reduced intensity, image contrast was higher, on average, with sensorless control. Wavefront sensorless control is a viable option for imaging the living human eye and future refinements of this technique may result in even greater optical gains. PMID:21934779

Reduced-Intensity Conditioning Combined with (188)Rhenium Radioimmunotherapy before Allogeneic Hematopoietic Stem Cell Transplantation in Elderly Patients with Acute Myeloid Leukemia: The Role of In Vivo T Cell Depletion.

PubMed

Schneider, Sebastian; Strumpf, Annette; Schetelig, Johannes; Wunderlich, Gerd; Ehninger, Gerhard; Kotzerke, Jörg; Bornhäuser, Martin

2015-10-01

The combination of reduced-intensity conditioning, (188)rhenium anti-CD66 radioimmunotherapy, and in vivo T cell depletion was successfully applied in elderly patients with acute myeloid leukemia or myelodysplastic syndrome. Within a prospective phase II protocol, we investigated whether a dose reduction of alemtuzumab (from 75 mg to 50 mg MabCampath) would improve leukemia-free survival by reducing the incidence of relapse. Fifty-eight patients (median age, 67 years; range, 54 to 76) received radioimmunotherapy followed by fludarabine 150 mg/m(2) and busulfan 8 mg/kg combined with either 75 mg (n = 26) or 50 mg (n = 32) alemtuzumab. Although we observed a trend towards a shorter duration of neutropenia in the 50 mg group (median, 19 versus 21 days; P = .07), the time from transplantation to neutrophil and platelet engraftment as well as the overall incidence of engraftment did not differ. The incidence of severe acute graft-versus-host disease tended to be higher after the lower alemtuzumab dose (17% versus 4%; P = .15). No significant differences in the cumulative incidences of relapse (38% versus 35%; P = .81) or nonrelapse mortality (46% versus 27%; P = .31) were observed. Accordingly, disease-free and overall survival were not significantly different between groups. Although the feasibility of radioimmunotherapy plus reduced-intensity conditioning could be demonstrated in elderly patients, the dose reduction of alemtuzumab had no positive impact on overall outcome. Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Feasibility of employing model-based optimization of pulse amplitude and electrode distance for effective tumor electropermeabilization.

PubMed

Sel, Davorka; Lebar, Alenka Macek; Miklavcic, Damijan

2007-05-01

In electrochemotherapy (ECT) electropermeabilization, parameters (pulse amplitude, electrode setup) need to be customized in order to expose the whole tumor to electric field intensities above permeabilizing threshold to achieve effective ECT. In this paper, we present a model-based optimization approach toward determination of optimal electropermeabilization parameters for effective ECT. The optimization is carried out by minimizing the difference between the permeabilization threshold and electric field intensities computed by finite element model in selected points of tumor. We examined the feasibility of model-based optimization of electropermeabilization parameters on a model geometry generated from computer tomography images, representing brain tissue with tumor. Continuous parameter subject to optimization was pulse amplitude. The distance between electrode pairs was optimized as a discrete parameter. Optimization also considered the pulse generator constraints on voltage and current. During optimization the two constraints were reached preventing the exposure of the entire volume of the tumor to electric field intensities above permeabilizing threshold. However, despite the fact that with the particular needle array holder and pulse generator the entire volume of the tumor was not permeabilized, the maximal extent of permeabilization for the particular case (electrodes, tissue) was determined with the proposed approach. Model-based optimization approach could also be used for electro-gene transfer, where electric field intensities should be distributed between permeabilizing threshold and irreversible threshold-the latter causing tissue necrosis. This can be obtained by adding constraints on maximum electric field intensity in optimization procedure.

Integrated numerical modeling of a landslide early warning system in a context of adaptation to future climatic pressures

NASA Astrophysics Data System (ADS)

Khabarov, Nikolay; Huggel, Christian; Obersteiner, Michael; Ramírez, Juan Manuel

2010-05-01

Mountain regions are typically characterized by rugged terrain which is susceptible to different types of landslides during high-intensity precipitation. Landslides account for billions of dollars of damage and many casualties, and are expected to increase in frequency in the future due to a projected increase of precipitation intensity. Early warning systems (EWS) are thought to be a primary tool for related disaster risk reduction and climate change adaptation to extreme climatic events and hydro-meteorological hazards, including landslides. An EWS for hazards such as landslides consist of different components, including environmental monitoring instruments (e.g. rainfall or flow sensors), physical or empirical process models to support decision-making (warnings, evacuation), data and voice communication, organization and logistics-related procedures, and population response. Considering this broad range, EWS are highly complex systems, and it is therefore difficult to understand the effect of the different components and changing conditions on the overall performance, ultimately being expressed as human lives saved or structural damage reduced. In this contribution we present a further development of our approach to assess a landslide EWS in an integral way, both at the system and component level. We utilize a numerical model using 6 hour rainfall data as basic input. A threshold function based on a rainfall-intensity/duration relation was applied as a decision criterion for evacuation. Damage to infrastructure and human lives was defined as a linear function of landslide magnitude, with the magnitude modelled using a power function of landslide frequency. Correct evacuation was assessed with a ‘true' reference rainfall dataset versus a dataset of artificially reduced quality imitating the observation system component. Performance of the EWS using these rainfall datasets was expressed in monetary terms (i.e. damage related to false and correct evacuation). We applied this model to a landslide EWS in Colombia that is currently being implemented within a disaster prevention project. We evaluated the EWS against rainfall data with artificially introduced error and computed with multiple model runs the probabilistic damage functions depending on rainfall error. Then we modified the original precipitation pattern to reflect possible climatic changes e.g. change in annual precipitation as well as change in precipitation intensity with annual values remaining constant. We let the EWS model adapt for changed conditions to function optimally. Our results show that for the same errors in rainfall measurements the system's performance degrades with expected changing climatic conditions. The obtained results suggest that EWS cannot internally adapt to climate change and require exogenous adaptive measures to avoid increase in overall damage. The model represents a first attempt to integrally simulate and evaluate EWS under future possible climatic pressures. Future work will concentrate on refining model components and spatially explicit climate scenarios.

Using silicon-coated gold nanoparticles to enhance the fluorescence of CdTe quantum dot and improve the sensing ability of mercury (II)

NASA Astrophysics Data System (ADS)

Zhu, Jian; Chang, Hui; Li, Jian-Jun; Li, Xin; Zhao, Jun-Wu

2018-01-01

The effect of silicon-coated gold nanoparticles with different gold core diameter and silica shell thickness on the fluorescence emission of CdTe quantum dots (QDs) was investigated. For gold nanoparticles with a diameter of 15 nm, silica coating can only results in fluorescence recover of the bare gold nanoparticle-induced quenching of QDs. However, when the size of gold nanoparticle is increased to 60 nm, fluorescence enhancement of the QDs could be obtained by silica coating. Because of the isolation of the silica shell-reduced quenching effect and local electric field effect, the fluorescence of QDs gets intense firstly and then decreases. The maximum fluorescence enhancement takes place as the silica shell has a thickness of 30 nm. This enhanced fluorescence from silicon-coated gold nanoparticles is demonstrated for sensing of Hg2 +. Under optimal conditions, the enhanced fluorescence intensity decreases linearly with the concentration of Hg2 + ranging from 0 to 200 ng/mL. The limit of detection for Hg2 + is 1.25 ng/mL. Interference test and real samples detection indicate that the influence from other metal ions could be neglected, and the Hg2 + could be specifically detected.

Enhanced therapeutic anti-inflammatory effect of betamethasone upon topical administration with low frequency, low intensity (20 kHz, 100 mW/cm2) ultrasound exposure on carrageenan-induced arthritis in mice model

PubMed Central

Cohen, Gadi; Natsheh, Hiba; Sunny, Youhan; Bawiec, Christopher R.; Touitou, Elka; Lerman, Melissa A.; Lazarovici, Philip; Lewin, Peter A.

2015-01-01

The purpose of this work was to investigate whether low frequency, low intensity (LFLI, 20 kHz, <100 mW/cm2, spatial-peak, temporal-peak) ultrasound (US), delivered by a light-weight (<100g), tether-free, fully wearable, battery powered applicator is capable of reducing inflammation in a mouse model of Rheumatoid Arthritis (RA). The therapeutic, acute, anti-inflammatory effect was estimated by the relative swelling induced in mice hind limb paws. In an independent, indirect approach, the inflammation was bio-imaged by measuring glycolytic activity with near infrared labeled 2-deoxy-glucose (2DG). The outcome of the experiments indicated that the combination of US exposure with topical application of 0.1% w/w betamethasone gel, exhibited statistically significant (p<0.05) enhanced anti-inflammatory properties in comparison with the drug or US treatment alone. The present study underscores the potential benefits of LFLI US assisted drug delivery. However, the proof of concept presented indicates the need for additional experiments to systematically evaluate and optimize the potential of, and the conditions for, safe, LFLI ultrasound promoted non-invasive drug delivery. PMID:26003010

Similar and Promising Outcomes in Lymphoma Patients Treated with Myeloablative or Nonmyeloablative Conditioning and Allogeneic Hematopoietic Cell Transplantation

PubMed Central

Tomblyn, Marcie; Brunstein, Claudio; Burns, Linda J.; Miller, Jeffrey S.; MacMillan, Margaret; DeFor, Todd E.; Weisdorf, Daniel J.

2008-01-01

We compared the outcomes of 141 consecutive patients who received allogeneic transplantation with either myeloablative (MA) or nonmyeloablative/reduced intensity (NMA) conditioning for non-Hodgkin and Hodgkin lymphoma at the University of Minnesota. All patients were transplanted between 1997 and 2004. NMA transplant recipients were older and received umbilical cord blood grafts more frequently (MA: 6 [9%]; NMA: 33 [43%], P < .001). NMA patients had more advanced disease and 30 (39%) patients had undergone prior autologous transplantation. The 4-year overall survival (OS) (MA: 46% versus NMA: 49%; p = .34) and the 3-year progression-free survival (PFS) (MA: 44% versus NMA: 31%; P = 0.82) were similar after MA or NMA conditioning. However, MA conditioning resulted in significantly higher 1-year treatment-related mortality (TRM) (MA: 43% versus NMA: 17%; P < .01) but a lower risk of relapse at 3 years (MA: 11% versus NMA: 36%; P < .01). We conclude that similar transplant outcomes are achieved after allogeneic hematopoietic stem cell transplantation using MA conditioning in younger patients and NMA conditioning in older patients or those with prior autologous transplantation not eligible for MA conditioning. Modifications to refine patient assignment to the preferred conditioning intensity and reduce relapse risks with NMA approaches are needed. PMID:18410896

[Transfer of allogeneic stem cell transplant recipients to the intensive care unit: Guidelines from the Francophone society of marrow transplantation and cellular therapy (SFGM-TC)].

PubMed

Moreau, Anne-Sophie; Bourhis, Jean-Henri; Contentin, Nathalie; Couturier, Marie-Anne; Delage, Jeremy; Dumesnil, Cécile; Gandemer, Virginie; Hichri, Yosr; Jost, Edgar; Platon, Laura; Jourdain, Mercé; Pène, Frédéric; Yakoub-Agha, Ibrahim

2016-11-01

Transferring a patient undergoing an allogeneic stem cell transplantation to the intensive care unit (ICU) is always a challenging situation on a medical and psychological point of view for the patient and his relatives as well as for the medical staff. Despite the progress in hematology and intensive care during the last decade, the prognosis of these patients admitted to the ICU remains poor and mortality is around 50 %. The harmonization working party of the SFGM-TC assembled hematologists and intensive care specialist in order to improve conditions and modalities of the transfer of a patient after allogeneic stem cell transplantation to the ICU. We propose a structured medical form comprising all essential information necessary for optimal medical care on ICU. Copyright © 2016. Published by Elsevier Masson SAS.

My gut feeling says rest: Increased intestinal permeability contributes to chronic diseases in high-intensity exercisers.

PubMed

Van Houten, Jason M; Wessells, Robert J; Lujan, Heidi L; DiCarlo, Stephen E

2015-12-01

Chronic diseases are the leading cause of death and disability worldwide, and many of these conditions are linked to chronic inflammation. One potential cause of chronic inflammation is an increased intestinal epithelial permeability. Recent studies have demonstrated that parasympathetic stimulation via the efferent abdominal vagus nerve increases the expression and proper localization of tight junction proteins and decreases intestinal epithelial permeability. This finding may provide a novel approach for treating and preventing many chronic conditions. Importantly, physical activity is associated with increased resting parasympathetic (vagal) activity and lower risk of chronic diseases. However, high intensity long duration exercise can be harmful to overall health. Specifically, individuals who frequently exercise strenuously and for longer time intervals have the same mortality rates as sedentary individuals. This may be explained, in part, by longer periods of reduced vagal activity as vagal activity is markedly reduced both during and after intense exercise. We hypothesize that one mechanism by which exercise provides its health benefits is by increasing resting vagal activity and decreasing intestinal epithelial permeability, thus decreasing chronic inflammation. Additionally, we hypothesize that long periods of reduced vagal activity in individuals who exercise at high intensities and for longer durations, decrease the integrity of the intestinal barrier, putting them at greater risk of chronic inflammation and a host of chronic diseases. Thus, this hypothesis provides a conceptual link between the well-established benefits of frequent exercise and the paradoxical deleterious effects of prolonged, high-intensity exercise without adequate rest. Copyright © 2015. Published by Elsevier Ltd.

Physical conditioning as part of a return to work strategy to reduce sickness absence for workers with back pain.

PubMed

Schaafsma, Frederieke G; Whelan, Karyn; van der Beek, Allard J; van der Es-Lambeek, Ludeke C; Ojajärvi, Anneli; Verbeek, Jos H

2013-08-30

Physical conditioning as part of a return to work strategy aims to improve work status for workers on sick leave due to back pain. This is the second update of a Cochrane Review (originally titled 'Work conditioning, work hardening and functional restoration for workers with back and neck pain') first published in 2003, updated in 2010, and updated again in 2013. To assess the effectiveness of physical conditioning as part of a return to work strategy in reducing time lost from work and improving work status for workers with back pain. Further, to assess which aspects of physical conditioning are related to a faster return to work for workers with back pain. We searched the following databases to March 2012: CENTRAL, MEDLINE (from 1966), EMBASE (from 1980), CINAHL (from 1982), PsycINFO (from 1967), and PEDro. Randomized controlled trials (RCTs) and cluster RCTs that studied workers with work disability related to back pain and who were included in physical conditioning programmes. Two review authors independently extracted data and assessed risk of bias. We used standard methodological procedures expected by The Cochrane Collaboration. We included 41 articles reporting on 25 RCTs with 4404 participants. Risk of bias was low in 16 studies.Three studies involved workers with acute back pain, eight studies workers with subacute back pain, and 14 studies workers with chronic back pain.In 14 studies, physical conditioning as part of a return to work strategy was compared to usual care. The physical conditioning mostly consisted of graded activity with work-related exercises aimed at increasing back strength and flexibility, together with a set date for return to work. The programmes were divided into a light version with a maximum of five sessions, or an intense version with more than five sessions up to full time or as inpatient treatment.For acute back pain, there was low quality evidence that both light and intense physical conditioning programmes made little or no difference in sickness absence duration compared with care as usual at three to 12 months follow-up (3 studies with 340 workers).For subacute back pain, the evidence on the effectiveness of intense physical conditioning combined with care as usual compared to usual care alone was conflicting (four studies with 395 workers). However, subgroup analysis showed low quality evidence that if the intervention was executed at the workplace, or included a workplace visit, it may have reduced sickness absence duration at 12 months follow-up (3 studies with 283 workers; SMD -0.42, 95% CI -0.65 to -0.18).For chronic back pain, there was low quality evidence that physical conditioning as part of integrated care management in addition to usual care may have reduced sickness absence days compared to usual care at 12 months follow-up (1 study, 134 workers; SMD -4.42, 95% CI -5.06 to -3.79). What part of the integrated care management was most effective remained unclear. There was moderate quality evidence that intense physical conditioning probably reduced sickness absence duration only slightly compared with usual care at 12 months follow-up (5 studies, 1093 workers; SMD -0.23, 95% CI -0.42 to -0.03).Physical conditioning compared to exercise therapy showed conflicting results for workers with subacute and chronic back pain. Cognitive behavioural therapy was probably not superior to physical conditioning as an alternative or in addition to physical conditioning. The effectiveness of physical conditioning as part of a return to work strategy in reducing sick leave for workers with back pain, compared to usual care or exercise therapy, remains uncertain. For workers with acute back pain, physical conditioning may have no effect on sickness absence duration. There is conflicting evidence regarding the reduction of sickness absence duration with intense physical conditioning versus usual care for workers with subacute back pain. It may be that including workplace visits or execution of the intervention at the workplace is the component that renders a physical conditioning programme effective. For workers with chronic back pain physical conditioning has a small effect on reducing sick leave compared to care as usual after 12 months follow-up. To what extent physical conditioning as part of integrated care management may alter the effect on sick leave for workers with chronic back pain needs further research.

Detecting Outliers in Marathon Data by Means of the Andrews Plot

NASA Astrophysics Data System (ADS)

Stehlík, Milan; Wald, Helmut; Bielik, Viktor; Petrovič, Juraj

2011-09-01

For an optimal race performance, it is important, that the runner keeps steady pace during most of the time of the competition. First time runners or athletes without many competitions often experience an "blow out" after a few kilometers of the race. This could happen, because of strong emotional experiences or low control of running intensity. Competition pace of half marathon of the middle level recreational athletes is approximately 10 sec quicker than their training pace. If an athlete runs the first third of race (7 km) at a pace that is 20 sec quicker than is his capacity (trainability), he would experience an "blow out" in the last third of the race. This would be reflected by reducing the running intensity and inability to keep steady pace in the last kilometers of the race and in the final time as well. In sports science, there are many diagnostic methods ([3], [2], [6]) that are used for prediction of optimal race pace tempo and final time. Otherwise there is lacking practical evidence of diagnostics methods and its use in the field (competition, race). One of the conditions that needs to be carried out is that athletes have not only similar final times, but it is important that they keep constant pace as much as possible during whole race. For this reason it is very important to find outliers. Our experimental group consisted of 20 recreational trained athletes (mean age 32,6 years±8,9). Before the race the athletes were instructed to run on the basis of their subjective feeling and previous experience. The data (running pace of each kilometer, average and maximal heart rate of each kilometer) were collected by GPS-enabled personal trainer Forerunner 305.

Filling the glass: Effects of a positive psychology intervention on executive task performance in chronic pain patients.

PubMed

Boselie, J J L M; Vancleef, L M G; Peters, M L

2018-03-24

Chronic pain is associated with emotional problems as well as difficulties in cognitive functioning. Prior experimental studies have shown that optimism, the tendency to expect that good things happen in the future, and positive emotions can counteract pain-induced task performance deficits in healthy participants. More specifically, induced optimism was found to buffer against the negative effects of experimental pain on executive functioning. This clinical experiment examined whether this beneficial effect can be extended to a chronic pain population. Patients (N = 122) were randomized to a positive psychology Internet-based intervention (PPI; n = 74) or a waiting list control condition (WLC; n = 48). The PPI consisted of positive psychology exercises that particularly target optimism, positive emotions and self-compassion. Results demonstrated that patients in the PPI condition scored higher on happiness, optimism, positive future expectancies, positive affect, self-compassion and ability to live a desired life despite pain, and scored lower on pain catastrophizing, depression and anxiety compared to patients in the WLC condition. However, executive task performance did not improve following completion of the PPI, compared to the WLC condition. Despite the lack of evidence that positive emotions and optimism can improve executive task performance in chronic pain patients, this study did convincingly demonstrate that it is possible to increase positive emotions and optimism in chronic pain patients with an online positive psychology intervention. It is imperative to further explore amendable psychological factors that may reduce the negative impact of pain on executive functioning. We demonstrated that an Internet-based positive psychology intervention strengthens optimism and positive emotions in chronic pain patients. These emotional improvements are not associated with improved executive task performance. As pain itself often cannot be relieved, it is imperative to have techniques to reduce the burden of living with chronic pain. © 2018 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation -EFIC®.

Estimated Benefits of Variable-Geometry Wing Camber Control for Transport Aircraft

NASA Technical Reports Server (NTRS)

Bolonkin, Alexander; Gilyard, Glenn B.

1999-01-01

Analytical benefits of variable-camber capability on subsonic transport aircraft are explored. Using aerodynamic performance models, including drag as a function of deflection angle for control surfaces of interest, optimal performance benefits of variable camber are calculated. Results demonstrate that if all wing trailing-edge surfaces are available for optimization, drag can be significantly reduced at most points within the flight envelope. The optimization approach developed and illustrated for flight uses variable camber for optimization of aerodynamic efficiency (maximizing the lift-to-drag ratio). Most transport aircraft have significant latent capability in this area. Wing camber control that can affect performance optimization for transport aircraft includes symmetric use of ailerons and flaps. In this paper, drag characteristics for aileron and flap deflections are computed based on analytical and wind-tunnel data. All calculations based on predictions for the subject aircraft and the optimal surface deflection are obtained by simple interpolation for given conditions. An algorithm is also presented for computation of optimal surface deflection for given conditions. Benefits of variable camber for a transport configuration using a simple trailing-edge control surface system can approach more than 10 percent, especially for nonstandard flight conditions. In the cruise regime, the benefit is 1-3 percent.

Development and clinical introduction of automated radiotherapy treatment planning for prostate cancer

NASA Astrophysics Data System (ADS)

Winkel, D.; Bol, G. H.; van Asselen, B.; Hes, J.; Scholten, V.; Kerkmeijer, L. G. W.; Raaymakers, B. W.

2016-12-01

To develop an automated radiotherapy treatment planning and optimization workflow to efficiently create patient specifically optimized clinical grade treatment plans for prostate cancer and to implement it in clinical practice. A two-phased planning and optimization workflow was developed to automatically generate 77Gy 5-field simultaneously integrated boost intensity modulated radiation therapy (SIB-IMRT) plans for prostate cancer treatment. A retrospective planning study (n  =  100) was performed in which automatically and manually generated treatment plans were compared. A clinical pilot (n  =  21) was performed to investigate the usability of our method. Operator time for the planning process was reduced to  <5 min. The retrospective planning study showed that 98 plans met all clinical constraints. Significant improvements were made in the volume receiving 72Gy (V72Gy) for the bladder and rectum and the mean dose of the bladder and the body. A reduced plan variance was observed. During the clinical pilot 20 automatically generated plans met all constraints and 17 plans were selected for treatment. The automated radiotherapy treatment planning and optimization workflow is capable of efficiently generating patient specifically optimized and improved clinical grade plans. It has now been adopted as the current standard workflow in our clinic to generate treatment plans for prostate cancer.

Optimization of in-cell accelerated solvent extraction technique for the determination of organochlorine pesticides in river sediments.

PubMed

Duodu, Godfred Odame; Goonetilleke, Ashantha; Ayoko, Godwin A

2016-04-01

Organochlorine pesticides (OCPs) are ubiquitous environmental contaminants with adverse impacts on aquatic biota, wildlife and human health even at low concentrations. However, conventional methods for their determination in river sediments are resource intensive. This paper presents an approach that is rapid and also reliable for the detection of OCPs. Accelerated Solvent Extraction (ASE) with in-cell silica gel clean-up followed by Triple Quadrupole Gas Chromatograph Mass Spectrometry (GCMS/MS) was used to recover OCPs from sediment samples. Variables such as temperature, solvent ratio, adsorbent mass and extraction cycle were evaluated and optimized for the extraction. With the exception of Aldrin, which was unaffected by any of the variables evaluated, the recovery of OCPs from sediment samples was largely influenced by solvent ratio and adsorbent mass and, to some extent, the number of cycles and temperature. The optimized conditions for OCPs extraction in sediment with good recoveries were determined to be 4 cycles, 4.5 g of silica gel, 105 °C, and 4:3 v/v DCM: hexane mixture. With the exception of two compounds (α-BHC and Aldrin) whose recoveries were low (59.73 and 47.66% respectively), the recovery of the other pesticides were in the range 85.35-117.97% with precision <10% RSD. The method developed significantly reduces sample preparation time, the amount of solvent used, matrix interference, and is highly sensitive and selective. Copyright © 2015 Elsevier B.V. All rights reserved.

Optimization of crystallization conditions for biological macromolecules.

PubMed

McPherson, Alexander; Cudney, Bob

2014-11-01

For the successful X-ray structure determination of macromolecules, it is first necessary to identify, usually by matrix screening, conditions that yield some sort of crystals. Initial crystals are frequently microcrystals or clusters, and often have unfavorable morphologies or yield poor diffraction intensities. It is therefore generally necessary to improve upon these initial conditions in order to obtain better crystals of sufficient quality for X-ray data collection. Even when the initial samples are suitable, often marginally, refinement of conditions is recommended in order to obtain the highest quality crystals that can be grown. The quality of an X-ray structure determination is directly correlated with the size and the perfection of the crystalline samples; thus, refinement of conditions should always be a primary component of crystal growth. The improvement process is referred to as optimization, and it entails sequential, incremental changes in the chemical parameters that influence crystallization, such as pH, ionic strength and precipitant concentration, as well as physical parameters such as temperature, sample volume and overall methodology. It also includes the application of some unique procedures and approaches, and the addition of novel components such as detergents, ligands or other small molecules that may enhance nucleation or crystal development. Here, an attempt is made to provide guidance on how optimization might best be applied to crystal-growth problems, and what parameters and factors might most profitably be explored to accelerate and achieve success.

