Pretreatment with myo-inositol in non polycystic ovary syndrome patients undergoing multiple follicular stimulation for IVF: a pilot study.

PubMed

Lisi, Franco; Carfagna, Piero; Oliva, Mario Montanino; Rago, Rocco; Lisi, Rosella; Poverini, Roberta; Manna, Claudio; Vaquero, Elena; Caserta, Donatella; Raparelli, Valeria; Marci, Roberto; Moscarini, Massimo

2012-07-23

Aim of this pilot study is to examine the effects of myo-inositol administration on ovarian response and oocytes and embryos quality in non PolyCystic Ovary Syndrome (PCOS) patients undergoing multiple follicular stimulation and in vitro insemination by conventional in vitro fertilization or by intracytoplasmic sperm injection. One hundred non-PCOS women aged <40 years and with basal FSH <10 mUI/ml were down-regulated with triptorelin acetate from the mid-luteal phase for 2 weeks, before starting the stimulation protocol for oocytes recovery. All patients received rFSH, at a starting dose of 150 IU for 6 days. The dose was subsequently adjusted according to individual response. Group B (n=50) received myo-inositol and folic acid for 3 months before the stimulation period and then during the stimulation itself. Group A (n-50) received only folic acid as additional treatment in the 3 months before and through treatment. Total length of the stimulation was similar between the two groups. Nevertheless, total amount of gonadotropins used to reach follicular maturation was found significantly lower in group B. In addition, the number of oocytes retrieved was significantly reduced in the group pretreated with myo-inositol. Clinical pregnancy and implantation rate were not significantly different in the two groups. Our findings suggest that the addition of myo-inositol to folic acid in non PCOS-patients undergoing multiple follicular stimulation for in-vitro fertilization may reduce the numbers of mature oocytes and the dosage of rFSH whilst maintaining clinical pregnancy rate. Further, a trend in favor of increased incidence of implantation in the group pretreated with myo-inositol was apparent in this study. Further investigations are warranted to clarify this pharmacological approach, and the benefit it may hold for patients.

In vitro terahertz spectroscopy of gelatin-embedded human brain tumors: a pilot study

NASA Astrophysics Data System (ADS)

Chernomyrdin, N. V.; Gavdush, A. A.; Beshplav, S.-I. T.; Malakhov, K. M.; Kucheryavenko, A. S.; Katyba, G. M.; Dolganova, I. N.; Goryaynov, S. A.; Karasik, V. E.; Spektor, I. E.; Kurlov, V. N.; Yurchenko, S. O.; Komandin, G. A.; Potapov, A. A.; Tuchin, V. V.; Zaytsev, K. I.

2018-04-01

We have performed the in vitro terahertz (THz) spectroscopy of human brain tumors. In order to fix tissues for the THz measurements, we have applied the gelatin embedding. It allows for preserving tissues from hydration/dehydration and sustaining their THz response similar to that of the freshly-excised tissues for a long time after resection. We have assembled an experimental setup for the reflection-mode measurements of human brain tissues based on the THz pulsed spectrometer. We have used this setup to study in vitro the refractive index and the amplitude absorption coefficient of 2 samples of malignant glioma (grade IV), 1 sample of meningioma (grade I), and samples of intact tissues. We have observed significant differences between the THz responses of normal and pathological tissues of the brain. The results of this paper highlight the potential of the THz technology in the intraoperative neurodiagnosis of tumors relying on the endogenous labels of tumorous tissues.

Nonwoven-Based Gelatin/Polycaprolactone Membrane Proves Suitability in a Preclinical Assessment for Treatment of Soft Tissue Defects

PubMed Central

Schulz, Simon; Angarano, Marco; Fabritius, Martin; Mülhaupt, Rolf; Dard, Michel; Obrecht, Marcel; Tomakidi, Pascal

2014-01-01

Standard preclinical assessments in vitro often have limitations regarding their transferability to human beings, mainly evoked by their nonhuman and tissue-different/nontissue-specific source. Here, we aimed at employing tissue-authentic simple and complex interactive fibroblast-epithelial cell systems and their in vivo-relevant biomarkers for preclinical in vitro assessment of nonwoven-based gelatin/polycaprolactone membranes (NBMs) for treatment of soft tissue defects. NBMs were composed of electrospun gelatin and polycaprolactone nanofiber nonwovens. Scanning electron microscopy in conjunction with actin/focal contact integrin fluorescence revealed successful adhesion and proper morphogenesis of keratinocytes and fibroblasts, along with cells' derived extracellular matrix deposits. The “feel-good factor” of cells under study on the NBM was substantiated by forming a confluent connective tissue entity, which was concomitant with a stratified epithelial equivalent. Immunohistochemistry proved tissue authenticity over time by abundance of the biomarker vimentin in the connective tissue entity, and chronological increase of keratins KRT1/10 and involucrin expression in epithelial equivalents. Suitability of the novel NBM as wound dressing was evidenced by an almost completion of epithelial wound closure in a pilot mini-pig study, after a surgical intervention-caused gingival dehiscence. In summary, preclinical assessment by tissue-authentic cell systems and the animal pilot study revealed the NBM as an encouraging therapeutic medical device for prospective clinical applications. PMID:24494668

Deciding how many embryos to transfer after in vitro fertilisation: development and pilot test of a decision aid.

PubMed

van Peperstraten, Arno M; Hermens, Rosella P M G; Nelen, Willianne L D M; Stalmeier, Peep F M; Wetzels, Alex M M; Maas, Pettie H M; Kremer, Jan A M; Grol, Richard P T M

2010-01-01

When deciding how many embryos to transfer during in vitro fertilisation (IVF), clinicians and patients have to balance optimizing the chance of pregnancy against preventing multiple pregnancies and the associated complications. This paper describes the development and pilot test of a patient decision aid (DA) for this purpose. The development of the DA consisted of a literature search, establishment of the format, and a pilot test among IVF patients. The DA development was supervised by a panel of experts in the fields of subfertility, obstetrics and DA-research and it was based on the criteria of the International Patient Decision Aid Standards. One Cochrane review and 34 articles were selected for the DA content. The DA presents information in text, summaries, tables, figures and through an interactive worksheet. The DA was reviewed positively and as acceptable for use in clinical practice by patients and professionals. The DA was thoroughly developed and is likely to be helpful for the decision-making process for the number of embryos transferred after IVF. Physicians and researchers can use the DA without restriction in clinical practice or research related to decision-making.

Topical Treatment With Liposomal Sodium Copper Chlorophyllin Complex in Subjects With Facial Redness and Erythematotelangiectatic Rosacea: Case Studies.

PubMed

Vasily, David B

2015-10-01

Physicians are often presented with patients complaining of facial redness and difficult to control rosacea. The water soluble sodium copper chlorophyllin complex has been shown to have anti-oxidant, anti-inflammatory, and anti-bacterial activities in vitro and anti-redness, pore reduction, and anti-acne activities in pilot clinical studies. In these case studies, the safety and efficacy of a topical gel containing a liposomal suspension of sodium copper chlorophyllin complex was assessed in subjects with facial redness and erythematotelangiectatic rosacea.

Whole-body biodistribution and brain PET imaging with [18F]AV-45, a novel amyloid imaging agent--a pilot study.

PubMed

Lin, Kun-Ju; Hsu, Wen-Chuin; Hsiao, Ing-Tsung; Wey, Shiaw-Pyng; Jin, Lee-Way; Skovronsky, Daniel; Wai, Yau-Yau; Chang, Hsiu-Ping; Lo, Chuan-Wei; Yao, Cheng Hsiang; Yen, Tzu-Chen; Kung, Mei-Ping

2010-05-01

The compound (E)-4-(2-(6-(2-(2-(2-(18)F-fluoroethoxy)ethoxy)ethoxy) pyridin-3-yl)vinyl)-N-methylbenzenamine ([(18)F]AV-45) is a novel radiopharmaceutical capable of selectively binding to beta-amyloid (A beta) plaques. This pilot study reports the safety, biodistribution, and radiation dosimetry of [(18)F]AV-45 in human subjects. In vitro autoradiography and fluorescent staining of postmortem brain tissue from patients with Alzheimer's disease (AD) and cognitively healthy subjects were performed to assess the specificity of the tracer. Biodistribution was assessed in three healthy elderly subjects (mean age: 60.0+/-5.2 years) who underwent 3-h whole-body positron emission tomography (PET)/computed tomographic (CT) scans after a bolus injection of 381.9+/-13.9 MBq of [(18)F]AV-45. Another six subjects (three AD patients and three healthy controls, mean age: 67.7+/-13.6 years) underwent brain PET studies. Source organs were delineated on PET/CT. All subjects underwent magnetic resonance imaging (MRI) for obtaining structural information. In vitro autoradiography revealed exquisitely high specific binding of [(18)F]AV-45 to postmortem AD brain sections, but not to the control sections. There were no serious adverse events throughout the study period. The peak uptake of the tracer in the brain was 5.12+/-0.41% of the injected dose. The highest absorbed organ dose was to the gallbladder wall (184.7+/-78.6 microGy/MBq, 4.8 h voiding interval). The effective dose equivalent and effective dose values for [(18)F]AV-45 were 33.8+/-3.4 microSv/MBq and 19.3+/-1.3 microSv/MBq, respectively. [(18)F]AV-45 binds specifically to A beta in vitro, and is a safe PET tracer for studying A beta distribution in human brain. The dosimetry is suitable for clinical and research application. (c) 2010 Elsevier Inc. All rights reserved.

In Vitro Activation of eNOS by Mangifera indica (Careless™) and Determination of an Effective Dosage in a Randomized, Double-Blind, Human Pilot Study on Microcirculation.

PubMed

Gerstgrasser, Alexandra; Röchter, Sigrid; Dressler, Dirk; Schön, Christiane; Reule, Claudia; Buchwald-Werner, Sybille

2016-03-01

Mangifera indica fruit preparation (Careless™) activates the evolutionary conserved metabolic sensors sirtuin 1 and adenosine monophosphate-activated protein kinase, which have been identified as playing a key role in microcirculation and endothelial function. Here, an acute effect of a single dose of 100 mg or 300 mg Careless™ on microcirculation was investigated in a randomized, double-blind, crossover pilot study in ten healthy women to determine the effective dosage. Microcirculation and endothelial function were assessed by the Oxygen-to-see system and pulse amplitude tonometry (EndoPAT™), respectively. Cutaneous blood flow was increased over time by 100 mg (54% over pre-values, p = 0.0157) and 300 mg (35% over pre-value, p = 0.209) Careless™. The EndoPAT™ reactive hyperemia response was slightly improved 3 h after intake compared to pretesting with 300 mg Careless™. Furthermore, activation of endothelial nitric oxide synthase, as an important regulator for endothelial function, was tested in vitro in primary human umbilical vein endothelial cells. Careless™, after simulation of digestion, increased the activated form of endothelial nitric oxide synthase dose-dependently by 23% (300 µg/mL), 42% (1500 µg/mL), and 60% (3000 µg/mL) compared to the untreated control. In conclusion, the study suggests moderate beneficial effects of Careless™ on microcirculation, which is at least partly mediated by endothelial nitric oxide synthase activation. Georg Thieme Verlag KG Stuttgart · New York.

Topical treatment of tinea pedis using 6% coriander oil in unguentum leniens: a randomized, controlled, comparative pilot study.

PubMed

Beikert, F C; Anastasiadou, Z; Fritzen, B; Frank, U; Augustin, M

2013-01-01

The antifungal activity of coriander oil has already been demonstrated in vitro. Evaluation of the efficacy and tolerability of 6% coriander oil in unguentum leniens in the treatment of interdigital tinea pedis. Half-side comparative pilot study on subjects with symmetric, bilateral interdigital tinea pedis. Active drug and placebo control were applied twice daily on the affected areas, and follow-up visits were performed on days 14 and 28. 40 participants (mean age 52.5 years, 60% male) were included in the study. For 6% coriander oil in unguentum leniens, a highly significant improvement of the clinical signs (p < 0.0001) was observed during the entire observation period; the number of positive fungal cultures also tended to decrease (p = 0.0654). The tolerability of the tested substances was good. Coriander oil is effective and well tolerated in the treatment of interdigital tinea pedis. Copyright © 2013 S. Karger AG, Basel.

Saffron in phytotherapy: pharmacology and clinical uses.

PubMed

Schmidt, Mathias; Betti, Georges; Hensel, Andreas

2007-01-01

Saffron (stigmata of Crocus sativus L.) has been used for medicinal purposes for millennia. Throughout history, uses against cancer and depressive mood can regularly be identified. These applications have also been in the focus of modern research. Promising and selective anti-cancer effects have been observed in vitro and in vivo, but not yet in clinical trials. Antidepressant effects were found in vivo and in clinical pilot studies. Saffron extracts thus have the potential to make a major contribution to rational phytotherapy.

Pretreatment with myo-inositol in non polycystic ovary syndrome patients undergoing multiple follicular stimulation for IVF: a pilot study

PubMed Central

2012-01-01

Background Aim of this pilot study is to examine the effects of myo-inositol administration on ovarian response and oocytes and embryos quality in non PolyCystic Ovary Syndrome (PCOS) patients undergoing multiple follicular stimulation and in vitro insemination by conventional in vitro fertilization or by intracytoplasmic sperm injection. Methods One hundred non-PCOS women aged <40 years and with basal FSH <10 mUI/ml were down-regulated with triptorelin acetate from the mid-luteal phase for 2 weeks, before starting the stimulation protocol for oocytes recovery. All patients received rFSH, at a starting dose of 150 IU for 6 days. The dose was subsequently adjusted according to individual response. Group B (n = 50) received myo-inositol and folic acid for 3 months before the stimulation period and then during the stimulation itself. Group A (n-50) received only folic acid as additional treatment in the 3 months before and through treatment. Results Total length of the stimulation was similar between the two groups. Nevertheless, total amount of gonadotropins used to reach follicular maturation was found significantly lower in group B. In addition, the number of oocytes retrieved was significantly reduced in the group pretreated with myo-inositol. Clinical pregnancy and implantation rate were not significantly different in the two groups. Conclusions Our findings suggest that the addition of myo-inositol to folic acid in non PCOS-patients undergoing multiple follicular stimulation for in-vitro fertilization may reduce the numbers of mature oocytes and the dosage of rFSH whilst maintaining clinical pregnancy rate. Further, a trend in favor of increased incidence of implantation in the group pretreated with myo-inositol was apparent in this study. Further investigations are warranted to clarify this pharmacological approach, and the benefit it may hold for patients. PMID:22823904

Temperature evaluation during PMMA screw augmentation in osteoporotic bone--an in vitro study about the risk of thermal necrosis in human femoral heads.

PubMed

Boner, Vanessa; Kuhn, Philipp; Mendel, Thomas; Gisep, Armando

2009-08-01

The use of polymethylmethacrylate (PMMA) bone cement to augment hip screws reduces cut-out risk but is associated with an exothermic reaction. This in vitro investigation evaluated the risk of thermal necrosis when augmenting the implant purchase with PMMA. A pilot study analyzed the effects of different PMMA layer thicknesses on temperatures around an implant. The main study used either 3.0 or 6.0 cc PMMA for hip screw augmentation in human femoral heads. The risk of thermal necrosis was estimated according to critical values reported in literature. Highest temperatures were measured inside the PMMA with a significant drop of average maximum temperatures from the center of the PMMA to the PMMA/bone interface. Risk of thermal necrosis exists with PMMA layer thicknesses greater than 5.0 mm. In the main study, we found no risk of thermal necrosis at the PMMA/bone interface or in the surrounding bone, neither with 3.0 nor 6.0 cc PMMA. The results of the two studies were consistent regarding average peak temperatures related to associated cement layer thicknesses. The results of this in vitro study reduce objections concerning the risk of thermal necrosis when augmenting cancellous bone around hip screws with up to 6.0 cc PMMA.

A pilot study in non-human primates shows no adverse response to intravenous injection of quantum dots.

PubMed

Ye, Ling; Yong, Ken-Tye; Liu, Liwei; Roy, Indrajit; Hu, Rui; Zhu, Jing; Cai, Hongxing; Law, Wing-Cheung; Liu, Jianwei; Wang, Kai; Liu, Jing; Liu, Yaqian; Hu, Yazhuo; Zhang, Xihe; Swihart, Mark T; Prasad, Paras N

2012-05-20

Quantum dots have been used in biomedical research for imaging, diagnostics and sensing purposes. However, concerns over the cytotoxicity of their heavy metal constituents and conflicting results from in vitro and small animal toxicity studies have limited their translation towards clinical applications. Here, we show in a pilot study that rhesus macaques injected with phospholipid micelle-encapsulated CdSe/CdS/ZnS quantum dots do not exhibit evidence of toxicity. Blood and biochemical markers remained within normal ranges following treatment, and histology of major organs after 90 days showed no abnormalities. Our results show that acute toxicity of these quantum dots in vivo can be minimal. However, chemical analysis revealed that most of the initial dose of cadmium remained in the liver, spleen and kidneys after 90 days. This means that the breakdown and clearance of quantum dots is quite slow, suggesting that longer-term studies will be required to determine the ultimate fate of these heavy metals and the impact of their persistence in primates.

Doxycycline-containing glass ionomer cement for arresting residual caries: an in vitro study and a pilot trial.

PubMed

Castilho, Aline Rogéria Freire de; Duque, Cristiane; Kreling, Paula Fernanda; Pereira, Jesse Augusto; Paula, Andreia Bolzan de; Sinhoreti, Mario Alexandre Coelho; Puppin-Rontani, Regina Maria

2018-01-01

In a previous study, we demonstrated that the incorporation of doxycycline hyclate (DOX) into resin-modified glass ionomer cement (RMGIC) inhibited important cariogenic microorganisms, without modifying its biological and mechanical characteristics. In this study, we keep focused on the effect of that experimental material as a potential therapy for arresting residual caries by analyzing other in vitro properties and conducting a pilot clinical trial assessing the in vivo effect of DOX-containing RMGIC on residual mutans streptococci after partial carious removal in primary molars. Specimens of the groups RMGIC (control); RMGIC + 1.5% DOX; RMGIC + 3% DOX; and RMGIC + 4.5% DOX were made to evaluate the effect of DOX incorporation on surface microhardness and fluoride release of RMGIC and against biofilm of Streptococcus mutans. Clinical intervention consisted of partial caries removal comparing RMGIC and RMGIC + 4.5% DOX as lining materials. After 3 months, clinical and microbiologic evaluations were performed. Data were submitted to ANOVA/Tukey or Wilcoxon/Mann-Whitney set as α=0.05. Fluoride release and surface microhardness was not influenced by the incorporation of DOX (p>0.05). There was a significant reduction of S. mutans biofilm over the material surface with the increase of DOX concentration. After clinical trial, the remaining dentin was hard and dry. Additionally, mutans streptococci were completely eliminated after 3 months of treatment with RMGIC + 4.5% DOX. The incorporation of DOX provided better antibiofilm effect, without jeopardizing fluoride release and surface microhardness of RMGIC. This combination also improved the in vivo shortterm microbiological effect of RMGIC after partial caries removal.