Optimization of crystallization conditions for biological macromolecules

PubMed Central

McPherson, Alexander; Cudney, Bob

2014-01-01

For the successful X-ray structure determination of macromolecules, it is first necessary to identify, usually by matrix screening, conditions that yield some sort of crystals. Initial crystals are frequently microcrystals or clusters, and often have unfavorable morphologies or yield poor diffraction intensities. It is therefore generally necessary to improve upon these initial conditions in order to obtain better crystals of sufficient quality for X-ray data collection. Even when the initial samples are suitable, often marginally, refinement of conditions is recommended in order to obtain the highest quality crystals that can be grown. The quality of an X-ray structure determination is directly correlated with the size and the perfection of the crystalline samples; thus, refinement of conditions should always be a primary component of crystal growth. The improvement process is referred to as optimization, and it entails sequential, incremental changes in the chemical parameters that influence crystallization, such as pH, ionic strength and precipitant concentration, as well as physical parameters such as temperature, sample volume and overall methodology. It also includes the application of some unique procedures and approaches, and the addition of novel components such as detergents, ligands or other small molecules that may enhance nucleation or crystal development. Here, an attempt is made to provide guidance on how optimization might best be applied to crystal-growth problems, and what parameters and factors might most profitably be explored to accelerate and achieve success. PMID:25372810

Phase retrieval using regularization method in intensity correlation imaging

NASA Astrophysics Data System (ADS)

Li, Xiyu; Gao, Xin; Tang, Jia; Lu, Changming; Wang, Jianli; Wang, Bin

2014-11-01

Intensity correlation imaging(ICI) method can obtain high resolution image with ground-based low precision mirrors, in the imaging process, phase retrieval algorithm should be used to reconstituted the object's image. But the algorithm now used(such as hybrid input-output algorithm) is sensitive to noise and easy to stagnate. However the signal-to-noise ratio of intensity interferometry is low especially in imaging astronomical objects. In this paper, we build the mathematical model of phase retrieval and simplified it into a constrained optimization problem of a multi-dimensional function. New error function was designed by noise distribution and prior information using regularization method. The simulation results show that the regularization method can improve the performance of phase retrieval algorithm and get better image especially in low SNR condition

Innovative grassland management systems for environmental and livelihood benefits.

PubMed

Kemp, David R; Guodong, Han; Xiangyang, Hou; Michalk, David L; Fujiang, Hou; Jianping, Wu; Yingjun, Zhang

2013-05-21

Grasslands occupy 40% of the world's land surface (excluding Antarctica and Greenland) and support diverse groups, from traditional extensive nomadic to intense livestock-production systems. Population pressures mean that many of these grasslands are in a degraded state, particularly in less-productive areas of developing countries, affecting not only productivity but also vital environmental services such as hydrology, biodiversity, and carbon cycles; livestock condition is often poor and household incomes are at or below poverty levels. The challenge is to optimize management practices that result in "win-win" outcomes for grasslands, the environment, and households. A case study is discussed from northwestern China, where it has been possible to reduce animal numbers considerably by using an energy-balance/market-based approach while improving household incomes, providing conditions within which grassland recovery is possible. This bottom-up approach was supported by informing and working with the six layers of government in China to build appropriate policies. Further policy implications are considered. Additional gains in grassland rehabilitation could be fostered through targeted environmental payment schemes. Other aspects of the livestock production system that can be modified are discussed. This work built a strategy that has implications for many other grassland areas around the world where common problems apply.

Variability of E. coli density and sources in an urban watershed.

PubMed

Wu, J; Rees, P; Dorner, S

2011-03-01

The objective of this study was to characterize the variability of Escherichia coli density and sources in an urban watershed, particularly to focus on the influences of weather and land use. E. coli as a microbial indicator was measured at fourteen sites in four wet weather events and four dry weather conditions in the upper Blackstone River watershed. The sources of E. coli were identified by ribotyping. The results showed that wet weather led to sharp increases of E. coli densities. Interestingly, an intense storm of short duration led to a higher E. coli density than a moderate storm of long duration (p<0.01). The ribotyping patterns revealed microbial sources were mainly attributed to humans and wildlife, but varied in different weather conditions and were associated with the patterns of land use. Human sources accounted for 24.43% in wet weather but only 9.09% in dry weather. In addition, human sources were more frequently observed in residential zones (>30% of the total sources), while wildlife sources were dominant in open land and forest zones (54%). The findings provide useful information for developing optimal management strategies aimed at reducing the level of pathogens in urban watersheds.

A Market Model for Evaluating Technologies That Impact Critical-Material Intensity

NASA Astrophysics Data System (ADS)

Iyer, Ananth V.; Vedantam, Aditya

2016-07-01

A recent Critical Materials Strategy report highlighted the supply chain risk associated with neodymium and dysprosium, which are used in the manufacturing of neodymium-iron-boron permanent magnets (PM). In response, the Critical Materials Institute is developing innovative strategies to increase and diversify primary production, develop substitutes, reduce material intensity and recycle critical materials. Our goal in this paper is to propose an economic model to quantify the impact of one of these strategies, material intensity reduction. Technologies that reduce material intensity impact the economics of magnet manufacturing in multiple ways because of: (1) the lower quantity of critical material required per unit PM, (2) more efficient use of limited supply, and (3) the potential impact on manufacturing cost. However, the net benefit of these technologies to a magnet manufacturer is an outcome of an internal production decision subject to market demand characteristics, availability and resource constraints. Our contribution in this paper shows how a manufacturer's production economics moves from a region of being supply-constrained, to a region enabling the market optimal production quantity, to a region being constrained by resources other than critical materials, as the critical material intensity changes. Key insights for engineers and material scientists are: (1) material intensity reduction can have a significant market impact, (2) benefits to manufacturers are non-linear in the material intensity reduction, (3) there exists a threshold value for material intensity reduction that can be calculated for any target PM application, and (4) there is value for new intellectual property (IP) when existing manufacturing technology is IP-protected.

Optimal irradiance for sintering of inkjet-printed Ag electrodes with a 532nm CW laser

NASA Astrophysics Data System (ADS)

Moon, Yoon Jae; Kang, Heuiseok; Kang, Kyungtae; Hwang, Jun Young; Moon, Seung Jae

2013-09-01

Industrial solar cell fabrication generally adopts printing process to deposit the front electrodes, which needs additional heat treatment after printing to enhance electrical conductivity. As a heating method, laser irradiation draws attention not only because of its special selectivity, but also because of its intense heating to achieve high electric conductivity which is essential to reduce ohmic loss of solar cells. In this study, variation of electric conductivity was examined with laser irradiation having various beam intensity. 532 nm continuous wave (CW) laser was irradiated on inkjet-printed silver lines on glass substrate and electrical resistance was measured in situ during the irradiation. The results demonstrate that electric conductivity varies nonlinearly with laser intensity, having minimum specific resistance of 4.1 x 10-8 Ωm at 529 W/cm2 irradiation. The results is interesting because the specific resistance achieved by the present laser irradiation was about 1.8 times lower than the best value obtainable by oven heating, even though it was still higher by 2.5 times than that of bulk silver. It is also demonstrated that the irradiation time, needed to finish sintering process, decreases with laser intensity. The numerical simulation of laser heating showed that the optimal heating temperature could be as high as 300 oC for laser sintering, while it was limited to 250 oC for oven sintering. The nonlinear response of sintering with heating intensity was discussed, based on the results of FESEM images and XRD analysis.

Numerical Leak Detection in a Pipeline Network of Complex Structure with Unsteady Flow

NASA Astrophysics Data System (ADS)

Aida-zade, K. R.; Ashrafova, E. R.

2017-12-01

An inverse problem for a pipeline network of complex loopback structure is solved numerically. The problem is to determine the locations and amounts of leaks from unsteady flow characteristics measured at some pipeline points. The features of the problem include impulse functions involved in a system of hyperbolic differential equations, the absence of classical initial conditions, and boundary conditions specified as nonseparated relations between the states at the endpoints of adjacent pipeline segments. The problem is reduced to a parametric optimal control problem without initial conditions, but with nonseparated boundary conditions. The latter problem is solved by applying first-order optimization methods. Results of numerical experiments are presented.

Thermal Analysis of AlGaN/GaN High-Electron-Mobility Transistor and Its RF Power Efficiency Optimization with Source-Bridged Field-Plate Structure.

PubMed

Kwak, Hyeon-Tak; Chang, Seung-Bo; Jung, Hyun-Gu; Kim, Hyun-Seok

2018-09-01

In this study, we consider the relationship between the temperature in a two-dimensional electron gas (2-DEG) channel layer and the RF characteristics of an AlGaN/GaN high-electron-mobility transistor by changing the geometrical structure of the field-plate. The final goal is to achieve a high power efficiency by decreasing the channel layer temperature. First, simulations were performed to compare and contrast the experimental data of a conventional T-gate head structure. Then, a source-bridged field-plate (SBFP) structure was used to obtain the lower junction temperature in the 2-DEG channel layer. The peak electric field intensity was reduced, and a decrease in channel temperature resulted in an increase in electron mobility. Furthermore, the gate-to-source capacitance was increased by the SBFP structure. However, under the large current flow condition, the SBFP structure had a lower maximum temperature than the basic T-gate head structure, which improved the device electron mobility. Eventually, an optimum position of the SBFP was used, which led to higher frequency responses and improved the breakdown voltages. Hence, the optimized SBFP structure can be a promising candidate for high-power RF devices.

Leisure-time physical activity patterns and relationship to generalized distress among Canadians with arthritis or rheumatism.

PubMed

Da Costa, Deborah; Lowensteyn, Ilka; Dritsa, Maria

2003-11-01

Little is known about the epidemiology and possible mental health benefits of leisure-time physical activity (LTPA) for persons with arthritis and other rheumatic conditions. We examined the prevalence of LTPA and its association to generalized distress among Canadians with rheumatic conditions. The 1996-97 National Population Health Survey interview data from respondents with rheumatic conditions (n = 10,700) and persons with no chronic conditions (n = 19791) in the same age range (20-79 yrs) were selected for analyses. Self-reported data on forms and frequency of LTPA engaged in over the past 3 months were collected. Intensity of LTPA was expressed as total energy expenditure, with respondents classified as Active (> or = 3.0 kcal/kg/day), Moderate (1.5-2.9 kcal/kg/day), and Inactive (< 1.5 kcal/kg/day). Generalized distress was assessed using a subset of items from the Composite International Diagnostic Interview. Similar to persons with no chronic conditions, roughly 56% of persons with rheumatic conditions engaged in regular LTPA (12 or more 15-minute sessions per month). Only 13.2% of women and 18.9% of men with rheumatic conditions were sufficiently active at the level recommended to yield optimal health benefits. Both moderate and higher intensity LTPA was associated with less generalized distress. This relationship was more pronounced for women and for middle-aged and older patients with rheumatic conditions. A significant proportion of Canadians with rheumatic conditions are physically inactive. Even moderate intensity LTPA is associated with decreased generalized distress. Better efforts must be directed at promoting LTPA as part of the multidisciplinary management of this condition.

Numerical Studies of Optimization and Aberration Correction Methods for the Preliminary Demonstration of the Parametric Ionization Cooling (PIC) Principle in the Twin Helix Muon Cooling Channel

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

Maloney, J. A.; Morozov, V. S.; Derbenev, Ya. S.

Muon colliders have been proposed for the next generation of particle accelerators that study high-energy physics at the energy and intensity frontiers. In this paper we study a possible implementation of muon ionization cooling, Parametric-resonance Ionization Cooling (PIC), in the twin helix channel. The resonant cooling method of PIC offers the potential to reduce emittance beyond that achievable with ionization cooling with ordinary magnetic focusing. We examine optimization of a variety of parameters, study the nonlinear dynamics in the twin helix channel and consider possible methods of aberration correction.

Optimization of extraction conditions for osthol, a melanogenesis inhibitor from Cnidium monnieri fruits.

PubMed

Beom Kim, Seon; Kim, CheongTaek; Liu, Qing; Hee Jo, Yang; Joo Choi, Hak; Hwang, Bang Yeon; Kyum Kim, Sang; Kyeong Lee, Mi

2016-08-01

Coumarin derivatives have been reported to inhibit melanin biosynthesis. The melanogenesis inhibitory activity of osthol, a major coumarin of the fruits of Cnidium monnieri Cusson (Umbelliferae), and optimized extraction conditions for the maximum yield from the isolation of osthol from C. monnieri fruits were investigated. B16F10 melanomas were treated with osthol at concentration of 1, 3, and 10 μM for 72 h. The expression of melanogenesis genes, such as tyrosinase, TRP-1, and TRP-2 was also assessed. For optimization, extraction factors such as extraction solvent, extraction time, and sample/solvent ratio were tested and optimized for maximum yield of osthol using response surface methodology with the Box-Behnken design (BBD). Osthol inhibits melanin content in B16F10 melanoma cells with an IC50 value of 4.9 μM. The melanogenesis inhibitory activity of osthol was achieved not by direct inhibition of tyrosinase activity but by inhibiting melanogenic enzyme expressions, such as tyrosinase, TRP-1, and TRP-2. The optimal condition was obtained as a sample/solvent ratio, 1500 mg/10 ml; an extraction time 30.3 min; and a methanol concentration of 97.7%. The osthol yield under optimal conditions was found to be 15.0 mg/g dried samples, which were well matched with the predicted value of 14.9 mg/g dried samples. These results will provide useful information about optimized extraction conditions for the development of osthol as cosmetic therapeutics to reduce skin hyperpigmentation.

Binaural Release from Masking for a Speech Sound in Infants, Preschoolers, and Adults.

ERIC Educational Resources Information Center

Nozza, Robert J.

1988-01-01

Binaural masked thresholds for a speech sound (/ba/) were estimated under two interaural phase conditions in three age groups (infants, preschoolers, adults). Differences as a function of both age and condition and effects of reducing intensity for adults were significant in indicating possible developmental binaural hearing changes, especially…

Optimization methods and silicon solar cell numerical models

NASA Technical Reports Server (NTRS)

Girardini, K.; Jacobsen, S. E.

1986-01-01

An optimization algorithm for use with numerical silicon solar cell models was developed. By coupling an optimization algorithm with a solar cell model, it is possible to simultaneously vary design variables such as impurity concentrations, front junction depth, back junction depth, and cell thickness to maximize the predicted cell efficiency. An optimization algorithm was developed and interfaced with the Solar Cell Analysis Program in 1 Dimension (SCAP1D). SCAP1D uses finite difference methods to solve the differential equations which, along with several relations from the physics of semiconductors, describe mathematically the performance of a solar cell. A major obstacle is that the numerical methods used in SCAP1D require a significant amount of computer time, and during an optimization the model is called iteratively until the design variables converge to the values associated with the maximum efficiency. This problem was alleviated by designing an optimization code specifically for use with numerically intensive simulations, to reduce the number of times the efficiency has to be calculated to achieve convergence to the optimal solution.

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

Beltran, C; Kamal, H

Purpose: To provide a multicriteria optimization algorithm for intensity modulated radiation therapy using pencil proton beam scanning. Methods: Intensity modulated radiation therapy using pencil proton beam scanning requires efficient optimization algorithms to overcome the uncertainties in the Bragg peaks locations. This work is focused on optimization algorithms that are based on Monte Carlo simulation of the treatment planning and use the weights and the dose volume histogram (DVH) control points to steer toward desired plans. The proton beam treatment planning process based on single objective optimization (representing a weighted sum of multiple objectives) usually leads to time-consuming iterations involving treatmentmore » planning team members. We proved a time efficient multicriteria optimization algorithm that is developed to run on NVIDIA GPU (Graphical Processing Units) cluster. The multicriteria optimization algorithm running time benefits from up-sampling of the CT voxel size of the calculations without loss of fidelity. Results: We will present preliminary results of Multicriteria optimization for intensity modulated proton therapy based on DVH control points. The results will show optimization results of a phantom case and a brain tumor case. Conclusion: The multicriteria optimization of the intensity modulated radiation therapy using pencil proton beam scanning provides a novel tool for treatment planning. Work support by a grant from Varian Inc.« less

Modeling ecohydrological impacts of land management and water use in the Silver Creek basin, Idaho

NASA Astrophysics Data System (ADS)

Loinaz, Maria C.; Gross, Dayna; Unnasch, Robert; Butts, Michael; Bauer-Gottwein, Peter

2014-03-01

A number of anthropogenic stressors, including land use change and intensive water use, have caused stream habitat deterioration in arid and semiarid climates throughout the western U.S. These often contribute to high stream temperatures, a widespread water quality problem. Stream temperature is an important indicator of stream ecosystem health and is affected by catchment-scale climate and hydrological processes, morphology, and riparian vegetation. To properly manage affected systems and achieve ecosystem sustainability, it is important to understand the relative impact of these factors. In this study, we predict relative impacts of different stressors using an integrated catchment-scale ecohydrological model that simulates hydrological processes, stream temperature, and fish growth. This type of model offers a suitable measure of ecosystem services because it provides information about the reproductive capability of fish under different conditions. We applied the model to Silver Creek, Idaho, a stream highly valued for its world-renowned trout fishery. The simulations indicated that intensive water use by agriculture and climate change are both major contributors to habitat degradation in the study area. Agricultural practices that increase water use efficiency and mitigate drainage runoff are feasible and can have positive impacts on the ecosystem. All of the mitigation strategies simulated reduced stream temperatures to varying degrees; however, not all resulted in increases in fish growth. The results indicate that temperature dynamics, rather than point statistics, determine optimal growth conditions for fish. Temperature dynamics are influenced by surface water-groundwater interactions. Combined restoration strategies that can achieve ecosystem stability under climate change should be further explored.

Minimum error discrimination between similarity-transformed quantum states

NASA Astrophysics Data System (ADS)

Jafarizadeh, M. A.; Sufiani, R.; Mazhari Khiavi, Y.

2011-07-01

Using the well-known necessary and sufficient conditions for minimum error discrimination (MED), we extract an equivalent form for the MED conditions. In fact, by replacing the inequalities corresponding to the MED conditions with an equivalent but more suitable and convenient identity, the problem of mixed state discrimination with optimal success probability is solved. Moreover, we show that the mentioned optimality conditions can be viewed as a Helstrom family of ensembles under some circumstances. Using the given identity, MED between N similarity transformed equiprobable quantum states is investigated. In the case that the unitary operators are generating a set of irreducible representation, the optimal set of measurements and corresponding maximum success probability of discrimination can be determined precisely. In particular, it is shown that for equiprobable pure states, the optimal measurement strategy is the square-root measurement (SRM), whereas for the mixed states, SRM is not optimal. In the case that the unitary operators are reducible, there is no closed-form formula in the general case, but the procedure can be applied in each case in accordance to that case. Finally, we give the maximum success probability of optimal discrimination for some important examples of mixed quantum states, such as generalized Bloch sphere m-qubit states, spin-j states, particular nonsymmetric qudit states, etc.

Minimum error discrimination between similarity-transformed quantum states

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

Jafarizadeh, M. A.; Institute for Studies in Theoretical Physics and Mathematics, Tehran 19395-1795; Research Institute for Fundamental Sciences, Tabriz 51664

2011-07-15

Using the well-known necessary and sufficient conditions for minimum error discrimination (MED), we extract an equivalent form for the MED conditions. In fact, by replacing the inequalities corresponding to the MED conditions with an equivalent but more suitable and convenient identity, the problem of mixed state discrimination with optimal success probability is solved. Moreover, we show that the mentioned optimality conditions can be viewed as a Helstrom family of ensembles under some circumstances. Using the given identity, MED between N similarity transformed equiprobable quantum states is investigated. In the case that the unitary operators are generating a set of irreduciblemore » representation, the optimal set of measurements and corresponding maximum success probability of discrimination can be determined precisely. In particular, it is shown that for equiprobable pure states, the optimal measurement strategy is the square-root measurement (SRM), whereas for the mixed states, SRM is not optimal. In the case that the unitary operators are reducible, there is no closed-form formula in the general case, but the procedure can be applied in each case in accordance to that case. Finally, we give the maximum success probability of optimal discrimination for some important examples of mixed quantum states, such as generalized Bloch sphere m-qubit states, spin-j states, particular nonsymmetric qudit states, etc.« less

Shortening Delivery Times of Intensity Modulated Proton Therapy by Reducing Proton Energy Layers During Treatment Plan Optimization

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

Water, Steven van de, E-mail: s.vandewater@erasmusmc.nl; Kooy, Hanne M.; Heijmen, Ben J.M.

2015-06-01

Purpose: To shorten delivery times of intensity modulated proton therapy by reducing the number of energy layers in the treatment plan. Methods and Materials: We have developed an energy layer reduction method, which was implemented into our in-house-developed multicriteria treatment planning system “Erasmus-iCycle.” The method consisted of 2 components: (1) minimizing the logarithm of the total spot weight per energy layer; and (2) iteratively excluding low-weighted energy layers. The method was benchmarked by comparing a robust “time-efficient plan” (with energy layer reduction) with a robust “standard clinical plan” (without energy layer reduction) for 5 oropharyngeal cases and 5 prostate cases.more » Both plans of each patient had equal robust plan quality, because the worst-case dose parameters of the standard clinical plan were used as dose constraints for the time-efficient plan. Worst-case robust optimization was performed, accounting for setup errors of 3 mm and range errors of 3% + 1 mm. We evaluated the number of energy layers and the expected delivery time per fraction, assuming 30 seconds per beam direction, 10 ms per spot, and 400 Giga-protons per minute. The energy switching time was varied from 0.1 to 5 seconds. Results: The number of energy layers was on average reduced by 45% (range, 30%-56%) for the oropharyngeal cases and by 28% (range, 25%-32%) for the prostate cases. When assuming 1, 2, or 5 seconds energy switching time, the average delivery time was shortened from 3.9 to 3.0 minutes (25%), 6.0 to 4.2 minutes (32%), or 12.3 to 7.7 minutes (38%) for the oropharyngeal cases, and from 3.4 to 2.9 minutes (16%), 5.2 to 4.2 minutes (20%), or 10.6 to 8.0 minutes (24%) for the prostate cases. Conclusions: Delivery times of intensity modulated proton therapy can be reduced substantially without compromising robust plan quality. Shorter delivery times are likely to reduce treatment uncertainties and costs.« less

Luminescent Method for Porcelain Identification

NASA Astrophysics Data System (ADS)

Platova, R. A.; Rassulov, V. A.; Platov, Yu. T.

2018-05-01

Porcelain identification according to the material type (hard, soft, and bone) was reduced to a system of classification functions that were constructed based on interrelationships of luminescence band intensities of optically active impurity centers (Fe3+ and Mn2+), a molecular center ({UO}_2^{2+}) , and intrinsic defects (O*, oxygen center). Porcelains with different compositions and calcination conditions had different combinations and intensity ratios of bands of optically active centers.

Optimization of 18 F-syntheses using 19 F-reagents at tracer-level concentrations and liquid chromatography/tandem mass spectrometry analysis: Improved synthesis of [18 F]MDL100907.

PubMed

Zhang, Xiang; Dunlow, Ryan; Blackman, Burchelle N; Swenson, Rolf E

2018-05-15

Traditional radiosynthetic optimization faces the challenges of high radiation exposure, cost, and inability to perform serial reactions due to tracer decay. To accelerate tracer development, we have developed a strategy to simulate radioactive 18 F-syntheses by using tracer-level (nanomolar) non-radioactive 19 F-reagents and LC-MS/MS analysis. The methodology was validated with fallypride synthesis under tracer-level 19 F-conditions, which showed reproducible and comparable results with radiosynthesis, and proved the feasibility of this process. Using this approach, the synthesis of [ 18 F]MDL100907 was optimized under 19 F-conditions with greatly improved yield. The best conditions were successfully transferred to radiosynthesis. A radiochemical yield of 19% to 22% was achieved with the radiochemical purity >99% and the molar activity 38.8 to 53.6 GBq/ μmol (n = 3). The tracer-level 19 F-approach provides a high-throughput and cost-effective process to optimize radiosynthesis with reduced radiation exposure. This new method allows medicinal and synthetic chemists to optimize radiolabeling conditions without the need to use radioactivity. Copyright © 2018 John Wiley & Sons, Ltd.

Ship Trim Optimization: Assessment of Influence of Trim on Resistance of MOERI Container Ship

PubMed Central

Duan, Wenyang

2014-01-01

Environmental issues and rising fuel prices necessitate better energy efficiency in all sectors. Shipping industry is a stakeholder in environmental issues. Shipping industry is responsible for approximately 3% of global CO2 emissions, 14-15% of global NOX emissions, and 16% of global SOX emissions. Ship trim optimization has gained enormous momentum in recent years being an effective operational measure for better energy efficiency to reduce emissions. Ship trim optimization analysis has traditionally been done through tow-tank testing for a specific hullform. Computational techniques are increasingly popular in ship hydrodynamics applications. The purpose of this study is to present MOERI container ship (KCS) hull trim optimization by employing computational methods. KCS hull total resistances and trim and sinkage computed values, in even keel condition, are compared with experimental values and found in reasonable agreement. The agreement validates that mesh, boundary conditions, and solution techniques are correct. The same mesh, boundary conditions, and solution techniques are used to obtain resistance values in different trim conditions at Fn = 0.2274. Based on attained results, optimum trim is suggested. This research serves as foundation for employing computational techniques for ship trim optimization. PMID:24578649

An experimental sample of the field gamma-spectrometer based on solid state Si-photomultiplier

NASA Astrophysics Data System (ADS)

Denisov, Viktor; Korotaev, Valery; Titov, Aleksandr; Blokhina, Anastasia; Kleshchenok, Maksim

2017-05-01

Design of optical-electronic devices and systems involves the selection of such technical patterns that under given initial requirements and conditions are optimal according to certain criteria. The original characteristic of the OES for any purpose, defining its most important feature ability is a threshold detection. Based on this property, will be achieved the required functional quality of the device or system. Therefore, the original criteria and optimization methods have to subordinate to the idea of a better detectability. Generally reduces to the problem of optimal selection of the expected (predetermined) signals in the predetermined observation conditions. Thus the main purpose of optimization of the system when calculating its detectability is the choice of circuits and components that provide the most effective selection of a target.

[Clinical laboratory approaches to parodontitis treatment optimization].

PubMed

Soboleva, L A; Shul'diakov, A A; Oseeva, A O; Aleksandrova, E A

2010-01-01

In order to determine cycloferon liniment clinical-pathogenetic efficacy in comprehensive parodontitis therapy examination and treatment of 80 patients was done. It was determined that the cycloferon liniment use in comprehensive treatment of patients with parodontitis let to reduce infectious load in parodontal pockets and local inflammation intensity, to normalize the secretory immunoglobulin level and immune status indices that provided speed up of healing process and reduction relapse frequency.

A study of the threshold method utilizing raingage data

NASA Technical Reports Server (NTRS)

Short, David A.; Wolff, David B.; Rosenfeld, Daniel; Atlas, David

1993-01-01

The threshold method for estimation of area-average rain rate relies on determination of the fractional area where rain rate exceeds a preset level of intensity. Previous studies have shown that the optimal threshold level depends on the climatological rain-rate distribution (RRD). It has also been noted, however, that the climatological RRD may be composed of an aggregate of distributions, one for each of several distinctly different synoptic conditions, each having its own optimal threshold. In this study, the impact of RRD variations on the threshold method is shown in an analysis of 1-min rainrate data from a network of tipping-bucket gauges in Darwin, Australia. Data are analyzed for two distinct regimes: the premonsoon environment, having isolated intense thunderstorms, and the active monsoon rains, having organized convective cell clusters that generate large areas of stratiform rain. It is found that a threshold of 10 mm/h results in the same threshold coefficient for both regimes, suggesting an alternative definition of optimal threshold as that which is least sensitive to distribution variations. The observed behavior of the threshold coefficient is well simulated by assumption of lognormal distributions with different scale parameters and same shape parameters.

Carbohydrate-Restriction with High-Intensity Interval Training: An Optimal Combination for Treating Metabolic Diseases?

PubMed Central

Francois, Monique E.; Gillen, Jenna B.; Little, Jonathan P.

2017-01-01

Lifestyle interventions incorporating both diet and exercise strategies remain cornerstone therapies for treating metabolic disease. Carbohydrate-restriction and high-intensity interval training (HIIT) have independently been shown to improve cardiovascular and metabolic health. Carbohydrate-restriction reduces postprandial hyperglycemia, thereby limiting potential deleterious metabolic and cardiovascular consequences of excessive glucose excursions. Additionally, carbohydrate-restriction has been shown to improve body composition and blood lipids. The benefits of exercise for improving insulin sensitivity are well known. In this regard, HIIT has been shown to rapidly improve glucose control, endothelial function, and cardiorespiratory fitness. Here, we report the available evidence for each strategy and speculate that the combination of carbohydrate-restriction and HIIT will synergistically maximize the benefits of both approaches. We hypothesize that this lifestyle strategy represents an optimal intervention to treat metabolic disease; however, further research is warranted in order to harness the potential benefits of carbohydrate-restriction and HIIT for improving cardiometabolic health. PMID:29075629

Poster — Thur Eve — 61: A new framework for MPERT plan optimization using MC-DAO

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

Baker, M; Lloyd, S AM; Townson, R

2014-08-15

This work combines the inverse planning technique known as Direct Aperture Optimization (DAO) with Intensity Modulated Radiation Therapy (IMRT) and combined electron and photon therapy plans. In particular, determining conditions under which Modulated Photon/Electron Radiation Therapy (MPERT) produces better dose conformality and sparing of organs at risk than traditional IMRT plans is central to the project. Presented here are the materials and methods used to generate and manipulate the DAO procedure. Included is the introduction of a powerful Java-based toolkit, the Aperture-based Monte Carlo (MC) MPERT Optimizer (AMMO), that serves as a framework for optimization and provides streamlined access tomore » underlying particle transport packages. Comparison of the toolkit's dose calculations to those produced by the Eclipse TPS and the demonstration of a preliminary optimization are presented as first benchmarks. Excellent agreement is illustrated between the Eclipse TPS and AMMO for a 6MV photon field. The results of a simple optimization shows the functioning of the optimization framework, while significant research remains to characterize appropriate constraints.« less

Research on breakdown characteristics of converter transformer oil-paper insulation under compound electric field in alpine region

NASA Astrophysics Data System (ADS)

Xu, C.; Gao, Z. W.; Lan, S.; Guo, H. X.; Gong, M. C.

2018-01-01

In the paper, existing research and operating experience was summarized. On the basis, the particularity of oil-paper insulation operation condition for converter transformer was combined for studying the influence of temperature on oil-paper insulation field intensity distribution of converter transformers under different AC contents within wide temperature scope (-40°C∼105°C). The law of temperature gradients on space charge accumulation was analyzed. The breakdown or flashover characteristics of typical oil-paper compound insulation structure under the action of DC, AC and AC-DC superposition voltage at different temperatures were explored. The design principles of converter transformer oil-paper insulation structures in alpine region was proposed. The principle was adjusted and optimized properly according to the operation temperature scope and withstood AC-DC proportion. The reliability of transformer operation was improved on the one hand, and the insulating medium can be rationally utilized for reducing the manufacturing cost of the transformer on the other hand.

Novel plasma source for safe beryllium spectral line studies in the presence of beryllium dust

NASA Astrophysics Data System (ADS)

Stankov, B. D.; Vinić, M.; Gavrilović Božović, M. R.; Ivković, M.

2018-05-01

Plasma source for beryllium spectral line studies in the presence of beryllium dust particles was realised. The guideline during construction was to prevent exposure to formed dust, considering the toxicity of beryllium. Plasma source characterization through determination of optimal working conditions is described. The necessary conditions for Be spectral line appearance and optimal conditions for line shape measurements are found. It is proven experimentally that under these conditions dust appears coincidently with the second current maximum. The electron density measured after discharge current maximum is determined from the peak separation of the hydrogen Balmer beta spectral line, and the electron temperature is determined from the ratios of the relative intensities of Be spectral lines emitted from successive ionized stages of atoms. Maximum values of electron density and temperature are measured to be 9.3 × 1022 m-3 and 16 800 K, respectively. Construction details and testing of the BeO discharge tube in comparison with SiO2 and Al2O3 discharge tubes are also presented in this paper.

Pitch Guidance Optimization for the Orion Abort Flight Tests

NASA Technical Reports Server (NTRS)

Stillwater, Ryan Allanque

2010-01-01

The National Aeronautics and Space Administration created the Constellation program to develop the next generation of manned space vehicles and launch vehicles. The Orion abort system is initiated in the event of an unsafe condition during launch. The system has a controller gains schedule that can be tuned to reduce the attitude errors between the simulated Orion abort trajectories and the guidance trajectory. A program was created that uses the method of steepest descent to tune the pitch gains schedule by an automated procedure. The gains schedule optimization was applied to three potential abort scenarios; each scenario tested using the optimized gains schedule resulted in reduced attitude errors when compared to the Orion production gains schedule.

Fluorescence Stability of Mercaptopropionic Acid Capped Cadmium Telluride Quantum Dots in Various Biochemical Buffers.

PubMed

Borse, Vivek; Kashikar, Adisha; Srivastava, Rohit

2018-04-01

Quantum dots are the semiconductor nanocrystals having unique optical and electronic properties. Quantum dots are category of fluorescent labels utilized for biological tagging, biosensing, bioassays, bioimaging and in vivo imaging as they exhibit very small size, signal brightness, photostability, tuning of light emission range, longer photoluminescence decay time as compared to organic dyes. In this work, we have synthesized and characterized mercaptopropionic acid capped cadmium telluride quantum dots (MPA-CdTe QDs) using hydrothermal method. The study further reports fluorescence intensity stability of quantum dots suspended in different buffers of varying concentration (1-100 mM), stored at various photophysical conditions. Fluorescence intensity values were reduced with increase in buffer concentration. When the samples were stored at room temperature in ambient light condition the quantum dots suspended in different buffers lost the fluorescence intensity after day 15 (except TRIS II). Fluorescence intensity values were found stable for more than 30 days when the samples were stored in dark condition. Samples stored in refrigerator displayed modest fluorescence intensity even after 300 days of storage. Thus, storage of MPA-CdTe QDs in refrigerator may be the suitable choice to maintain its fluorescence stability for longer time for further application.

Climate warming alters effects of management on population viability of threatened species: results from a 30-year experimental study on a rare orchid.

PubMed

Sletvold, Nina; Dahlgren, Johan P; Oien, Dag-Inge; Moen, Asbjørn; Ehrlén, Johan

2013-09-01

Climate change is expected to influence the viability of populations both directly and indirectly, via species interactions. The effects of large-scale climate change are also likely to interact with local habitat conditions. Management actions designed to preserve threatened species therefore need to adapt both to the prevailing climate and local conditions. Yet, few studies have separated the direct and indirect effects of climatic variables on the viability of local populations and discussed the implications for optimal management. We used 30 years of demographic data to estimate the simultaneous effects of management practice and among-year variation in four climatic variables on individual survival, growth and fecundity in one coastal and one inland population of the perennial orchid Dactylorhiza lapponica in Norway. Current management, mowing, is expected to reduce competitive interactions. Statistical models of how climate and management practice influenced vital rates were incorporated into matrix population models to quantify effects on population growth rate. Effects of climate differed between mown and control plots in both populations. In particular, population growth rate increased more strongly with summer temperature in mown plots than in control plots. Population growth rate declined with spring temperature in the inland population, and with precipitation in the coastal population, and the decline was stronger in control plots in both populations. These results illustrate that both direct and indirect effects of climate change are important for population viability and that net effects depend both on local abiotic conditions and on biotic conditions in terms of management practice and intensity of competition. The results also show that effects of management practices influencing competitive interactions can strongly depend on climatic factors. We conclude that interactions between climate and management should be considered to reliably predict future population viability and optimize conservation actions. © 2013 John Wiley & Sons Ltd.

Determining optimal operation parameters for reducing PCDD/F emissions (I-TEQ values) from the iron ore sintering process by using the Taguchi experimental design.

PubMed

Chen, Yu-Cheng; Tsai, Perng-Jy; Mou, Jin-Luh

2008-07-15

This study is the first one using the Taguchi experimental design to identify the optimal operating condition for reducing polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/ Fs) formations during the iron ore sintering process. Four operating parameters, including the water content (Wc; range = 6.0-7.0 wt %), suction pressure (Ps; range = 1000-1400 mmH2O), bed height (Hb; range = 500-600 mm), and type of hearth layer (including sinter, hematite, and limonite), were selected for conducting experiments in a pilot scale sinter pot to simulate various sintering operating conditions of a real-scale sinter plant We found that the resultant optimal combination (Wc = 6.5 wt%, Hb = 500 mm, Ps = 1000 mmH2O, and hearth layer = hematite) could decrease the emission factor of total PCDD/Fs (total EF(PCDD/Fs)) up to 62.8% by reference to the current operating condition of the real-scale sinter plant (Wc = 6.5 wt %, Hb = 550 mm, Ps = 1200 mmH2O, and hearth layer = sinter). Through the ANOVA analysis, we found that Wc was the most significant parameter in determining total EF(PCDD/Fs (accounting for 74.7% of the total contribution of the four selected parameters). The resultant optimal combination could also enhance slightly in both sinter productivity and sinter strength (30.3 t/m2/day and 72.4%, respectively) by reference to those obtained from the reference operating condition (29.9 t/m (2)/day and 72.2%, respectively). The above results further ensure the applicability of the obtained optimal combination for the real-scale sinter production without interfering its sinter productivity and sinter strength.

Optimization of Bioethanol Production Using Whole Plant of Water Hyacinth as Substrate in Simultaneous Saccharification and Fermentation Process

PubMed Central

Zhang, Qiuzhuo; Weng, Chen; Huang, Huiqin; Achal, Varenyam; Wang, Duanchao

2016-01-01

Water hyacinth was used as substrate for bioethanol production in the present study. Combination of acid pretreatment and enzymatic hydrolysis was the most effective process for sugar production that resulted in the production of 402.93 mg reducing sugar at optimal condition. A regression model was built to optimize the fermentation factors according to response surface method in saccharification and fermentation (SSF) process. The optimized condition for ethanol production by SSF process was fermented at 38.87°C in 81.87 h when inoculated with 6.11 ml yeast, where 1.291 g/L bioethanol was produced. Meanwhile, 1.289 g/L ethanol was produced during experimentation, which showed reliability of presented regression model in this research. The optimization method discussed in the present study leading to relatively high bioethanol production could provide a promising way for Alien Invasive Species with high cellulose content. PMID:26779125

Impacts of Climate Change on Malaria Transmission in Africa

NASA Astrophysics Data System (ADS)

Eltahir, E. A. B.; Endo, N.; Yamana, T. K.

2017-12-01

Malaria is a major vector-borne parasitic disease transmitted to humans by Anopheles spp mosquitoes. Africa is the hotspot for malaria transmission where more than 90% of malaria deaths occur every year. Malaria transmission is an intricate function of climatic factors, which non-linearly affect the development of vectors and parasites. We project that the risk of malaria will increase towards the end of the 21st century in east Africa, but decrease in west Africa. We combine a novel malaria transmission simulator, HYDREMATS, that has been developed based on comprehensive multi-year field surveys both in East Africa and West Africa, and the most reliable climate projections through regional dynamical downscaling and rigorous selection of GCMs from among CMIP5 models. We define a bell-shaped relation between malaria intensity and temperature, centered around a temperature of 30°C. Future risks of malaria are projected for two highly populated regions in Africa: the highlands in East Africa and the fringes of the desert in West Africa. In the highlands of East Africa, temperature is substantially colder than this optimal temperature; warmer future climate exacerbate malaria conditions. In the Sahel fringes in West Africa, temperature is around this optimal temperature; warming is not likely to exacerbate and might even reduce malaria burden. Unlike the highlands of East Africa, which receive significant amounts of annual rainfall, dry conditions also limit malaria transmission in the Sahel fringes in West Africa. This disproportionate risk of malaria due to climate change should guide strategies for climate adaptation over Africa.

Thioredoxins Play a Crucial Role in Dynamic Acclimation of Photosynthesis in Fluctuating Light.

PubMed

Thormählen, Ina; Zupok, Arkadiusz; Rescher, Josephin; Leger, Jochen; Weissenberger, Stefan; Groysman, Julia; Orwat, Anne; Chatel-Innocenti, Gilles; Issakidis-Bourguet, Emmanuelle; Armbruster, Ute; Geigenberger, Peter

2017-01-09

Sunlight represents the energy source for photosynthesis and plant growth. When growing in the field, plant photosynthesis has to manage strong fluctuations in light intensities. Regulation based on the thioredoxin (Trx) system is believed to ensure light-responsive control of photosynthetic reactions in the chloroplast. However, direct evidence for a role of this system in regulating dynamic acclimation of photosynthesis in fluctuating conditions is largely lacking. In this report we show that the ferredoxin-dependent Trxs m1 and m2 as well as the NADPH-dependent NTRC are both indispensable for photosynthetic acclimation in fluctuating light intensities. Arabidopsis mutants with combined deficiency in Trxs m1 and m2 show wild-type growth and photosynthesis under constant light condition, while photosynthetic parameters are strongly modified in rapidly alternating high and low light. Two independent trxm1m2 mutants show lower photosynthetic efficiency in high light, but surprisingly significantly higher photosynthetic efficiency in low light. Our data suggest that a main target of Trx m1 and m2 is the NADP-malate dehydrogenase involved in export of excess reductive power from the chloroplast. The decreased photosynthetic efficiency in the high-light peaks may thus be explained by a reduced capacity of the trxm1m2 mutants in the rapid light activation of this enzyme. In the ntrc mutant, dynamic responses of non-photochemical quenching of excitation energy and plastoquinone reduction state both were strongly attenuated in fluctuating light intensities, leading to a massive decrease in PSII quantum efficiency and a specific decrease in plant growth under these conditions. This is likely due to the decreased ability of the ntrc mutant to control the stromal NADP(H) redox poise. Taken together, our results indicate that NTRC is indispensable in ensuring the full range of dynamic responses of photosynthesis to optimize photosynthesis and maintain growth in fluctuating light, while Trxs m1 and m2 are indispensable for full activation of photosynthesis in the high-light periods but negatively affect photosynthetic efficiency in the low-light periods of fluctuating light. Copyright © 2017 The Author. Published by Elsevier Inc. All rights reserved.

Optical Frequency Optimization of a High Intensity Laser Power Beaming System Utilizing VMJ Photovoltaic Cells

NASA Technical Reports Server (NTRS)

Raible, Daniel E.; Dinca, Dragos; Nayfeh, Taysir H.

2012-01-01

An effective form of wireless power transmission (WPT) has been developed to enable extended mission durations, increased coverage and added capabilities for both space and terrestrial applications that may benefit from optically delivered electrical energy. The high intensity laser power beaming (HILPB) system enables long range optical 'refueling" of electric platforms such as micro unmanned aerial vehicles (MUAV), airships, robotic exploration missions and spacecraft platforms. To further advance the HILPB technology, the focus of this investigation is to determine the optimal laser wavelength to be used with the HILPB receiver, which utilizes vertical multi-junction (VMJ) photovoltaic cells. Frequency optimization of the laser system is necessary in order to maximize the conversion efficiency at continuous high intensities, and thus increase the delivered power density of the HILPB system. Initial spectral characterizations of the device performed at the NASA Glenn Research Center (GRC) indicate the approximate range of peak optical-to-electrical conversion efficiencies, but these data sets represent transient conditions under lower levels of illumination. Extending these results to high levels of steady state illumination, with attention given to the compatibility of available commercial off-the-shelf semiconductor laser sources and atmospheric transmission constraints is the primary focus of this paper. Experimental hardware results utilizing high power continuous wave (CW) semiconductor lasers at four different operational frequencies near the indicated band gap of the photovoltaic VMJ cells are presented and discussed. In addition, the highest receiver power density achieved to date is demonstrated using a single photovoltaic VMJ cell, which provided an exceptionally high electrical output of 13.6 W/sq cm at an optical-to-electrical conversion efficiency of 24 percent. These results are very promising and scalable, as a potential 1.0 sq m HILPB receiver of similar construction would be able to generate 136 kW of electrical power under similar conditions.

A retrospective study of long-term treatment outcomes for reduced vocal intensity in hypokinetic dysarthria.

PubMed

Watts, Christopher R

2016-01-01

Reduced vocal intensity is a core impairment of hypokinetic dysarthria in Parkinson's disease (PD). Speech treatments have been developed to rehabilitate the vocal subsystems underlying this impairment. Intensive treatment programs requiring high-intensity voice and speech exercises with clinician-guided prompting and feedback have been established as effective for improving vocal function. Less is known, however, regarding long-term outcomes of clinical benefit in speakers with PD who receive these treatments. A retrospective cohort design was utilized. Data from 78 patient files across a three year period were analyzed. All patients received a structured, intensive program of voice therapy focusing on speaking intent and loudness. The dependent variable for all analyses was vocal intensity in decibels (dBSPL). Vocal intensity during sustained vowel production, reading, and novel conversational speech was compared at pre-treatment, post-treatment, six month follow-up, and twelve month follow-up periods. Statistically significant increases in vocal intensity were found at post-treatment, 6 months, and 12 month follow-up periods with intensity gains ranging from 5 to 17 dB depending on speaking condition and measurement period. Significant treatment effects were found in all three speaking conditions. Effect sizes for all outcome measures were large, suggesting a strong degree of practical significance. Significant increases in vocal intensity measured at 6 and 12 moth follow-up periods suggested that the sample of patients maintained treatment benefit for up to a year. These findings are supported by outcome studies reporting treatment outcomes within a few months post-treatment, in addition to prior studies that have reported long-term outcome results. The positive treatment outcomes experienced by the PD cohort in this study are consistent with treatment responses subsequent to other treatment approaches which focus on high-intensity, clinician guided motor learning for voice and speech production in PD. Theories regarding the underlying neurophysiological response to treatment will be discussed.

Generalized Pauli constraints in reduced density matrix functional theory.

PubMed

Theophilou, Iris; Lathiotakis, Nektarios N; Marques, Miguel A L; Helbig, Nicole

2015-04-21

Functionals of the one-body reduced density matrix (1-RDM) are routinely minimized under Coleman's ensemble N-representability conditions. Recently, the topic of pure-state N-representability conditions, also known as generalized Pauli constraints, received increased attention following the discovery of a systematic way to derive them for any number of electrons and any finite dimensionality of the Hilbert space. The target of this work is to assess the potential impact of the enforcement of the pure-state conditions on the results of reduced density-matrix functional theory calculations. In particular, we examine whether the standard minimization of typical 1-RDM functionals under the ensemble N-representability conditions violates the pure-state conditions for prototype 3-electron systems. We also enforce the pure-state conditions, in addition to the ensemble ones, for the same systems and functionals and compare the correlation energies and optimal occupation numbers with those obtained by the enforcement of the ensemble conditions alone.

Improving IMRT delivery efficiency using intensity limits during inverse planning.

PubMed

Coselmon, Martha M; Moran, Jean M; Radawski, Jeffrey D; Fraass, Benedick A

2005-05-01

Inverse planned intensity modulated radiotherapy (IMRT) fields can be highly modulated due to the large number of degrees of freedom involved in the inverse planning process. Additional modulation typically results in a more optimal plan, although the clinical rewards may be small or offset by additional delivery complexity and/or increased dose from transmission and leakage. Increasing modulation decreases delivery efficiency, and may lead to plans that are more sensitive to geometrical uncertainties. The purpose of this work is to assess the use of maximum intensity limits in inverse IMRT planning as a simple way to increase delivery efficiency without significantly affecting plan quality. Nine clinical cases (three each for brain, prostate, and head/neck) were used to evaluate advantages and disadvantages of limiting maximum intensity to increase delivery efficiency. IMRT plans were generated using in-house protocol-based constraints and objectives for the brain and head/neck, and RTOG 9406 dose volume objectives in the prostate. Each case was optimized at a series of maximum intensity ratios (the product of the maximum intensity and the number of beams divided by the prescribed dose to the target volume), and evaluated in terms of clinical metrics, dose-volume histograms, monitor units (MU) required per fraction (SMLC and DMLC delivery), and intensity map variation (a measure of the beam modulation). In each site tested, it was possible to reduce total monitor units by constraining the maximum allowed intensity without compromising the clinical acceptability of the plan. Monitor unit reductions up to 38% were observed for SMLC delivery, while reductions up to 29% were achieved for DMLC delivery. In general, complicated geometries saw a smaller reduction in monitor units for both delivery types, although DMLC delivery required significantly more monitor units in all cases. Constraining the maximum intensity in an inverse IMRT plan is a simple way to improve delivery efficiency without compromising plan objectives.

Convex reformulation of biologically-based multi-criteria intensity-modulated radiation therapy optimization including fractionation effects

NASA Astrophysics Data System (ADS)

Hoffmann, Aswin L.; den Hertog, Dick; Siem, Alex Y. D.; Kaanders, Johannes H. A. M.; Huizenga, Henk

2008-11-01

Finding fluence maps for intensity-modulated radiation therapy (IMRT) can be formulated as a multi-criteria optimization problem for which Pareto optimal treatment plans exist. To account for the dose-per-fraction effect of fractionated IMRT, it is desirable to exploit radiobiological treatment plan evaluation criteria based on the linear-quadratic (LQ) cell survival model as a means to balance the radiation benefits and risks in terms of biologic response. Unfortunately, the LQ-model-based radiobiological criteria are nonconvex functions, which make the optimization problem hard to solve. We apply the framework proposed by Romeijn et al (2004 Phys. Med. Biol. 49 1991-2013) to find transformations of LQ-model-based radiobiological functions and establish conditions under which transformed functions result in equivalent convex criteria that do not change the set of Pareto optimal treatment plans. The functions analysed are: the LQ-Poisson-based model for tumour control probability (TCP) with and without inter-patient heterogeneity in radiation sensitivity, the LQ-Poisson-based relative seriality s-model for normal tissue complication probability (NTCP), the equivalent uniform dose (EUD) under the LQ-Poisson model and the fractionation-corrected Probit-based model for NTCP according to Lyman, Kutcher and Burman. These functions differ from those analysed before in that they cannot be decomposed into elementary EUD or generalized-EUD functions. In addition, we show that applying increasing and concave transformations to the convexified functions is beneficial for the piecewise approximation of the Pareto efficient frontier.

Modern bioanalysis of proteins by electrophoretic techniques.

PubMed

Krizkova, Sona; Ryvolova, Marketa; Masarik, Michal; Zitka, Ondrej; Adam, Vojtech; Hubalek, Jaromir; Eckschlager, Tomas; Kizek, Rene

2014-01-01

In 1957, protein rich in cysteine able to bind cadmium was isolated from horse kidney and named as metallothionein according to its structural properties. Further, this protein and metallothionein-like proteins have been found in tissues of other animal species, yeasts, fungi and plants. MT is as a potential cancer marker in the focus of interest, and its properties, functions, and behavior under various conditions are intensively studied. Our protocol describes separation of two major mammalian isoforms of MT (MT-1 and MT-2) using capillary electrophoresis (CE) coupled with UV detector. This protocol enables separation of MT isoforms and studying of their basic behavior as well as their quantification with detection limit in units of ng per μL. Sodium borate buffer (20 mM, pH 9.5) was optimized as a background electrolyte, and the separation was carried out in fused silica capillary with internal diameter of 75 μm and electric field intensity of 350 V/cm. Optimal detection wavelength was 254 nm.