Aspiration and ethanol sclerotherapy to treat recurrent ovarian endometriomas prior to in vitro fertilization - a pilot study.

PubMed

André, Gustavo Mendonça; Vilarino, Fábia Lima; Christofolini, Denise Maria; Bianco, Bianca; Barbosa, Caio Parente

2011-12-01

To describe the evolution of controlled ovarian hyperstimulation in women with recurrent ovarian endometriomas treated with sclerotherapy. Twenty-one patients with a laparoscopic diagnosis of stage III or IV endometriosis who had an endometrioma larger than 3 cm before ovarian hyperstimulation for in vitro fertilization were included in the study. After using a GnRH agonist analog for at least 20 days, the cysts were punctured using ultrasound guidance and subsequent ethanol sclerotherapy was performed. Then, the patients were stimulated with 100 or 200 U/day of recombinant follicle stimulating hormone, varying the dose according to the patient's age or history of a previous unilateral oophorectomy. The ovarian cysts had an average diameter of 4.7 ± 1.4 cm and did not recur after aspiration during the ovulation induction. Oocyte extraction occurred after 11 days of hyperstimulation, with 3.95 ± 3.30 oocytes obtained per cycle, on average. Embryo transfer occurred in 71.4% (15/21) of patients, and the pregnancy rate after transfer was 20% (3/15). Aspiration followed by ethanol sclerotherapy prior to in vitro fertilization can be an option for patients who desire a pregnancy and have recurrent endometriomas.

Morphologic and molecular evaluation of Chlamydia trachomatis growth in human endocervix reveals distinct growth patterns

PubMed Central

Lewis, Maria E.; Belland, Robert J.; AbdelRahman, Yasser M.; Beatty, Wandy L.; Aiyar, Ashok A.; Zea, Arnold H.; Greene, Sheila J.; Marrero, Luis; Buckner, Lyndsey R.; Tate, David J.; McGowin, Chris L.; Kozlowski, Pamela A.; O'Brien, Michelle; Lillis, Rebecca A.; Martin, David H.; Quayle, Alison J.

2014-01-01

In vitro models of Chlamydia trachomatis growth have long been studied to predict growth in vivo. Alternative or persistent growth modes in vitro have been shown to occur under the influence of numerous stressors but have not been studied in vivo. Here, we report the development of methods for sampling human infections from the endocervix in a manner that permits a multifaceted analysis of the bacteria, host and the endocervical environment. Our approach permits evaluating total bacterial load, transcriptional patterns, morphology by immunofluorescence and electron microscopy, and levels of cytokines and nutrients in the infection microenvironment. By applying this approach to two pilot patients with disparate infections, we have determined that their contrasting growth patterns correlate with strikingly distinct transcriptional biomarkers, and are associated with differences in local levels of IFNγ. Our multifaceted approach will be useful to dissect infections in the human host and be useful in identifying patients at risk for chronic disease. Importantly, the molecular and morphological analyses described here indicate that persistent growth forms can be isolated from the human endocervix when the infection microenvironment resembles the in vitro model of IFNγ-induced persistence. PMID:24959423

Influence of a new surface modification of intraocular lenses with fluoroalkylsilan on the adherence of endophthalmitis-causing bacteria in vitro.

PubMed

Kienast, Antonia; Kämmerer, Regine; Weiss, Claudia; Klinger, Matthias; Menz, Dirk-Henning; Dresp, Joachim; Ohgke, Helge; Solbach, Werner; Laqua, Horst; Hoerauf, Hans

2006-09-01

Dynasilan is a fluoroalkylsilan that is able to interact with surface active centres on intraocular lenses (IOL), offering a new way for surface modification of different IOL materials. The purpose of this in vitro study was to investigate the influence of this new surface modification on the adherence of two typical endophthalmitis causing bacteria (Staphylococcus epidermidis, Propionibacterium acnes). In a pilot experiment, the effect of Dynasilan coating on the adherence of S. epidermidis was tested on glass slides. Forty-two Dynasilan-modified and 42 unmodified IOL (14 PMMA, 14 silicone and 14 hydrogel) were incubated at 37 degrees C in brain heart infusion broth (10(8) CFU/ml) with either S. epidermidis for 24 h or with P. acnes for 1 h. Subsequently, the adherent bacteria were resuspended using ultrasonification at 35 kHz for 3x45 s. After dilution series and incubation at 37 degrees C on Petri dishes for 24 h and 3 days, respectively, the colonies were counted. In the pilot experiment, a markedly lower number of adherent S. epidermidis was observed on Dynasilan-modified glass slides. Of all IOL materials incubated with S. epidermidis, those modified with Dynasilan showed a lower mean number of adherent bacteria (mean 1.37x10(7); SD 2.37x10(7)) than those untreated (2.43x10(7); SD 3.04x10(7)). IOLs incubated with P. acnes showed a significantly lower mean number of adherent bacteria of 2.51x10(4) (SD 2.71x10(4)) on Dynasilan-modified IOLs versus 6.27x10(4) (SD 7.70x10(4)) on untreated IOLs. The presented in vitro results indicate that Dynasilan surface modification is able to reduce the adherence of S. epidermidis and P. acnes on all IOL materials tested. Further studies regarding the stability of this modification and its biocompatibility must be performed.

In vitro and in vivo anti-microbial activity evaluation of inactivated cells of Lactobacillus salivarius CECT 5713 against Streptococcus mutans.

PubMed

Sañudo, Ana I; Luque, Roberto; Díaz-Ropero, Mª Paz; Fonollá, Juristo; Bañuelos, Óscar

2017-12-01

Defining the etiology of dental caries is a complex problem. The microbiological approach has included Streptococcus mutans as one of the bacterial species involved in this disease. This research investigates the inhibitory effects of heat-inactivated Lactobacillus salivarius CECT 5713 against S. mutans using in vitro and in vivo assays. On the one hand, the effect of non-viable L. salivarius CECT 5713 on the in vitro adhesion of S. mutans to hydroxyapatite discs was evaluated. On the other hand, levels of Streptococcus mutans, amount of salivary flow and salivary pH before and after taking the rinse with the non-viable L. salivarius CECT 5713 in healthy volunteers were assessed (self-controlled open-label pilot study). The levels of S. mutans seemed to decrease in the in vitro and in vivo assays (p<0.05). The in vitro effect of non-viable L. salivarius was maintained until 36 months of storage. In addition, the reduction of S. mutans salivary concentration in the volunteers was statistically significant from the third day until two weeks of treatment. Heat-inactivated L. salivarius CECT 5713 prevents S. mutans adhesion to hydroxyapatite and could be used as a strategy to reduce the salivary concentration of this oral pathogen. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of plant sterol-enriched turkey meat on cholesterol bio-accessibility during in vitro digestion and Caco-2 cell uptake.

PubMed

Grasso, S; Harrison, S M; Monahan, F J; Brayden, D; Brunton, N P

2018-03-01

This study evaluated the effect of a plant sterol-enriched turkey product on cholesterol bio-accessibility during in vitro digestion and cholesterol uptake by Caco-2 monolayers. Turkey products, one plant sterol-enriched (PS) and one plant sterol-free (C), were produced in an industrial pilot plant. Before simulated digestion, matrices were spiked with cholesterol (1:5 weight ratio of cholesterol to plant sterol). Plant sterols were included at a concentration equivalent to the minimum daily intake recommended by the European Food Safety Authority (EFSA) for cholesterol lowering. After simulated digestion, the percentage of cholesterol micellarization and uptake by Caco-2 cells in the presence of PS meat were measured. Compared to C meat, PS meat significantly inhibited cholesterol micellarization on average by 24% and Caco-2 cell accumulation by 10%. This study suggests that plant sterols in meat can reduce cholesterol uptake by intestinal epithelia and it encourages efforts to make new PS-based functional foods.

Critical reappraisal of embryo quality as a predictive parameter for pregnancy outcome: a pilot study.

PubMed

Campo, R; Binda, M M; Van Kerkhoven, G; Frederickx, V; Serneels, A; Roziers, P; Lopes, A S; Gordts, S; Puttemans, P; Gordts, S

2010-01-01

Pilot study to analyse the efficacy and embryo morphology using a new human embryo culture medium (GM501) versus the conventional used medium (ISM1). Over a four-month period, all patients at the Leuven Institute of Fertility and Embryology (LIFE) were -randomly allocated to have their embryos cultured in either the standard sequential culture medium ISM1 (control) or in a new universal medium (GM501) (study group). Primary outcome parameters were clinical pregnancy and live birth rate. The secondary outcome parameter was the correlation of embryo fragmentation rate with pregnancy outcome. We did not observe any differences between the ISM1 control group and GM501 study group with regard to fertilization, pregnancy, implantation rates, ongoing pregnancy, and babies born. The number of embryos with a minimal fragmentation rate (less than 30%) was significantly higher in the GM501 study group. Although a significant higher embryo fragmentation rate was seen in In vitro culture of embryos in GM501, pregnancy outcome results were comparable to those of embryos cultured in ISM1. According to our results the value of embryo morphological criteria as a parameter for pregnancy outcome should be examined and discussed again.

A pilot study on the use of geometrically accurate face models to replicate ex vivo N95 mask fit.

PubMed

Golshahi, Laleh; Telidetzki, Karla; King, Ben; Shaw, Diana; Finlay, Warren H

2013-01-01

To test the feasibility of replicating a face mask seal in vitro, we created 5 geometrically accurate reconstructions of the head and neck of an adult human subject using different materials. Three breathing patterns were simulated with each replica and an attached N95 mask. Quantitative fit testing on the subject and the replicas showed that none of the 5 isotropic materials used allowed duplication of the ex vivo mask seal for the specific mask-face combination studied. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Doxycycline-containing glass ionomer cement for arresting residual caries: an in vitro study and a pilot trial

PubMed Central

Duque, Cristiane; Kreling, Paula Fernanda; Pereira, Jesse Augusto; de Paula, Andreia Bolzan; Sinhoreti, Mario Alexandre Coelho; Puppin-Rontani, Regina Maria

2018-01-01

Abstract In a previous study, we demonstrated that the incorporation of doxycycline hyclate (DOX) into resin-modified glass ionomer cement (RMGIC) inhibited important cariogenic microorganisms, without modifying its biological and mechanical characteristics. In this study, we keep focused on the effect of that experimental material as a potential therapy for arresting residual caries by analyzing other in vitro properties and conducting a pilot clinical trial assessing the in vivo effect of DOX-containing RMGIC on residual mutans streptococci after partial carious removal in primary molars. Specimens of the groups RMGIC (control); RMGIC + 1.5% DOX; RMGIC + 3% DOX; and RMGIC + 4.5% DOX were made to evaluate the effect of DOX incorporation on surface microhardness and fluoride release of RMGIC and against biofilm of Streptococcus mutans. Clinical intervention consisted of partial caries removal comparing RMGIC and RMGIC + 4.5% DOX as lining materials. After 3 months, clinical and microbiologic evaluations were performed. Data were submitted to ANOVA/Tukey or Wilcoxon/Mann-Whitney set as α=0.05. Fluoride release and surface microhardness was not influenced by the incorporation of DOX (p>0.05). There was a significant reduction of S. mutans biofilm over the material surface with the increase of DOX concentration. After clinical trial, the remaining dentin was hard and dry. Additionally, mutans streptococci were completely eliminated after 3 months of treatment with RMGIC + 4.5% DOX. The incorporation of DOX provided better antibiofilm effect, without jeopardizing fluoride release and surface microhardness of RMGIC. This combination also improved the in vivo shortterm microbiological effect of RMGIC after partial caries removal. PMID:29742263

A PILOT INVESTIGATION OF THE RELATIVE TOXICITY OF INDOOR AND OUTDOOR FINE PARTICLES: IN-VITRO EFFECTS OF ENDOTOXIN AND OTHER PARTICULATE PROPERTIES. (R827353C003)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

A PILOT INVESTIGATION OF THE RELATIVE TOXICITY OF INDOOR AND OUTDOOR FINE PARTICLES: IN-VITRO EFFECTS OF ENDOTOXIN AND OTHER PARTICULATE PROPERTIES. (R827353C001)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Rapid Prototyping for In Vitro Knee Rig Investigations of Prosthetized Knee Biomechanics: Comparison with Cobalt-Chromium Alloy Implant Material

PubMed Central

Schröder, Christian; Steinbrück, Arnd; Müller, Tatjana; Woiczinski, Matthias; Chevalier, Yan; Müller, Peter E.; Jansson, Volkmar

2015-01-01

Retropatellar complications after total knee arthroplasty (TKA) such as anterior knee pain and subluxations might be related to altered patellofemoral biomechanics, in particular to trochlear design and femorotibial joint positioning. A method was developed to test femorotibial and patellofemoral joint modifications separately with 3D-rapid prototyped components for in vitro tests, but material differences may further influence results. This pilot study aims at validating the use of prostheses made of photopolymerized rapid prototype material (RPM) by measuring the sliding friction with a ring-on-disc setup as well as knee kinematics and retropatellar pressure on a knee rig. Cobalt-chromium alloy (standard prosthesis material, SPM) prostheses served as validation standard. Friction coefficients between these materials and polytetrafluoroethylene (PTFE) were additionally tested as this latter material is commonly used to protect pressure sensors in experiments. No statistical differences were found between friction coefficients of both materials to PTFE. UHMWPE shows higher friction coefficient at low axial loads for RPM, a difference that disappears at higher load. No measurable statistical differences were found in knee kinematics and retropatellar pressure distribution. This suggests that using polymer prototypes may be a valid alternative to original components for in vitro TKA studies and future investigations on knee biomechanics. PMID:25879019

Critical reappraisal of embryo quality as a predictive parameter for pregnancy outcome: a pilot study

PubMed Central

Campo, R.; Binda, M.M.; Van Kerkhoven, G.; Frederickx, V.; Serneels, A.; Roziers, P.; Lopes, A.S.; Gordts, S.; Puttemans, P.; Gordts, S.

2010-01-01

Aim of the study: Pilot study to analyse the efficacy and embryo morphology using a new human embryo culture medium (GM501) versus the conventional used medium (ISM1). Methods: Over a four-month period, all patients at the Leuven Institute of Fertility and Embryology (LIFE) were randomly allocated to have their embryos cultured in either the standard sequential culture medium ISM1 (control) or in a new universal medium (GM501) (study group). Primary outcome parameters were clinical pregnancy and live birth rate. The secondary outcome parameter was the correlation of embryo fragmentation rate with pregnancy outcome. Results: We did not observe any differences between the ISM1 control group and GM501 study group with regard to fertilization, pregnancy, implantation rates, ongoing pregnancy, and babies born. The number of embryos with a minimal fragmentation rate (less than 30%) was significantly higher in the GM501 study group. Conclusion: Although a significant higher embryo fragmentation rate was seen in In vitro culture of embryos in GM501, pregnancy outcome results were comparable to those of embryos cultured in ISM1. According to our results the value of embryo morphological criteria as a parameter for pregnancy outcome should be examined and discussed again. PMID:25009716

Does erosion progress differently on teeth already presenting clinical signs of erosive tooth wear than on sound teeth? An in vitro pilot trial.

PubMed

Carvalho, Thiago Saads; Baumann, Tommy; Lussi, Adrian

2016-07-07

Erosive tooth wear (ETW) is clinically characterized by a loss of tooth surface, and different enamel depths may have different susceptibility to demineralization. Therefore, the aim of this in vitro pilot study was to assess if the progression of erosive demineralization is faster on teeth already presenting signs of ETW when compared to originally sound teeth. We selected 23 central incisors: 14 were clinically sound (Sound) and 9 presented clinical signs of early erosive tooth wear (ETW-teeth). The teeth were embedded in resin, leaving an uncovered window of native enamel (6.69 ± 2.30 mm(2)) on the incisal half of the labial surface. We measured enamel surface reflection intensity (SRI) initially and after each consecutive erosive challenge (1 % citric acid, total of 4, 8, 12, 16, 20 and 24 min). Calcium released to the citric acid was measured with an atomic absorption spectrometer. We observed higher initial SRI values in ETW-teeth than in Sound teeth (p = 0.007). During in vitro erosive demineralization, we observed that erosion on originally Sound teeth progressed significantly slower (p = 0.033) than on ETW-teeth: SRI decreased by 75 % (from 100 to 25 %) on Sound teeth, and by 89 % (from 100 to 11 %) on ETW-teeth. Calcium release increased during erosion, but presented no significant differences (p = 0.643) between originally Sound (0.031 μmol/mm(2)) and ETW-teeth (0.032 μmol/mm(2)). There was satisfactory correlation between calcium release and rSRI values (r s  = -0.66). The optical reflectometer distinguished originally sound teeth from those with signs of ETW, and the results suggest that acid demineralization progresses differently on teeth already presenting clinical signs of ETW than on sound teeth.

Cytotoxicity analysis of alendronate on cultured endothelial cells and subcutaneous tissue. a pilot study.

PubMed

Moreira, Maria Stella; Katayama, Emilio; Bombana, Antonio Carlos; Marques, Márcia Martins

2005-12-01

The use of alendronate, a bisphosphonate which is able to inhibit bone resorption, in order to prevent dental root resorption after tooth replantation would be of clinical relevance. However, this drug must be biocompatible to the periapical tissues. The aim of this study was to analyze the effect of an alendronate paste in polyethyleneglycol (2 g ml(-1)) on endothelial cells in culture (in vitro) and on rat subcutaneous tissue (in vivo). For the in vitro study the paste was applied on round glass coverslips that were immersed into confluent cell cultures (clone Cips). The cell viability percentages of these cultures were obtained 0, 6 and 12 h after contact with the substance. As control, cultures that received plain coverslips were used. This analysis was carried out in triplicate using the Trypan blue dye exclusion assay. For the in vivo study the paste was introduced into polyethylene tubes that were placed into the rat subcutaneous tissue. The rats were killed 7 and 14 days later; then, the tissue sections stained with hematoxylin-eosin were analyzed. In vitro, the alendronate caused a significant decrease in the cell viability in 6 h (P < 0.05) and 12 h (P < 0.01), when compared with the control cultures. In vivo the tissue response was exuberant and similar at the two experimental times. There was a necrosis in a comprehensive area in contact with the open end of the tube. Presence of micro-abscesses and intense inflammatory infiltrate in the hypoderm permeating the muscle fibers and fat lobules were observed. In conclusion, the alendronate paste in polyethylene glycol as used showed to be highly cytotoxic in vitro as well as in vivo.

Leap forward in the treatment of Pythium insidiosum keratitis.