[DETERMINATION OF THE OPTIMAL SAFE MODE OF PHYSICAL ACTIVITY FOR THE MILITARY SERVANTS UNDER CONDITIONS CLOSE TO FIGHTING].

PubMed

Chernozub, A; Radchenko, Y

2015-01-01

The paper presents the results of research, allowing to establish the need for and feasibility of an integrated method to determine the most effective but at the same time safe modes of load to the body troops. We found that despite the rather promising application of our proposed mode of load of high intensity (Ra = 0.71) to increase the level of physical military training as soon as possible in time of peace (with a minimum set of combat equipment), problematic issue is that in most cases there is a complete-mismatch achieved in the degree of physical development of the body of military requirements and the challenges posed in terms of direct hostilities. Using the integral method developed by us we determine the safest modes of exercise for the military servants to optimize the most appropriate parameters of volume and intensity of the load, and speed up the adaptive changes in their body to enhance maximum performance at this stage of preparation.

Optimized co-production of lipids and carotenoids from Ettlia sp. by regulating stress conditions.

PubMed

Lee, Nakyeong; Ko, So-Ra; Ahn, Chi-Yong; Oh, Hee-Mock

2018-06-01

This study used a single strain Ettlia sp. YC001 and two stages to optimize the production of three materials: lipids, lutein, and β-carotene. In the cultivation stage for lutein production, different temperatures, light qualities, and intensities were applied. The highest biomass was obtained at 35 °C, but the maximum lutein productivity of 6.1 mg/L/d achieved at 25 °C. In the stress stage for lipids and β-carotene production, UV-A and nitrogen starvation were applied. While UV stress increased the chlorophyll-a and β-carotene content. The β-carotene, oleic acid, and lipids significantly increased under nitrogen starvation with a high light intensity of 1200 µmol/m 2 /s, plus the Ettlia sp. changed from green to red. The results showed that Ettlia sp. can be an effective microalga for the co-production of lutein, β-carotene, and biodiesel. Copyright © 2018 Elsevier Ltd. All rights reserved.

Optimization and Calculation of Probability Performances of Processes of Storage and Processing of Refrigerator Containerized Cargoes

NASA Astrophysics Data System (ADS)

Nyrkov, A. P.; Sokolov, S. S.; Chernyi, S. G.; Shnurenko, A. A.; Pavlova, L. A.

2016-08-01

In the work the queueing system of the disconnected multi-channel type to which irregular, uniform or not uniform flows of requests with a unlimited latency period arrive is considered. The system is considered on an example of the container terminal having conditional-functional sections with a definite mark-to-space ratio on which the irregular inhomogeneous traffic flow with resultant intensity acts.

Flow injection chemiluminescence determination of loxoprofen and naproxen with the acidic permanganate-sulfite system.

PubMed

Wang, Li-Juan; Tang, Yu-Hai; Liu, Yang-Hao

2011-02-01

A novel flow injection chemiluminescence (CL) method for the determination of loxoprofen and naproxen was proposed based on the CL system of KMnO 4 , and Na 2 SO 3 in acid media. The CL intensity of KMnO 4 -Na 2 SO 3 was greatly enhaneed in the presence of loxoprofen and naproxen. The mechanism of the CL reaction was studied by the kinetic proecss and UV-vis absorption and the conditions were optimized. Under optimized conditions, the CL intensity was linear with loxoprofen and naproxen concentration in the range of 7.0 × 10 -8 - 1.0 × 10 -5 g/mL and 2.0 × 10 -7 - 4.0 × 10 -6 g/mL with the detection limit of 2.0 × 10 -8 g/mL and 3.0 × 10 -8 g/mL (S/N = 3), respectively. Thc relative standard deviations were 2.39% and 1.37% for 5.0 × 10 -7 g/mL naproxen and 5.0 × 10 -7 g/mL loxoprofen ( n = 10), respectively. The proposed method was satisfactorily applied to thc determination of loxoprofen and naproxen in pharmaceutical preparations.

Including robustness in multi-criteria optimization for intensity-modulated proton therapy

NASA Astrophysics Data System (ADS)

Chen, Wei; Unkelbach, Jan; Trofimov, Alexei; Madden, Thomas; Kooy, Hanne; Bortfeld, Thomas; Craft, David

2012-02-01

We present a method to include robustness in a multi-criteria optimization (MCO) framework for intensity-modulated proton therapy (IMPT). The approach allows one to simultaneously explore the trade-off between different objectives as well as the trade-off between robustness and nominal plan quality. In MCO, a database of plans each emphasizing different treatment planning objectives, is pre-computed to approximate the Pareto surface. An IMPT treatment plan that strikes the best balance between the different objectives can be selected by navigating on the Pareto surface. In our approach, robustness is integrated into MCO by adding robustified objectives and constraints to the MCO problem. Uncertainties (or errors) of the robust problem are modeled by pre-calculated dose-influence matrices for a nominal scenario and a number of pre-defined error scenarios (shifted patient positions, proton beam undershoot and overshoot). Objectives and constraints can be defined for the nominal scenario, thus characterizing nominal plan quality. A robustified objective represents the worst objective function value that can be realized for any of the error scenarios and thus provides a measure of plan robustness. The optimization method is based on a linear projection solver and is capable of handling large problem sizes resulting from a fine dose grid resolution, many scenarios, and a large number of proton pencil beams. A base-of-skull case is used to demonstrate the robust optimization method. It is demonstrated that the robust optimization method reduces the sensitivity of the treatment plan to setup and range errors to a degree that is not achieved by a safety margin approach. A chordoma case is analyzed in more detail to demonstrate the involved trade-offs between target underdose and brainstem sparing as well as robustness and nominal plan quality. The latter illustrates the advantage of MCO in the context of robust planning. For all cases examined, the robust optimization for each Pareto optimal plan takes less than 5 min on a standard computer, making a computationally friendly interface possible to the planner. In conclusion, the uncertainty pertinent to the IMPT procedure can be reduced during treatment planning by optimizing plans that emphasize different treatment objectives, including robustness, and then interactively seeking for a most-preferred one from the solution Pareto surface.

Plasmonic platforms of self-assembled silver nanostructures in application to fluorescence

PubMed Central

Luchowski, Rafal; Calander, Nils; Shtoyko, Tanya; Apicella, Elisa; Borejdo, Julian; Gryczynski, Zygmunt; Gryczynski, Ignacy

2011-01-01

Fluorescence intensity changes were investigated theoretically and experimentally using self-assembled colloidal structures on silver semitransparent mirrors. Using a simplified quasi-static model and finite element method, we demonstrate that near-field interactions of metallic nanostructures with a continuous metallic surface create conditions that produce enormously enhanced surface plasmon resonances. The results were used to explain the observed enhancements and determine the optimal conditions for the experiment. The theoretical parts of the studies are supported with reports on detailed emission intensity changes which provided multiple fluorescence hot spots with 2–3 orders of enhancements. We study two kinds of the fluorophores: dye molecules and fluorescent nanospheres characterized with similar spectral emission regions. Using a lifetime-resolved fluorescence/reflection confocal microscopy technique, we find that the largest rate for enhancement (~1000-fold) comes from localized areas of silver nanostructures. PMID:21403765

Resonance light scattering technique for the determination of proteins with polymethacrylic acid (PMAA)

NASA Astrophysics Data System (ADS)

Chen, Yanhua; Gao, Dejiang; Tian, Yuan; Ai, Peng; Zhang, Hanqi; Yu, Aimin

2007-07-01

As a resonance light scattering (RLS) probe, the polyelectrolyte polymethacrylic acid (PMAA) was applied in this assay. The bovine serum albumin (BSA) and human serum albumin (HSA) were determined by the electrostatic interaction of PMAA and proteins. At pH 3.8 Na 2HPO 4-citric acid buffer solution, the RLS intensities of PMAA-BSA (HSA) system were greatly enhanced. The characteristic peaks were appeared at the wavelength 320, 546 and 594 nm. The optimization conditions of the reaction were also examined and selected. Under the selected conditions, the RLS intensities were proportional to the protein concentrations in the range of (0.0200-2.00) × 10 -6 mol/L for BSA and (0.0200-2.40) × 10 -6 mol/L for HSA. The influences of some foreign substances were also examined. The synthetic samples containing proteins and some real samples were analyzed and the results obtained were satisfactory.

Resonance light scattering technique for the determination of proteins with polymethacrylic acid (PMAA).

PubMed

Chen, Yanhua; Gao, Dejiang; Tian, Yuan; Ai, Peng; Zhang, Hanqi; Yu, Aimin

2007-07-01

As a resonance light scattering (RLS) probe, the polyelectrolyte polymethacrylic acid (PMAA) was applied in this assay. The bovine serum albumin (BSA) and human serum albumin (HSA) were determined by the electrostatic interaction of PMAA and proteins. At pH 3.8 Na(2)HPO(4)-citric acid buffer solution, the RLS intensities of PMAA-BSA (HSA) system were greatly enhanced. The characteristic peaks were appeared at the wavelength 320, 546 and 594 nm. The optimization conditions of the reaction were also examined and selected. Under the selected conditions, the RLS intensities were proportional to the protein concentrations in the range of (0.0200-2.00) x 10(-6) mol/L for BSA and (0.0200-2.40) x 10(-6) mol/L for HSA. The influences of some foreign substances were also examined. The synthetic samples containing proteins and some real samples were analyzed and the results obtained were satisfactory.

Droplet microfluidics for synthetic biology

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

Gach, Philip Charles; Iwai, Kosuke; Kim, Peter Wonhee

Here, synthetic biology is an interdisciplinary field that aims to engineer biological systems for useful purposes. Organism engineering often requires the optimization of individual genes and/or entire biological pathways (consisting of multiple genes). Advances in DNA sequencing and synthesis have recently begun to enable the possibility of evaluating thousands of gene variants and hundreds of thousands of gene combinations. However, such large-scale optimization experiments remain cost-prohibitive to researchers following traditional molecular biology practices, which are frequently labor-intensive and suffer from poor reproducibility. Liquid handling robotics may reduce labor and improve reproducibility, but are themselves expensive and thus inaccessible to mostmore » researchers. Microfluidic platforms offer a lower entry price point alternative to robotics, and maintain high throughput and reproducibility while further reducing operating costs through diminished reagent volume requirements. Droplet microfluidics have shown exceptional promise for synthetic biology experiments, including DNA assembly, transformation/transfection, culturing, cell sorting, phenotypic assays, artificial cells and genetic circuits.« less

Droplet microfluidics for synthetic biology

DOE PAGES

Gach, Philip Charles; Iwai, Kosuke; Kim, Peter Wonhee; ...

2017-08-10

Here, synthetic biology is an interdisciplinary field that aims to engineer biological systems for useful purposes. Organism engineering often requires the optimization of individual genes and/or entire biological pathways (consisting of multiple genes). Advances in DNA sequencing and synthesis have recently begun to enable the possibility of evaluating thousands of gene variants and hundreds of thousands of gene combinations. However, such large-scale optimization experiments remain cost-prohibitive to researchers following traditional molecular biology practices, which are frequently labor-intensive and suffer from poor reproducibility. Liquid handling robotics may reduce labor and improve reproducibility, but are themselves expensive and thus inaccessible to mostmore » researchers. Microfluidic platforms offer a lower entry price point alternative to robotics, and maintain high throughput and reproducibility while further reducing operating costs through diminished reagent volume requirements. Droplet microfluidics have shown exceptional promise for synthetic biology experiments, including DNA assembly, transformation/transfection, culturing, cell sorting, phenotypic assays, artificial cells and genetic circuits.« less

Quantification of calcium using localized normalization on laser-induced breakdown spectroscopy data

NASA Astrophysics Data System (ADS)

Sabri, Nursalwanie Mohd; Haider, Zuhaib; Tufail, Kashif; Aziz, Safwan; Ali, Jalil; Wahab, Zaidan Abdul; Abbas, Zulkifly

2017-03-01

This paper focuses on localized normalization for improved calibration curves in laser-induced breakdown spectroscopy (LIBS) measurements. The calibration curves have been obtained using five samples consisting of different concentrations of calcium (Ca) in potassium bromide (KBr) matrix. The work has utilized Q-switched Nd:YAG laser installed in LIBS2500plus system with fundamental wavelength and laser energy of 650 mJ. Optimization of gate delay can be obtained from signal-to-background ratio (SBR) of Ca II 315.9 and 317.9 nm. The optimum conditions are determined in which having high spectral intensity and SBR. The highest spectral lines of ionic and emission lines of Ca at gate delay of 0.83 µs. From SBR, the optimized gate delay is at 5.42 µs for both Ca II spectral lines. Calibration curves consist of three parts; original intensity from LIBS experimentation, normalization and localized normalization of the spectral line intensity. The R2 values of the calibration curves plotted using locally normalized intensities of Ca I 610.3, 612.2 and 616.2 nm spectral lines are 0.96329, 0.97042, and 0.96131, respectively. The enhancement from calibration curves using the regression coefficient allows more accurate analysis in LIBS. At the request of all authors of the paper, and with the agreement of the Proceedings Editor, an updated version of this article was published on 24 May 2017.

Galerkin v. discrete-optimal projection in nonlinear model reduction

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

Carlberg, Kevin Thomas; Barone, Matthew Franklin; Antil, Harbir

Discrete-optimal model-reduction techniques such as the Gauss{Newton with Approximated Tensors (GNAT) method have shown promise, as they have generated stable, accurate solutions for large-scale turbulent, compressible ow problems where standard Galerkin techniques have failed. However, there has been limited comparative analysis of the two approaches. This is due in part to difficulties arising from the fact that Galerkin techniques perform projection at the time-continuous level, while discrete-optimal techniques do so at the time-discrete level. This work provides a detailed theoretical and experimental comparison of the two techniques for two common classes of time integrators: linear multistep schemes and Runge{Kutta schemes.more » We present a number of new ndings, including conditions under which the discrete-optimal ROM has a time-continuous representation, conditions under which the two techniques are equivalent, and time-discrete error bounds for the two approaches. Perhaps most surprisingly, we demonstrate both theoretically and experimentally that decreasing the time step does not necessarily decrease the error for the discrete-optimal ROM; instead, the time step should be `matched' to the spectral content of the reduced basis. In numerical experiments carried out on a turbulent compressible- ow problem with over one million unknowns, we show that increasing the time step to an intermediate value decreases both the error and the simulation time of the discrete-optimal reduced-order model by an order of magnitude.« less

Long-term lifestyle intervention with optimized high-intensity interval training improves body composition, cardiometabolic risk, and exercise parameters in patients with abdominal obesity.

PubMed

Gremeaux, Vincent; Drigny, Joffrey; Nigam, Anil; Juneau, Martin; Guilbeault, Valérie; Latour, Elise; Gayda, Mathieu

2012-11-01

The aim of this study was to study the impact of a combined long-term lifestyle and high-intensity interval training intervention on body composition, cardiometabolic risk, and exercise tolerance in overweight and obese subjects. Sixty-two overweight and obese subjects (53.3 ± 9.7 yrs; mean body mass index, 35.8 ± 5 kg/m(2)) were retrospectively identified at their entry into a 9-mo program consisting of individualized nutritional counselling, optimized high-intensity interval exercise, and resistance training two to three times a week. Anthropometric measurements, cardiometabolic risk factors, and exercise tolerance were measured at baseline and program completion. Adherence rate was 97%, and no adverse events occurred with high-intensity interval exercise training. Exercise training was associated with a weekly energy expenditure of 1582 ± 284 kcal. Clinically and statistically significant improvements were observed for body mass (-5.3 ± 5.2 kg), body mass index (-1.9 ± 1.9 kg/m(2)), waist circumference (-5.8 ± 5.4 cm), and maximal exercise capacity (+1.26 ± 0.84 metabolic equivalents) (P < 0.0001 for all parameters). Total fat mass and trunk fat mass, lipid profile, and triglyceride/high-density lipoprotein ratio were also significantly improved (P < 0.0001). At program completion, the prevalence of metabolic syndrome was reduced by 32.5% (P < 0.05). Independent predictors of being a responder to body mass and waist circumference loss were baseline body mass index and resting metabolic rate; those for body mass index decrease were baseline waist circumference and triglyceride/high-density lipoprotein cholesterol ratio. A long-term lifestyle intervention with optimized high-intensity interval exercise improves body composition, cardiometabolic risk, and exercise tolerance in obese subjects. This intervention seems safe, efficient, and well tolerated and could improve adherence to exercise training in this population.

Optimization of the Upper Surface of Hypersonic Vehicle Based on CFD Analysis

NASA Astrophysics Data System (ADS)

Gao, T. Y.; Cui, K.; Hu, S. C.; Wang, X. P.; Yang, G. W.

2011-09-01

For the hypersonic vehicle, the aerodynamic performance becomes more intensive. Therefore, it is a significant event to optimize the shape of the hypersonic vehicle to achieve the project demands. It is a key technology to promote the performance of the hypersonic vehicle with the method of shape optimization. Based on the existing vehicle, the optimization to the upper surface of the Simplified hypersonic vehicle was done to obtain a shape which suits the project demand. At the cruising condition, the upper surface was parameterized with the B-Spline curve method. The incremental parametric method and the reconstruction technology of the local mesh were applied here. The whole flow field was been calculated and the aerodynamic performance of the craft were obtained by the computational fluid dynamic (CFD) technology. Then the vehicle shape was optimized to achieve the maximum lift-drag ratio at attack angle 3°, 4° and 5°. The results will provide the reference for the practical design.

Elucidating the Mechanism of p27 Inactivation by the Bcr-Abl Tyrosine Kinase

DTIC Science & Technology

2005-10-01

Grants 2002- Leukemia Research Fund Membership in Scientific Committees 2000- Molecular diagnostics (German competence network acute...transplantation, including reduced intensity conditioning. Hematological Diagnostics Standard morphology. Supervised molecular diagnostics in the

The Advantages of Collimator Optimization for Intensity Modulated Radiation Therapy

NASA Astrophysics Data System (ADS)

Doozan, Brian

The goal of this study was to improve dosimetry for pelvic, lung, head and neck, and other cancers sites with aspherical planning target volumes (PTV) using a new algorithm for collimator optimization for intensity modulated radiation therapy (IMRT) that minimizes the x-jaw gap (CAX) and the area of the jaws (CAA) for each treatment field. A retroactive study on the effects of collimator optimization of 20 patients was performed by comparing metric results for new collimator optimization techniques in Eclipse version 11.0. Keeping all other parameters equal, multiple plans are created using four collimator techniques: CA 0, all fields have collimators set to 0°, CAE, using the Eclipse collimator optimization, CAA, minimizing the area of the jaws around the PTV, and CAX, minimizing the x-jaw gap. The minimum area and the minimum x-jaw angles are found by evaluating each field beam's eye view of the PTV with ImageJ and finding the desired parameters with a custom script. The evaluation of the plans included the monitor units (MU), the maximum dose of the plan, the maximum dose to organs at risk (OAR), the conformity index (CI) and the number of fields that are calculated to split. Compared to the CA0 plans, the monitor units decreased on average by 6% for the CAX method with a p-value of 0.01 from an ANOVA test. The average maximum dose remained within 1.1% difference between all four methods with the lowest given by CAX. The maximum dose to the most at risk organ was best spared by the CAA method, which decreased by 0.62% compared to the CA0. Minimizing the x-jaws significantly reduced the number of split fields from 61 to 37. In every metric tested the CAX optimization produced comparable or superior results compared to the other three techniques. For aspherical PTVs, CAX on average reduced the number of split fields, lowered the maximum dose, minimized the dose to the surrounding OAR, and decreased the monitor units. This is achieved while maintaining the same control of the PTV.

Optimal control of vancomycin-resistant enterococci using preventive care and treatment of infections.

PubMed

Lowden, Jonathan; Miller Neilan, Rachael; Yahdi, Mohammed

2014-03-01

The rising prevalence of vancomycin-resistant enterococci (VRE) is a major health problem in intensive care units (ICU) because of its association with increased mortality and high health care costs. We present a mathematical framework for determining cost-effective strategies for prevention and treatment of VRE in the ICU. A system of five ordinary differential equations describes the movement of ICU patients in and out of five VRE-related states. Two control variables representing the prevention and treatment of VRE are incorporated into the system. The basic reproductive number is derived and calculated for different levels of the two controls. An optimal control problem is formulated to minimize VRE-related deaths and costs associated with prevention and treatment controls over a finite time period. Numerical solutions illustrate optimal single and dual allocations of the controls for various cost values. Results show that preventive care has the greatest impact in reducing the basic reproductive number, while treatment of VRE infections has the most impact on reducing VRE-related deaths. Copyright © 2014 Elsevier Inc. All rights reserved.

Local sharpening and subspace wavefront correction with predictive dynamic digital holography

NASA Astrophysics Data System (ADS)

Sulaiman, Sennan; Gibson, Steve

2017-09-01

Digital holography holds several advantages over conventional imaging and wavefront sensing, chief among these being significantly fewer and simpler optical components and the retrieval of complex field. Consequently, many imaging and sensing applications including microscopy and optical tweezing have turned to using digital holography. A significant obstacle for digital holography in real-time applications, such as wavefront sensing for high energy laser systems and high speed imaging for target racking, is the fact that digital holography is computationally intensive; it requires iterative virtual wavefront propagation and hill-climbing to optimize some sharpness criteria. It has been shown recently that minimum-variance wavefront prediction can be integrated with digital holography and image sharpening to reduce significantly large number of costly sharpening iterations required to achieve near-optimal wavefront correction. This paper demonstrates further gains in computational efficiency with localized sharpening in conjunction with predictive dynamic digital holography for real-time applications. The method optimizes sharpness of local regions in a detector plane by parallel independent wavefront correction on reduced-dimension subspaces of the complex field in a spectral plane.

Linear energy transfer incorporated intensity modulated proton therapy optimization

NASA Astrophysics Data System (ADS)

Cao, Wenhua; Khabazian, Azin; Yepes, Pablo P.; Lim, Gino; Poenisch, Falk; Grosshans, David R.; Mohan, Radhe

2018-01-01

The purpose of this study was to investigate the feasibility of incorporating linear energy transfer (LET) into the optimization of intensity modulated proton therapy (IMPT) plans. Because increased LET correlates with increased biological effectiveness of protons, high LETs in target volumes and low LETs in critical structures and normal tissues are preferred in an IMPT plan. However, if not explicitly incorporated into the optimization criteria, different IMPT plans may yield similar physical dose distributions but greatly different LET, specifically dose-averaged LET, distributions. Conventionally, the IMPT optimization criteria (or cost function) only includes dose-based objectives in which the relative biological effectiveness (RBE) is assumed to have a constant value of 1.1. In this study, we added LET-based objectives for maximizing LET in target volumes and minimizing LET in critical structures and normal tissues. Due to the fractional programming nature of the resulting model, we used a variable reformulation approach so that the optimization process is computationally equivalent to conventional IMPT optimization. In this study, five brain tumor patients who had been treated with proton therapy at our institution were selected. Two plans were created for each patient based on the proposed LET-incorporated optimization (LETOpt) and the conventional dose-based optimization (DoseOpt). The optimized plans were compared in terms of both dose (assuming a constant RBE of 1.1 as adopted in clinical practice) and LET. Both optimization approaches were able to generate comparable dose distributions. The LET-incorporated optimization achieved not only pronounced reduction of LET values in critical organs, such as brainstem and optic chiasm, but also increased LET in target volumes, compared to the conventional dose-based optimization. However, on occasion, there was a need to tradeoff the acceptability of dose and LET distributions. Our conclusion is that the inclusion of LET-dependent criteria in the IMPT optimization could lead to similar dose distributions as the conventional optimization but superior LET distributions in target volumes and normal tissues. This may have substantial advantages in improving tumor control and reducing normal tissue toxicities.

Box-Behnken statistical design to optimize thermal performance of energy storage systems

NASA Astrophysics Data System (ADS)

Jalalian, Iman Joz; Mohammadiun, Mohammad; Moqadam, Hamid Hashemi; Mohammadiun, Hamid

2018-05-01

Latent heat thermal storage (LHTS) is a technology that can help to reduce energy consumption for cooling applications, where the cold is stored in phase change materials (PCMs). In the present study a comprehensive theoretical and experimental investigation is performed on a LHTES system containing RT25 as phase change material (PCM). Process optimization of the experimental conditions (inlet air temperature and velocity and number of slabs) was carried out by means of Box-Behnken design (BBD) of Response surface methodology (RSM). Two parameters (cooling time and COP value) were chosen to be the responses. Both of the responses were significantly influenced by combined effect of inlet air temperature with velocity and number of slabs. Simultaneous optimization was performed on the basis of the desirability function to determine the optimal conditions for the cooling time and COP value. Maximum cooling time (186 min) and COP value (6.04) were found at optimum process conditions i.e. inlet temperature of (32.5), air velocity of (1.98) and slab number of (7).

Wear resistance and mechanisms of composite hardfacings at abrasive impact erosion wear

NASA Astrophysics Data System (ADS)

Surzhenkov, A.; Viljus, M.; Simson, T.; Tarbe, R.; Saarna, M.; Casesnoves, F.

2017-05-01

Tungsten carbide based hardmetal containing sprayed and melted composite hardfacings are prospective for protection against abrasive wear. For selection of abrasive wear resistant hardfacings under intensive impact wear conditions, both mechanical properties (hardness, fracture toughness, etc.) and abrasive wear conditions (type of abrasive, impact velocity, etc.) should be considered. This study focuses on the wear (wear rate and mechanisms) of thick metal-matrix composite hardfacings with hardmetal (WC-Co) reinforcement produced by powder metallurgy technology. The influence of the hardmetal reinforcement type on the wear resistance at different abrasive impact erosion wear (AIEW) conditions was studied. An optimal reinforcement for various wear conditions is described. Based on wear mechanism studies, a mathematical model for wear prediction was drafted.