PubMed

Bagga, Bhupesh; Sharma, Savitri; Madhuri Guda, Sai Jeevan; Nagpal, Ritu; Joseph, Joveeta; Manjulatha, Kodiganti; Mohamed, Ashik; Garg, Prashant

2018-03-15

Pythium insidiosum is a parafungus that causes keratitis resembling fungal keratitis. This study compares outcome in a large cohort of patients with P insidiosum keratitis treated with antifungal drugs, to a pilot group treated with antibacterial antibiotics. Between January 2014 and December 2016, 114 patients with culture positive P insidiosum keratitis were included in the study. A subset of culture isolates was tested in vitro for response to nine antibacterial antibiotics by disc diffusion and E test. Patients were treated with topical natamycin in 2014, 2015 and up until mid 2016. Thereafter, the patients received a combination of topical linezolid and topical and oral azithromycin. Therapeutic penetrating keratoplasty (TPK) was done for patients not responding to medical therapy. In vitro disc diffusion assay showed linezolid to be most effective. The rate of TPK was significantly higher in 2015 compared with 2016 (43/45, 95.6% vs 22/32, 68.8%; p=0.002). Eighteen patients were treated with antibacterial and 14 were treated with antifungal antibiotic in 2016. One patient was lost to follow-up in each group. The rate of TPK was higher and proportion of healed ulcers was lower (p=0.21, Fisher's exact test) in the group on antifungal therapy (TPK-11/13, 84.6%; Healed-2/13, 15.3%) compared with the group on antibacterial therapy (TPK-11/17, 64.7%; Healed-6/17, 35.2%). We report favourable but not statistically significant response of P insidiosum keratitis to antibacterial agents in a pilot series of patients. Further evaluation of this strategy in larger number of patients is recommended. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Ecotoxicological assessment of sediment, suspended matter and water samples in the upper Danube River. A pilot study in search for the causes for the decline of fish catches.

PubMed

Keiter, Steffen; Rastall, Andrew; Kosmehl, Thomas; Wurm, Karl; Erdinger, Lothar; Braunbeck, Thomas; Hollert, Henner

2006-09-01

Fish populations, especially those of the grayling (Thymallus thymallus), have declined over the last two decades in the upper Danube River between Sigmaringen and Ulm, despite intensive and continuous stocking and improvement of water quality since the 1970s. Similar problems have been reported for other rivers, e.g. in Switzerland, Great Britain, the United States and Canada. In order to assess if ecotoxicological effects might be related to the decline in fish catch at the upper Danube River, sediment, suspended matter and waste water samples from sewage treatment plants were collected at selected locations and analyzed in a bioanalytical approach using a battery of bioassays. The results of this pilot study will be used to decide if a comprehensive weight-of-evidence study is needed. Freeze-dried sediments and suspended particulate matters were extracted with acetone in a Soxhlet apparatus. Organic pollutants from sewage water were concentrated using XAD-resins. In order to investigate the ecotoxicological burden, the following bioassays were used: (1) neutral red assay with RTL-W1 cells (cytotoxicity), (2) comet assay with RTL-W1 cells (genotoxicity), (3) Arthrobacter globiformis dehydrogenase assay (toxicity to bacteria), (4) yeast estrogen screen assay (endocrine disruption), (5) fish egg assay with the zebrafish (Danio rerio; embryo toxicity) and (6) Ames test with TA98 (mutagenicity). The results of the in vitro tests elucidated a considerable genotoxic, cytotoxic, mutagenic, bacteriotoxic, embryotoxic and estrogenic burden in the upper Danube River, although with a very inhomogeneous distribution of effects. The samples taken from Riedlingen, for example, induced low embryo toxicity, but the second highest 17beta-estradiol equivalent concentration (1.8 ng/L). Using the fish egg assay with native sediments, a broad range of embryotoxic effects could be elucidated, with clear-cut dose-response relationships for the embryotoxic effects of contaminated sediments. With native sediments, embryotoxicity was clearly higher than with corresponding pore waters, thus corroborating the view that--at least for fish eggs--the bioavailability of particle-bound lipophilic substances in native sediments is higher than generally assumed. The effect observed most frequently in the fish egg assay was a developmental delay. A comparison of our own results with locations along the rivers Rhine and Neckar demonstrated similar or even higher ranges of ecotoxicological burdens in the Danube River. The complex pattern of ecotoxicological effects caused by environmental samples from the Danube River, when assessed in an in vitro biotest battery using both acute and more specific endpoints, showed that integration of different endpoints is essential for appropriate hazard assessment. Overall, the ecotoxicological hazard potential shown has indeed to be considered as one potential reason for the decline in fish catches at the upper Danube River. However, based on the results of this pilot study, it is not possible to elucidate that chemically induced alterations are responsible for the fish decline. In order to confirm the ecological relevance of the in vitro results for the situation in the field and especially for the decline of the grayling and other fishes, further integrated investigations are required. For linking the weight of evidence obtained by in vitro assays and fish population investigations, the application of additional, more specific biomarkers (e.g. vitellogenin induction, EROD and micronucleus assay) has been initiated in fish taken from the field as well as in situ investigations.

Pulsed cold plasma-induced blood coagulation and its pilot application in stanching bleeding during rat hepatectomy

NASA Astrophysics Data System (ADS)

Keping, YAN; Qikang, JIN; Chao, ZHENG; Guanlei, DENG; Shengyong, YIN; Zhen, LIU

2018-04-01

This paper presents plasma-induced blood coagulation and its pilot application in rat hepatectomy by using a home-made pulsed cold plasma jet. Experiments were conducted on blood coagulation in vitro, the influence of plasma on tissue in vivo, and the pilot application of rat hepatectomy. Experimental results show that the cold plasma can lead to rapid blood coagulation. Compared with the control sample, the plasma-induced agglomerated layer of blood is thicker and denser, and is mostly composed of broken platelets. When the surface of the liver was treated by plasma, the influence of the plasma can penetrate into the liver to a depth of about 500 μm. During the rat hepatectomy, cold plasma was proved to be effective for stanching bleeding on incision. No obvious bleeding was found in the abdominal cavities of all six rats 48 h after the hepatectomy. This implies that cold plasma can be an effective modality to control bleeding during surgical operation.

Use of an absorbable membrane to position biologically inductive materials in the periprosthetic space of cemented joints.

PubMed

DiResta, Gene R; Brown, Holly; Aiken, Sean; Doty, Steven; Schneider, Robert; Wright, Timothy; Healey, John H

2006-01-01

A device is presented that positions ultrahigh molecular weight polyethylene (UHMWPE) debris against periprosthetic bone surfaces. This can facilitate the study of aseptic loosening associated with cemented joint prostheses by speeding the appearance of this debris within the periprosthetic space. The device, composed of a 100 microm thick bioabsorbable membrane impregnated with 1.4 x 10(9) sub-micron particles of UHMWPE debris, is positioned on the endosteum of the bone prior to the insertion of the cemented orthopedic implant. An in vitro pullout study and an in vivo canine pilot study were performed to investigate its potential to accelerate "time to aseptic loosening" of cemented prosthetic joints. Pullout studies characterized the influence of the membrane on initial implant fixation. The tensile stresses (mean+/-std.dev.) required to withdraw a prosthesis cemented into canine femurs with and without the membrane were 1.15+/-0.3 and 1.54+/-0.01 MPa, respectively; these findings were not significantly different (p > 0.4). The in vivo pilot study, involving five dogs, was performed to evaluate the efficacy of the debris to accelerate loosening in a canine cemented hip arthroplasty. Aseptic loosening and lameness occurred within 12 months, quicker than the 30 months reported in a retrospective clinical review of canine hip arthroplasty.

Laser-assisted treatment of dentinal hypersensitivity: a literature review

PubMed Central

Biagi, Roberto; Cossellu, Gianguido; Sarcina, Michele; Pizzamiglio, Ilaria Tina; Farronato, Giampietro

2015-01-01

Summary The purpose of this literature review was to evaluate the effectiveness of the laser-assisted treatment of dentinal hypersensitivity. A review with inclusion and exclusion criteria was performed from January 2009 to December 2014 with electronic data-bases: MedLine via PubMed, Science Direct and Cochrane Library. Research of paper magazines by hand was not considered. Forty-three articles were selected between literature reviews, in vitro studies, clinical trials, pilot and preliminary studies. The items were divided into laser-used groups for an accurate description, and then the reading of results into various typologies. Laser-assisted treatment reduces dentinal hypersensitivity-related pain, but also a psychosomatic component must be considered, so further studies and more suitable follow-ups are necessary. PMID:26941892

A new alternative method for testing skin irritation using a human skin model: a pilot study.

PubMed

Miles, A; Berthet, A; Hopf, N B; Gilliet, M; Raffoul, W; Vernez, D; Spring, P

2014-03-01

Studies assessing skin irritation to chemicals have traditionally used laboratory animals; however, such methods are questionable regarding their relevance for humans. New in vitro methods have been validated, such as the reconstructed human epidermis (RHE) model (Episkin®, Epiderm®). The comparison (accuracy) with in vivo results such as the 4-h human patch test (HPT) is 76% at best (Epiderm®). There is a need to develop an in vitro method that better simulates the anatomo-pathological changes encountered in vivo. To develop an in vitro method to determine skin irritation using human viable skin through histopathology, and compare the results of 4 tested substances to the main in vitro methods and in vivo animal method (Draize test). Human skin removed during surgery was dermatomed and mounted on an in vitro flow-through diffusion cell system. Ten chemicals with known non-irritant (heptylbutyrate, hexylsalicylate, butylmethacrylate, isoproturon, bentazon, DEHP and methylisothiazolinone (MI)) and irritant properties (folpet, 1-bromohexane and methylchloroisothiazolinone (MCI/MI)), a negative control (sodiumchloride) and a positive control (sodiumlaurylsulphate) were applied. The skin was exposed at least for 4h. Histopathology was performed to investigate irritation signs (spongiosis, necrosis, vacuolization). We obtained 100% accuracy with the HPT model; 75% with the RHE models and 50% with the Draize test for 4 tested substances. The coefficients of variation (CV) between our three test batches were <0.1, showing good reproducibility. Furthermore, we reported objectively histopathological irritation signs (irritation scale): strong (folpet), significant (1-bromohexane), slight (MCI/MI at 750/250ppm) and none (isoproturon, bentazon, DEHP and MI). This new in vitro test method presented effective results for the tested chemicals. It should be further validated using a greater number of substances; and tested in different laboratories in order to suitably evaluate reproducibility. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Fracture strength of elastic and conventional fibre-reinforced composite intraradicular posts--an in vitro pilot study].

PubMed

Fráter, Mark; Forster, András; Jantyik, Ádám; Braunitzer, Gábor; Nagy, Katalin

2015-12-01

The purpose of this in vitro investigation was to evaluate the reinforcing effect of different fibre-reinforced composite (FRC) posts and insertion techniques in premolar teeth when using minimal invasive post space preparation. Thirty two extracted and endodontically treated premolar teeth were used and divided into four groups (n = 8) depending on the post used (Group 1-4). 1: one single conventional post, 2: one main conventional and one collateral post, 3: one flexible post, 4: one main flexible and one collateral post. After cementation and core build-up the specimens were submitted to static fracture toughness test. Fracture thresholds and fracture patterns were recorded and evaluated. The multi-post techniques (group 2 and 4) showed statistically higher fracture resistance compared to group one. Regarding fracture patterns there was no statistically significant difference between the tested groups. The application of multiple posts seems to be beneficial regarding fracture resistance independent from the used FRC post. Fracture pattern was not influenced by the elasticity of the post.

Shearwave Dispersion Ultrasonic Vibrometry (SDUV) for measuring prostate shear stiffness and viscosity – An in vitro pilot study

PubMed Central

Urban, M.W.; Fatemi, M.; Greenleaf, J.F.

2011-01-01

This paper reports shear stiffness and viscosity “virtual biopsy” measurements of three excised non-cancerous human prostates using shearwave dispersion ultrasound vibrometry (SDUV) in vitro. Improved methods for prostate guided-biopsy are required to effectively guide needle biopsy to the suspected site. In addition, tissue stiffness measurement helps identifying a suspected site to perform biopsy because stiffness has been shown to correlate with pathology. More importantly, early detection of prostate cancer may guide minimally-invasive therapy and eliminate insidious procedures. In this work, “virtual” biopsies were taken in multiple locations in three excised prostates. Then, SDUV shear elasticity and viscosity measurements have been performed at the selected “suspicious” locations within the prostates. SDUV measurements of prostate elasticity and viscosity are generally in agreement with preliminary values reported previously in the literature. It is however important to emphasize that the obtained viscoelastic parameters values are local, and not a mean value for the whole prostate. PMID:20595086

Migration of phthalates on culture plates - an important challenge to consider for in vitro studies.

PubMed

Frohnert Hansen, Juliana; Boas, Malene; Møller Brorson, Marianne; Frederiksen, Hanne; Hartoft-Nielsen, Marie-Louise; Krogh Rasmussen, Åse; Main, Katharina M; Feldt-Rasmussen, Ulla

2016-01-01

Phthalates are endocrine disruptors of the reproductive system and suspected to influence many other organ and hormone systems. They are also semi-volatile organic compounds present in the gas phase in the environment. Their mode of action has been investigated in numerous in vitro studies. Multi-well culture plates are typically used to study phthalates in cell cultures. In a pilot study, we observed evidence of phthalate migration in 24-well culture plates. As this has not previously been described, we investigated the phenomenon in more detail. Primary human thyroid epithelial cell cultures (n = 8 cultures) were exposed to either di-ethyl phthalate (DEP), di-n-butyl phthalate (DnBP), mono-n-butyl phthalate (MnBP) or di-(2-ethylhexyl) phthalate (DEHP). Measurement of phthalate metabolites by mass spectrometry demonstrated that the short-branched DEP was able to migrate to adjacent wells when added to cell culture plates. DnBP also seemed to be able to migrate, unlike the long-branched DEHP or the monoester MnBP which did not seem to have this ability. High background levels of phthalate metabolites were also observed, which might compromise results from low dose phthalate studies. In conclusion, the migration of phthalates which is probably caused by their volatile properties might lead to false interpretation of study results.

The Effects of Orally Administered Beta-Glucan on Innate Immune Responses in Humans, a Randomized Open-Label Intervention Pilot-Study

PubMed Central

Leentjens, Jenneke; Quintin, Jessica; Gerretsen, Jelle; Kox, Matthijs; Pickkers, Peter; Netea, Mihai G.

2014-01-01

Rationale To prevent or combat infection, increasing the effectiveness of the immune response is highly desirable, especially in case of compromised immune system function. However, immunostimulatory therapies are scarce, expensive, and often have unwanted side-effects. β-glucans have been shown to exert immunostimulatory effects in vitro and in vivo in experimental animal models. Oral β-glucan is inexpensive and well-tolerated, and therefore may represent a promising immunostimulatory compound for human use. Methods We performed a randomized open-label intervention pilot-study in 15 healthy male volunteers. Subjects were randomized to either the β -glucan (n = 10) or the control group (n = 5). Subjects in the β-glucan group ingested β-glucan 1000 mg once daily for 7 days. Blood was sampled at various time-points to determine β-glucan serum levels, perform ex vivo stimulation of leukocytes, and analyze microbicidal activity. Results β-glucan was barely detectable in serum of volunteers at all time-points. Furthermore, neither cytokine production nor microbicidal activity of leukocytes were affected by orally administered β-glucan. Conclusion The present study does not support the use of oral β-glucan to enhance innate immune responses in humans. Trial Registration ClinicalTrials.gov NCT01727895 PMID:25268806

A Comprehensive Environmental Assessment Approach to Making Informed Decisions about Engineered Nanoparticles

DTIC Science & Technology

2011-05-01

fuel oxygenate MBTE Adapted from Davis, 2007 4 ( 1 ) A multimedia environmental perspective built on a product life cycle framework is essential. (2...Picatinney Arsenal Nanotechnology Research Center: Radiofrequency (RF) Induction Plasma reactor (Tekna Plasma Systems) pilot plant Synthesis Challenges: ( 1 ...Genotoxicity in vivo and in vitro, secondary to ROS (?)23 BUILDING STRONG® CEA: Lessons Learned with fuel oxygenate MBTE Adapted from Davis, 2007 24 ( 1

Development and experimental design of a novel controlled-release matrix tablet formulation for indapamide hemihydrate.

PubMed

Antovska, Packa; Ugarkovic, Sonja; Petruševski, Gjorgji; Stefanova, Bosilka; Manchevska, Blagica; Petkovska, Rumenka; Makreski, Petre

2017-11-01

Development, experimental design and in vitro in vivo correlation (IVIVC) of controlled-release matrix formulation. Development of novel oral controlled delivery system for indapamide hemihydrate, optimization of the formulation by experimental design and evaluation regarding IVIVC on a pilot scale batch as a confirmation of a well-established formulation. In vitro dissolution profiles of controlled-release tablets of indapamide hemihydrate from four different matrices had been evaluated in comparison to the originator's product Natrilix (Servier) as a direction for further development and optimization of a hydroxyethylcellulose-based matrix controlled-release formulation. A central composite factorial design had been applied for the optimization of a chosen controlled-release tablet formulation. The controlled-release tablets with appropriate physical and technological properties had been obtained with a matrix: binder concentration variations in the range: 20-40w/w% for the matrix and 1-3w/w% for the binder. The experimental design had defined the design space for the formulation and was prerequisite for extraction of a particular formulation that would be a subject for transfer on pilot scale and IVIV correlation. The release model of the optimized formulation has shown best fit to the zero order kinetics depicted with the Hixson-Crowell erosion-dependent mechanism of release. Level A correlation was obtained.

Efficacy and Safety of a Novel Autologous Wound Matrix in the Management of Complicated, Chronic Wounds: A Pilot Study.

PubMed

Kushnir, Igal; Kushnir, Alon; Serena, Thomas E; Garfinkel, Doron

2016-09-01

The objective of this pilot study was to evaluate the efficacy and safety of a novel method using an autologous whole blood clot formed with the RedDress Wound Care System (RD1, RedDress Ltd, Israel), a provisional whole blood clot matrix used in the treatment of chronic wounds of various etiologies. Patients were treated at the bedside with the whole blood clot matrix. Blood was withdrawn from each patient using citrate, mixed with a calcium gluconate/kaolin suspension, and injected into an RD1 clotting tray. Within 10 minutes, a clot was formed, placed upon the wound, and fixed with primary and secondary dressings. Wounds were redressed weekly with a whole blood clot matrix. Treatment was terminated when complete healing was achieved, or when the clinician determined that the wound could not further improve without additional invasive procedures. Seven patients with multiple and serious comorbidities and 9 chronic wounds were treated with 35 clot matrices. Complete healing was achieved in 7 of 9 wounds (78%). In 1 venous ulcer with a nonhealing fistula, 77% healing was achieved. Treatment was terminated in 1 pressure ulcer at 82% closure, because an unexpected mechanical trauma resulted in deterioration; this was the only adverse event reported, unrelated to the product. No systemic adverse events occurred. This pilot study demonstrates the in vitro autologous whole blood clot matrix is effective and safe for treating patients with chronic wounds of different etiologies. A larger clinical trial is needed to assess the relative success rate of the matrix in different types of wounds in a diverse population with comorbidities.

Blaptica dubia as sentinels for exposure to chemical warfare agents - a pilot study.