Synergistic effects of seasonal rainfall, parasites and demography on fluctuations in springbok body condition

PubMed Central

Turner, Wendy C.; Versfeld, Wilferd D.; Kilian, J. Werner; Getz, Wayne M.

2011-01-01

Summary 1. Seasonality of rainfall can exert a strong influence on animal condition and on host-parasite interactions. The body condition of ruminants fluctuates seasonally in response to changes in energy requirements, foraging patterns and resource availability, and seasonal variation in parasite infections may further alter ruminant body condition. 2. This study disentangles effects of rainfall and gastrointestinal parasite infections on springbok (Antidorcas marsupialis) body condition and determines how these factors vary among demographic groups. 3. Using data from four years and three study areas, we investigated i) the influence of rainfall variation, demographic factors and parasite interactions on parasite prevalence or infection intensity, ii) whether parasitism or rainfall is a more important predictor of springbok body condition and iii) how parasitism and condition vary among study areas along a rainfall gradient. 4. We found that increased parasite intensity is associated with reduced body condition only for adult females. For all other demographic groups, body condition was significantly related to prior rainfall and not to parasitism. Rainfall lagged by two months had a positive effect on body condition. 5. Adult females showed evidence of a “periparturient rise” in parasite intensity, and had higher parasite intensity and lower body condition than adult males after parturition and during early lactation. After juveniles were weaned, adult females had lower parasite intensity than adult males. Sex differences in parasitism and condition may be due to differences between adult females and males in the seasonal timing of reproductive effort and its effects on host immunity, as well as documented sex differences in vulnerability to predation. 6. Our results highlight that parasites and the environment can synergistically affect host populations, but that these interactions might be masked by their interwoven relationships, their differential impacts on demographic groups, and the different time scales at which they operate. PMID:21831195

Infectious Complications in Children With Acute Myeloid Leukemia and Down Syndrome: Analysis of the Prospective Multicenter Trial AML-BFM 2004.

PubMed

Hassler, Angela; Bochennek, Konrad; Gilfert, Julia; Perner, Corinna; Schöning, Stefan; Creutzig, Ursula; Reinhardt, Dirk; Lehrnbecher, Thomas

2016-06-01

Children with acute myeloid leukemia (AML) and Down syndrome have high survival rates with intensity-reduced chemotherapeutic regimens, although the optimal balance between dose intensity and treatment toxicity has not been determined. We, therefore, characterized infectious complications in children with AML and Down syndrome treated according to AML-BFM 2004 study (ClinicalTrials.gov NCT00111345; amended 2006 for Down syndrome with reduced intensity). Data on infectious complications were gathered from the medical records in the hospital where the patient was treated. Infectious complications were categorized as fever without identifiable source (FUO), or as microbiologically or clinically documented infections. A total of 157 infections occurred in 61 patients (60.5% FUO, 9.6% and 29.9% clinically and microbiologically documented infections, respectively). Almost 90% of the pathogens isolated from the bloodstream were Gram-positive bacteria, and approximately half of them were viridans group streptococci. All seven microbiologically documented episodes of pneumonia were caused by viruses. Infection-related mortality was 4.9%, and all three patients died due to viral infection. Our data demonstrate that a reduced-intensity chemotherapeutic regimen in children with AML and Down syndrome is still associated with high morbidity. Although no patient died due to bacteria or fungi, viruses were responsible for all lethal events. Future studies, therefore, have to focus on the impact of viruses on morbidity and mortality of patients with AML and Down syndrome. © 2016 Wiley Periodicals, Inc.

Acute post-exercise energy and macronutrient intake in lean and obese youth: a systematic review and meta-analysis.

PubMed

Thivel, D; Rumbold, P L; King, N A; Pereira, B; Blundell, J E; Mathieu, M-E

2016-10-01

This review aims to determine if acute exercise affects subsequent energy and macronutrients intake in obese and non-obese children and adolescents. Databases were searched between January 2015 and December 2015 for studies reporting energy and/or macronutrients intake immediately after an acute exercise and control condition, in children and adolescents. From the initial 118 references found, 14 were included for subsequent analysis after screening representing 31 acute exercise conditions that varied in intensity, duration and modality. One study found increased energy intake after exercise, seven decreased and 23 revealed no change. The meta-analysis revealed a significant effect of acute exercise on intake in obese but not in lean youth by a mean difference of -0.430 (95% confidence interval=-0.703 to -0.157, P=0.002) displaying low heterogeneity (I 2 =0.000; Q=5.875; d f =9, P=0.752). The analysis showed that intense exercise only reduces intake in obese children (no intensity effect in lean). Unchanged macronutrients intake was reported in nine studies as opposed to three which found modified lipids, protein and/or carbohydrate intake. Although acute exercise does not affect energy intake in lean, it appears to reduced food intake in obese youth when intense, without altering the macronutrients composition of the meal.

Dynamic modeling of green algae cultivation in a photobioreactor for sustainable biodiesel production.

PubMed

Del Rio-Chanona, Ehecatl A; Liu, Jiao; Wagner, Jonathan L; Zhang, Dongda; Meng, Yingying; Xue, Song; Shah, Nilay

2018-02-01

Biodiesel produced from microalgae has been extensively studied due to its potentially outstanding advantages over traditional transportation fuels. In order to facilitate its industrialization and improve the process profitability, it is vital to construct highly accurate models capable of predicting the complex behavior of the investigated biosystem for process optimization and control, which forms the current research goal. Three original contributions are described in this paper. Firstly, a dynamic model is constructed to simulate the complicated effect of light intensity, nutrient supply and light attenuation on both biomass growth and biolipid production. Secondly, chlorophyll fluorescence, an instantly measurable variable and indicator of photosynthetic activity, is embedded into the model to monitor and update model accuracy especially for the purpose of future process optimal control, and its correlation between intracellular nitrogen content is quantified, which to the best of our knowledge has never been addressed so far. Thirdly, a thorough experimental verification is conducted under different scenarios including both continuous illumination and light/dark cycle conditions to testify the model predictive capability particularly for long-term operation, and it is concluded that the current model is characterized by a high level of predictive capability. Based on the model, the optimal light intensity for algal biomass growth and lipid synthesis is estimated. This work, therefore, paves the way to forward future process design and real-time optimization. © 2017 Wiley Periodicals, Inc.

Optimizing the triple-axis spectrometer PANDA at the MLZ for small samples and complex sample environment conditions

NASA Astrophysics Data System (ADS)

Utschick, C.; Skoulatos, M.; Schneidewind, A.; Böni, P.

2016-11-01

The cold-neutron triple-axis spectrometer PANDA at the neutron source FRM II has been serving an international user community studying condensed matter physics problems. We report on a new setup, improving the signal-to-noise ratio for small samples and pressure cell setups. Analytical and numerical Monte Carlo methods are used for the optimization of elliptic and parabolic focusing guides. They are placed between the monochromator and sample positions, and the flux at the sample is compared to the one achieved by standard monochromator focusing techniques. A 25 times smaller spot size is achieved, associated with a factor of 2 increased intensity, within the same divergence limits, ± 2 ° . This optional neutron focusing guide shall establish a top-class spectrometer for studying novel exotic properties of matter in combination with more stringent sample environment conditions such as extreme pressures associated with small sample sizes.

Effects of plant size, temperature, and light intensity on flowering of Phalaenopsis hybrids in Mediterranean greenhouses.

PubMed

Paradiso, Roberta; De Pascale, Stefania

2014-01-01

Mediterranean greenhouses for cultivation of Phalaenopsis orchids reproduce the warm, humid, and shaded environment of tropical underbrush. Heating represents the highest production cost, due to the high thermal requirements and the long unproductive phase of juvenility, in which plants attain the critical size for flowering. Our researches aimed to investigate the effect of plant size, temperature, and light intensity, during the phase of flower induction, on flowering of modern genotypes selected for Mediterranean greenhouses. Three experiments were carried out to compare (i) plant size: reduced size versus size considered optimal for flowering (hybrids "Sogo Yukidian," "Chain Xen Diamond," and "Pinlong"); (ii) temperature: moderate reduction of temperature versus standard thermal regime (hybrid "Premium"); (iii) light intensity: supplemental lighting versus reference light intensity (hybrid "Premium"). The premature exposure of plants to the inductive treatment delayed the beginning of flowering and reduced the flower stem quality, in all the tested hybrids. In "Premium," the lower temperature did not affect flowering earliness and commercial quality of flower stems compared to the standard regime, whereas it promoted stem branching. In the same hybrid, supplemental lighting anticipated flowering and promoted the emission of the second stem and the stem branching, compared to the reference light regime.

High-Speed Terahertz Waveform Measurement for Intense Terahertz Light Using 100-kHz Yb-Doped Fiber Laser.

PubMed

Tsubouchi, Masaaki; Nagashima, Keisuke

2018-06-14

We demonstrate a high-speed terahertz (THz) waveform measurement system for intense THz light with a scan rate of 100 Hz. To realize the high scan rate, a loudspeaker vibrating at 50 Hz is employed to scan the delay time between THz light and electro-optic sampling light. Because the fast scan system requires a high data sampling rate, we develop an Yb-doped fiber laser with a repetition rate of 100 kHz optimized for effective THz light generation with the output electric field of 1 kV/cm. The present system drastically reduces the measurement time of the THz waveform from several minutes to 10 ms.

[Efficacy of a rapid test to diagnose Plasmodium vivax in symptomatic patients of Chiapas, Mexico].

PubMed

González-Cerón, Lilia; Rodríguez, Mario H; Betanzos, Angel F; Abadía, Acatl

2005-01-01

To evaluate, under laboratory conditions, the sensitivity and specificity of a rapid diagnostic test (OptiMAL), based on immunoreactive strips, to detect Plasmodium vivax infection in febrile patients in Southern Chiapas, Mexico. The presence of parasites in blood samples of 893 patients was investigated by Giemsa-stained thick blood smear microscopic examination (gold standard). A blood drop from the same sample was smeared on immunoreactive strips to investigate the presence of the parasite pLDH. Discordant results were resolved by PCR amplification of the parasite's 18S SSU rRNA, to discard infection. OptiMAL had an overall sensitivity of 93.3% and its specificity was 99.5%. Its positive and negative predictive values were 96.5% and 98.9%, respectively. Signal intensity in OptiMAL strips correlated well with the parasitemia density in the blood samples (r = 0.601, p = 0.0001). This rapid test had acceptable sensitivity and specificity to detect P. vivax under laboratory conditions and could be useful for malaria diagnosis in field operations in Mexico.

Optimization of pulsed ultrasound-assisted technique for extraction of phenolics from pomegranate peel of Malas variety: Punicalagin and hydroxybenzoic acids.

PubMed

Kazemi, Milad; Karim, Roselina; Mirhosseini, Hamed; Abdul Hamid, Azizah

2016-09-01

Pomegranate peel is a rich source of phenolic compounds (such as punicalagin and hydroxybenzoic acids). However, the content of such bioactive compounds in the peel extract can be affected by extraction type and condition. It was hypothesized that the optimization of a pulsed ultrasound-assisted extraction (PUAE) technique could result in the pomegranate peel extract with higher yield and antioxidant activity. The main goal was to optimize PUAE condition resulting in the highest yield and antioxidant activity as well as the highest contents of punicalagin and hydroxybenzoic acids. The operation at the intensity level of 105W/cm(2) and duty cycle of 50% for a short time (10min) had a high efficiency for extraction of phenolics from pomegranate peel. The application of such short extraction can save the energy and cost of the production. Punicalagin and ellagic acid were the most predominant phenolic compounds quantified in the pomegranate peel extract (PPE) from Malas variety. PPE contained a minor content of gallic acid. Copyright © 2016 Elsevier Ltd. All rights reserved.

Statistical Power and Optimum Sample Allocation Ratio for Treatment and Control Having Unequal Costs Per Unit of Randomization

ERIC Educational Resources Information Center

Liu, Xiaofeng

2003-01-01

This article considers optimal sample allocation between the treatment and control condition in multilevel designs when the costs per sampling unit vary due to treatment assignment. Optimal unequal allocation may reduce the cost from that of a balanced design without sacrificing any power. The optimum sample allocation ratio depends only on the…

Geographic risk modeling of childhood cancer relative to county-level crops, hazardous air pollutants and population density characteristics in Texas.

PubMed

Thompson, James A; Carozza, Susan E; Zhu, Li

2008-09-25

Childhood cancer has been linked to a variety of environmental factors, including agricultural activities, industrial pollutants and population mixing, but etiologic studies have often been inconclusive or inconsistent when considering specific cancer types. More specific exposure assessments are needed. It would be helpful to optimize future studies to incorporate knowledge of high-risk locations or geographic risk patterns. The objective of this study was to evaluate potential geographic risk patterns in Texas accounting for the possibility that multiple cancers may have similar geographic risks patterns. A spatio-temporal risk modeling approach was used, whereby 19 childhood cancer types were modeled as potentially correlated within county-years. The standard morbidity ratios were modeled as functions of intensive crop production, intensive release of hazardous air pollutants, population density, and rapid population growth. There was supportive evidence for elevated risks for germ cell tumors and "other" gliomas in areas of intense cropping and for hepatic tumors in areas of intense release of hazardous air pollutants. The risk for Hodgkin lymphoma appeared to be reduced in areas of rapidly growing population. Elevated spatial risks included four cancer histotypes, "other" leukemias, Central Nervous System (CNS) embryonal tumors, CNS other gliomas and hepatic tumors with greater than 95% likelihood of elevated risks in at least one county. The Bayesian implementation of the Multivariate Conditional Autoregressive model provided a flexible approach to the spatial modeling of multiple childhood cancer histotypes. The current study identified geographic factors supporting more focused studies of germ cell tumors and "other" gliomas in areas of intense cropping, hepatic cancer near Hazardous Air Pollutant (HAP) release facilities and specific locations with increased risks for CNS embryonal tumors and for "other" leukemias. Further study should be performed to evaluate potentially lower risk for Hodgkin lymphoma and malignant bone tumors in counties with rapidly growing population.

Sono-synthesis of solar light responsive S-N-C-tri doped TiO2 photo-catalyst under optimized conditions for degradation and mineralization of Diclofenac.

PubMed

Ramandi, Sara; Entezari, Mohammad H; Ghows, Narjes

2017-09-01

C-N-S-tri doped TiO 2 anatase phase was synthesized using a facile, effective and novel sonochemical method at low frequency (20kHz) and at room temperature. Titanium butoxide as the titanium precursor and thiourea as the dopant source were used in the synthesis of the photo-catalyst. The effects of important parameters such as thiourea/Ti molar ratio, ultrasound intensity, sonication time and temperature were studied on the synthesis of tri-doped TiO 2 . The XPS results confirmed the presence of N, S, and C in the photo-catalyst. The photo-catalytic efficiency of the synthesized catalyst was studied toward the removal of Diclofenac as a model pharmaceutical organic pollutant. The results confirmed that the photo-catalyst synthesized with narrower band gap energy, shorter sonication time and higher ultrasound intensity leads to a rapid removal of Diclofenac. The effect of operational variables on the photo-catalytic activity of C-N-S tri doped TiO 2 nanoparticles was studied and optimized using the Taguchi method as a statistical technique. Additionally, the degradation process followed the pseudo-first-order kinetics model and the highest apparent rate constant of 0.0632min -1 achieved in 90min. Chemical oxygen demand (COD) analysis confirmed that the mineralization took place completely (100%) under the optimized conditions in 180min. Different scavengers were applied during the degradation process and active species such as OH and O 2 - had key roles in the photo-catalytic process. Copyright © 2017 Elsevier B.V. All rights reserved.

Self-balancing dynamic scheduling of electrical energy for energy-intensive enterprises

NASA Astrophysics Data System (ADS)

Gao, Yunlong; Gao, Feng; Zhai, Qiaozhu; Guan, Xiaohong

2013-06-01

Balancing production and consumption with self-generation capacity in energy-intensive enterprises has huge economic and environmental benefits. However, balancing production and consumption with self-generation capacity is a challenging task since the energy production and consumption must be balanced in real time with the criteria specified by power grid. In this article, a mathematical model for minimising the production cost with exactly realisable energy delivery schedule is formulated. And a dynamic programming (DP)-based self-balancing dynamic scheduling algorithm is developed to obtain the complete solution set for such a multiple optimal solutions problem. For each stage, a set of conditions are established to determine whether a feasible control trajectory exists. The state space under these conditions is partitioned into subsets and each subset is viewed as an aggregate state, the cost-to-go function is then expressed as a function of initial and terminal generation levels of each stage and is proved to be a staircase function with finite steps. This avoids the calculation of the cost-to-go of every state to resolve the issue of dimensionality in DP algorithm. In the backward sweep process of the algorithm, an optimal policy is determined to maximise the realisability of energy delivery schedule across the entire time horizon. And then in the forward sweep process, the feasible region of the optimal policy with the initial and terminal state at each stage is identified. Different feasible control trajectories can be identified based on the region; therefore, optimising for the feasible control trajectory is performed based on the region with economic and reliability objectives taken into account.

Design and Optimization of Composite Automotive Hatchback Using Integrated Material-Structure-Process-Performance Method

NASA Astrophysics Data System (ADS)

Yang, Xudong; Sun, Lingyu; Zhang, Cheng; Li, Lijun; Dai, Zongmiao; Xiong, Zhenkai

2018-03-01

The application of polymer composites as a substitution of metal is an effective approach to reduce vehicle weight. However, the final performance of composite structures is determined not only by the material types, structural designs and manufacturing process, but also by their mutual restrict. Hence, an integrated "material-structure-process-performance" method is proposed for the conceptual and detail design of composite components. The material selection is based on the principle of composite mechanics such as rule of mixture for laminate. The design of component geometry, dimension and stacking sequence is determined by parametric modeling and size optimization. The selection of process parameters are based on multi-physical field simulation. The stiffness and modal constraint conditions were obtained from the numerical analysis of metal benchmark under typical load conditions. The optimal design was found by multi-discipline optimization. Finally, the proposed method was validated by an application case of automotive hatchback using carbon fiber reinforced polymer. Compared with the metal benchmark, the weight of composite one reduces 38.8%, simultaneously, its torsion and bending stiffness increases 3.75% and 33.23%, respectively, and the first frequency also increases 44.78%.

Understanding space charge and controlling beam loss in high intensity synchrotrons

NASA Astrophysics Data System (ADS)

Cousineau, Sarah M.

Future high intensity synchrotrons will require unprecedented control of beam loss in order to comply with radiation safety regulations and to allow for safe, hands-on maintenance of machine hardware. A major cause of beam loss in high intensity synchrotrons is the space charge force of the beam, which can lead to beam halo and emittance dilution. This dissertation presents a comprehensive study of space charge effects in high intensity synchrotron beams. Experimental measurements taken at the Proton Storage Ring (PSR) in Los Alamos National Laboratory and detailed simulations of the experiments are used to identify and characterize resonances that affect these beams. The collective motion of the beam is extensively studied and is shown to be more relevant than the single particle dynamics in describing the resonance response. The emittance evolution of the PSR beam and methods for reducing the space-charge-induced emittance growth are addressed. In a separate study, the emittance evolution of an intense space charge beam is experimentally measured at the Cooler Injector Synchrotron (CIS) at Indiana University. This dissertation also investigates the sophisticated two-stage collimation system of the future Spallation Neutron Source (SNS) high intensity accumulator ring. A realistic Monte-Carlo collimation simulation is developed and used to optimize the SNS ring collimation system parameters. The finalized parameters and predicted beam loss distribution around the ring are presented. The collimators will additionally be used in conjunction with a set of fast kickers to remove the beam from the gap region before the rise of the extraction magnets. The gap cleaning process is optimized and the cleaning efficiency versus momentum spread of the beam is examined.

Light intensity affects the uptake and metabolism of glycine by pakchoi (Brassica chinensis L.)

NASA Astrophysics Data System (ADS)

Ma, Qingxu; Cao, Xiaochuang; Wu, Lianghuan; Mi, Wenhai; Feng, Ying

2016-02-01

The uptake of glycine by pakchoi (Brassica chinensis L.), when supplied as single N-source or in a mixture of glycine and inorganic N, was studied at different light intensities under sterile conditions. At the optimal intensity (414 μmol m-2 s-1) for plant growth, glycine, nitrate, and ammonium contributed 29.4%, 39.5%, and 31.1% shoot N, respectively, and light intensity altered the preferential absorption of N sources. The lower 15N-nitrate in root but higher in shoot and the higher 15N-glycine in root but lower in shoot suggested that most 15N-nitrate uptake by root transported to shoot rapidly, with the shoot being important for nitrate assimilation, and the N contribution of glycine was limited by post-uptake metabolism. The amount of glycine that was taken up by the plant was likely limited by root uptake at low light intensities and by the metabolism of ammonium produced by glycine at high light intensities. These results indicate that pakchoi has the ability to uptake a large quantity of glycine, but that uptake is strongly regulated by light intensity, with metabolism in the root inhibiting its N contribution.

SU-E-T-175: Clinical Evaluations of Monte Carlo-Based Inverse Treatment Plan Optimization for Intensity Modulated Radiotherapy

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

Chi, Y; Li, Y; Tian, Z

2015-06-15

Purpose: Pencil-beam or superposition-convolution type dose calculation algorithms are routinely used in inverse plan optimization for intensity modulated radiation therapy (IMRT). However, due to their limited accuracy in some challenging cases, e.g. lung, the resulting dose may lose its optimality after being recomputed using an accurate algorithm, e.g. Monte Carlo (MC). It is the objective of this study to evaluate the feasibility and advantages of a new method to include MC in the treatment planning process. Methods: We developed a scheme to iteratively perform MC-based beamlet dose calculations and plan optimization. In the MC stage, a GPU-based dose engine wasmore » used and the particle number sampled from a beamlet was proportional to its optimized fluence from the previous step. We tested this scheme in four lung cancer IMRT cases. For each case, the original plan dose, plan dose re-computed by MC, and dose optimized by our scheme were obtained. Clinically relevant dosimetric quantities in these three plans were compared. Results: Although the original plan achieved a satisfactory PDV dose coverage, after re-computing doses using MC method, it was found that the PTV D95% were reduced by 4.60%–6.67%. After re-optimizing these cases with our scheme, the PTV coverage was improved to the same level as in the original plan, while the critical OAR coverages were maintained to clinically acceptable levels. Regarding the computation time, it took on average 144 sec per case using only one GPU card, including both MC-based beamlet dose calculation and treatment plan optimization. Conclusion: The achieved dosimetric gains and high computational efficiency indicate the feasibility and advantages of the proposed MC-based IMRT optimization method. Comprehensive validations in more patient cases are in progress.« less

Exercise-induced myalgia may limit the cardiovascular benefits of statins.

PubMed

Opie, Lionel H

2013-12-01

The positive health benefits of statins extend beyond the cardiovascular and include increased flow mediated dilation, decreased atrial fibrillation, modest antihypertensive effects and reduced risks of malignancies. Prominent among the statin side-effects are myalgia and muscular weakness, which may be associated with a rise in circulating creatine kinase values. In increasing severity and decreasing incidence, the statin-induced muscle related conditions are myalgia, myopathy with elevated creatine kinase (CK) levels with or without symptoms, and rhabdomyolysis. Statin use may increase CK levels without decreasing average muscle strength or exercise performance. In one large study, only about 2 % had myalgia that could be attributed to statin use. A novel current hypothesis is that statins optimize cardiac mitochondrial function but impair the vulnerable skeletal muscle by inducing different levels of reactive oxygen species (ROS) in these two sites. In an important observational study, both statins and exercise reduced the adverse outcomes of cardiovascular disease, and the effects were additive. The major unresolved problem is that either can cause muscular symptoms with elevation of blood creatine kinase levels. There is, as yet, no clearly defined outcomes based policy to deal with such symptoms from use of either statins or exercise or both. A reasonable practical approach is to assess the creatine kinase levels, and if elevated to reduce the statin dose or the intensity of exercise.

Efficacy of tacrolimus/mycophenolate mofetil as acute graft-versus-host disease prophylaxis and the impact of subtherapeutic tacrolimus levels in children after matched sibling donor allogeneic hematopoietic cell transplantation.

PubMed

Offer, Katharine; Kolb, Michelle; Jin, Zhezhen; Bhatia, Monica; Kung, Andrew L; George, Diane; Garvin, James H; Robinson, Chalitha; Sosna, Jean; Karamehmet, Esra; Satwani, Prakash

2015-03-01

Only a few studies in children have evaluated the efficacy of prophylactic regimens using tacrolimus on acute graft-versus-host disease (aGVHD). As a result, optimal tacrolimus levels in children after matched sibling donor allogeneic hematopoietic cell transplantation (alloHCT) are not well defined. We measured the association between subtherapeutic levels (<10 ng/mL) during weeks 1 to 4 after alloHCT and the cumulative incidence of grades II to IV aGVHD in children. Additionally, we identified optimal lower cutoff levels for tacrolimus. Sixty patients (median age, 8 years) received tacrolimus/mycophenolate mofetil between March 2003 and September 2012. Twenty-three had a malignant disease and 37 nonmalignant disorders. The stem cell source included peripheral blood stem cells (n = 12) and bone marrow or cord blood (n = 48). Conditioning regimen varied. Specifically, 38.3% received a myeloablative regimen, 36.7% receiving a reduced-toxicity regimen, and 25% receiving a reduced-intensity regimen. Tacrolimus was initiated at .03 mg/kg/day via continuous i.v. infusion or .12 mg/kg/day orally. The dose was adjusted to maintain daily steady state concentrations within a range of 10 to 20 ng/mL. The overall incidence of grades II to IV aGVHD was 33.3%. On multivariate analysis, a mean tacrolimus level < 10 ng/mL during week 3 (P = .042; 95% confidence interval, 1.051 to 14.28) was significantly associated with increased incidence of grades II to IV aGVHD. Using weekly receiver operator curves, the optimal lower cutoff for tacrolimus levels was 10 to 11.2 ng/mL. Further prospective studies are warranted to study the incidence of aGVHD comparing the conventional tacrolimus levels of 5 to 15 versus 10 to 15 ng/mL. Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Reducing the metabolic cost of walking with an ankle exoskeleton: interaction between actuation timing and power.

PubMed

Galle, Samuel; Malcolm, Philippe; Collins, Steven Hartley; De Clercq, Dirk

2017-04-27

Powered ankle-foot exoskeletons can reduce the metabolic cost of human walking to below normal levels, but optimal assistance properties remain unclear. The purpose of this study was to test the effects of different assistance timing and power characteristics in an experiment with a tethered ankle-foot exoskeleton. Ten healthy female subjects walked on a treadmill with bilateral ankle-foot exoskeletons in 10 different assistance conditions. Artificial pneumatic muscles assisted plantarflexion during ankle push-off using one of four actuation onset timings (36, 42, 48 and 54% of the stride) and three power levels (average positive exoskeleton power over a stride, summed for both legs, of 0.2, 0.4 and 0.5 W∙kg -1 ). We compared metabolic rate, kinematics and electromyography (EMG) between conditions. Optimal assistance was achieved with an onset of 42% stride and average power of 0.4 W∙kg -1 , leading to 21% reduction in metabolic cost compared to walking with the exoskeleton deactivated and 12% reduction compared to normal walking without the exoskeleton. With suboptimal timing or power, the exoskeleton still reduced metabolic cost, but substantially less so. The relationship between timing, power and metabolic rate was well-characterized by a two-dimensional quadratic function. The assistive mechanisms leading to these improvements included reducing muscular activity in the ankle plantarflexors and assisting leg swing initiation. These results emphasize the importance of optimizing exoskeleton actuation properties when assisting or augmenting human locomotion. Our optimal assistance onset timing and average power levels could be used for other exoskeletons to improve assistance and resulting benefits.

Benefit of an electronic medical record-based alarm in the optimization of stress ulcer prophylaxis.

PubMed

Saad, Emanuel José; Bedini, Marianela; Becerra, Ana Florencia; Martini, Gustavo Daniel; Gonzalez, Jacqueline Griselda; Bolomo, Andrea; Castellani, Luciana; Quiroga, Silvana; Morales, Cristian; Leathers, James; Balderramo, Domingo; Albertini, Ricardo Arturo

2018-06-09

The use of stress ulcer prophylaxis (SUP) has risen in recent years, even in patients without a clear indication for therapy. To evaluate the efficacy of an electronic medical record (EMR)-based alarm to improve appropriate SUP use in hospitalized patients. We conducted an uncontrolled before-after study comparing SUP prescription in intensive care unit (ICU) patients and non-ICU patients, before and after the implementation of an EMR-based alarm that provided the correct indications for SUP. 1627 patients in the pre-intervention and 1513 patients in the post-intervention cohorts were included. The EMR-based alarm improved appropriate (49.6% vs. 66.6%, p<0.001) and reduced inappropriate SUP use (50.4% vs. 33.3%, p<0.001) in ICU patients only. These differences were related to the optimization of SUP in low risk patients. There was no difference in overt gastrointestinal bleeding between the two cohorts. Unjustified costs related to SUP were reduced by a third after EMR-based alarm use. The use of an EMR-based alarm improved appropriate and reduced inappropriate use of SUP in ICU patients. This benefit was limited to optimization in low risk patients and associated with a decrease in SUP costs. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

2010 report from the Center for International Blood and Marrow Transplant Research (CIBMTR): current uses and outcomes of hematopoietic cell transplants for blood and bone marrow disorders.

PubMed

Pasquini, Marcelo C; Wang, Zhiwei; Horowitz, Mary M; Gale, Robert Peter

2010-01-01

These data indicate increasing use of HCT for persons with blood and bone marrow disorders. Recent trends include increasing use of alternative donors including HLA-matched unrelated persons and of HLA-matched umbilical cord blood cells, increasing use of blood cell rather than bone marrow grafts and increasing use of reduced-intensity pretransplant conditioning regimens. Many of these shifts are driven by logistical considerations like the need for donors in persons without an HLA-identical sibling or expanding access to allotransplants to older patients. In other instances, like the shift from bone marrow to blood cell grafts or from conventional to reduced-intensity pretransplant conditioning regimens few randomized clinical trials have been reported to justify these shifts. More data are needed to critically-assess the impact of these changes.

Vector-model-supported approach in prostate plan optimization

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

Liu, Eva Sau Fan; Department of Health Technology and Informatics, The Hong Kong Polytechnic University; Wu, Vincent Wing Cheung

Lengthy time consumed in traditional manual plan optimization can limit the use of step-and-shoot intensity-modulated radiotherapy/volumetric-modulated radiotherapy (S&S IMRT/VMAT). A vector model base, retrieving similar radiotherapy cases, was developed with respect to the structural and physiologic features extracted from the Digital Imaging and Communications in Medicine (DICOM) files. Planning parameters were retrieved from the selected similar reference case and applied to the test case to bypass the gradual adjustment of planning parameters. Therefore, the planning time spent on the traditional trial-and-error manual optimization approach in the beginning of optimization could be reduced. Each S&S IMRT/VMAT prostate reference database comprised 100more » previously treated cases. Prostate cases were replanned with both traditional optimization and vector-model-supported optimization based on the oncologists' clinical dose prescriptions. A total of 360 plans, which consisted of 30 cases of S&S IMRT, 30 cases of 1-arc VMAT, and 30 cases of 2-arc VMAT plans including first optimization and final optimization with/without vector-model-supported optimization, were compared using the 2-sided t-test and paired Wilcoxon signed rank test, with a significance level of 0.05 and a false discovery rate of less than 0.05. For S&S IMRT, 1-arc VMAT, and 2-arc VMAT prostate plans, there was a significant reduction in the planning time and iteration with vector-model-supported optimization by almost 50%. When the first optimization plans were compared, 2-arc VMAT prostate plans had better plan quality than 1-arc VMAT plans. The volume receiving 35 Gy in the femoral head for 2-arc VMAT plans was reduced with the vector-model-supported optimization compared with the traditional manual optimization approach. Otherwise, the quality of plans from both approaches was comparable. Vector-model-supported optimization was shown to offer much shortened planning time and iteration number without compromising the plan quality.« less

Design and demonstration of a storage assisted air conditioning system

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

Avril, F.; Irvine, T.F.

1982-04-01

The report describes the design and demonstration of a storage-assisted air conditioning system for residential central air conditioning applications. The system was designed to reduce peak air conditioning loads by storing coolness to fulfill daytime air conditioning requirements. The system design analyses, as well as performance data obtained from a residential installation on Long Island, are presented, along with an economic evaluation of the system. The results of the study indicate that such a system can reduce air conditioning peak load requirements while maintaining house temperature and humidity within prescribed limits. However, further system optimization is required, as well asmore » either equipment costs reduction or increased incentives, to make this system economically attractive for use in New York State.« less

Practical implementation of tetrahedral mesh reconstruction in emission tomography

PubMed Central

Boutchko, R.; Sitek, A.; Gullberg, G. T.

2014-01-01

This paper presents a practical implementation of image reconstruction on tetrahedral meshes optimized for emission computed tomography with parallel beam geometry. Tetrahedral mesh built on a point cloud is a convenient image representation method, intrinsically three-dimensional and with a multi-level resolution property. Image intensities are defined at the mesh nodes and linearly interpolated inside each tetrahedron. For the given mesh geometry, the intensities can be computed directly from tomographic projections using iterative reconstruction algorithms with a system matrix calculated using an exact analytical formula. The mesh geometry is optimized for a specific patient using a two stage process. First, a noisy image is reconstructed on a finely-spaced uniform cloud. Then, the geometry of the representation is adaptively transformed through boundary-preserving node motion and elimination. Nodes are removed in constant intensity regions, merged along the boundaries, and moved in the direction of the mean local intensity gradient in order to provide higher node density in the boundary regions. Attenuation correction and detector geometric response are included in the system matrix. Once the mesh geometry is optimized, it is used to generate the final system matrix for ML-EM reconstruction of node intensities and for visualization of the reconstructed images. In dynamic PET or SPECT imaging, the system matrix generation procedure is performed using a quasi-static sinogram, generated by summing projection data from multiple time frames. This system matrix is then used to reconstruct the individual time frame projections. Performance of the new method is evaluated by reconstructing simulated projections of the NCAT phantom and the method is then applied to dynamic SPECT phantom and patient studies and to a dynamic microPET rat study. Tetrahedral mesh-based images are compared to the standard voxel-based reconstruction for both high and low signal-to-noise ratio projection datasets. The results demonstrate that the reconstructed images represented as tetrahedral meshes based on point clouds offer image quality comparable to that achievable using a standard voxel grid while allowing substantial reduction in the number of unknown intensities to be reconstructed and reducing the noise. PMID:23588373

Practical implementation of tetrahedral mesh reconstruction in emission tomography

NASA Astrophysics Data System (ADS)

Boutchko, R.; Sitek, A.; Gullberg, G. T.

2013-05-01

This paper presents a practical implementation of image reconstruction on tetrahedral meshes optimized for emission computed tomography with parallel beam geometry. Tetrahedral mesh built on a point cloud is a convenient image representation method, intrinsically three-dimensional and with a multi-level resolution property. Image intensities are defined at the mesh nodes and linearly interpolated inside each tetrahedron. For the given mesh geometry, the intensities can be computed directly from tomographic projections using iterative reconstruction algorithms with a system matrix calculated using an exact analytical formula. The mesh geometry is optimized for a specific patient using a two stage process. First, a noisy image is reconstructed on a finely-spaced uniform cloud. Then, the geometry of the representation is adaptively transformed through boundary-preserving node motion and elimination. Nodes are removed in constant intensity regions, merged along the boundaries, and moved in the direction of the mean local intensity gradient in order to provide higher node density in the boundary regions. Attenuation correction and detector geometric response are included in the system matrix. Once the mesh geometry is optimized, it is used to generate the final system matrix for ML-EM reconstruction of node intensities and for visualization of the reconstructed images. In dynamic PET or SPECT imaging, the system matrix generation procedure is performed using a quasi-static sinogram, generated by summing projection data from multiple time frames. This system matrix is then used to reconstruct the individual time frame projections. Performance of the new method is evaluated by reconstructing simulated projections of the NCAT phantom and the method is then applied to dynamic SPECT phantom and patient studies and to a dynamic microPET rat study. Tetrahedral mesh-based images are compared to the standard voxel-based reconstruction for both high and low signal-to-noise ratio projection datasets. The results demonstrate that the reconstructed images represented as tetrahedral meshes based on point clouds offer image quality comparable to that achievable using a standard voxel grid while allowing substantial reduction in the number of unknown intensities to be reconstructed and reducing the noise.

How Positive Is Their Future? Assessing the Role of Optimism and Social Support in Understanding Mental Health Symptomatology among Homeless Adults.

PubMed

Fitzpatrick, Kevin M

2017-04-01

Optimism has been noted as a primary protective factor in understanding mental health symptomatology in clinical and non-clinical settings. Any exploration of optimism has been absent in understanding mental health outcomes among homeless people. This study, using intensive interviews with 168 homeless adults in Northwest Arkansas, examines the role that social support and optimism play in lessening the negative impact of homeless circumstances/experiences on mental health symptomatology. Using OLS, findings support a mediating/protective role that social support and optimism play in lowering the negative effects of childhood life experiences on depressive symptoms among homeless persons. Despite the overwhelming conditions of homelessness, persons with higher levels of optimism and social support report lower depression and anxiety symptoms. The findings are discussed paying particular attention to the importance of developing and maintaining the perception of support and resiliency in preserving a positive outlook for the future among homeless persons facing often-debilitating circumstances. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

An intervention for parents with AIDS and their adolescent children.

PubMed

Rotheram-Borus, M J; Lee, M B; Gwadz, M; Draimin, B

2001-08-01

This study evaluated an intervention designed to improve behavioral and mental health outcomes among adolescents and their parents with AIDS. Parents with AIDS (n = 307) and their adolescent children (n = 412) were randomly assigned to an intensive intervention or a standard care control condition. Ninety-five percent of subjects were reassessed at least once annually over 2 years. Adolescents in the intensive intervention condition reported significantly lower levels of emotional distress, of multiple problem behaviors, of conduct problems, and of family-related stressors and higher levels of self-esteem than adolescents in the standard care condition. Parents with AIDS in the intervention condition also reported significantly lower levels of emotional distress and multiple problem behaviors. Coping style, levels of disclosure regarding serostatus, and formation of legal custody plans were similar across intervention conditions. Interventions can reduce the long-term impact of parents' HIV status on themselves and their children.

Partial Overhaul and Initial Parallel Optimization of KINETICS, a Coupled Dynamics and Chemistry Atmosphere Model

NASA Technical Reports Server (NTRS)

Nguyen, Howard; Willacy, Karen; Allen, Mark

2012-01-01

KINETICS is a coupled dynamics and chemistry atmosphere model that is data intensive and computationally demanding. The potential performance gain from using a supercomputer motivates the adaptation from a serial version to a parallelized one. Although the initial parallelization had been done, bottlenecks caused by an abundance of communication calls between processors led to an unfavorable drop in performance. Before starting on the parallel optimization process, a partial overhaul was required because a large emphasis was placed on streamlining the code for user convenience and revising the program to accommodate the new supercomputers at Caltech and JPL. After the first round of optimizations, the partial runtime was reduced by a factor of 23; however, performance gains are dependent on the size of the data, the number of processors requested, and the computer used.

Charging power optimization for nonlinear vibration energy harvesting systems subjected to arbitrary, persistent base excitations

NASA Astrophysics Data System (ADS)

Dai, Quanqi; Harne, Ryan L.

2018-01-01

The vibrations of mechanical systems and structures are often a combination of periodic and random motions. Emerging interest to exploit nonlinearities in vibration energy harvesting systems for charging microelectronics may be challenged by such reality due to the potential to transition between favorable and unfavorable dynamic regimes for DC power delivery. Therefore, a need exists to devise an optimization method whereby charging power from nonlinear energy harvesters remains maximized when excitation conditions are neither purely harmonic nor purely random, which have been the attention of past research. This study meets the need by building from an analytical approach that characterizes the dynamic response of nonlinear energy harvesting platforms subjected to combined harmonic and stochastic base accelerations. Here, analytical expressions are formulated and validated to optimize charging power while the influences of the relative proportions of excitation types are concurrently assessed. It is found that about a 2 times deviation in optimal resistive loads can reduce the charging power by 20% when the system is more prominently driven by harmonic base accelerations, whereas a greater proportion of stochastic excitation results in a 11% reduction in power for the same resistance deviation. In addition, the results reveal that when the frequency of a predominantly harmonic excitation deviates by 50% from optimal conditions the charging power reduces by 70%, whereas the same frequency deviation for a more stochastically dominated excitation reduce total DC power by only 20%. These results underscore the need for maximizing direct current power delivery for nonlinear energy harvesting systems in practical operating environments.

Adjoint assimilation of altimetric, surface drifter, and hydrographic data in a quasi-geostrophic model of the Azores Current

NASA Astrophysics Data System (ADS)

Morrow, Rosemary; de Mey, Pierre

1995-12-01

The flow characteristics in the region of the Azores Current are investigated by assimilating TOPEX/POSEIDON and ERS 1 altimeter data into the multilevel Harvard quasigeostrophic (QG) model with open boundaries (Miller et al., 1983) using an adjoint variational scheme (Moore, 1991). The study site lies in the path of the Azores Current, where a branch retroflects to the south in the vicinity of the Madeira Rise. The region was the site of an intensive field program in 1993, SEMAPHORE. We had two main aims in this adjoint assimilation project. The first was to see whether the adjoint method could be applied locally to optimize an initial guess field, derived from the continous assimilation of altimetry data using optimal interpolation (OI). The second aim was to assimilate a variety of different data sets and evaluate their importance in constraining our QG model. The adjoint assimilation of surface data was effective in optimizing the initial conditions from OI. After 20 iterations the cost function was generally reduced by 50-80%, depending on the chosen data constraints. The primary adjustment process was via the barotropic mode. Altimetry proved to be a good constraint on the variable flow field, in particular, for constraining the barotropic field. The excellent data quality of the TOPEX/POSEIDON (T/P) altimeter data provided smooth and reliable forcing; but for our mesoscale study in a region of long decorrelation times O(30 days), the spatial coverage from the combined T/P and ERS 1 data sets was more important for constraining the solution and providing stable flow at all levels. Surface drifters provided an excellent constraint on both the barotropic and baroclinic model fields. More importantly, the drifters provided a reliable measure of the mean field. Hydrographic data were also applied as a constraint; in general, hydrography provided a weak but effective constraint on the vertical Rossby modes in the model. Finally, forecasts run over a 2-month period indicate that the initial conditions optimized by the 20-day adjoint assimilation provide more stable, longer-term forecasts.

Disease-specific hematopoietic stem cell transplantation in children with inherited bone marrow failure syndromes.

PubMed

Li, Qian; Luo, Changying; Luo, Chengjuan; Wang, Jianmin; Li, Benshang; Ding, Lixia; Chen, Jing

2017-08-01

Hematopoietic stem cell transplantation (HSCT) using an optimized conditioning regimen is essential for the long-term survival of patients with inherited bone marrow failure syndromes (IBMFS). We report HSCT in 24 children with Fanconi anemia (FA, n = 12), Diamond-Blackfan anemia (DBA, n = 7), and dyskeratosis congenita (DC, n = 5) from a single HSCT center. The graft source was peripheral blood stem cells (n = 19) or cord blood stem cells (n = 5). FA and DC patients received reduced-intensity conditioning, while DBA patients had myeloablative conditioning. The median numbers of infused mononuclear cells and CD34+ cells were 14.20 × 10 8 /kg and 4.3 × 10 6 /kg, respectively. The median time for neutrophil and platelet recovery was 12 and 18 days, respectively. Complete donor engraftment was achieved in 23 of 24 patients. There was one primary graft failure. During a median follow-up of 27.5 months (range, 2-130 months), the overall survival in all patients was 95.8%. The incidence of grade II-III acute graft versus host disease (GvHD) and chronic GvHD was 29.2% and 16.7%, respectively. We conclude that HSCT can be a curative option for patients with IBMFS. Modification of the conditioning regimen based on the type of disease may lead to encouraging long-term outcomes.

Analysis of a Two-Dimensional Thermal Cloaking Problem on the Basis of Optimization

NASA Astrophysics Data System (ADS)

Alekseev, G. V.

2018-04-01

For a two-dimensional model of thermal scattering, inverse problems arising in the development of tools for cloaking material bodies on the basis of a mixed thermal cloaking strategy are considered. By applying the optimization approach, these problems are reduced to optimization ones in which the role of controls is played by variable parameters of the medium occupying the cloaking shell and by the heat flux through a boundary segment of the basic domain. The solvability of the direct and optimization problems is proved, and an optimality system is derived. Based on its analysis, sufficient conditions on the input data are established that ensure the uniqueness and stability of optimal solutions.

Direct aperture optimization: a turnkey solution for step-and-shoot IMRT.

PubMed

Shepard, D M; Earl, M A; Li, X A; Naqvi, S; Yu, C

2002-06-01

IMRT treatment plans for step-and-shoot delivery have traditionally been produced through the optimization of intensity distributions (or maps) for each beam angle. The optimization step is followed by the application of a leaf-sequencing algorithm that translates each intensity map into a set of deliverable aperture shapes. In this article, we introduce an automated planning system in which we bypass the traditional intensity optimization, and instead directly optimize the shapes and the weights of the apertures. We call this approach "direct aperture optimization." This technique allows the user to specify the maximum number of apertures per beam direction, and hence provides significant control over the complexity of the treatment delivery. This is possible because the machine dependent delivery constraints imposed by the MLC are enforced within the aperture optimization algorithm rather than in a separate leaf-sequencing step. The leaf settings and the aperture intensities are optimized simultaneously using a simulated annealing algorithm. We have tested direct aperture optimization on a variety of patient cases using the EGS4/BEAM Monte Carlo package for our dose calculation engine. The results demonstrate that direct aperture optimization can produce highly conformal step-and-shoot treatment plans using only three to five apertures per beam direction. As compared with traditional optimization strategies, our studies demonstrate that direct aperture optimization can result in a significant reduction in both the number of beam segments and the number of monitor units. Direct aperture optimization therefore produces highly efficient treatment deliveries that maintain the full dosimetric benefits of IMRT.

Neural Network and Regression Approximations in High Speed Civil Transport Aircraft Design Optimization

NASA Technical Reports Server (NTRS)

Patniak, Surya N.; Guptill, James D.; Hopkins, Dale A.; Lavelle, Thomas M.

1998-01-01

Nonlinear mathematical-programming-based design optimization can be an elegant method. However, the calculations required to generate the merit function, constraints, and their gradients, which are frequently required, can make the process computational intensive. The computational burden can be greatly reduced by using approximating analyzers derived from an original analyzer utilizing neural networks and linear regression methods. The experience gained from using both of these approximation methods in the design optimization of a high speed civil transport aircraft is the subject of this paper. The Langley Research Center's Flight Optimization System was selected for the aircraft analysis. This software was exercised to generate a set of training data with which a neural network and a regression method were trained, thereby producing the two approximating analyzers. The derived analyzers were coupled to the Lewis Research Center's CometBoards test bed to provide the optimization capability. With the combined software, both approximation methods were examined for use in aircraft design optimization, and both performed satisfactorily. The CPU time for solution of the problem, which had been measured in hours, was reduced to minutes with the neural network approximation and to seconds with the regression method. Instability encountered in the aircraft analysis software at certain design points was also eliminated. On the other hand, there were costs and difficulties associated with training the approximating analyzers. The CPU time required to generate the input-output pairs and to train the approximating analyzers was seven times that required for solution of the problem.

Time-resolved measurements of statistics for a Nd:YAG laser.

PubMed

Hubschmid, W; Bombach, R; Gerber, T

1994-08-20

Time-resolved measurements of the fluctuating intensity of a multimode frequency-doubled Nd:YAG laser have been performed. For various operating conditions the enhancement factors in nonlinear optical processes that use a fluctuating instead of a single-mode laser have been determined up to the sixth order. In the case of reduced flash-lamp excitation and a switched-off laser amplifier, the intensity fluctuations agree with the normalized Gaussian model for the fluctuations of the fundamental frequency, whereas strong deviations are found under usual operating conditions. The frequencydoubled light has in the latter case enhancement factors not so far from values of Gaussian statistics.

Performance Comparison of Optimized Designs of Francis Turbines Exposed to Sediment Erosion in various Operating Conditions

NASA Astrophysics Data System (ADS)

Shrestha, K. P.; Chitrakar, S.; Thapa, B.; Dahlhaug, O. G.

2018-06-01

Erosion on hydro turbine mostly depends on impingement velocity, angle of impact, concentration, shape, size and distribution of erodent particle and substrate material. In the case of Francis turbines, the sediment particles tend to erode more in the off-designed conditions than at the best efficiency point. Previous studies focused on the optimized runner blade design to reduce erosion at the designed flow. However, the effect of the change in the design on other operating conditions was not studied. This paper demonstrates the performance of optimized Francis turbine exposed to sediment erosion in various operating conditions. Comparative study has been carryout among the five different shapes of runner, different set of guide vane and stay vane angles. The effect of erosion is studied in terms of average erosion density rate on optimized design Francis runner with Lagrangian particle tracking method in CFD analysis. The numerical sensitivity of the results are investigated by comparing two turbulence models. Numerical results are validated from the velocity measurements carried out in the actual turbine. Results show that runner blades are susceptible to more erosion at part load conditions compared to BEP, whereas for the case of guide vanes, more erosion occurs at full load conditions. Out of the five shapes compared, Shape 5 provides an optimum combination of efficiency and erosion on the studied operating conditions.

Illuminant-adaptive color reproduction for mobile display

NASA Astrophysics Data System (ADS)

Kim, Jong-Man; Park, Kee-Hyon; Kwon, Oh-Seol; Cho, Yang-Ho; Ha, Yeong-Ho

2006-01-01

This paper proposes an illuminant-adaptive reproduction method using light adaptation and flare conditions for a mobile display. Mobile displays, such as PDAs and cellular phones, are viewed under various lighting conditions. In particular, images displayed in daylight are perceived as quite dark due to the light adaptation of the human visual system, as the luminance of a mobile display is considerably lower than that of an outdoor environment. In addition, flare phenomena decrease the color gamut of a mobile display by increasing the luminance of dark areas and de-saturating the chroma. Therefore, this paper presents an enhancement method composed of lightness enhancement and chroma compensation. First, the ambient light intensity is measured using a lux-sensor, then the flare is calculated based on the reflection ratio of the display device and the ambient light intensity. The relative cone response is nonlinear to the input luminance. This is also changed by the ambient light intensity. Thus, to improve the perceived image, the displayed luminance is enhanced by lightness linearization. In this paper, the image's luminance is transformed by linearization of the response to the input luminance according to the ambient light intensity. Next, the displayed image is compensated according to the physically reduced chroma, resulting from flare phenomena. The reduced chroma value is calculated according to the flare for each intensity. The chroma compensation method to maintain the original image's chroma is applied differently for each hue plane, as the flare affects each hue plane differently. At this time, the enhanced chroma also considers the gamut boundary. Based on experimental observations, the outer luminance-intensity generally ranges from 1,000 lux to 30,000 lux. Thus, in the case of an outdoor environment, i.e. greater than 1,000 lux, this study presents a color reproduction method based on an inverse cone response curve and flare condition. Consequently, the proposed algorithm improves the quality of the perceived image adaptive to an outdoor environment.