PubMed

Worek, Franz; Seeger, Thomas; Neumaier, Katharina; Wille, Timo; Thiermann, Horst

2016-11-16

The increased interest of terrorist groups in toxic chemicals and chemical warfare agents presents a continuing threat to our societies. Early warning and detection is a key component for effective countermeasures against such deadly agents. Presently available and near term solutions have a number of major drawbacks, e.g. lack of automated, remote warning and detection of primarily low volatile chemical warfare agents. An alternative approach is the use of animals as sentinels for exposure to toxic chemicals. To overcome disadvantages of vertebrates the present pilot study was initiated to investigate the suitability of South American cockroaches (Blaptica dubia) as warning system for exposure to chemical warfare nerve and blister agents. Initial in vitro experiments with nerve agents showed an increasing inhibitory potency in the order tabun - cyclosarin - sarin - soman - VX of cockroach cholinesterase. Exposure of cockroaches to chemical warfare agents resulted in clearly visible and reproducible reactions, the onset being dependent on the agent and dose. With nerve agents the onset was related to the volatility of the agents. The blister agent lewisite induced signs largely comparable to those of nerve agents while sulfur mustard exposed animals exhibited a different sequence of events. In conclusion, this first pilot study indicates that Blaptica dubia could serve as a warning system to exposure of chemical warfare agents. A cockroach-based system will not detect or identify a particular chemical warfare agent but could trigger further actions, e.g. specific detection and increased protective status. By designing appropriate boxes with (IR) motion sensors and remote control (IR) camera automated off-site warning systems could be realized. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Pathogens in Ornamental Waters: A Pilot Study

PubMed Central

Nascimento, Maria; Rodrigues, Joao Carlos; Reis, Lucia; Nogueira, Isabel; Carvalho, Patricia A.; Brandão, João; Duarte, Aida; Jordao, Luisa

2016-01-01

In parks, ornamental waters of easy access and populated with animals are quite attractive to children and yet might hide threats to human health. The present work focuses on the microbiota of the ornamental waters of a Lisboa park, characterized during 2015. The results show a dynamic microbiota integrating human pathogens such as Klebsiella pneumoniae, Aeromonas spp. and Enterobacter spp., and also antibiotic resistant bacteria. K. pneumoniae and Aeromonas spp. were present as planktonic and biofilm organized bacteria. In vitro K. pneumoniae and Aeromonas spp. showed an enhanced ability to assemble biofilm at 25 °C than at 37 °C. Bacteria recovered from biofilm samples showed an increased antibiotic resistance compared to the respective planktonic counterparts. PMID:26891309

Anti-Listeria starters: in vitro selection and production plant evaluation.

PubMed

Raimondi, Stefano; Popovic, Mina; Amaretti, Alberto; Di Gioia, Diana; Rossi, Maddalena

2014-05-01

Anti-Listeria bacterial starters are highly demanded by the meat industry. Novel bioprotective anti-Listeria starters were searched among Lactobacillus species strains isolated from artisanal sausages. The screening confirmed that anti-Listeria activity is a strain-specific property and yielded only 1 strain (of 36) exhibiting a satisfactory level of inhibition, L. delbrueckii WC0286. This strain was compared with two commercial bioprotective starters, SafePro B-SF-43 and SafePro B-LC-20, in a model simulating in vitro the first step of the fermentation process. The presence of the bioprotective starters did not modify the pH in such a way that could affect the safety or organoleptic properties of the product. Both SafePro B-SF-43 and SafePro B-LC-20 effected an important reduction of Listeria counts (0.56 and 0.72 log CFU g(-1), respectively, in 72 h), while the anti-Listeria effect of L. delbrueckii WC0286 was minor (0.15 log CFU g(-1)). These results discouraged the utilization of L. delbrueckii WC0286 for a challenge test in a pilot salami production, in favor of the best-performing bioprotective starter, SafePro B-LC-20. The test confirmed that SafePro B-LC-20 did not alter the acidification trend of sausages and was capable of inhibiting Listeria, which decreased by 1.21 log CFU g(-1). This information is relevant to address research activity toward the development of new bioprotective starters. The data herein presented demonstrate that the efficacy in Listeria control of potentially bioprotective bacterial starters requires further validation in real meat matrixes, possibly by using in vitro meat fermentation experiments to narrow down the list of candidates before pilot scale challenge tests.

Installation Restoration of Rocky Mountain Arsenal, Pilot Containment Operations, Final Environmental Impact Statement, Part 1.

DTIC Science & Technology

1977-02-01

0. . IIU w 00 Z -J-. z 00 D 0 0 !9 I- A, On ~ 0w NON 0~ CoQ UU 00 co qc 00NC r-.N) 0 Lf) C*12 ICD U) o C 14 N0 WU Lo LC LX...for carcinogenic, mutagenic or teratogenic activity in vitro. One report (17) stated that DIMP does not inhibit the enzyme cholinesterase, although no

In Vivo Caprine Model for Osteomyelitis and Evaluation of Biofilm-Resistant Intramedullary Nails

PubMed Central

Tran, Nhiem; Tran, Phong A.; Jarrell, John D.; Engiles, Julie B.; Thomas, Nathan P.; Young, Matthew D.; Hayda, Roman A.; Born, Christopher T.

2013-01-01

Bone infection remains a formidable challenge to the medical field. The goal of the current study is to evaluate antibacterial coatings in vitro and to develop a large animal model to assess coated bone implants. A novel coating consisting of titanium oxide and siloxane polymer doped with silver was created by metal-organic methods. The coating was tested in vitro using rapid screening techniques to determine compositions which inhibited Staphylococcus aureus growth, while not affecting osteoblast viability. The coating was then applied to intramedullary nails and evaluated in vivo in a caprine model. In this pilot study, a fracture was created in the tibia of the goat, and Staphylococcus aureus was inoculated directly into the bone canal. The fractures were fixed by either coated (treated) or non-coated intramedullary nails (control) for 5 weeks. Clinical observations as well as microbiology, mechanical, radiology, and histology testing were used to compare the animals. The treated goat was able to walk using all four limbs after 5 weeks, while the control was unwilling to bear weight on the fixed leg. These results suggest the antimicrobial potential of the hybrid coating and the feasibility of the goat model for antimicrobial coated intramedullary implant evaluation. PMID:23841085

Immunological Assays as an Opportunity of Assessment of Health Risks of Airborne Particle Mixture Including Nanoparticles

NASA Astrophysics Data System (ADS)

Brzicová, Táňa; Lochman, Ivo; Danihelka, Pavel; Lochmanová, Alexandra; Lach, Karel; Mička, Vladimír

2013-04-01

The aim of this pilot study was to evaluate perspectives of the assessment of nonspecific biological effects of airborne particulate matter including nanoparticles using appropriate immunological assays. We have selected various in vitro immunological assays to establish an array allowing us to monitor activation of the cell-mediated and humoral response of both the innate and adaptive immunity. To assess comprehensive interactions and effects, the assays were performed in whole blood cultures from healthy volunteers and we used an original airborne particle mixture from high pollution period in Ostrava region representing areas with one of the most polluted air in Europe. Even if certain effects were observed, the results of the immunological assays did not prove significant effects of airborne particles on immune cells' functions of healthy persons. However, obtained data do not exclude health risks of long-term exposure to airborne particles, especially in case of individuals with genetic predisposition to certain diseases or already existing disease. This study emphasizes the in vitro assessment of complex effects of airborne particles in conditions similar to actual ones in an organism exposed to particle mixture present in the polluted air.

Pharmacokinetics and In Vitro Blood-Brain Barrier Screening of the Plant-Derived Alkaloid Tryptanthrin.

PubMed

Jähne, Evelyn A; Eigenmann, Daniela E; Sampath, Chethan; Butterweck, Veronika; Culot, Maxime; Cecchelli, Roméo; Gosselet, Fabien; Walter, Fruzsina R; Deli, Mária A; Smieško, Martin; Hamburger, Matthias; Oufir, Mouhssin

2016-07-01

The indolo[2,1-b]quinazoline alkaloid tryptanthrin was previously identified as a potent anti-inflammatory compound with a unique pharmacological profile. It is a potent inhibitor of cyclooxygenase-2, 5-lipooxygenase-catalyzed leukotriene synthesis, and nitric oxide production catalyzed by the inducible nitric oxide synthase. To characterize the pharmacokinetic properties of tryptanthrin, we performed a pilot in vivo study in male Sprague-Dawley rats (2 mg/kg bw i. v.). Moreover, the ability of tryptanthrin to cross the blood-brain barrier was evaluated in three in vitro human and animal blood-brain barrier models. Bioanalytical UPLC-MS/MS methods used were validated according to current international guidelines. A half-life of 40.63 ± 6.66 min and a clearance of 1.00 ± 0.36 L/h/kg were found in the in vivo pharmacokinetic study. In vitro data obtained with the two primary animal blood-brain barrier models showed a good correlation with an immortalized human monoculture blood-brain barrier model (hBMEC cell line), and were indicative of a high blood-brain barrier permeation potential of tryptanthrin. These findings were corroborated by the in silico prediction of blood-brain barrier penetration. P-glycoprotein interaction of tryptanthrin was assessed by calculation of the efflux ratio in bidirectional permeability assays. An efflux ratio below 2 indicated that tryptanthrin is not subjected to active efflux. Georg Thieme Verlag KG Stuttgart · New York.

The Use of a Pressure-Indicating Sensor Film to Provide Feedback upon Hydrogel-Forming Microneedle Array Self-Application In Vivo.

PubMed

Vicente-Pérez, Eva M; Quinn, Helen L; McAlister, Emma; O'Neill, Shannon; Hanna, Lezley-Anne; Barry, Johanne G; Donnelly, Ryan F

2016-12-01

To evaluate the combination of a pressure-indicating sensor film with hydrogel-forming microneedle arrays, as a method of feedback to confirm MN insertion in vivo. Pilot in vitro insertion studies were conducted using a Texture Analyser to insert MN arrays, coupled with a pressure-indicating sensor film, at varying forces into excised neonatal porcine skin. In vivo studies involved twenty human volunteers, who self-applied two hydrogel-forming MN arrays, one with a pressure-indicating sensor film incorporated and one without. Optical coherence tomography was employed to measure the resulting penetration depth and colorimetric analysis to investigate the associated colour change of the pressure-indicating sensor film. Microneedle insertion was achieved in vitro at three different forces, demonstrating the colour change of the pressure-indicating sensor film upon application of increasing pressure. When self-applied in vivo, there was no significant difference in the microneedle penetration depth resulting from each type of array, with a mean depth of 237 μm recorded. When the pressure-indicating sensor film was present, a colour change occurred upon each application, providing evidence of insertion. For the first time, this study shows how the incorporation of a simple, low-cost pressure-indicating sensor film can indicate microneedle insertion in vitro and in vivo, providing visual feedback to assure the user of correct application. Such a strategy may enhance usability of a microneedle device and, hence, assist in the future translation of the technology to widespread clinical use.

A pilot study of the efficacy of wipes containing chlorhexidine 0.3%, climbazole 0.5% and Tris-EDTA to reduce Malassezia pachydermatis populations on canine skin.

PubMed

Cavana, Paola; Peano, Andrea; Petit, Jean-Yanique; Tizzani, Paolo; Perrot, Sébastien; Bensignor, Emmanuel; Guillot, Jacques

2015-08-01

Wipes containing chlorhexidine and azole derivates have been recommended for veterinary use. No study has been published about their activity against Malassezia pachydermatis. To evaluate the in vivo and in vitro activity of wipes soaked in a chlorhexidine, climbazole and Tris-EDTA solution against Malassezia pachydermatis. Five research colony shar-pei dogs. Wipes were applied once daily onto the left axilla, left groin and perianal area (protocol A), and twice daily on the right axilla, right groin and umbilical region (protocol B) for 3 days. In vivo activity was evaluated by quantifying Malassezia colonies through contact plates on the selected body areas before and after wipe application. The activity of the solution in which the wipes were soaked was assessed in vitro by contact tests following the European Standard UNI EN 1275 guidelines. Samples collected after wipe application showed a significant and rapid reduction of Malassezia yeast CFU. No significant difference in the Malassezia reduction was found between protocols A and B. In vitro assay showed 100% activity against Malassezia yeasts after a 15 min contact time with the wipe solution. Wipes containing chlorhexidine, climbazole and Tris-EDTA substantially reduced the M. pachydermatis population on the skin of dogs. The results, although this was an uncontrolled study performed on a small number of dogs, suggest that these wipes may be useful for topical therapy of Malassezia dermatitis involving the lips, paws, perianal area and skin folds. © 2015 ESVD and ACVD.

Platelet concentrate in bovine reproduction: effects on in vitro embryo production and after intrauterine administration in repeat breeder cows.

PubMed

Lange-Consiglio, Anna; Cazzaniga, Nadia; Garlappi, Rosangela; Spelta, Chiara; Pollera, Claudia; Perrini, Claudia; Cremonesi, Fausto

2015-06-19

A repeat breeder cow (RBC) can be defined as an animal that after 3 or more inseminations cannot get pregnant because of fertilization failure or early embryonic death. If no cause is identified precisely, inadequate uterine receptivity is responsible for implantation failures. Since a large number of identified molecular mediators, such as cytokines, growth factors and lipids have been postulated to be involved in early feto-maternal interaction, in this study a different approach to the treatment of RBC syndrome has been employed using a platelet concentrate (PC) that contains a significant amount of growth factors accumulated in its α-granules. Three explorative studies were performed. Initially, PC was supplemented in the in vitro embryo culture medium to study its effect on embryo-development. After the pilot study, 4 RBCs were treated with intrauterine administration of PC to evaluate proliferative potential of endometrium by immunohistochemical expression of the antigen Ki-67. Lastly, the effect of intrauterine administration of PC at 48 hrs after artificial insemination in RBCs was evaluated. The in vitro results show that 5 % of PC and 5 % of fetal calf serum (FCS) increase the rate of blastocysts compared with the control containing 10 % FCS only (43.04 % vs 35.00 % respectively). The immunohistochemical study shows more proliferating nuclei in the treated uterine horn compared to the control one. After intrauterine insemination in RBCs, the percentage of pregnant cows in the control group was 33.33 % compared to 70 % of the treated animals. We suppose that when embryo descends in uterus could find a more appropriate environment for nesting and subsequent pregnancy.

Three-Dimensional Printing of Surgical Clips: An In Vitro Pilot Study and Trial of Efficacy.

PubMed

Canvasser, Noah E; De, Shuvro; Koseoglu, Ersin; Lay, Aaron H; Sorokin, Igor; Fernandez, Raul; Cadeddu, Jeffrey A

2017-09-01

Three-dimensional (3D) printing applications have increased over the past decade. Our objective was to test rapid prototyping of a 3D printed surgical clip for intraoperative use. Our prototype was modeled after the 10 mm Weck ® Hem-o-lok ® polymer clip (Teleflex, Inc., Wayne, PA). A 3D computer-aided design model of the Hem-o-lok clip was reverse engineered using commercial microscopy and printing was done using an Objet Connex500 multijetting system (Stratasys, Eden Prairie, MN). The initial polymer was Objet VeroWhitePlus RGD835; the addition of Objet TangoBlackPlus FLX980 during the design process improved hinge flexibility. The 3D printed clips were then pressure tested on rubber Penrose tubing and compared in vitro versus commercial Hem-o-lok clips. Initial 3D printed clips were not functional as they split at the hinge upon closure of the clip jaws. Design changes were made to add Objet TangoBlackPlus FLX980 at the hinge to improve flexibility. Additional modifications were made to allow for clips to be compatible with the Hem-o-lok endoscopic clip applier. A total of 50 clips were tested. Fracture rate for the printed clips using a clip applier was 54% (n = 27), whereas none of the commercial Hem-o-lok clips broke upon closure. Of the 23 printed clips that closed, mean leak was at 20.7 κPa (range 4.8-42.7). In contrast, none of the commercial clips leaked, and fill continued until Penrose rupture at mean 46.2 κPa (44.8-47.6). This pilot study demonstrates feasibility of 3D printing functional surgical clips. However, the performance of our first generation clips is poor compared with commercial grade product. Refinement in printers and materials available may allow for customization of such printed surgical instruments that could be economically competitive to purchasing and stocking product.

Removing Distortion of Periapical Radiographs in Dental Digital Radiography Using Embedded Markers in an External frame.

PubMed

Kafieh, Rahele; Shahamoradi, Mahdi; Hekmatian, Ehsan; Foroohandeh, Mehrdad; Emamidoost, Mostafa

2012-10-01

To carry out in vivo and in vitro comparative pilot study to evaluate the preciseness of a newly proposed digital dental radiography setup. This setup was based on markers placed on an external frame to eliminate the measurement errors due to incorrect geometry in relative positioning of cone, teeth and the sensor. Five patients with previous panoramic images were selected to undergo the proposed periapical digital imaging for in vivo phase. For in vitro phase, 40 extracted teeth were replanted in dry mandibular sockets and periapical digital images were prepared. The standard reference for real scales of the teeth were obtained through extracted teeth measurements for in vitro application and were calculated through panoramic imaging for in vivo phases. The proposed image processing thechnique was applied on periapical digital images to distinguish the incorrect geometry. The recognized error was inversely applied on the image and the modified images were compared to the correct values. The measurement findings after the distortion removal were compared to our gold standards (results of panoramic imaging or measurements from extracted teeth) and showed the accuracy of 96.45% through in vivo examinations and 96.0% through in vitro tests. The proposed distortion removal method is perfectly able to identify the possible inaccurate geometry during image acquisition and is capable of applying the inverse transform to the distorted radiograph to obtain the correctly modified image. This can be really helpful in applications like root canal therapy, implant surgical procedures and digital subtraction radiography, which are essentially dependent on precise measurements.

Removing Distortion of Periapical Radiographs in Dental Digital Radiography Using Embedded Markers in an External frame

PubMed Central

Kafieh, Rahele; Shahamoradi, Mahdi; Hekmatian, Ehsan; Foroohandeh, Mehrdad; Emamidoost, Mostafa

2012-01-01

To carry out in vivo and in vitro comparative pilot study to evaluate the preciseness of a newly proposed digital dental radiography setup. This setup was based on markers placed on an external frame to eliminate the measurement errors due to incorrect geometry in relative positioning of cone, teeth and the sensor. Five patients with previous panoramic images were selected to undergo the proposed periapical digital imaging for in vivo phase. For in vitro phase, 40 extracted teeth were replanted in dry mandibular sockets and periapical digital images were prepared. The standard reference for real scales of the teeth were obtained through extracted teeth measurements for in vitro application and were calculated through panoramic imaging for in vivo phases. The proposed image processing thechnique was applied on periapical digital images to distinguish the incorrect geometry. The recognized error was inversely applied on the image and the modified images were compared to the correct values. The measurement findings after the distortion removal were compared to our gold standards (results of panoramic imaging or measurements from extracted teeth) and showed the accuracy of 96.45% through in vivo examinations and 96.0% through in vitro tests. The proposed distortion removal method is perfectly able to identify the possible inaccurate geometry during image acquisition and is capable of applying the inverse transform to the distorted radiograph to obtain the correctly modified image. This can be really helpful in applications like root canal therapy, implant surgical procedures and digital subtraction radiography, which are essentially dependent on precise measurements. PMID:23724372

Effect of Silymarin Administration on Cisplatin Nephrotoxicity: Report from A Pilot, Randomized, Double-Blinded, Placebo-Controlled Clinical Trial.