Anatomical robust optimization to account for nasal cavity filling variation during intensity-modulated proton therapy: a comparison with conventional and adaptive planning strategies

NASA Astrophysics Data System (ADS)

van de Water, Steven; Albertini, Francesca; Weber, Damien C.; Heijmen, Ben J. M.; Hoogeman, Mischa S.; Lomax, Antony J.

2018-01-01

The aim of this study is to develop an anatomical robust optimization method for intensity-modulated proton therapy (IMPT) that accounts for interfraction variations in nasal cavity filling, and to compare it with conventional single-field uniform dose (SFUD) optimization and online plan adaptation. We included CT data of five patients with tumors in the sinonasal region. Using the planning CT, we generated for each patient 25 ‘synthetic’ CTs with varying nasal cavity filling. The robust optimization method available in our treatment planning system ‘Erasmus-iCycle’ was extended to also account for anatomical uncertainties by including (synthetic) CTs with varying patient anatomy as error scenarios in the inverse optimization. For each patient, we generated treatment plans using anatomical robust optimization and, for benchmarking, using SFUD optimization and online plan adaptation. Clinical target volume (CTV) and organ-at-risk (OAR) doses were assessed by recalculating the treatment plans on the synthetic CTs, evaluating dose distributions individually and accumulated over an entire fractionated 50 GyRBE treatment, assuming each synthetic CT to correspond to a 2 GyRBE fraction. Treatment plans were also evaluated using actual repeat CTs. Anatomical robust optimization resulted in adequate CTV doses (V95%  ⩾  98% and V107%  ⩽  2%) if at least three synthetic CTs were included in addition to the planning CT. These CTV requirements were also fulfilled for online plan adaptation, but not for the SFUD approach, even when applying a margin of 5 mm. Compared with anatomical robust optimization, OAR dose parameters for the accumulated dose distributions were on average 5.9 GyRBE (20%) higher when using SFUD optimization and on average 3.6 GyRBE (18%) lower for online plan adaptation. In conclusion, anatomical robust optimization effectively accounted for changes in nasal cavity filling during IMPT, providing substantially improved CTV and OAR doses compared with conventional SFUD optimization. OAR doses can be further reduced by using online plan adaptation.

Framework for the rapid optimization of soluble protein expression in Escherichia coli combining microscale experiments and statistical experimental design.

PubMed

Islam, R S; Tisi, D; Levy, M S; Lye, G J

2007-01-01

A major bottleneck in drug discovery is the production of soluble human recombinant protein in sufficient quantities for analysis. This problem is compounded by the complex relationship between protein yield and the large number of variables which affect it. Here, we describe a generic framework for the rapid identification and optimization of factors affecting soluble protein yield in microwell plate fermentations as a prelude to the predictive and reliable scaleup of optimized culture conditions. Recombinant expression of firefly luciferase in Escherichia coli was used as a model system. Two rounds of statistical design of experiments (DoE) were employed to first screen (D-optimal design) and then optimize (central composite face design) the yield of soluble protein. Biological variables from the initial screening experiments included medium type and growth and induction conditions. To provide insight into the impact of the engineering environment on cell growth and expression, plate geometry, shaking speed, and liquid fill volume were included as factors since these strongly influence oxygen transfer into the wells. Compared to standard reference conditions, both the screening and optimization designs gave up to 3-fold increases in the soluble protein yield, i.e., a 9-fold increase overall. In general the highest protein yields were obtained when cells were induced at a relatively low biomass concentration and then allowed to grow slowly up to a high final biomass concentration, >8 g.L-1. Consideration and analysis of the model results showed 6 of the original 10 variables to be important at the screening stage and 3 after optimization. The latter included the microwell plate shaking speeds pre- and postinduction, indicating the importance of oxygen transfer into the microwells and identifying this as a critical parameter for subsequent scale translation studies. The optimization process, also known as response surface methodology (RSM), predicted there to be a distinct optimum set of conditions for protein expression which could be verified experimentally. This work provides a generic approach to protein expression optimization in which both biological and engineering variables are investigated from the initial screening stage. The application of DoE reduces the total number of experiments needed to be performed, while experimentation at the microwell scale increases experimental throughput and reduces cost.

Effective laser-induced breakdown spectroscopy (LIBS) detection using double pulse at optimum configuration.

PubMed

Choi, Soo Jin; Yoh, Jack J

2011-08-01

A short laser pulse is irradiated on a sample to create a highly energetic plasma that emits light of a specific peak wavelength according to the material. By identifying different peaks for the analyzed samples, their chemical composition can be rapidly determined. The characteristics of the laser-induced breakdown spectroscopy (LIBS) plasma are strongly dependent on the ambient conditions. Research aimed at enhancing LIBS intensity is of great benefit in advancing LIBS for the exploration of harsh environments. By using double-pulse LIBS, the signal intensity of Al and Ca lines was enhanced by five times compared to the single-pulse signal. Also, the angles of the target and detector are adjusted to simulate samples of arbitrary shape. We verified that there exists an optimal angle at which specific elements of a test sample may be detected with stronger signal intensity. We provide several optimum configurations for the LIBS system for maximizing the signal intensity for the analysis of a nonstandard aluminum sample.

Analytical Modelling and Optimization of the Temperature-Dependent Dynamic Mechanical Properties of Fused Deposition Fabricated Parts Made of PC-ABS.

PubMed

Mohamed, Omar Ahmed; Masood, Syed Hasan; Bhowmik, Jahar Lal

2016-11-04

Fused deposition modeling (FDM) additive manufacturing has been intensively used for many industrial applications due to its attractive advantages over traditional manufacturing processes. The process parameters used in FDM have significant influence on the part quality and its properties. This process produces the plastic part through complex mechanisms and it involves complex relationships between the manufacturing conditions and the quality of the processed part. In the present study, the influence of multi-level manufacturing parameters on the temperature-dependent dynamic mechanical properties of FDM processed parts was investigated using IV-optimality response surface methodology (RSM) and multilayer feed-forward neural networks (MFNNs). The process parameters considered for optimization and investigation are slice thickness, raster to raster air gap, deposition angle, part print direction, bead width, and number of perimeters. Storage compliance and loss compliance were considered as response variables. The effect of each process parameter was investigated using developed regression models and multiple regression analysis. The surface characteristics are studied using scanning electron microscope (SEM). Furthermore, performance of optimum conditions was determined and validated by conducting confirmation experiment. The comparison between the experimental values and the predicted values by IV-Optimal RSM and MFNN was conducted for each experimental run and results indicate that the MFNN provides better predictions than IV-Optimal RSM.

Analytical Modelling and Optimization of the Temperature-Dependent Dynamic Mechanical Properties of Fused Deposition Fabricated Parts Made of PC-ABS

PubMed Central

Mohamed, Omar Ahmed; Masood, Syed Hasan; Bhowmik, Jahar Lal

2016-01-01

Fused deposition modeling (FDM) additive manufacturing has been intensively used for many industrial applications due to its attractive advantages over traditional manufacturing processes. The process parameters used in FDM have significant influence on the part quality and its properties. This process produces the plastic part through complex mechanisms and it involves complex relationships between the manufacturing conditions and the quality of the processed part. In the present study, the influence of multi-level manufacturing parameters on the temperature-dependent dynamic mechanical properties of FDM processed parts was investigated using IV-optimality response surface methodology (RSM) and multilayer feed-forward neural networks (MFNNs). The process parameters considered for optimization and investigation are slice thickness, raster to raster air gap, deposition angle, part print direction, bead width, and number of perimeters. Storage compliance and loss compliance were considered as response variables. The effect of each process parameter was investigated using developed regression models and multiple regression analysis. The surface characteristics are studied using scanning electron microscope (SEM). Furthermore, performance of optimum conditions was determined and validated by conducting confirmation experiment. The comparison between the experimental values and the predicted values by IV-Optimal RSM and MFNN was conducted for each experimental run and results indicate that the MFNN provides better predictions than IV-Optimal RSM. PMID:28774019

An optimal thermal evaporation synthesis of c-axis oriented ZnO nanowires with excellent UV sensing and emission characteristics

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

Saha, Tridib, E-mail: tridib.saha@monash.edu; Achath Mohanan, Ajay, E-mail: ajay.mohanan@monash.edu; Swamy, Varghese, E-mail: varghese.swamy@monash.edu

Highlights: • c-Axis alignment of ZnO nanowires was optimized using self-seeding thermal evaporation method. • Influence of purified air on the morphology and optoelectronic properties were studied. • Nanowires grown under optimal conditions exhibit strong UV emission peak in PL spectrum. • Optimized growth condition establish nanowires of excellent UV sensing characteristics - Abstract: Well-aligned (c-axis oriented) ZnO nanowire arrays were successfully synthesized on Si (1 0 0) substrates through an optimized self-seeding thermal evaporation method. An open-ended chemical vapor deposition (CVD) setup was used in the experiment, with argon and purified air as reaction gases. Epitaxial growth of c-axismore » oriented ZnO nanowires was observed for 5 sccm flow rate of purified air, whereas Zn/Zn suboxide layers and multiple polycrystalline layers of ZnO were obtained for absence and excess of purified air, respectively. Ultraviolet (UV) sensing and emission properties of the as-grown ZnO nanostructures were investigated through the current–voltage (I–V) characteristics of the nanowires under UV (λ = 365 nm) illumination of 8 mW/cm{sup 2} and using photoluminescence spectra. Nanowires grown under optimum flow of air emitted four times higher intensity of 380 nm UV light as well as exhibited 34 times higher UV radiation sensitivity compared to that of other nanostructures synthesized in this study.« less

Fifth Symposium on the Role of the Vestibular Organs in Space Exploration

NASA Technical Reports Server (NTRS)

1973-01-01

Vestibular problems of manned space flight are investigated for weightlessness and reduced gravity conditions with emphasis on space station development. Intensive morphological studies on the vestibular system and its central nervous system connections are included.

Context-dependent survival, fecundity and predicted population-level consequences of brucellosis in African buffalo

USGS Publications Warehouse

Gorsich, Erin E.; Ezenwa, Vanessa O.; Cross, Paul C.; Bengis, Roy G.; Jolles, Anna E.

2015-01-01

Our results suggest that brucellosis infection can potentially result in reduced population growth rates, but because these effects varied with demographic and environmental conditions, they may remain unseen without intensive, longitudinal monitoring.

Effects of lighting and air-conditioning systems on growth weight and functional composition of frill-lettuce produced in plant factory

NASA Astrophysics Data System (ADS)

Yoshida, Atsumasa; Okamura, Nobuya; Furukawa, Hajime; Myojin, Chiho; Moriuchi, Koji; Kinoshita, Shinichi

2017-06-01

The aim of the present study was to develop optimal air-conditioning systems for plant factories. To verify the effect of particular air-conditioning and lighting systems, cultivation experiments were performed with frill-lettuce for two weeks. In the present study, the relationship between the cultivation condition, the yield (i.e., increase in edible portion weight), and the functional components were discussed. Based on the measured data, increased photosynthetic photon flux density increased antioxidative activity and edible portion weight, possibly because high light intensities are stressful for frill lettuce. Antioxidative activity also increased under conditions of low CO2 concentration, weak and strong winds, and high air temperature because these conditions became stresses for the plants. However, a decrease in edible portion weight was observed under these conditions, implying there is a negative correlation between antioxidative activity and edible portion weight.

Disentangling Emotion Processes in Borderline Personality Disorder: Physiological and Self-reported Assessment of Biological Vulnerability, Baseline Intensity, and Reactivity to Emotionally-Evocative Stimuli

PubMed Central

Kuo, Janice R.; Linehan, Marsha M.

2014-01-01

This study investigated Linehan’s (1993) theory that individuals meeting criteria for borderline personality disorder (BPD) have high biological vulnerability to emotion dysregulation, including high baseline emotional intensity and high reactivity to emotionally-evocative stimuli. Twenty individuals with BPD, 20 age-matched individuals with generalized social anxiety disorder (SAD), and 20 age-matched normal controls (NC) participated in two separate emotion induction conditions, a standardized condition and a personally-relevant condition. Respiratory sinus arrhythmia (RSA), skin conductance response (SCR), and self-report measures were collected throughout the experiment. BPD participants displayed heightened biological vulnerability compared with NC as indicated by reduced basal RSA. BPD participants also exhibited high baseline emotional intensity, characterized by heightened SCR and heightened self-reported negative emotions at baseline. However, the BPD group did not display heightened reactivity as their physiological and self-reported changes from baseline to the emotion inductions tasks were not greater than the other two groups. PMID:19685950

A LAGRANGIAN GAUSS-NEWTON-KRYLOV SOLVER FOR MASS- AND INTENSITY-PRESERVING DIFFEOMORPHIC IMAGE REGISTRATION.

PubMed

Mang, Andreas; Ruthotto, Lars

2017-01-01

We present an efficient solver for diffeomorphic image registration problems in the framework of Large Deformations Diffeomorphic Metric Mappings (LDDMM). We use an optimal control formulation, in which the velocity field of a hyperbolic PDE needs to be found such that the distance between the final state of the system (the transformed/transported template image) and the observation (the reference image) is minimized. Our solver supports both stationary and non-stationary (i.e., transient or time-dependent) velocity fields. As transformation models, we consider both the transport equation (assuming intensities are preserved during the deformation) and the continuity equation (assuming mass-preservation). We consider the reduced form of the optimal control problem and solve the resulting unconstrained optimization problem using a discretize-then-optimize approach. A key contribution is the elimination of the PDE constraint using a Lagrangian hyperbolic PDE solver. Lagrangian methods rely on the concept of characteristic curves. We approximate these curves using a fourth-order Runge-Kutta method. We also present an efficient algorithm for computing the derivatives of the final state of the system with respect to the velocity field. This allows us to use fast Gauss-Newton based methods. We present quickly converging iterative linear solvers using spectral preconditioners that render the overall optimization efficient and scalable. Our method is embedded into the image registration framework FAIR and, thus, supports the most commonly used similarity measures and regularization functionals. We demonstrate the potential of our new approach using several synthetic and real world test problems with up to 14.7 million degrees of freedom.

Geometric Design of Scalable Forward Scatterers for Optimally Efficient Solar Transformers.

PubMed

Kim, Hye-Na; Vahidinia, Sanaz; Holt, Amanda L; Sweeney, Alison M; Yang, Shu

2017-11-01

It will be ideal to deliver equal, optimally efficient "doses" of sunlight to all cells in a photobioreactor system, while simultaneously utilizing the entire solar resource. Backed by the numerical scattering simulation and optimization, here, the design, synthesis, and characterization of the synthetic iridocytes that recapitulated the salient forward-scattering behavior of the Tridacnid clam system are reported, which presents the first geometric solution to allow narrow, precise forward redistribution of flux, utilizing the solar resource at the maximum quantum efficiency possible in living cells. The synthetic iridocytes are composed of silica nanoparticles in microspheres embedded in gelatin, both are low refractive index materials and inexpensive. They show wavelength selectivity, have little loss (the back-scattering intensity is reduced to less than ≈0.01% of the forward-scattered intensity), and narrow forward scattering cone similar to giant clams. Moreover, by comparing experiments and theoretical calculation, it is confirmed that the nonuniformity of the scatter sizes is a "feature not a bug" of the design, allowing for efficient, forward redistribution of solar flux in a micrometer-scaled paradigm. This method is environmentally benign, inexpensive, and scalable to produce optical components that will find uses in efficiency-limited solar conversion technologies, heat sinks, and biofuel production. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Research on land use structure optimization based on nonpoint source dissolved nitrogen load estimation in Shuaishui watershed].

PubMed

Lu, Yu-Chao; Bi, Meng-Fei; Li, Ze-Li; Sha, Jian; Wang, Yu-Qiu; Qian, Li-Ping

2014-06-01

Regional Nutrient Management (ReNuMa) was applied to estimate dissolved nitrogen (DN) load and perform source apportionment in Shuaishui watershed during 2000-2010. Satisfactory performance of ReNuMa was revealed by the E(ns) and R2 of greater than 0.9 in calibrating and validating streamflow and DN. The average nonpoint DN load in this watershed was 1.11 x 10(3) t x a(-1), with the load intensity of (0.75 +/- 0.22) t x km(-2). Among all the land uses, paddy field had the largest DN load intensity [28.60 kg x (hm2 x a)(-1)], while forest had the least [2.71 kg x (hm2 x a)(-1)]. Agricultural land (including paddy, grain, cash crop, tea plant and orchard) contributed most to DN load in Shuaishui watershed, indicating that the human dominated agricultural activities was the major contributor of nonpoint source pollution. Land use structure optimization for Shuaishui watershed in 2015 was conducted under the rule of reducing pollutants loads and maximizing the agricultural output value. The results demonstrated that agricultural monetary growth was accompanied with the increasing DN load at the optimal level, although output increment was higher than that of DN load.

Effects of urbanization on benthic macroinvertebrate assemblages in contrasting environmental settings: Boston, Massachusetts; Birmingham, Alabama; and Salt Lake City, Utah

USGS Publications Warehouse

Cuffney, T.F.; Zappia, H.; Giddings, E.M.P.; Coles, J.F.

2005-01-01

Responses of invertebrate assemblages along gradients of urban intensity were examined in three metropolitan areas with contrasting climates and topography (Boston, Massachusetts; Birmingham, Alabama; Salt Lake City, Utah). Urban gradients were defined using an urban intensity index (UII) derived from basin-scale population, infrastructure, land-use, land-cover, and socioeconomic characteristics. Responses based on assemblage metrics, indices of biotic integrity (B-IBI), and ordinations were readily detected in all three urban areas and many responses could be accurately predicted simply using regional UIIs. Responses to UII were linear and did not indicate any initial resistance to urbanization. Richness metrics were better indicators of urbanization than were density metrics. Metrics that were good indicators were specific to each study except for a richness-based tolerance metric (TOLr) and one B-IBI. Tolerances to urbanization were derived for 205 taxa. These tolerances differed among studies and with published tolerance values, but provided similar characterizations of site conditions. Basin-scale land-use changes were the most important variables for explaining invertebrate responses to urbanization. Some chemical and instream physical habitat variables were important in individual studies, but not among studies. Optimizing the study design to detect basin-scale effects may have reduced the ability to detect local-scale effects. ?? 2005 by the American Fisheries Society.

Deep tissue penetration of nanoparticles using pulsed-high intensity focused ultrasound

NASA Astrophysics Data System (ADS)

You, Dong Gil; Yoon, Hong Yeol; Jeon, Sangmin; Um, Wooram; Son, Sejin; Park, Jae Hyung; Kwon, Ick Chan; Kim, Kwangmeyung

2017-11-01

Recently, ultrasound (US)-based drug delivery strategies have received attention to improve enhanced permeation and retention (EPR) effect-based passive targeting efficiency of nanoparticles in vitro and in vivo conditions. Among the US treatment techniques, pulsed-high intensity focused ultrasound (pHIFU) have specialized for improving tissue penetration of various macromolecules and nanoparticles without irreversible tissue damages. In this study, we have demonstrated that pHIFU could be utilized to improve tissue penetration of fluorescent dye-labeled glycol chitosan nanoparticles (FCNPs) in femoral tissue of mice. pHIFU could improve blood flow of the targeted-blood vessel in femoral tissue. In addition, tissue penetration of FCNPs was specifically increased 5.7-, 8- and 9.3-folds than that of non-treated (0 W pHIFU) femoral tissue, when the femoral tissue was treated with 10, 20 and 50 W of pHIFU, respectively. However, tissue penetration of FCNPs was significantly reduced after 3 h post-pHIFU treatment (50 W). Because overdose (50 W) of pHIFU led to irreversible tissue damages, including the edema and chapped red blood cells. These overall results support that pHIFU treatment can enhance the extravasation and tissue penetration of FCNPs as well as induce irreversible tissue damages. We expect that our results can provide advantages to optimize pHIFU-mediated delivery strategy of nanoparticles for further clinical applications.

Thermal effects of white light illumination during microsurgery: clinical pilot study on the application safety of surgical microscopes.

PubMed

Hibst, Raimund; Saal, David; Russ, Detlef; Kunzi-Rapp, Karin; Kienle, Alwin; Stock, Karl

2010-01-01

Modern operating microscopes offer high power illumination to ensure optimal visualization, but can also cause thermal damage. The aim of our study is to quantify the thermal effects in vivo and discuss conditions for safe use. In a pilot study on volunteers, we measured the temperature at the skin surface during microscope illumination, including the influence of anaesthesia and the effects of staining, draping, or moistening of the skin. Irradiation within the limit given by safety regulations (200 mW/cm(2)) results in skin surface temperature of 43 degrees C. Higher intensities (forearm 335 mW/cm(2), back 250 mW/cm(2)) are tolerated, resulting in reversible hyperaemia. At a very high illumination intensity (750 mW/cm(2)), pain occurs within 30 s at temperatures of 46 degrees C+/-1 degrees C (hand and forearm), and 43 degrees C+/-2 degrees C (back), respectively. Anaesthesia has no distinct effect on the temperature, whereas staining and drapes result in much higher temperatures (>100 degrees C). Moistening at practicable flow rates can reduce temperature efficiently when combined with a light absorbing and water absorbent drape. In conclusion, surgeons must be aware that surgical microscope illumination without protective means can cause skin temperatures to rise much above pain threshold, which in our study serves as a (conservative) benchmark for potential damage.

Thermal effects of white light illumination during microsurgery: clinical pilot study on the application safety of surgical microscopes

NASA Astrophysics Data System (ADS)

Hibst, Raimund; Saal, David; Russ, Detlef; Kunzi-Rapp, Karin; Kienle, Alwin; Stock, Karl

2010-07-01

Modern operating microscopes offer high power illumination to ensure optimal visualization, but can also cause thermal damage. The aim of our study is to quantify the thermal effects in vivo and discuss conditions for safe use. In a pilot study on volunteers, we measured the temperature at the skin surface during microscope illumination, including the influence of anaesthesia and the effects of staining, draping, or moistening of the skin. Irradiation within the limit given by safety regulations (200 mW/cm2) results in skin surface temperature of 43 °C. Higher intensities (forearm 335 mW/cm2, back 250 mW/cm2) are tolerated, resulting in reversible hyperaemia. At a very high illumination intensity (750 mW/cm2), pain occurs within 30 s at temperatures of 46 °C+/-1 °C (hand and forearm), and 43 °C+/-2 °C (back), respectively. Anaesthesia has no distinct effect on the temperature, whereas staining and drapes result in much higher temperatures (>100 °C). Moistening at practicable flow rates can reduce temperature efficiently when combined with a light absorbing and water absorbent drape. In conclusion, surgeons must be aware that surgical microscope illumination without protective means can cause skin temperatures to rise much above pain threshold, which in our study serves as a (conservative) benchmark for potential damage.

[Early activation of heart-operated patients as a tool for optimization of cardio-surgery curation (review)].

PubMed

2014-04-01

During last years in foreign countries there was widely introduced tactic of early activation of cardio-surgery patients. Necessary components of this methodical approach are early finishing of post-operation artificial respiration and extubation of trachea, shortening of time spending in intensive therapy till 1 day and sign out from stationary after 5 days. As a result of reducing hospitalization period, the curation costs are reduced significantly. Goal of this research was the analysis of methods of anesthesia that allow early extubation and activation after cardio-surgery interventions. There were analyzed data of protocols of anesthesia and post-operation periods for 270 patients. It was concluded that applied methods of anesthesia ensure adequate protection from operation stress and allow reduce time of post-operation artificial respiration, early activation of patients without reducing level of their safety. It was also proved that application of any type of anesthesia medicines is not influencing the temp of post-operation activation. Conducted research is proving the advisability of using tactic of early activation of patients after heart operations and considers this as a tool for optimization of cardio-surgery curation.

Short-term high-intensity interval and moderate-intensity continuous training reduce leukocyte TLR4 in inactive adults at elevated risk of type 2 diabetes.

PubMed

Robinson, Emily; Durrer, Cody; Simtchouk, Svetlana; Jung, Mary E; Bourne, Jessica E; Voth, Elizabeth; Little, Jonathan P

2015-09-01

Exercise can have anti-inflammatory effects in obesity, but the optimal type and intensity of exercise are not clear. This study compared short-term high-intensity interval training (HIIT) with moderate-intensity continuous training (MICT) in terms of improvement in cardiorespiratory fitness, markers of inflammation, and glucose control in previously inactive adults at elevated risk of developing type 2 diabetes. Thirty-nine inactive, overweight/obese adults (32 women) were randomly assigned to 10 sessions over 2 wk of progressive HIIT (n = 20, four to ten 1-min sessions at ∼90% peak heart rate, 1-min rest periods) or MICT (n = 19, 20-50 min at ∼65% peak heart rate). Before and 3 days after training, participants performed a peak O2 uptake test, and fasting blood samples were obtained. Both HIIT (1.8 ± 0.4 vs. 1.9 ± 0.4 l/min, pre vs. post) and MICT (1.8 ± 0.5 vs. 1.9 ± 0.5 l/min, pre vs. post) improved peak O2 uptake (P < 0.001) and lowered plasma fructosamine (P < 0.05). Toll-like receptor (TLR) 4 (TLR4) expression was reduced on lymphocytes and monocytes after both HIIT and MICT (P < 0.05) and on neutrophils after MICT (P < 0.01). TLR2 on lymphocytes was reduced after HIIT and MICT (P < 0.05). Plasma inflammatory cytokines were unchanged after training in both groups, but MICT led to a reduction in fasting plasma glucose (P < 0.05, 5.9 ± 1.0 vs. 5.6 ± 1.0 mmol/l, pre vs. post). Ten days of either HIIT or MICT can improve cardiorespiratory fitness and glucose control and lead to reductions in TLR2 and TLR4 expression. MICT, which involved a longer duration of exercise, may be superior for reducing fasting glucose. Copyright © 2015 the American Physiological Society.