PubMed

Shahbazi, Foroud; Sadighi, Sanambar; Dashti-Khavidaki, Simin; Shahi, Farhad; Mirzania, Mehrzad; Abdollahi, Alireza; Ghahremani, Mohammad-Hossein

2015-07-01

Despite several introduced preventive modalities, cisplatin nephrotoxicity remains a clinical problem. Some in vitro and in vivo studies have addressed the protective effects of silymarin against cisplatin nephrotoxicity. This study evaluated the effects of silymarin administration on cisplatin nephrotoxicity as the first human study. During this pilot, randomized, double-blinded, placebo-controlled clinical trial, the effect of oral silymarin 420 mg daily in three divided doses starting 24-48 h before the initiation of cisplatin infusion and continuing to the end of three 21-day cisplatin-containing chemotherapy courses on cisplatin-induced renal electrolytes wasting and kidney function were assessed. Cisplatin-associated acute kidney injury (AKI) occurred in 8% of the patients. Urine neutrophil gelatinase-associated lipocalin to urine creatinine ratio (NGAL/Cr) and urinary magnesium and potassium wasting increased significantly after cisplatin infusion in both groups. Significant positive correlation was found between cumulative dose of cisplatin and urine NGAL/Cr after three courses of cisplatin infusion. Incidence of AKI and the magnitude of urinary magnesium and potassium wasting did not differ between silymarin and placebo groups. No adverse reaction was reported by silymarin administration. Prophylactic administration of conventional form of silymarin tablets could not prevent cisplatin-induced urine electrolyte wasting or renal function impairment. Copyright © 2015 John Wiley & Sons, Ltd.

A rare eicosanoid precursor analogue, sciadonic acid (5Z,11Z,14Z-20:3), detected in vivo in hormone positive breast cancer tissue.

PubMed

Park, H G; Zhang, J Y; Foster, C; Sudilovsky, D; Schwed, D A; Mecenas, J; Devapatla, S; Lawrence, P; Kothapalli, K S D; Brenna, J T

2018-07-01

Numerous genetic alterations of HSA 11q13 are found frequently in several cancer types, including breast cancer (BC). The 11q13 locus harbors FADS2 encoding Δ6 desaturation which is not functional in several cancer cell lines, including hormone positive MCF7 BC cells. In vitro, the non-functional FADS2 activity unmasks 18:2n-6 elongation to 20:2n-6 and Δ5 desaturation by FADS1 to yield 5Z,11Z,14Z-20:3 (sciadonic acid) rather than 5Z,8Z,11Z,14Z-20:4 (arachidonic acid). In this pilot study we aimed to determine whether 5,11,14-20:3 appears in vivo in hormone positive human BC tissue. Fatty acids were profiled in surgically removed human breast tumor and adjacent normal tissue (n = 9). Sciadonic acid was detected in three of nine breast tumor samples and was below detect limits in normal breast tissue. The internal Δ8 double bond of arachidonic acid is required for normal eicosanoid synthesis but is missing in sciadonic acid. This pilot study demonstrates for the first time in vivo sciadonic acid in hormone positive BC tissue, warranting a larger survey study to further evaluate its appearance and the functional implications. Copyright © 2018. Published by Elsevier Ltd.

Comparison of 2 kinds of pedicle screws in primary spinal instrumentation: biomechanical and interfacial evaluations in sheep vertebrae in vitro.

PubMed

Liu, Da; Zhang, Yi; Lei, Wei; Wang, Cai-ru; Xie, Qing-yun; Liao, Dong-fa; Jiang, Kai; Zhou, Jin-song; Zhang, Bo; Pan, Xian-ming

2014-04-01

Expansive pedicle screw (EPS) and polymethylmethacrylate-augmented pedicle screw (PMMA-PS) were inserted in sheep vertebrae in vitro and were evaluated by performing biomechanical tests, radiographic examinations and histological observations. The objective of the study was to compare the biomechanical and interfacial performances of EPS and PMMA-PS in sheep lumbar vertebrae in vitro. It is a great challenge for orthopedic surgeons performing transpedicular fixation in the osteoporotic spine. It was reported that either the EPS or PMMA-PS could increase the screw stability. However, there are no studies comparing the 2 kinds of screws especially in primary spinal instrumentation. A total of 60 sheep lumbar vertebrae were randomly divided into 3 groups. A pilot hole was made in advance in all samples using the same method. Thereafter, the conventional pedicle screw (CPS) was inserted directly into the pilot hole in the CPS group; the hole in PMMA-PS group was first filled with polymethylmethacrylate (PMMA; 1.0 mL) and then inserted with CPS; and the EPS was inserted directly into the vertebrae in EPS group. After a period of 24 hours, biomechanical tests were performed to evaluate screw stability, and x-ray examination, micro-computerized tomography analysis, and histologic observation were performed to evaluate the interface between screw and bone. Compared with the stability of CPS, those of EPS and PMMA-PS were significantly enhanced. However, no significant differences were detected between the stabilities of EPS and PMMA-PS. The PMMA surrounding the screw blocked direct contact between bone and screw and formed a "screw-PMMA-bone" interface in the PMMA-PS group. There was a "screw-bone" interface in both CPS and EPS groups. Nevertheless, the expanded anterior part of EPS formed a claw-like structure pressing the surrounding bone trabeculae, which made the local bone tissue more compacted and denser than that in the CPS group. EPS can enhance the screw stability as markedly as the traditional PMMA-PS in primary surgery, and EPS can form a better immediate interface between screw and bone compared with PMMA-PS. EPS also can effectively avoid thermal injury, leakage, and compression caused by PMMA. A great feasibility was proved in this study to perform comparisons between the 2 kinds of pedicle screws in osteoporotic sheep vertebrae in vivo in the further research. In conclusion, we propose that EPS has a great application potential in augmentation of screw stability in the clinic.

Intravitreal Controlled Release of Dexamethasone from Engineered Microparticles of Porous Silicon Dioxide

PubMed Central

Wang, Chengyun; Hou, Huiyuan; Nan, Kaihui; Sailor, Michael J; Freeman, William R.; Cheng, Lingyun

2014-01-01

Dexamethasone is a glucocorticoid that is widely used in the ophthalmic arena. The recent FDA approved dexamethasone implant can provide a three month efficacy but with high rate of drug related cataract and high intraocular pressure (IOP). It seems that higher steroid in aqueous humor and around lens may be associated with these complications based on clinical fact that higher IOP was observed with intravitreal triamcinolone acetonide (TA) than with subtenon TA. We hypothesize that placing a sustained dexamethasone release system near back of the eye through a fine needle can maximize efficacy while mitigate higher rate of IOP rise and cataract. To develop a sustained intravitreal dexamethasone delivery system, porous silicon dioxide (pSiO2) microparticles were fabricated and functionalized with amines as well as carboxyl groups. Dexamethasone was conjugated to pSiO2 through the Steglich Esterificaion Reaction between hydroxyl of dexamethasone and carboxyl groups on the pSiO2. The drug loading was confirmed by Fourier transform infrared spectroscopy (FTIR) and loading efficiency was quantitated using thermogravimetric analysis (TGA). In vitro release was conducted for three months and dexamethasone was confirmed in the released samples using liquid chromatography-tandem mass spectrometry (LC/MS/MS). A pilot ocular safety and determination of vitreous drug level was performed in rabbit eyes. The drug loading study demonstrated that loading efficiency was from 5.96% to 10.77% depending on the loading reaction time, being higher with longer loading reaction time before reaching saturation around 7 days. In vitro drug release study revealed that dexamethasone release from pSiO2 particles was sustainable for over 90 days and was 80 days longer than free dexamethasone or infiltration-loaded pSiO2 particle formulation in the same setting. Pilot in vivo study demonstrated no sign of ocular adverse reaction in rabbit eyes following a single 3 mg intravitreal injection and free drug level at 2-week was 107.23+/−10.54 ng/mL that is well above the therapeutic level but only around 20% level of dexamethasone released from OZURDEX ® (dexamethasone intravitreal implant) in a rabbit eye model. In conclusion, dexamethasone is able to covalently load to the pSiO2 particles and provide sustained drug release for at least 3 months in vitro. Intravitreal injection of these particles were well tolerated in rabbit eyes and free drug level in vitreous at 2-week was well above the therapeutic level. PMID:25446320

Efficacy of some colloidal silver preparations and silver salts against Proteus bacteria, one possible cause of rheumatoid arthritis.

PubMed

Disaanayake, D M B T; Faoagali, Joan; Laroo, Hans; Hancock, Gerald; Whitehouse, Michael

2014-04-01

There has been increased interest in the role of anti-Proteus antibodies in the aetiology of rheumatoid arthritis (RA) and whether chemotherapeutic agents active against Proteus species might reduce the risk and/or exacerbations of RA. We examined the in vitro antibacterial effects of ten different silver preparations which were either ionic silver [Ag(I)] solutions or nanoparticulate silver (NPS) (Ag(0)) suspensions against ATCC and two wild (clinical) strains of Proteus. The data establish the low minimum inhibitory concentration and minimum bactericidal concentration of all the silver formulations tested against these four Proteus strains. In a pilot study, a potent NPS preparation ex vivo showed long-lasting anti-Proteus activity in a normal human volunteer.

Model studies of diffusion-controlled (2-hydroxyethyl methacrylate) HEMA hydrogel membranes for controlled release of proteins

NASA Astrophysics Data System (ADS)

Appawu, Jennifer A. M.

This thesis project consisted of three main components that were connected by roots in chemical analysis for studies in tissue engineering. The first part focused on characterizing the structural parameters of synthetic cross-linked poly (2-hydroxyethyl methacrylate) (Poly(HEMA) hydrogel membranes to determine optimal formulations for clinical studies. Poly(HEMA) membranes were loaded with Keratincocyte Growth Factor (KGF) for controlled release studies. Protein loading and release kinetics were determined with fluorescence spectroscopy. The spatial distribution of a protein in the membrane was determined using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). The last part of the project focused on determining the biological effects of the polymer membranes in-vitro with a model cell line and a pilot in-vivo animal study. Based on the components completed in this project, five chapters are included in this dissertation document and are summarized below. A new protocol was developed using fluorescence spectroscopy that measured the rate of protein diffusion into cross-linked polymer membranes by measuring the change in the fluorescence intensity of the protein solution. This technique was also able to detect a conformational change that occurs within protein when KGF was imbibed within these cross-linked polymer membranes. ToF-SIMS chemical imaging and 3D depth profiling was used to determine the spatial distribution of KGF protein in frozen-hydrated HEMA hydrogel membranes. The 3D depth profiles showed that the KGF protein was aggregated in bright spots that indicated that KGF was not spatially homogenous on the surface and through the depth profiles. 3D depth profiles of the membranes studied at various times during release studies show that areas with aggregated proteins were retained during release, and at times with maximum release. The interpretation of the bright regions is that the KGf protein interacted with the cross-linked network of the hydrogel membranes, making it not available for release. The in-vitro biological experiments with the HaCaT cell line showed that the HEMA hydrogels were capable of sustaining cell viability, proliferation, and adhesion through cell adhesion and wounding experiments. The pilot in-vivo animal study also revealed that KGF protein had retained its pharmacological activity. The study also showed that the KGF protein enhanced the rate of wound closure.

The use of an oxidising mouthwash to reduce staining associated with chlorhexidine. Studies in vitro and in vivo.

PubMed

Addy, M; al-Arrayed, F; Moran, J

1991-04-01

Discolouration of the teeth, tongue and dental restorative materials associated with the use of cationic antiseptics is still the limiting factor in long-term usage of antiplaque agents such as chlorhexidine. Oxidising agents have been used successfully to remove dental stain in animals, but products and regimens have not been evaluated in humans. These pilot studies in vitro and in vivo assessed a long-established oxidising mouthwash, based on peroxyborate, for stain removal from teeth and acrylic. The laboratory studies measured chlorhexidine tea stain removal from tooth and acrylic specimens. The oxidising agent markedly reduced staining on specimens. In a short-term clinical experiment, dental staining was forced over a 2 1/2-day period by reciprocal chlorhexidine and tea rinsing. 5 rinses with the oxidising mouthwash during the next 1 1/2 days dramatically reduced staining compared with water after rinses. Additionally, a single rinse with peroxyborate following the 5 water after rinses, again considerably reduced the residual staining. Effects on tongue staining were less impressive. Both experimental models produced findings consistent with those from the animal model. The results suggest proprietary oxidising mouthwashes could have a place in the control of dental stain associated with the use of chlorhexidine. Further studies to evaluate such products in a more conventional chlorhexidine regimen are indicated.

A tutorial on pilot studies: the what, why and how

PubMed Central

2010-01-01

Pilot studies for phase III trials - which are comparative randomized trials designed to provide preliminary evidence on the clinical efficacy of a drug or intervention - are routinely performed in many clinical areas. Also commonly know as "feasibility" or "vanguard" studies, they are designed to assess the safety of treatment or interventions; to assess recruitment potential; to assess the feasibility of international collaboration or coordination for multicentre trials; to increase clinical experience with the study medication or intervention for the phase III trials. They are the best way to assess feasibility of a large, expensive full-scale study, and in fact are an almost essential pre-requisite. Conducting a pilot prior to the main study can enhance the likelihood of success of the main study and potentially help to avoid doomed main studies. The objective of this paper is to provide a detailed examination of the key aspects of pilot studies for phase III trials including: 1) the general reasons for conducting a pilot study; 2) the relationships between pilot studies, proof-of-concept studies, and adaptive designs; 3) the challenges of and misconceptions about pilot studies; 4) the criteria for evaluating the success of a pilot study; 5) frequently asked questions about pilot studies; 7) some ethical aspects related to pilot studies; and 8) some suggestions on how to report the results of pilot investigations using the CONSORT format. PMID:20053272

Evaluation of anti-plaque microbial activity of Azadirachta indica (neem oil) in vitro: A pilot study.

PubMed

Elavarasu, Sugumari; Abinaya, P; Elanchezhiyan, S; Thangakumaran; Vennila, K; Naziya, K B

2012-08-01

Probably microbial plaque is the main etiology for periodontal tissue inflammation. Various chemical agents have been evaluated over the years with respect to their antimicrobial effects in the oral cavity. However, all are associated with side effects that prohibit regular long-term use. Therefore, the effectiveness of Azadirachta indica (neem) against plaque formation is considered to be vital, with lesser side effects. The aim of the present study is to evaluate and prove the antimicrobial activity of neem using plaque samples. Culture was prepared using brain heart infusion broth reagent. Dental plaque samples were used for that. Kirby-Bauer antimicrobial susceptibility test procedure was carried away with the sample. Neem oil was kept in the agar plate with culture and the diameter of inhibition zones was calculated. Results showed inhibition zones on the agar plate around neem oil. Study shows definite antiplaque activity of neem oil.

Pharmaceutical applications of magnetic resonance imaging (MRI).

PubMed

Richardson, J Craig; Bowtell, Richard W; Mäder, Karsten; Melia, Colin D

2005-06-15

Magnetic resonance imaging (MRI) is a powerful imaging modality that provides internal images of materials and living organisms on a microscopic and macroscopic scale. It is non-invasive and non-destructive, and one of very few techniques that can observe internal events inside undisturbed specimens in situ. It is versatile, as a wide range of NMR modalities can be accessed, and 2D and 3D imaging can be undertaken. Despite widespread use and major advances in clinical MRI, it has seen limited application in the pharmaceutical sciences. In vitro studies have focussed on drug release mechanisms in polymeric delivery systems, but isolated studies of bioadhesion, tablet properties, and extrusion and mixing processes illustrate the wider potential. Perhaps the greatest potential however, lies in investigations of pharmaceuticals in vivo, where pilot human and animal studies have demonstrated we can obtain unique insights into the behaviour of gastrointestinal, topical, colloidal, and targeted drug delivery systems.

Blood-brain barrier (BBB) toxicity and permeability assessment after L-(4-¹⁰Boronophenyl)alanine, a conventional B-containing drug for boron neutron capture therapy, using an in vitro BBB model.

PubMed

Roda, E; Nion, S; Bernocchi, G; Coccini, T

2014-10-02

Since brain tumours are the primary candidates for treatment by Boron Neutron Capture Therapy, one major challenge in the selective drug delivery to CNS is the crossing of the blood-brain barrier (BBB). The present pilot study investigated (i) the transport of a conventional B-containing product (i.e., L-(4-(10)Boronophenyl)alanine, L-(10)BPA), already used in medicine but still not fully characterized regarding its CNS interactions, as well as (ii) the effects of the L-(10)BPA on the BBB integrity using an in vitro model, consisting of brain capillary endothelial cells co-cultured with glial cells, closely mimicking the in vivo conditions. The multi-step experimental strategy (i.e. Integrity test, Filter study, Transport assay) checked L-(10)BPA toxicity at 80 µg Boron equivalent/ml, and its ability to cross the BBB, additionally by characterizing the cytoskeletal and TJ's proteins by immunocytochemistry and immunoblotting. In conclusion, a lack of toxic effects of L-(10)BPA was demonstrated, nevertheless accompanied by cellular stress phenomena (e.g. vimentin expression modification), paralleled by a low permeability coefficient (0.39 ± 0.01 × 10(-3)cm min(-1)), corroborating the scarce probability that L-(10)BPA would reach therapeutically effective cerebral concentration. These findings emphasized the need for novel strategies aimed at optimizing boron delivery to brain tumours, trying to ameliorate the compound uptake or developing new targeted products suitable to safely and effectively treat head cancer. Thus, the use of in vitro BBB model for screening studies may provide a useful early safety assessment for new effective compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

Preimplantation genetic screening for all 24 chromosomes by microarray comparative genomic hybridization significantly increases implantation rates and clinical pregnancy rates in patients undergoing in vitro fertilization with poor prognosis

PubMed Central

Majumdar, Gaurav; Majumdar, Abha; Lall, Meena; Verma, Ishwar C.; Upadhyaya, Kailash C.

2016-01-01

CONTEXT: A majority of human embryos produced in vitro are aneuploid, especially in couples undergoing in vitro fertilization (IVF) with poor prognosis. Preimplantation genetic screening (PGS) for all 24 chromosomes has the potential to select the most euploid embryos for transfer in such cases. AIM: To study the efficacy of PGS for all 24 chromosomes by microarray comparative genomic hybridization (array CGH) in Indian couples undergoing IVF cycles with poor prognosis. SETTINGS AND DESIGN: A retrospective, case–control study was undertaken in an institution-based tertiary care IVF center to compare the clinical outcomes of twenty patients, who underwent 21 PGS cycles with poor prognosis, with 128 non-PGS patients in the control group, with the same inclusion criterion as for the PGS group. MATERIALS AND METHODS: Single cells were obtained by laser-assisted embryo biopsy from day 3 embryos and subsequently analyzed by array CGH for all 24 chromosomes. Once the array CGH results were available on the morning of day 5, only chromosomally normal embryos that had progressed to blastocyst stage were transferred. RESULTS: The implantation rate and clinical pregnancy rate (PR) per transfer were found to be significantly higher in the PGS group than in the control group (63.2% vs. 26.2%, P = 0.001 and 73.3% vs. 36.7%, P = 0.006, respectively), while the multiple PRs sharply declined from 31.9% to 9.1% in the PGS group. CONCLUSIONS: In this pilot study, we have shown that PGS by array CGH can improve the clinical outcome in patients undergoing IVF with poor prognosis. PMID:27382234

Cell-free DNA and telomere length among women undergoing in vitro fertilization treatment.

PubMed

Czamanski-Cohen, J; Sarid, O; Cwikel, J; Douvdevani, A; Levitas, E; Lunenfeld, E; Har-Vardi, I

2015-11-01

The current research is aimed at finding potential non-invasive bio-markers that will help us learn more about the mechanisms at play in failed assisted reproduction treatment. This exploratory pilot study examined the relationship between cell-free DNA (CFD) in plasma and telomere length in lymphocytes among women undergoing in vitro fertilization (IVF) and compared telomere length and CFD levels to a healthy control group. Blood of 20 women undergoing IVF was collected at three time points during the IVF cycle. We assessed the relationship between CFD and telomere length as well as controlling for morning cortisol levels. We also collected blood of 10 healthy controls at two time points (luteal and follicular phases of the menstrual cycle) and compared mean telomere length, CFD, and cortisol levels between the IVF patients and healthy controls. The results revealed an inverse relationship between CFD levels and telomere lengths at several time points that remained significant even after controlling for cortisol levels. Women undergoing IVF had statistically significant higher levels of CFD and shorter telomeres compared to healthy controls. The relationship between telomere length and CFD should be further explored in larger studies in order to uncover potential mechanisms that cause both shortened telomere length and elevated CFD in women undergoing IVF.

Pamidronate Disodium for Palliative Therapy of Feline Bone-Invasive Tumors

PubMed Central

Wypij, Jackie M.; Heller, David A.

2014-01-01

This study sought to quantify in vitro antiproliferative effects of pamidronate in feline cancer cells and assess feasibility of use of pamidronate in cats by assessing short-term toxicity and dosing schedule in cats with bone-invasive cancer. A retrospective pilot study included eight cats with bone invasive cancer treated with intravenous pamidronate. In vitro, pamidronate reduced proliferation in feline cancer cells (P < 0.05). One cat treated with pamidronate in combination with chemotherapy and two cats treated with pamidronate as a single agent after failing prior therapy had subjective clinically stable disease; median progression free interval in these cats from initial pamidronate treatment was 81 days. Three cats developed azotemia while undergoing various treatment modalities including nonsteroidal anti-inflammatory drugs and pamidronate. Median overall survival was 116.5 days for all cats and 170 days for cats with oral squamous cell carcinoma. Median progression free survival was 55 days for all cats and 71 days for cats with oral squamous cell carcinoma. Pamidronate therapy appears feasible for administration in cancer bearing cats with aggressive bone lesions in the dose range of 1-2 mg/kg every 21–28 days for multiple treatments. No acute or short-term toxicity was directly attributable to pamidronate. PMID:25013741

Polymeric Nanoparticle-Based Photodynamic Therapy for Chronic Periodontitis in Vivo.

PubMed

de Freitas, Laura Marise; Calixto, Giovana Maria Fioramonti; Chorilli, Marlus; Giusti, Juçaíra Stella M; Bagnato, Vanderlei Salvador; Soukos, Nikolaos S; Amiji, Mansoor M; Fontana, Carla Raquel

2016-05-20

Antimicrobial photodynamic therapy (aPDT) is increasingly being explored for treatment of periodontitis. Here, we investigated the effect of aPDT on human dental plaque bacteria in suspensions and biofilms in vitro using methylene blue (MB)-loaded poly(lactic-co-glycolic) (PLGA) nanoparticles (MB-NP) and red light at 660 nm. The effect of MB-NP-based aPDT was also evaluated in a clinical pilot study with 10 adult human subjects with chronic periodontitis. Dental plaque samples from human subjects were exposed to aPDT-in planktonic and biofilm phases-with MB or MB-NP (25 µg/mL) at 20 J/cm² in vitro. Patients were treated either with ultrasonic scaling and scaling and root planing (US + SRP) or ultrasonic scaling + SRP + aPDT with MB-NP (25 µg/mL and 20 J/cm²) in a split-mouth design. In biofilms, MB-NP eliminated approximately 25% more bacteria than free MB. The clinical study demonstrated the safety of aPDT. Both groups showed similar improvements of clinical parameters one month following treatments. However, at three months ultrasonic SRP + aPDT showed a greater effect (28.82%) on gingival bleeding index (GBI) compared to ultrasonic SRP. The utilization of PLGA nanoparticles encapsulated with MB may be a promising adjunct in antimicrobial periodontal treatment.

WE-FG-BRA-01: Cancer Treatment Utilizing Photo-Activation of Psoralen with KV X-Rays

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

Oldham, M; Yoon, S; Meng, B

Purpose: This work investigates X-PACT (X-ray Psoralen Activated Cancer Therapy): a new approach for the treatment of cancer. X-PACT utilizes psoralen, a potent anti-cancer therapeutic with immunogenic anti-cancer potential. Psoralen therapies have been limited due to the requirement for psoralen activation by UVA light. X-PACT solves this challenge by activating psoralen with UV light emitted from novel non-tethered phosphors (co-incubated with psoralen) that absorb x-rays and reradiate (phosphoresce) at UV wavelengths. Methods: The efficacy of X-PACT was evaluated in both in-vitro and in-vivo settings. In-vitro studies utilized breast (4T1), glioma (CT2A) and sarcoma (KP-B) cell lines. Cells were exposed tomore » X-PACT treatments where the concentrations of drug (psoralen and phosphor) and radiation parameters (energy, dose, and dose rate) were varied. Efficacy was evaluated primarily using flow cell cytometry to investigate treatment induced apoptosis. Methylene blue staining, and WST assays were also used. X-PACT was then evaluated in an in-vivo pilot study on BALBc mice with syngeneic 4T1 tumors, including control arms for X-PACT components. Analysis focused on tumor growth delay. Results: A multivariable regression analysis of 36 independent in-vitro irradiation experiments demonstrated that X-PACT induces significant tumor cell apoptosis and cytotoxicity on all three tumor cell lines in-vitro (p<0.0001). Neither psoralen nor phosphor alone had a strongly significant effect. The in-vivo studies show a pronounced tumor growth delay when compared to controls (42% reduction at 25 days, p=0.0002). Conclusions: These studies demonstrate for the first time a therapeutic effect for X-PACT, and provide a foundation and rationale for future studies. X-PACT represents a novel treatment approach in which well-tolerated low doses of x-ray radiation generate UVA light in-situ (including deep seated lesions) which in-turn photo-activates powerful anticancer therapeutics which may lead to short and long term therapeutic effect. This work was supported by Immunolight Llc.« less

Using In Vitro High-Throughput Screening Data for Predicting Benzo[k]Fluoranthene Human Health Hazards.

PubMed

Burgoon, Lyle D; Druwe, Ingrid L; Painter, Kyle; Yost, Erin E

2017-02-01

Today there are more than 80,000 chemicals in commerce and the environment. The potential human health risks are unknown for the vast majority of these chemicals as they lack human health risk assessments, toxicity reference values, and risk screening values. We aim to use computational toxicology and quantitative high-throughput screening (qHTS) technologies to fill these data gaps, and begin to prioritize these chemicals for additional assessment. In this pilot, we demonstrate how we were able to identify that benzo[k]fluoranthene may induce DNA damage and steatosis using qHTS data and two separate adverse outcome pathways (AOPs). We also demonstrate how bootstrap natural spline-based meta-regression can be used to integrate data across multiple assay replicates to generate a concentration-response curve. We used this analysis to calculate an in vitro point of departure of 0.751 μM and risk-specific in vitro concentrations of 0.29 μM and 0.28 μM for 1:1,000 and 1:10,000 risk, respectively, for DNA damage. Based on the available evidence, and considering that only a single HSD17B4 assay is available, we have low overall confidence in the steatosis hazard identification. This case study suggests that coupling qHTS assays with AOPs and ontologies will facilitate hazard identification. Combining this with quantitative evidence integration methods, such as bootstrap meta-regression, may allow risk assessors to identify points of departure and risk-specific internal/in vitro concentrations. These results are sufficient to prioritize the chemicals; however, in the longer term we will need to estimate external doses for risk screening purposes, such as through margin of exposure methods. © 2016 Society for Risk Analysis.

Establishing the Effect of Brushing and a Day’s Diet on Tooth Tissue Loss in Vitro

PubMed Central

Forbes-Haley, Claire; Jones, Siân Bodfel; Davies, Maria; West, Nicola X.

2016-01-01

To develop an in vitro model to mimic the effects of meals equivalent to a day’s diet on tooth tissue loss (TTL). To identify how diet effects tooth wear and to test the efficacy of dental products designed to reduce tooth wear in a more realistic environment. A typical Friday diet was devised comprising: Breakfast then brushing, lunch, dinner then brushing. Groups of enamel samples were exposed to one meal, or all three in series, a control group was exposed to water and brushed. The daily cycle was repeated to represent two days’ consumption; TTL was quantified by non-contact profilometry. This pilot study highlighted adaptions that could be made to the model such as human enamel and saliva to further replicate natural eating habits. The sum of the TTL measured after Breakfast, lunch and dinner (bovine enamel specimens exposed to single meals) was less than that exhibited by the group of samples exposed to the series of meals but this difference was not significant (p = 0.09).In the absence and presence of brushing, TTL caused by breakfast and dinner was similar, but significantly greater than that caused by lunch (p < 0.05). While brushing increased TTL, this increase was not significant. It is possible to model a daily diet in vitro, and the data obtained confirms that the combination of food and drink affects the degree of TTL. This supports the further development of an in vitro model that includes alternative foodstuffs. This would aid understanding of the effects different diets have on TTL and could test new products designed to prevent TTL. PMID:29563467

Why undertake a pilot in a qualitative PhD study? Lessons learned to promote success.

PubMed

Wray, Jane; Archibong, Uduak; Walton, Sean

2017-01-23

Background Pilot studies can play an important role in qualitative studies. Methodological and practical issues can be shaped and refined by undertaking pilots. Personal development and researchers' competence are enhanced and lessons learned can inform the development and quality of the main study. However, pilot studies are rarely published, despite their potential to improve knowledge and understanding of the research. Aim To present the main lessons learned from undertaking a pilot in a qualitative PhD study. Discussion This paper draws together lessons learned when undertaking a pilot as part of a qualitative research project. Important methodological and practical issues identified during the pilot study are discussed including access, recruitment, data collection and the personal development of the researcher. The resulting changes to the final study are also highlighted. Conclusion Sharing experiences of and lessons learned in a pilot study enhances personal development, improves researchers' confidence and competence, and contributes to the understanding of research. Implications for practice Pilots can be used effectively in qualitative studies to refine the final design, and provide the researcher with practical experience to enhance confidence and competence.

Sub-antimicrobial Doxycycline for Periodontitis Reduces Hemoglobin A1c in Subjects with Type 2 Diabetes: a Pilot Study

PubMed Central

Engebretson, Steven P.; Hey-Hadavi, Judith

2011-01-01

In vitro and animal studies suggest a possible role for the tetracycline class of drugs in the inhibition of non-enzymatic protein glycation. We conducted a 3-month, randomized placebo-controlled pilot clinical trial of conventional sub-gingival debridement, (periodontal therapy) combined with either a three month regimen of sub-antimicrobial-dose doxycycline (SDD), a two week regimen of antimicrobial-dose doxycycline (ADD), or placebo in 45 patients with long-standing type 2 diabetes (mean duration 9 years) and untreated chronic periodontitis. Subjects were taking stable doses of oral hypoglycemic medications and/or insulin. Treatment response was assessed by measuring hemoglobin A1c (HbA1c),plasma glucose, and clinical periodontal disease measures. At one-month and three-month follow-up, clinical measures of periodontitis were decreased in all groups(data to be presented elsewhere). At three months, mean HbA1c levels in the SDD group were reduced 0.9% unitsfrom 7.2% units ± 2.2(±SD), to 6.3% units ±1.1, which represents a 12.5% improvement. In contrast, there was no significant change in HbA1c in the ADD (7.5%± 2.0 to 7.8%± 2.1) or placebo (8.5%± 2.0 to 8.5%± 2.6) groups. Mean HbA1c change from baseline was significantly greater in the SDD group compared with the ADD group (p=0.04) but not placebo (p=0.22). Moreover, a larger proportion of subjects in the SDD group experienced improvement (p<0.05) compared to the ADD or placebo groups. Mean plasma glucose levels were not significantly different between or within the groups. The results of this pilot study suggest that the treatment of periodontitis with sub-gingival debridement and 3-months of daily sub-antimicrobial-dose doxycycline may decrease HbA1c in patients with type 2 diabetes taking normally prescribed hypoglycemic agents. PMID:21782948

Short communication: Iodine concentrations in serum, milk, and tears after feeding Ascophyllum nodosum to dairy cows-A pilot study.

PubMed

Sorge, U S; Henriksen, M; Bastan, A; Cremers, N; Olsen, K; Crooker, B A

2016-10-01

Kelp (Ascophyllum nodosum) is rich in iodine and often fed by organic dairy producers as a mineral supplement to support animal health. A commonly held belief is that kelp supplementation decreases susceptibility to infectious bovine keratoconjunctivitis due to increased iodine concentrations in tears. Whereas serum and milk iodine concentrations are positively correlated and modulated by oral iodine supplementation, nothing is known about the iodine concentration of tears. Therefore, the 3 objectives of this pilot study were to determine (1) the iodine content of tears, milk, and serum of cows after being fed kelp for 30d; (2) the trace mineral and thyroid status of cows before (d 0) and after being fed kelp for 30d; and (3) the in vitro growth rate of bacteria in tears (Moraxella bovis) or milk (Staphylococcus aureus, Escherichia coli, Streptococcus uberis) collected from cows fed no kelp (d 0) or kelp (d 30). Cows (n=3/treatment) were individually fed 56g of kelp per day (n=3/treatment) or not (n=3/no treatment) for 30 d. Daily feed intake of the TMR was recorded and weekly TMR, kelp, milk, blood and tear samples were collected and analyzed for iodine. The feed samples were pooled and further analyzed for other minerals. On d 0 and 30, liver biopsies and blood samples were collected and analyzed for mineral content and thyroid hormone concentrations, respectively. An inhibition test used milk and tear-soaked plates from kelp-fed cows (d 0 and 30) as well as 1 and 7.5% iodine as positive and distilled water as negative control. As expected, serum iodine concentrations were positively correlated with milk and tear iodine concentrations. Whereas the iodine concentrations in serum increased significantly in the kelp-fed cows during the 30-d study, milk and tear iodine concentrations increased only numerically in these cows compared with the control group. Liver mineral profiles were comparable between groups and generally did not change over the course of the study. Thyroid hormones remained overall within the reference range throughout the trial. Neither milk nor tears from kelp-fed cows inhibited in vitro growth of any of the plated bacteria. In summary, serum iodine concentration was correlated with the iodine concentration in milk and tears and feeding kelp increased only the serum iodine levels of cows in this trial. Bacterial growth was not inhibited in milk and tears of kelp-fed cattle in vitro, and prevention of infectious bovine keratoconjunctivitis would not be based solely on increased iodine concentrations in tears. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effect of the French Oak Wood Extract Robuvit on Markers of Oxidative Stress and Activity of Antioxidant Enzymes in Healthy Volunteers: A Pilot Study

PubMed Central

Orszaghova, Zuzana; Laubertova, Lucia; Sabaka, Peter; Rohdewald, Peter; Durackova, Zdenka; Muchova, Jana

2014-01-01

We examined in vitro antioxidant capacity of polyphenolic extract obtained from the wood of oak Quercus robur (QR), Robuvit, using TEAC (Trolox equivalent antioxidant capacity) method and the effect of its intake on markers of oxidative stress, activity of antioxidant enzymes, and total antioxidant capacity in plasma of 20 healthy volunteers. Markers of oxidative damage to proteins, DNA, and lipids and activities of Cu/Zn-superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined in the erythrocytes. We have found an in vitro antioxidant capacity of Robuvit of 6.37 micromole Trolox equivalent/mg of Robuvit. One month intake of Robuvit in daily dose of 300 mg has significantly decreased the serum level of advanced oxidation protein products (AOPP) and lipid peroxides (LP). Significantly increased activities of SOD and CAT as well as total antioxidant capacity of plasma after one month intake of Robuvit have been shown. In conclusion, we have demonstrated for the first time that the intake of Robuvit is associated with decrease of markers of oxidative stress and increase of activity of antioxidant enzymes and total antioxidant capacity of plasma in vivo. PMID:25254080

Stability of prototype two-piece zirconia and titanium implants after artificial aging: an in vitro pilot study.

PubMed

Kohal, Ralf-Joachim; Finke, Hans Christian; Klaus, Gerold

2009-12-01

Zirconia oral implants are a new topic in implant dentistry. So far, no data are available on the biomechanical behavior of two-piece zirconia implants. Therefore, the purpose of this pilot investigation was to test in vitro the fracture strength of two-piece cylindrical zirconia implants after aging in a chewing simulator. This laboratory in vitro investigation comprised three different treatment groups. Each group consisted of 16 specimens. In group 1, two-piece zirconia implants were restored with zirconia crowns (zirconia copings veneered with Triceram; Esprident, Ispringen, Germany), and in group 2 zirconia implants received Empress 2 single crowns (Ivoclar Vivadent AG, Schaan, Liechtenstein). The implants, including the abutments, in the two zirconia groups were identical. In group 3, similar titanium implants were reconstructed with porcelain-fused-to-metal crowns. Eight samples of each group were submitted to artificial aging with a long-term load test in the artificial mouth (chewing simulator). Subsequently, all not artificially aged samples and all artificially aged samples that survived the long-term loading of each group were submitted to a fracture strength test in a universal testing machine. For the pairwise comparisons in the different test groups with or without artificial loading and between the different groups at a given artificial loading condition, the Wilcoxon rank-sum test for independent samples was used. The significance level was set at 5%. One sample of group 1 (veneer fracture), none of group 2, and six samples of group 3 (implant abutment screw fractures) failed while exposed to the artificial mouth. The values for the fracture strength after artificial loading with 1.2 million cycles for group 1 were between 45 and 377 N (mean: 275.7 N), in group 2 between 240 and 314 N (mean: 280.7 N), and in the titanium group between 45 and 582 N (mean: 165.7 N). The fracture strength results without artificial load for group 1 amounted to between 270 and 393 N (mean: 325.1 N), for group 2 between 235 and 321 N (mean: 281.8 N), and between 474 and 765 N (mean: 595.2 N) for the titanium group. The failure mode during the fracture testing in the zirconia implant groups was a fracture of the implant head and a bending/fracture of the abutment screw in the titanium group. Within the limits of this pilot investigation, the biomechanical stability of all tested prototype implant groups seems to be - compared with the possibly exerted occlusal forces - borderline for clinical use. A high number of failures occurred already during the artificial loading in the titanium group at the abutment screw level. The zirconia implant groups showed irreparable implant head fractures at relatively low fracture loads. Therefore, the clinical use of the presented prototype implants has to be questioned.

Thermodynamic effects of laser irradiation of implants placed in bone: an in vitro study.