Short-term high-intensity interval and moderate-intensity continuous training reduce leukocyte TLR4 in inactive adults at elevated risk of type 2 diabetes

PubMed Central

Robinson, Emily; Durrer, Cody; Simtchouk, Svetlana; Jung, Mary E.; Bourne, Jessica E.; Voth, Elizabeth

2015-01-01

Exercise can have anti-inflammatory effects in obesity, but the optimal type and intensity of exercise are not clear. This study compared short-term high-intensity interval training (HIIT) with moderate-intensity continuous training (MICT) in terms of improvement in cardiorespiratory fitness, markers of inflammation, and glucose control in previously inactive adults at elevated risk of developing type 2 diabetes. Thirty-nine inactive, overweight/obese adults (32 women) were randomly assigned to 10 sessions over 2 wk of progressive HIIT (n = 20, four to ten 1-min sessions at ∼90% peak heart rate, 1-min rest periods) or MICT (n = 19, 20-50 min at ∼65% peak heart rate). Before and 3 days after training, participants performed a peak O2 uptake test, and fasting blood samples were obtained. Both HIIT (1.8 ± 0.4 vs. 1.9 ± 0.4 l/min, pre vs. post) and MICT (1.8 ± 0.5 vs. 1.9 ± 0.5 l/min, pre vs. post) improved peak O2 uptake (P < 0.001) and lowered plasma fructosamine (P < 0.05). Toll-like receptor (TLR) 4 (TLR4) expression was reduced on lymphocytes and monocytes after both HIIT and MICT (P < 0.05) and on neutrophils after MICT (P < 0.01). TLR2 on lymphocytes was reduced after HIIT and MICT (P < 0.05). Plasma inflammatory cytokines were unchanged after training in both groups, but MICT led to a reduction in fasting plasma glucose (P < 0.05, 5.9 ± 1.0 vs. 5.6 ± 1.0 mmol/l, pre vs. post). Ten days of either HIIT or MICT can improve cardiorespiratory fitness and glucose control and lead to reductions in TLR2 and TLR4 expression. MICT, which involved a longer duration of exercise, may be superior for reducing fasting glucose. PMID:26139217

Glucose control and use of continuous glucose monitoring in the intensive care unit: a critical review.

PubMed

De Block, Christophe; Manuel-y-Keenoy, Begoña; Rogiers, Peter; Jorens, Philippe; Van Gaal, Luc

2008-08-01

Stress hyperglycemia recently became a major therapeutic target in the Intensive Care Unit (ICU) since it occurs in most critically ill patients and is associated with adverse outcome, including increased mortality. Intensive insulin therapy to achieve normoglycemia may reduce mortality, morbidity and the length of ICU and in-hospital stay. However, obtaining normoglycemia requires extensive efforts from the medical staff, including frequent glucose monitoring and adjustment of insulin dose. Current insulin titration is based upon discrete glucose measurements, which may miss fast changes in glycemia and which does not give a full picture of overall glycemic control. Recent evidence suggests that continuous monitoring of glucose levels may help to signal glycemic excursions and eventually to optimize insulin titration in the ICU. In this review we will summarise monitoring and treatment strategies to achieve normoglycemia in the ICU, with special emphasis on the possible advantages of continuous glucose monitoring.

From cosmos to connectomes: the evolution of data-intensive science.

PubMed

Burns, Randal; Vogelstein, Joshua T; Szalay, Alexander S

2014-09-17

The analysis of data requires computation: originally by hand and more recently by computers. Different models of computing are designed and optimized for different kinds of data. In data-intensive science, the scale and complexity of data exceeds the comfort zone of local data stores on scientific workstations. Thus, cloud computing emerges as the preeminent model, utilizing data centers and high-performance clusters, enabling remote users to access and query subsets of the data efficiently. We examine how data-intensive computational systems originally built for cosmology, the Sloan Digital Sky Survey (SDSS), are now being used in connectomics, at the Open Connectome Project. We list lessons learned and outline the top challenges we expect to face. Success in computational connectomics would drastically reduce the time between idea and discovery, as SDSS did in cosmology. Copyright © 2014 Elsevier Inc. All rights reserved.

Large Artery Atherosclerotic Occlusive Disease.

PubMed

Cole, John W

2017-02-01

Extracranial or intracranial large artery atherosclerosis is often identified as a potential etiologic cause for ischemic stroke and transient ischemic attack. Given the high prevalence of large artery atherosclerosis in the general population, determining whether an identified atherosclerotic lesion is truly the cause of a patient's symptomatology can be difficult. In all cases, optimally treating each patient to minimize future stroke risk is paramount. Extracranial or intracranial large artery atherosclerosis can be broadly compartmentalized into four distinct clinical scenarios based upon the individual patient's history, examination, and anatomic imaging findings: asymptomatic and symptomatic extracranial carotid stenosis, intracranial atherosclerosis, and extracranial vertebral artery atherosclerotic disease. This review provides a framework for clinicians evaluating and treating such patients. Intensive medical therapy achieves low rates of stroke and death in asymptomatic carotid stenosis. Evidence indicates that patients with severe symptomatic carotid stenosis should undergo carotid revascularization sooner rather than later and that the risk of stroke or death is lower using carotid endarterectomy than with carotid stenting. Specific to stenting, the risk of stroke or death is greatest among older patients and women. Continuous vascular risk factor optimization via sustained behavioral modifications and intensive medical therapy is the mainstay for stroke prevention in the setting of intracranial and vertebral artery origin atherosclerosis. Lifelong vascular risk factor optimization via sustained behavioral modifications and intensive medical therapy are the key elements to reduce future stroke risk in the setting of large artery atherosclerosis. When considering a revascularization procedure for carotid stenosis, patient demographics, comorbidities, and the periprocedural risks of stroke and death should be carefully considered.

Large Artery Atherosclerotic Occlusive Disease

PubMed Central

Cole, John W.

2017-01-01

ABSTRACT Purpose of Review: Extracranial or intracranial large artery atherosclerosis is often identified as a potential etiologic cause for ischemic stroke and transient ischemic attack. Given the high prevalence of large artery atherosclerosis in the general population, determining whether an identified atherosclerotic lesion is truly the cause of a patient’s symptomatology can be difficult. In all cases, optimally treating each patient to minimize future stroke risk is paramount. Extracranial or intracranial large artery atherosclerosis can be broadly compartmentalized into four distinct clinical scenarios based upon the individual patient’s history, examination, and anatomic imaging findings: asymptomatic and symptomatic extracranial carotid stenosis, intracranial atherosclerosis, and extracranial vertebral artery atherosclerotic disease. This review provides a framework for clinicians evaluating and treating such patients. Recent Findings: Intensive medical therapy achieves low rates of stroke and death in asymptomatic carotid stenosis. Evidence indicates that patients with severe symptomatic carotid stenosis should undergo carotid revascularization sooner rather than later and that the risk of stroke or death is lower using carotid endarterectomy than with carotid stenting. Specific to stenting, the risk of stroke or death is greatest among older patients and women. Continuous vascular risk factor optimization via sustained behavioral modifications and intensive medical therapy is the mainstay for stroke prevention in the setting of intracranial and vertebral artery origin atherosclerosis. Summary: Lifelong vascular risk factor optimization via sustained behavioral modifications and intensive medical therapy are the key elements to reduce future stroke risk in the setting of large artery atherosclerosis. When considering a revascularization procedure for carotid stenosis, patient demographics, comorbidities, and the periprocedural risks of stroke and death should be carefully considered. PMID:28157748

Optimal Control of Connected and Automated Vehicles at Roundabouts

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

Zhao, Liuhui; Malikopoulos, Andreas; Rios-Torres, Jackeline

Connectivity and automation in vehicles provide the most intriguing opportunity for enabling users to better monitor transportation network conditions and make better operating decisions to improve safety and reduce pollution, energy consumption, and travel delays. This study investigates the implications of optimally coordinating vehicles that are wirelessly connected to each other and to an infrastructure in roundabouts to achieve a smooth traffic flow without stop-and-go driving. We apply an optimization framework and an analytical solution that allows optimal coordination of vehicles for merging in such traffic scenario. The effectiveness of the efficiency of the proposed approach is validated through simulationmore » and it is shown that coordination of vehicles can reduce total travel time by 3~49% and fuel consumption by 2~27% with respect to different traffic levels. In addition, network throughput is improved by up to 25% due to elimination of stop-and-go driving behavior.« less

Estimating the intensity of ward admission and its effect on emergency department access block.

PubMed

Luo, Wei; Cao, Jiguo; Gallagher, Marcus; Wiles, Janet

2013-07-10

Emergency department access block is an urgent problem faced by many public hospitals today. When access block occurs, patients in need of acute care cannot access inpatient wards within an optimal time frame. A widely held belief is that access block is the end product of a long causal chain, which involves poor discharge planning, insufficient bed capacity, and inadequate admission intensity to the wards. This paper studies the last link of the causal chain-the effect of admission intensity on access block, using data from a metropolitan hospital in Australia. We applied several modern statistical methods to analyze the data. First, we modeled the admission events as a nonhomogeneous Poisson process and estimated time-varying admission intensity with penalized regression splines. Next, we established a functional linear model to investigate the effect of the time-varying admission intensity on emergency department access block. Finally, we used functional principal component analysis to explore the variation in the daily time-varying admission intensities. The analyses suggest that improving admission practice during off-peak hours may have most impact on reducing the number of ED access blocks. Copyright © 2012 John Wiley & Sons, Ltd.

Effect of local cooling on short-term, intense exercise.

PubMed

Kwon, Young S; Robergs, Robert A; Schneider, Suzanne M

2013-07-01

The widespread belief that local cooling impairs short-term, strenuous exercise performance is controversial. Eighteen original investigations involving cooling before and intermittent cooling during short-term, intensive exercise are summarized in this review. Previous literature examining short-term intensive exercise and local cooling primarily has been limited to the effects on muscle performance immediately or within minutes following cold application. Most previous cooling studies used equal and longer than 10 minutes of pre-cooling, and found that cooling reduced strength, performance and endurance. Because short duration, high intensity exercise requires adequate warm-up to prepare for optimal performance, prolonged pre-cooling is not an effective method to prepare for this type of exercise. The literature related to the effect of acute local cooling immediately before short duration, high intensity isotonic exercise such as weight lifting is limited. However, local intermittent cooling during short-term, high intense exercise may provide possible beneficial effects; first, by pain reduction, caused by an "irritation effect" from hand thermal receptors which block pain sensation, or second, by a cooling effect, whereby stimulation of hand thermal receptors or a slight lowering of blood temperature might alter central fatigue.

Multi-GPU configuration of 4D intensity modulated radiation therapy inverse planning using global optimization

NASA Astrophysics Data System (ADS)

Hagan, Aaron; Sawant, Amit; Folkerts, Michael; Modiri, Arezoo

2018-01-01

We report on the design, implementation and characterization of a multi-graphic processing unit (GPU) computational platform for higher-order optimization in radiotherapy treatment planning. In collaboration with a commercial vendor (Varian Medical Systems, Palo Alto, CA), a research prototype GPU-enabled Eclipse (V13.6) workstation was configured. The hardware consisted of dual 8-core Xeon processors, 256 GB RAM and four NVIDIA Tesla K80 general purpose GPUs. We demonstrate the utility of this platform for large radiotherapy optimization problems through the development and characterization of a parallelized particle swarm optimization (PSO) four dimensional (4D) intensity modulated radiation therapy (IMRT) technique. The PSO engine was coupled to the Eclipse treatment planning system via a vendor-provided scripting interface. Specific challenges addressed in this implementation were (i) data management and (ii) non-uniform memory access (NUMA). For the former, we alternated between parameters over which the computation process was parallelized. For the latter, we reduced the amount of data required to be transferred over the NUMA bridge. The datasets examined in this study were approximately 300 GB in size, including 4D computed tomography images, anatomical structure contours and dose deposition matrices. For evaluation, we created a 4D-IMRT treatment plan for one lung cancer patient and analyzed computation speed while varying several parameters (number of respiratory phases, GPUs, PSO particles, and data matrix sizes). The optimized 4D-IMRT plan enhanced sparing of organs at risk by an average reduction of 26% in maximum dose, compared to the clinical optimized IMRT plan, where the internal target volume was used. We validated our computation time analyses in two additional cases. The computation speed in our implementation did not monotonically increase with the number of GPUs. The optimal number of GPUs (five, in our study) is directly related to the hardware specifications. The optimization process took 35 min using 50 PSO particles, 25 iterations and 5 GPUs.

Multi-GPU configuration of 4D intensity modulated radiation therapy inverse planning using global optimization.

PubMed

Hagan, Aaron; Sawant, Amit; Folkerts, Michael; Modiri, Arezoo

2018-01-16

We report on the design, implementation and characterization of a multi-graphic processing unit (GPU) computational platform for higher-order optimization in radiotherapy treatment planning. In collaboration with a commercial vendor (Varian Medical Systems, Palo Alto, CA), a research prototype GPU-enabled Eclipse (V13.6) workstation was configured. The hardware consisted of dual 8-core Xeon processors, 256 GB RAM and four NVIDIA Tesla K80 general purpose GPUs. We demonstrate the utility of this platform for large radiotherapy optimization problems through the development and characterization of a parallelized particle swarm optimization (PSO) four dimensional (4D) intensity modulated radiation therapy (IMRT) technique. The PSO engine was coupled to the Eclipse treatment planning system via a vendor-provided scripting interface. Specific challenges addressed in this implementation were (i) data management and (ii) non-uniform memory access (NUMA). For the former, we alternated between parameters over which the computation process was parallelized. For the latter, we reduced the amount of data required to be transferred over the NUMA bridge. The datasets examined in this study were approximately 300 GB in size, including 4D computed tomography images, anatomical structure contours and dose deposition matrices. For evaluation, we created a 4D-IMRT treatment plan for one lung cancer patient and analyzed computation speed while varying several parameters (number of respiratory phases, GPUs, PSO particles, and data matrix sizes). The optimized 4D-IMRT plan enhanced sparing of organs at risk by an average reduction of [Formula: see text] in maximum dose, compared to the clinical optimized IMRT plan, where the internal target volume was used. We validated our computation time analyses in two additional cases. The computation speed in our implementation did not monotonically increase with the number of GPUs. The optimal number of GPUs (five, in our study) is directly related to the hardware specifications. The optimization process took 35 min using 50 PSO particles, 25 iterations and 5 GPUs.

Metal-free virucidal effects induced by g-C3N4 under visible light irradiation: Statistical analysis and parameter optimization.

PubMed

Zhang, Chi; Li, Yi; Zhang, Wenlong; Wang, Peifang; Wang, Chao

2018-03-01

Waterborne viruses with a low infectious dose and a high pathogenic potential pose a serious risk for humans all over the world, calling for a cost-effective and environmentally-friendly inactivation method. Optimizing operational parameters during the disinfection process is a facile and efficient way to achieve the satisfactory viral inactivation efficiency. Here, the antiviral effects of a metal-free visible-light-driven graphitic carbon nitride (g-C 3 N 4 ) photocatalyst were optimized by varying operating parameters with response surface methodology (RSM). Twenty sets of viral inactivation experiments were performed by changing three operating parameters, namely light intensity, photocatalyst loading and reaction temperature, at five levels. According to the experimental data, a semi-empirical model was developed with a high accuracy (determination coefficient R 2  = 0.9908) and then applied to predict the final inactivation efficiency of MS2 (a model virus) after 180 min exposure to the photocatalyst and visible light illumination. The corresponding optimal values were found to be 199.80 mW/cm 2 , 135.40 mg/L and 24.05 °C for light intensity, photocatalyst loading and reaction temperature, respectively. Under the optimized conditions, 8 log PFU/mL of viruses could be completely inactivated by g-C 3 N 4 without regrowth within 240 min visible light irradiation. Our study provides not only an extended application of RSM in photocatalytic viral inactivation but also a green and effective method for water disinfection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chronic Wasting Disease: Transmission Mechanisms and the Possibility of Harvest Management

PubMed Central

Potapov, Alex; Merrill, Evelyn; Pybus, Margo; Lewis, Mark A.

2016-01-01

We develop a model of CWD management by nonselective deer harvest, currently the most feasible approach available for managing CWD in wild populations. We use the model to explore the effects of 6 common harvest strategies on disease prevalence and to identify potential optimal harvest policies for reducing disease prevalence without population collapse. The model includes 4 deer categories (juveniles, adult females, younger adult males, older adult males) that may be harvested at different rates, a food-based carrying capacity, which influences juvenile survival but not adult reproduction or survival, and seasonal force of infection terms for each deer category under differing frequency-dependent transmission dynamics resulting from environmental and direct contact mechanisms. Numerical experiments show that the interval of transmission coefficients β where the disease can be controlled is generally narrow and efficiency of a harvest policy to reduce disease prevalence depends crucially on the details of the disease transmission mechanism, in particular on the intensity of disease transmission to juveniles and the potential differences in the behavior of older and younger males that influence contact rates. Optimal harvest policy to minimize disease prevalence for each of the assumed transmission mechanisms is shown to depend on harvest intensity. Across mechanisms, a harvest that focuses on antlered deer, without distinguishing between age classes reduces disease prevalence most consistently, whereas distinguishing between young and older antlered deer produces higher uncertainty in the harvest effects on disease prevalence. Our results show that, despite uncertainties, a modelling approach can determine classes of harvest strategy that are most likely to be effective in combatting CWD. PMID:26963921

Viscous Aerodynamic Shape Optimization with Installed Propulsion Effects

NASA Technical Reports Server (NTRS)

Heath, Christopher M.; Seidel, Jonathan A.; Rallabhandi, Sriram K.

2017-01-01

Aerodynamic shape optimization is demonstrated to tailor the under-track pressure signature of a conceptual low-boom supersonic aircraft. Primarily, the optimization reduces nearfield pressure waveforms induced by propulsion integration effects. For computational efficiency, gradient-based optimization is used and coupled to the discrete adjoint formulation of the Reynolds-averaged Navier Stokes equations. The engine outer nacelle, nozzle, and vertical tail fairing are axi-symmetrically parameterized, while the horizontal tail is shaped using a wing-based parameterization. Overall, 48 design variables are coupled to the geometry and used to deform the outer mold line. During the design process, an inequality drag constraint is enforced to avoid major compromise in aerodynamic performance. Linear elastic mesh morphing is used to deform volume grids between design iterations. The optimization is performed at Mach 1.6 cruise, assuming standard day altitude conditions at 51,707-ft. To reduce uncertainty, a coupled thermodynamic engine cycle model is employed that captures installed inlet performance effects on engine operation.

Multiobjective optimization of low impact development stormwater controls

NASA Astrophysics Data System (ADS)

Eckart, Kyle; McPhee, Zach; Bolisetti, Tirupati

2018-07-01

Green infrastructure such as Low Impact Development (LID) controls are being employed to manage the urban stormwater and restore the predevelopment hydrological conditions besides improving the stormwater runoff water quality. Since runoff generation and infiltration processes are nonlinear, there is a need for identifying optimal combination of LID controls. A coupled optimization-simulation model was developed by linking the U.S. EPA Stormwater Management Model (SWMM) to the Borg Multiobjective Evolutionary Algorithm (Borg MOEA). The coupled model is capable of performing multiobjective optimization which uses SWMM simulations as a tool to evaluate potential solutions to the optimization problem. The optimization-simulation tool was used to evaluate low impact development (LID) stormwater controls. A SWMM model was developed, calibrated, and validated for a sewershed in Windsor, Ontario and LID stormwater controls were tested for three different return periods. LID implementation strategies were optimized using the optimization-simulation model for five different implementation scenarios for each of the three storm events with the objectives of minimizing peak flow in the stormsewers, reducing total runoff, and minimizing cost. For the sewershed in Windsor, Ontario, the peak run off and total volume of the runoff were found to reduce by 13% and 29%, respectively.

Structural analysis of a reflux pool-boiler solar receiver

NASA Astrophysics Data System (ADS)

Hoffman, E. L.; Stone, C. M.

1991-06-01

Coupled thermal-structural finite element calculations of a reflux pool-boiler solar receiver were performed to characterize the operating stresses and to address issues affecting the service life of the receiver. Analyses performed using shell elements provided information for receiver material selection and design optimization. Calculations based on linear elastic fracture mechanics principles were performed using continuum elements to assess the vulnerability of a seam-weld to fatigue crack growth. All calculations were performed using ABAQUS, a general purpose finite element code, and elements specifically formulated for coupled thermal-structural analysis. Two materials were evaluated: 316L SS and Haynes 230 alloys. The receiver response was simulated for a combination of structural and thermal loads that represent the startup and operating conditions of the receiver. For both materials, maximum stresses in the receiver developed shortly after startup due to uneven temperature distribution across the receiver surface. The largest effective stress was near yield in the 316L SS receiver and below 39 percent of yield in the Haynes 230 receiver. The calculations demonstrated that stress reductions of over 25 percent could be obtained by reducing the aft dome thickness to one closer to the absorber. The fatigue calculations demonstrated that the stress distribution near the seam-weld notch depends primarily on the structural load created by internal pressurization of the receiver rather than the thermal, indicating that the thermal loads can be neglected when assessing the stress intensity near the seam-weld notch. The stress intensity factor, computed using the J-integral method and crack opening-displacement field equations, was significantly below the fatigue threshold for most steels. The calculations indicated that the weld notch was always loaded in compression, a condition which is not conducive to fatigue crack growth.

Successful report of reduced-intensity stem cell transplantation from unrelated umbilical cord blood in a girl with chronic active Epstein-Barr virus infection.

PubMed

Iguchi, Akihiro; Kobayashi, Ryoji; Sato, Tomonobu Z; Nakajima, Masahide; Kaneda, Makoto; Ariga, Tadashi

2006-04-01

We describe an 8-year-old girl with chronic active Epstein-Barr virus (EBV) infection (CAEBV) who was treated successfully by reduced-intensity stem cell transplantation (RIST) from unrelated cord blood (CB). She had been suffering from fever, abdominal pain, and interstitial lymphadenopathy, and CAEBV was diagnosed. After chemotherapy that included etoposide, the amount of EBV decreased transiently below the detection level. However, the disease due to CAEBV worsened despite the chemotherapy, and she finally needed chemotherapy every week. Therefore, instead of conventional myeloablative transplantation, we performed CB transplantation with reduced-intensity conditioning regimens consisting of low-dose total body irradiation, fludarabine, and etoposide. CB, for which human leukocyte antigen (HLA) was 2-loci mismatched on the DR loci from an unrelated donor, was infused after conditioning. Although grade III acute graft-versus-host disease (GVHD) in the gut and chronic GVHD in the lung developed, the symptoms of GVHD disappeared with immunosuppressive therapy. After 15 months, the patient remained a complete chimera, with undetectable levels of EBV in peripheral blood and bone marrow. We conclude that RIST from unrelated CB can be indicated for some cases of CAEBV who are refractory to chemotherapy and have no HLA-matched related and unrelated donors as the source of bone marrow or peripheral blood stem cells.

Optimization of electrochemical dechlorination of trichloroethylene in reducing electrolytes

PubMed Central

Mao, Xuhui; Ciblak, Ali; Baek, Kitae; Amiri, Mohammad; Loch-Caruso, Rita; Alshawabkeh, Akram N.

2012-01-01

Electrochemical dechlorination of trichloroethylene (TCE) in aqueous solution is investigated in a closed, liquid-recirculation system. The anodic reaction of cast iron generates ferrous species, creating a chemically reducing electrolyte (negative ORP value). The reduction of TCE on the cathode surface is enhanced under this reducing electrolyte because of the absence of electron competition. In the presence of the iron anode, the performances of different cathodes are compared in a recirculated electrolysis system. The copper foam shows superior capability for dechlorination of aqueous TCE. Electrolysis by cast iron anode and copper foam cathode is further optimized though a multivariable experimental design and analysis. The conductivity of the electrolyte is identified as an important factor for both final elimination efficiency (FEE) of TCE and specific energy consumption. The copper foam electrode exhibits high TCE elimination efficiency in a wide range of initial TCE concentration. Under coulostatic conditions, the optimal conditions to achieve the highest FEE are 9.525 mm thick copper foam electrode, 40 mA current and 0.042 mol L−1 Na2SO4. This novel electrolysis system is proposed to remediate groundwater contaminated by chlorinated organic solvents, or as an improved iron electrocoagulation process capable of treating the wastewater co-contaminated with chlorinated compounds. PMID:22264798

Comparison of response surface methodology and artificial neural network to enhance the release of reducing sugars from non-edible seed cake by autoclave assisted HCl hydrolysis.

PubMed

Shet, Vinayaka B; Palan, Anusha M; Rao, Shama U; Varun, C; Aishwarya, Uday; Raja, Selvaraj; Goveas, Louella Concepta; Vaman Rao, C; Ujwal, P

2018-02-01

In the current investigation, statistical approaches were adopted to hydrolyse non-edible seed cake (NESC) of Pongamia and optimize the hydrolysis process by response surface methodology (RSM). Through the RSM approach, the optimized conditions were found to be 1.17%v/v of HCl concentration at 54.12 min for hydrolysis. Under optimized conditions, the release of reducing sugars was found to be 53.03 g/L. The RSM data were used to train the artificial neural network (ANN) and the predictive ability of both models was compared by calculating various statistical parameters. A three-layered ANN model consisting of 2:12:1 topology was developed; the response of the ANN model indicates that it is precise when compared with the RSM model. The fit of the models was expressed with the regression coefficient R 2 , which was found to be 0.975 and 0.888, respectively, for the ANN and RSM models. This further demonstrated that the performance of ANN was better than that of RSM.