PubMed

Leja, Chris; Geminiani, Alessandro; Caton, Jack; Romanos, Georgios E

2013-11-01

Lasers have been proposed for various applications involving dental implants, including uncovering implants and treating peri-implantitis. However, the effect of laser irradiation on the implant surface temperature is only partially known. The aim of this pilot study was to determine the effect of irradiation with diode, carbon dioxide, and Er:YAG lasers on the surface temperature of dental implants placed in bone, in vitro. For this study, one dental implant was placed in a bovine rib. A trephine bur was used to create a circumferential defect to simulate peri-implantitis, and thermocouples were placed at the coronal and apical aspect of the implant. The implant was irradiated for 60 s using four different lasers independently and change in temperature as well as time to reach a 10 °C increase in temperature were recorded. There was wide variability in results among the lasers and settings. Time for a 10 °C increase ranged from 0.9 to over 60 s for the coronal thermocouple and from 18 to over 60 s for the apical thermocouple. Maximum temperature ranged from 5.9 to 70.9 °C coronally and from 1.4 to 23.4 °C apically. During laser irradiation of dental implants, a surface temperature increase beyond the "critical threshold" of 10 °C can be reached after only 18 s.

Pilot study assessing differentiation of steatosis hepatis, hepatic iron overload, and combined disease using two-point dixon MRI at 3 T: in vitro and in vivo results of a 2D decomposition technique.

PubMed

Boll, Daniel T; Marin, Daniele; Redmon, Grace M; Zink, Stephen I; Merkle, Elmar M

2010-04-01

The purpose of our study was to evaluate whether two-point Dixon MRI using a 2D decomposition technique facilitates metabolite differentiation between lipids and iron in standardized in vitro liver phantoms with in vivo patient validation and allows semiquantitative in vitro assessment of metabolites associated with steatosis, iron overload, and combined disease. The acrylamide-based phantoms were made to reproduce the T1- and T2-weighted MRI appearances of physiologic hepatic parenchyma and hepatic steatosis-iron overload by the admixture of triglycerides and ferumoxides. Combined disease was simulated using joint admixtures of triglycerides and ferumoxides at various concentrations. For phantom validation, 30 patients were included, of whom 10 had steatosis, 10 had iron overload, and 10 had no liver disease. For MRI an in-phase/opposed-phase T1-weighted sequence with TR/TE(opposed-phase)/TE(in-phase) of 4.19/1.25/2.46 was used. Fat/water series were obtained by Dixon-based algorithms. In-phase and opposed-phase and fat/water ratios were calculated. Statistical cluster analysis assessed ratio pairs of physiologic liver, steatosis, iron overload, and combined disease in 2D metabolite discrimination plots. Statistical assessment proved that metabolite decomposition in phantoms simulating steatosis (1.77|0.22; in-phase/opposed-phase|fat/water ratios), iron overload (0.75|0.21), and healthy control subjects (1.09|0.05) formed three clusters with distinct ratio pairs. Patient validation for hepatic steatosis (3.29|0.51), iron overload (0.56|0.41), and normal control subjects (0.99|0.05) confirmed this clustering (p < 0.001). One-dimensional analysis assessing in vitro combined disease only with in-phase/opposed-phase ratios would have failed to characterize metabolites. The 2D analysis plotting in-phase/opposed-phase and fat/water ratios (2.16|0.59) provided accurate semiquantitative metabolite decomposition (p < 0.001). MR Dixon imaging facilitates metabolite decomposition of intrahepatic lipids and iron using in vitro phantoms with in vivo patient validation. The proposed decomposition technique identified distinct in-phase/opposed-phase and fat/water ratios for in vitro steatosis, iron overload, and combined disease.

The Effects of Longitudinal Control-System Dynamics on Pilot Opinion and Response Characteristics as Determined from Flight Tests and from Ground Simulator Studies

NASA Technical Reports Server (NTRS)

Sadoff, Melvin

1958-01-01

The results of a fixed-base simulator study of the effects of variable longitudinal control-system dynamics on pilot opinion are presented and compared with flight-test data. The control-system variables considered in this investigation included stick force per g, time constant, and dead-band, or stabilizer breakout force. In general, the fairly good correlation between flight and simulator results for two pilots demonstrates the validity of fixed-base simulator studies which are designed to complement and supplement flight studies and serve as a guide in control-system preliminary design. However, in the investigation of certain problem areas (e.g., sensitive control-system configurations associated with pilot- induced oscillations in flight), fixed-base simulator results did not predict the occurrence of an instability, although the pilots noted the system was extremely sensitive and unsatisfactory. If it is desired to predict pilot-induced-oscillation tendencies, tests in moving-base simulators may be required. It was found possible to represent the human pilot by a linear pilot analog for the tracking task assumed in the present study. The criterion used to adjust the pilot analog was the root-mean-square tracking error of one of the human pilots on the fixed-base simulator. Matching the tracking error of the pilot analog to that of the human pilot gave an approximation to the variation of human-pilot behavior over a range of control-system dynamics. Results of the pilot-analog study indicated that both for optimized control-system dynamics (for poor airplane dynamics) and for a region of good airplane dynamics, the pilot response characteristics are approximately the same.

76 FR 70152 - Pilot Program for Early Feasibility Study Investigational Device Exemption Applications

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-10

...] Pilot Program for Early Feasibility Study Investigational Device Exemption Applications AGENCY: Food and... feasibility study investigational device exemption (IDE) applications. The pilot program will conform to the... Feasibility Medical Device Clinical Studies, Including Certain First in Human (FIH) Studies.'' Under the pilot...

Effects of clopidogrel therapy on whole blood platelet aggregation, the Plateletworks® assay and coagulation parameters in cats with asymptomatic hypertrophic cardiomyopathy: a pilot study.

PubMed

den Toom, M L; van Leeuwen, M W; Szatmári, V; Teske, E

2017-12-01

Although scientific evidence is limited, clopidogrel is frequently used as prophylaxis for arterial thromboembolism in cats with hypertrophic cardiomyopathy (HCM). Evaluating effects of clopidogrel therapy in asymptomatic cats with HCM on (1) conventional whole blood aggregation (WBA), (2) alternative platelet aggregation assessed with tubes of the Plateletworks® assay and (3) standard coagulation parameters. Prospective, randomized, double-blind, placebo-controlled pilot study. Fourteen asymptomatic HCM cats were randomly allocated to receive placebo (n = 5) or clopidogrel (18.75 mg/cat q24h, n = 9) as part of a larger study. Aggregation responses (to 20 µM adenosine diphosphate (ADP) and 10 µg/ml collagen) in WBA and the Plateletworks® assay and standard coagulation parameters were evaluated at baseline and after seven days of therapy. Clopidogrel therapy significantly reduced aggregation responses to ADP and collagen in the Plateletworks® agonists tubes (ADP and collagen: P < 0.001), but did not significantly reduce aggregation responses to ADP and collagen in the WBA technique (ADP: P = 0.07, collagen: P = 0.30). Clopidogrel therapy did not show a significant effect on prothrombin time, activated partial thromboplastin time, antithrombin, D-dimers and fibrinogen concentrations. Clopidogrel therapy at a dose of 18.75 mg/cat q24h for seven days causes a significant decrease in in vitro platelet aggregation evaluated with the Plateletworks® assay, without affecting standard coagulation parameters in cats with asymptomatic HCM.

A Study of the Characteristics of Human-Pilot Control Response to Simulated Aircraft Lateral Motions

NASA Technical Reports Server (NTRS)

Cheatham, Donald C

1954-01-01

Report presents the results of studies made in an attempt to provide information on the control operations of the human pilot. These studies included an investigation of the ability of pilots to control simulated unstable yawing oscillations, a study of the basic characteristics of human-pilot control response, and a study to determine whether and to what extent pilot control response can be represented in an analytical form.

Pulsed Electromagnetic Field Assisted in vitro Electroporation: A Pilot Study

NASA Astrophysics Data System (ADS)

Novickij, Vitalij; Grainys, Audrius; Lastauskienė, Eglė; Kananavičiūtė, Rūta; Pamedytytė, Dovilė; Kalėdienė, Lilija; Novickij, Jurij; Miklavčič, Damijan

2016-09-01

Electroporation is a phenomenon occurring due to exposure of cells to Pulsed Electric Fields (PEF) which leads to increase of membrane permeability. Electroporation is used in medicine, biotechnology, and food processing. Recently, as an alternative to electroporation by PEF, Pulsed ElectroMagnetic Fields (PEMF) application causing similar biological effects was suggested. Since induced electric field in PEMF however is 2-3 magnitudes lower than in PEF electroporation, the membrane permeabilization mechanism remains hypothetical. We have designed pilot experiments where Saccharomyces cerevisiae and Candida lusitaniae cells were subjected to single 100-250 μs electrical pulse of 800 V with and without concomitant delivery of magnetic pulse (3, 6 and 9 T). As expected, after the PEF pulses only the number of Propidium Iodide (PI) fluorescent cells has increased, indicative of membrane permeabilization. We further show that single sub-millisecond magnetic field pulse did not cause detectable poration of yeast. Concomitant exposure of cells to pulsed electric (PEF) and magnetic field (PMF) however resulted in the increased number PI fluorescent cells and reduced viability. Our results show increased membrane permeability by PEF when combined with magnetic field pulse, which can explain electroporation at considerably lower electric field strengths induced by PEMF compared to classical electroporation.

Pulsed Electromagnetic Field Assisted in vitro Electroporation: A Pilot Study

PubMed Central

Novickij, Vitalij; Grainys, Audrius; Lastauskienė, Eglė; Kananavičiūtė, Rūta; Pamedytytė, Dovilė; Kalėdienė, Lilija; Novickij, Jurij; Miklavčič, Damijan

2016-01-01

Electroporation is a phenomenon occurring due to exposure of cells to Pulsed Electric Fields (PEF) which leads to increase of membrane permeability. Electroporation is used in medicine, biotechnology, and food processing. Recently, as an alternative to electroporation by PEF, Pulsed ElectroMagnetic Fields (PEMF) application causing similar biological effects was suggested. Since induced electric field in PEMF however is 2–3 magnitudes lower than in PEF electroporation, the membrane permeabilization mechanism remains hypothetical. We have designed pilot experiments where Saccharomyces cerevisiae and Candida lusitaniae cells were subjected to single 100–250 μs electrical pulse of 800 V with and without concomitant delivery of magnetic pulse (3, 6 and 9 T). As expected, after the PEF pulses only the number of Propidium Iodide (PI) fluorescent cells has increased, indicative of membrane permeabilization. We further show that single sub-millisecond magnetic field pulse did not cause detectable poration of yeast. Concomitant exposure of cells to pulsed electric (PEF) and magnetic field (PMF) however resulted in the increased number PI fluorescent cells and reduced viability. Our results show increased membrane permeability by PEF when combined with magnetic field pulse, which can explain electroporation at considerably lower electric field strengths induced by PEMF compared to classical electroporation. PMID:27634482

Pilot Screening to Determine Antimicrobial Synergies in a Multidrug-Resistant Bacterial Strain Library

PubMed Central

Kim, Si-Hyun; Park, Chulmin; Chun, Hye-Sun; Choi, Jae-Ki; Lee, Hyo-Jin; Cho, Sung-Yeon; Park, Sun Hee; Choi, Su-Mi; Choi, Jung-Hyun; Yoo, Jin-Hong

2016-01-01

With the rise in multidrug-resistant (MDR) bacterial infections, there has been increasing interest in combinations of ≥2 antimicrobial agents with synergistic effects. We established an MDR bacterial strain library to screen for in vitro antimicrobial synergy by using a broth microdilution checkerboard method and high-throughput luciferase-based bacterial cell viability assay. In total, 39 MDR bacterial strains, including 23 carbapenem-resistant gram-negative bacteria, 9 vancomycin-intermediate Staphylococcus aureus, and 7 vancomycin-resistant Enterococcus faecalis, were used to screen for potential antimicrobial synergies. Synergies were more frequently identified with combinations of imipenem plus trimethoprim–sulfamethoxazole for carbapenem-resistant Acinetobacter baumannii in the library. To verify this finding, we tested 34 A. baumannii clinical isolates resistant to both imipenem and trimethoprim–sulfamethoxazole by the checkerboard method. The imipenem plus trimethoprim–sulfamethoxazole combination showed synergy in the treatment of 21 (62%) of the clinical isolates. The results indicate that pilot screening for antimicrobial synergy in the MDR bacterial strain library could be valuable in the selection of combination therapeutic regimens to treat MDR bacterial infections. Further studies are warranted to determine whether this screening system can be useful to screen for the combined effects of conventional antimicrobials and new-generation antimicrobials or nonantimicrobials. PMID:26974861

Development and validation of a discriminative dissolution method for atorvastatin calcium tablets using in vivo data by LC and UV methods.

PubMed

Machado, J C; Lange, A D; Todeschini, V; Volpato, N M

2014-02-01

A dissolution method to analyze atorvastatin tablets using in vivo data for RP and test pilot (PB) was developed and validated. The appropriate conditions were determined after solubility tests using different media, and sink conditions were established. The conditions used were equipment paddle at 50 rpm and 900 mL of potassium phosphate buffer pH 6.0 as dissolution medium. In vivo release profiles were obtained from the bioequivalence study of RP and the generic candidate PB. The fraction of dose absorbed was calculated using the Loo-Riegelman method. It was necessary to use a scale factor of time similar to 6.0, to associate the values of absorbed fraction and dissolved fraction, obtaining an in vivo-in vitro correlation level A. The dissolution method to quantify the amount of drug dissolved was validated using high-performance liquid chromatography and ultraviolet spectrophotometry, and validated according to the USP protocol. The discriminative power of dissolution conditions was assessed using two different pilot batches of atorvastatin tablets (PA and PB) and RP. The dissolution test was validated and may be used as a discriminating method in quality control and in the development of the new formulations.

Nanoparticle mediated ablation of breast cancer cells using a nanosecond pulsed electric field

NASA Astrophysics Data System (ADS)

Burford, Christopher

In the past, both nanomaterials and various heating modalities have been researched as means for treating cancers. However, many of the current methodologies have the flaws of inconsistent tumor ablation and significant destruction of healthy cells. Based on research performed using constant radiofrequency electric fields and metallic nanoparticles (where cell necrosis is induced by the heating of these nanoparticles) we have developed a modality that simlarly uses functionalized metallic nanoparticles, specific for the T47D breast cancer cell line, and nanosecond pulsed electric fields as the hyperthermic inducer. Using both iron oxide and gold nanoparticles the results of our pilot studies indicated that up to 90% of the cancer cells were ablated given the optimal treatment parameters. These quantities of ablated cells were achieved using a cumulative exposure time 6 orders of magnitude less than most in vitro radiofrequency electric field studies.

Pilot Certification, Age of Pilot, and Drug Use in Fatal Civil Aviation Accidents.

PubMed

Akparibo, Issaka Y; Stolfi, Adrienne

2017-10-01

This study examined the association between mean age of pilot, pilot license, pilot medical certificate and drug use trends in pilots fatally injured in aircraft accidents. The prevalence of prescription drugs, OTC drugs, controlled drugs and drugs that may be potentially impairing was also examined. This study was a descriptive observational study in which the NTSB Aviation Accident Database was searched from the period beginning January 1, 2012 to December 31, 2014. During the study period a total of 706 accidents involving 711 fatalities were investigated by the NTSB. This study included 633 of these accidents, involving 646 fatalities. Of these pilots, 42.1% had drugs in their biological samples. The prevalence of prescription drugs, controlled drugs, OTC drugs, opioids, and potentially impairing drugs in the fatally injured pilot population over the study period was 28.9%, 15.0%, 20.1%, 5.1%, and 25.5%, respectively. Pilots with any drugs in their samples were significantly older than those without drugs. Medical certificate held was associated with drug use; pilots who held third class certificates had the highest prevalence at 54.1%. Pilot license was not associated with drug use. In 3.8% of the accidents, drugs were a contributing factor in the cause. Despite current FAA medical regulations, potentially impairing drugs are frequently found in biological samples of fatally injured pilots in the U.S. More education of airmen by aviation medical examiners is needed on the safety of drug use.Akparibo IY, Stolfi A. Pilot certification, age of pilot, and drug use in fatal civil aviation accidents. Aerosp Med Hum Perform. 2017; 88(10):931-936.

Consumption of Dried Apple Peel Powder Increases Joint Function and Range of Motion

PubMed Central

Attridge, Victoria L.; Benson, Kathleen F.; Beaman, Joni L.; Carter, Steve G.; Ager, David

2014-01-01

Abstract The goal for this study was to evaluate the effects of consumption of dried apple peel powder (DAPP) on joint function and range of motion (ROM). Additional in vitro and clinical testing was performed to suggest specific mechanisms of action. An open-label clinical pilot study involved 12 healthy people with moderate loss of joint ROM and associated chronic pain. The subjects consumed 4.25 g DAPP daily for 12 weeks, with evaluations at baseline, 2, 4, 8, and 12 weeks. ROM was evaluated at each visit using dual digital inclinometry. Pain scores were collected using Visual Analogue Scales. Blood draws enabled testing of serum antioxidant protective capacity using the cellular antioxidant protection (CAP-e) bioassay. Additional in vitro testing involved testing of cyclooxygenase-2 (COX-2) and lipoxygenase inhibition, cellular antioxidant protection by the CAP-e bioassay, and formation of reactive oxygen species (ROS) by polymorphonuclear (PMN) cells by flow cytometry. Twelve weeks of consumption of DAPP was associated with improved ROM. DAPP provided antioxidants that were available to enter into and protect cells from oxidative damage in vitro, and consumption of DAPP for 12 weeks was associated with a statistically significant improvement in serum antioxidant protective status. DAPP inhibited both COX-2 and lipoxygenase enzymes, and pretreatment of inflammatory PMN cells with DAPP before inflammatory stimulus resulted in reduced ROS formation. This suggests multifaceted anti-inflammatory properties of DAPP. Consumption of DAPP was associated with improved joint function and improved serum antioxidant protection status. The observed pain reduction may be associated with the improved antioxidant status and linked to the apple polyphenols' anti-inflammatory effects. PMID:25271471

Nanoimmunoassay to Detect Responses in Head and Neck Cancer: Feasibility in a Mouse Model.

PubMed

Hubbard, Matthew A; Khalil, Ashraf A; Schoeff, Stephen S; Allak, Amir; VanKoevering, Kyle K; Maxwell, Anne K; Adejumo, Oluwayemisi; Mendez, Rolando E; Jameson, Mark J

2014-07-01

To demonstrate the feasibility of detecting and quantifying extracellular signal-related kinase (ERK) phosphorylation status using nanoimmunoassay (NIA). Analyses using Cal27, SCC25, and OSC19 head and neck squamous carcinoma cell lines in vitro and in a murine xenograft model. NIA and immunoblot were performed on whole-cell lysates, tumor lysates, and fine-needle aspirate biopsies to detect ERK phosphorylation states. Using NIA, all 6 isoforms of ERK1/2, including nonphosphorylated, monophosphorylated, and diphosphorylated species, could be reliably detected, distinguished, and quantified in a single assay using a single antibody. In vitro treatment of Cal27 cells with the epidermal growth factor receptor inhibitor gefitinib abolished phospho-ERK detection by immunoblot but resulted in residual detectable species by NIA. Residual phospho-ERK in gefitinib-treated cells could be further reduced by the addition of the insulin-like growth factor 1 receptor inhibitor OSI-906; this correlated with an additional decrease in proliferation over gefitinib alone. In a pilot study of 4 murine xenograft tumors, NIA performed on tumor lysates and fine-needle aspirate biopsies demonstrated altered ERK profiles after 2 days of gefitinib treatment compared with untreated mice. NIA offers a novel approach to quantitating the activation state of signaling molecules such as ERK in nanoscale in vitro and in vivo samples across a wide dynamic range. As such, it has potential to provide molecular diagnostic information before, during, and after treatment using a minimally invasive technique. Further study is warranted to determine its utility in assessing signaling proteins as biomolecular outcome predictors in clinical trials. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

In vitro effects of CpG oligodeoxynucleotides delivered by gelatin nanoparticles on canine peripheral blood mononuclear cells of atopic and healthy dogs - a pilot study.

PubMed

Prélaud, Ana Rostaher; Fuchs, Sebastian; Weber, Karin; Winter, Gerhard; Coester, Conrad; Mueller, Ralf S

2013-10-01

Cytosine-phosphate-guanine (CpG) oligodeoxynucleotides offer a novel promising immunotherapeutic approach for atopic dermatitis (AD) both in humans and animals. Gelatin nanoparticles (GNP) enhance and prolong CpG-associated immunomodulatory effects and minimize adverse effects both in vitro and in vivo. Information about the effects of this combination in dogs is lacking. The aim of this study was to evaluate immunological effects of CpG coupled to GNP on canine peripheral blood mononuclear cells (PBMCs) in vitro. Eight dogs with AD, diagnosed by standard criteria and with a concurrent immediate hypersensitivity to house dust mites were included. Control samples were taken from eight healthy, age-matched control dogs without history or evidence of cutaneous or systemic illness. Peripheral blood mononuclear cells of healthy and allergic dogs were incubated with CpG-GNP and the uptake of CpG-GNP was demonstrated using confocal laser scanning microscopy. Cell culture supernatant concentrations of interferon gamma (IFN-γ), interleukin (IL)-4, IL-6 and IL-10 were measured by Canine Cytokine Milliplex. No significant changes in IFN-γ and IL-4 were found when comparing PBMCs incubated with CpG and CpG-GNP with the negative controls in atopic and healthy dogs. Interleukin-6 was not detected in any of the groups. However, a statistically significant increase in IL-10 concentration was found after 24 h stimulation with CpG-GNP compared with CpG alone both in atopic and healthy dogs. As IL-10 is considered an immunosuppressive cytokine playing a key role in peripheral tolerance; the reported CpG-GNP formulation could be a new approach in allergy treatment. © 2013 ESVD and ACVD.

Cloning, production, and purification of proteins for a medium-scale structural genomics project.

PubMed

Quevillon-Cheruel, Sophie; Collinet, Bruno; Trésaugues, Lionel; Minard, Philippe; Henckes, Gilles; Aufrère, Robert; Blondeau, Karine; Zhou, Cong-Zhao; Liger, Dominique; Bettache, Nabila; Poupon, Anne; Aboulfath, Ilham; Leulliot, Nicolas; Janin, Joël; van Tilbeurgh, Herman

2007-01-01

The South-Paris Yeast Structural Genomics Pilot Project (http://www.genomics.eu.org) aims at systematically expressing, purifying, and determining the three-dimensional structures of Saccharomyces cerevisiae proteins. We have already cloned 240 yeast open reading frames in the Escherichia coli pET system. Eighty-two percent of the targets can be expressed in E. coli, and 61% yield soluble protein. We have currently purified 58 proteins. Twelve X-ray structures have been solved, six are in progress, and six other proteins gave crystals. In this chapter, we present the general experimental flowchart applied for this project. One of the main difficulties encountered in this pilot project was the low solubility of a great number of target proteins. We have developed parallel strategies to recover these proteins from inclusion bodies, including refolding, coexpression with chaperones, and an in vitro expression system. A limited proteolysis protocol, developed to localize flexible regions in proteins that could hinder crystallization, is also described.

Pharmacodynamic effects of EV-077 in patients with diabetes mellitus and coronary artery disease on aspirin or clopidogrel monotherapy: results of an in vitro pilot investigation.

PubMed

Rollini, Fabiana; Tello-Montoliu, Antonio; Patel, Ronakkumar; Darlington, Andrew; Wilson, Ryan E; Franchi, Francesco; Muñiz-Lozano, Ana; Desai, Bhaloo; Bender, Norbert; Sakariassen, Kjell S; Angiolillo, Dominick J

2014-01-01

Patients with diabetes mellitus (DM) have increased propensity to generate thromboxane A2 (TXA2) and other eicosanoids which can contribute to their heightened platelet reactivity. EV-077 is a potent thromboxane receptor antagonist and thromboxane synthase inhibitor and thus represents an attractive therapy in patients with DM. However, the effects of EV-077 on pharmacodynamic (PD) profiles in patients with DM and coronary artery disease (CAD) while on antiplatelet therapy is poorly explored and represented the aim of this in vitro pilot investigation. Patients with DM and stable CAD (n = 10) on low-dose aspirin (81 mg/day) were enrolled and then switched to clopidogrel (75 mg/day) monotherapy for 7-10 days. PD assessments were conducted while on aspirin and on clopidogrel using light transmittance aggregometry following stimuli with U-46619 [TXA2 stable analogue (7 μM)], arachidonic acid [AA (1 mM)], collagen (3 μg/mL) and adenosine diphosphate [ADP (5 μM and 20 μM)] with and without in vitro EV-077. EV-077 completely inhibited U-46619-stimulated platelet aggregation (p = 0.005 for both aspirin and clopidogrel) and also showed a significant reduction of collagen-induced aggregation (aspirin p = 0.008; clopidogrel p = 0.005). EV-077 significantly reduced AA-induced platelet aggregation in clopidogrel (p = 0.009), but not aspirin (p = 0.667) treated patients. Ultimately, EV-077 significantly reduced ADP-mediated platelet aggregation in both aspirin (ADP 5 μM p = 0.012; ADP 20 μM p = 0.032) and clopidogrel (ADP 5 μM p = 0.007; ADP 20 μM p = 0.008) treated patients. In conclusion, in DM patients with CAD on aspirin or clopidogrel monotherapy, in vitro EV-077 exerts potent platelet inhibitory effects on multiple platelet signaling pathways. These data support that EV-077 has only additive platelet inhibiting effects on top of standard antiplatelet therapies. These findings warrant further investigation in ex vivo settings.

Formulation of poorly water-soluble drugs via coacervation--a pilot study using febantel.

PubMed

De Jaeghere, W; De Geest, B G; Van Bocxlaer, J; Remon, J P; Vervaet, C; Antunes da Fonseca, A

2013-11-01

In this study, febantel was dissolved under increased temperature in a nonionic surfactant Lutrol L44® and subsequently mixed into an aqueous maltodextrin solution. After 8h under static conditions, coacervation or phase separation took place. (1)H NMR spectra and HPLC analysis showed that the upper phase contained mainly all febantel, while no febantel was detected in the lower phase. Fluorescent microscopy showed that maltodextrin is distributed in the lower phase. Coacervation proved to be a promising formulation technology for certain poorly water-soluble drugs, such as febantel. The coacervate phase showed an increase in in vitro dissolution kinetics, compared to Rintal® granules. These results were confirmed in an in vivo study performed on dogs. Febantel and fenbendazole showed a significant increase in plasma concentration compared to Rintal® granules. Further studies have to be performed to transform coacervates into a solid dosage form and to prove broad applicability to other poorly soluble drugs. Copyright © 2013 Elsevier B.V. All rights reserved.

Pilot-model analysis and simulation study of effect of control task desired control response

NASA Technical Reports Server (NTRS)

Adams, J. J.; Gera, J.; Jaudon, J. B.

1978-01-01

A pilot model analysis was performed that relates pilot control compensation, pilot aircraft system response, and aircraft response characteristics for longitudinal control. The results show that a higher aircraft short period frequency is required to achieve superior pilot aircraft system response in an altitude control task than is required in an attitude control task. These results were confirmed by a simulation study of target tracking. It was concluded that the pilot model analysis provides a theoretical basis for determining the effect of control task on pilot opinions.

Evaluation of the effect of photodynamic antimicrobial therapy in dentin caries: a pilot in vivo study

NASA Astrophysics Data System (ADS)

Borges, F. M. C.; de-Melo, M. A. S.; Lima, J. M. P.; Zanin, I. C. J.; Rodrigues, L. K. A.; Nobre-dos-Santos, M.

2010-02-01

In vitro and in situ studies have demonstrated that the photodynamic antimicrobial therapy (PACT) is effective in reducing Streptococcus mutans population in artificially carious dentin. This pilot in vivo study evaluated the antimicrobial effect of PACT using toluidine blue O (TBO) and a light-emitting diode (LED) in carious dentin lesions. Five healthy adult volunteers (19-36 yr), with at least 4 active carious cavities each, participated in this study. Teeth of each volunteer were randomly divided into four groups: (1) without TBO and without light (Control); (2) with TBO alone (TBO); (3) with LED at 94/J cm2 alone (LED); and (4) with TBO plus LED at 94 J/cm2 (PACT). Each cavity was divided into two halves. The baseline carious dentin sample was collected from half of each cavity. Following, the treatments were performed using a random distribution of tooth into treatments. Then, the second collection of carious dentin samples was performed. Before and after treatments, dentin samples were analyzed with regard to the counts of total viable microorganisms, total streptococci, mutans streptococci, and lactobacilli. The data were statistically analyzed by Kruskal-Wallis and Student-Newman-Keuls tests (α=5%). Log reductions ranged from -0.12 to 2.68 and significant reductions were observed for PACT (group 4) when compared to the other groups (1, 2, and 3) for total streptococci and mutans streptococci. Concluding, PACT was effective in killing oral microorganisms present in in vivo carious dentin lesions and may be a promising technique for eliminating bacteria from dentin before restoration.

Pre-implantation genetic screening using fluorescence in situ hybridization in couples of Indian ethnicity: Is there a scope?

PubMed Central

Saxena, Shailaja Gada; Desai, Kundanbala; Shewale, Lata; Ranjan, Prabhat

2014-01-01

CONTEXT: There is a high incidence of numerical chromosomal aberration in couples with repeated in vitro fertilization (IVF) failure, advanced maternal age, repeated unexplained abortions, severe male factor infertility and unexplained infertility. Pre-implantation genetic screening (PGS), a variant of pre-implantation genetic diagnosis, screens numerical chromosomal aberrations in couples with normal karyotype, experiencing poor reproductive outcome. The present study includes the results of the initial pilot study on 9 couples who underwent 10 PGS cycles. AIM: The aim of the present study was to evaluate the beneficial effects of PGS in couples with poor reproductive outcome. SETTINGS AND DESIGN: Data of initial 9 couples who underwent 10 PGS for various indications was evaluated. SUBJECTS AND METHODS: Blastomere biopsy was performed on cleavage stage embryos and subjected to two round fluorescence in situ hybridization (FISH) testing for chromosomes 13, 18, 21, X and Y as a two-step procedure. RESULTS: Six of the 9 couples (10 PGS cycles) conceived, including a twin pregnancy in a couple with male factor infertility, singleton pregnancies in a couple with secondary infertility, in three couples with adverse obstetric outcome in earlier pregnancies and in one couple with repeated IVF failure. CONCLUSION: In the absence of availability of array-comparative genomic hybridization in diagnostic clinical scenario for PGS and promising results with FISH based PGS as evident from the current pilot study, it is imperative to offer the best available services in the present scenario for better pregnancy outcome for patients. PMID:24829527

SUPERFUND TREATABILITY CLEARINGHOUSE: SOIL STABILIZATION PILOT STUDY, UNITED CHROME NPL SITE PILOT STUDY AND HEALTH AND SAFETY PROGRAM, UNITED CHROME NPL SITE PILOT STUDY

EPA Science Inventory

This document is a project plan for a pilot study at the United Chrome NPL site, Corvallis, Oregon and includes the health and safety and quality assurance/quality control plans. The plan reports results of a bench-scale study of the treatment process as iieasured by the ...

Characterization of Porous, Dexamethasone-Releasing Polyurethane Coatings for Glucose Sensors

PubMed Central

Vallejo-Heligon, Suzana G.; Klitzman, Bruce; Reichert, William M.

2014-01-01

Commercially available implantable needle-type glucose sensors for diabetes management are robust analytically but can be unreliable clinically primarily due to tissue-sensor interactions. Here, we present the physical, drug release, and bioactivity characterization of tubular, porous dexamethasone (Dex) releasing polyurethane coatings designed to attenuate local inflammation in the tissue-sensor interface. Porous polyurethane coatings were produced by the salt-leaching/gas-foaming method. Scanning electron microscopy (SEM) and Micro-computed tomography (Micro-CT) showed a controlled porosity and coating thickness. In vitro drug release from coatings monitored over two weeks presented an initial fast release followed by a slower release. Total release from coatings was highly dependent on initial drug loading amount. Functional in vitro testing of glucose sensors deployed with porous coatings against glucose standards demonstrated that highly porous coatings minimally affected signal strength and response rate. Bioactivity of the released drug was determined by monitoring Dex-mediated, dose-dependent apoptosis of human peripheral blood derived monocytes in culture. Acute animal studies were used to determine the appropriate Dex payload for the implanted porous coatings. Pilot short-term animal studies showed that Dex released from porous coatings implanted in rat subcutis attenuated the initial inflammatory response to sensor implantation. These results suggest that deploying sensors with the porous, Dex-releasing coatings is a promising strategy to improve glucose sensor performance. PMID:25065548

Typha capensis (Rohrb.)N.E.Br. (bulrush) extract scavenges free radicals, inhibits collagenase activity and affects human sperm motility and mitochondrial membrane potential in vitro: a pilot study.

PubMed

Henkel, R; Fransman, W; Hipler, U-C; Wiegand, C; Schreiber, G; Menkveld, R; Weitz, F; Fisher, D

2012-05-01

The biodiversity in South Africa provides more than 30,000 higher plants, of which more than 3000 are used by traditional healers to treat diseases. Typha capensis (bulrush) is one of the medicinal plants used in South Africa to treat male fertility problems. Considering that South African traditional healers have been recognised by Law and the health benefits of T. capensis have not been scientifically investigated yet, this study aimed at investigating the in vitro effects of aqueous extracts from this plant on male reproductive functions. Both leaves and rhizomes of T. capensis were dried, infused with distilled water and freeze-dried. Motile sperm from 50 men were isolated by swim-up and incubated with 1 μg ml(-1) aqueous extract of Typha rhizome for 1 h at 37 °C. Vitality, motility, sperm production of reactive oxygen species and mitochondrial membrane potential were analysed in the test sample, a control and in the pellet from the swim-up. Results showed that the rhizome extract had significant (P < 0.0001) negative effects on all parameters. The extracts from the leaves and rhizomes revealed dose-dependent inhibitory activity for collagenase and free radical formation. No inhibitory activity for elastase was found. The inhibitory activity for collagenase might indicate possible anti-cancer effects. © 2011 Blackwell Verlag GmbH.

A pilot study of an in-vitro bovine trachea model of the effect of continuous positive airway pressure breathing on airway surface liquid.

PubMed

White, David E; Nates, Roy J; Bartley, Jim

2014-02-06

Continuous positive air pressure (CPAP) users frequently report troublesome symptoms of airway dryness and nasal congestion. Clinical investigations have demonstrated that supplementary humidification reduces these symptoms but the reason for their occurrence remains unexplained. Investigations using human computational air-conditioning models are unable to reproduce or quantify the apparent airway drying experienced during CPAP therapy. The purpose of this study was to determine whether augmented air pressures change overall mucosal airway surface liquid (ASL) water supply and, if so, the extent of this effect. In an original in vitro experimental set up, maximal ASL supply was determined in whole bovine trachea when exposed to simulated tidal breathing stresses over a range of air pressures. At ambient pressure, the maximal supply of ASL was found to compare well to previously published data (31.2 μl/cm2.hr). CPAP pressures from 5 cm H2O above ambient were found to reduce ASL supply by 22%. Statistical analysis (n = 8) showed a significant difference existed between the ambient and CPAP results (p < 0.0001), and that there was no significant variation between all pressurized results (p = 0.716). These findings provide preliminary data that ASL supply is reduced by CPAP therapy which may explain the airway drying symptoms associated with this therapy.

Polyglycolic acid-hyaluronan scaffolds loaded with bone marrow-derived mesenchymal stem cells show chondrogenic differentiation in vitro and cartilage repair in the rabbit model.

PubMed

Patrascu, Jenel M; Krüger, Jan Philipp; Böss, Hademar G; Ketzmar, Anna-Katharina; Freymann, Undine; Sittinger, Michael; Notter, Michael; Endres, Michaela; Kaps, Christian

2013-10-01

In cartilage repair, scaffold-assisted one-step approaches are used to improve the microfracture (Mfx) technique. Since the number of progenitors in Mfx is low and may further decrease with age, aim of our study was to analyze the chondrogenic potential of freeze-dried polyglycolic acid-hyaluronan (PGA-HA) implants preloaded with mesenchymal stem cells (MSCs) in vitro and in a rabbit articular cartilage defect model. Human bone marrow-derived MSC from iliac crest were cultured in freeze-dried PGA-HA implants for chondrogenic differentiation. In a pilot study, implants were loaded with autologous rabbit MSC and used to cover 5 mm × 6 mm full-thickness femoral articular cartilage defects (n = 4). Untreated defects (n = 3) served as controls. Gene expression analysis and histology showed induction of typical chondrogenic marker genes like type II collagen and formation of hyaline-like cartilaginous tissue in MSC-laden PGA-HA implants. Histological evaluation of rabbit repair tissue formation after 30 and 45 days showed formation of repair tissue, rich in chondrocytic cells and of a hyaline-like appearance. Controls showed no articular resurfacing, tissue repair in the subchondral zone and fibrin formation. These results suggest that MSC-laden PGA-HA scaffolds have chondrogenic potential and are a promising option for stem cell-mediated cartilage regeneration. Copyright © 2013 Wiley Periodicals, Inc.

SUPERFUND TREATABILITY CLEARINGHOUSE: PILOT STUDY OF ENCLOSED THERMAL SOIL AERATION FOR REMOVAL OF VOLATILE ORGANIC CONTAMINATION AT THE MCKIN SUPERFUND SITE

EPA Science Inventory

This paper reports on the results of a pilot study that treated vadose zone soil contaminated with VOCs in an enclosed thermal aeration system. The McKin site, an NPL site in Grey, Maine, was the location of the pilot study. The pilot study was chosen to demonstrate the viabili...

Cross-Site Reliability of Human Induced Pluripotent Stem-Cell Derived Cardiomyocyte Based Safety Assays using Microelectrode Arrays: Results from a Blinded CiPA Pilot Study.

PubMed

Millard, Daniel; Dang, Qianyu; Shi, Hong; Zhang, Xiaou; Strock, Chris; Kraushaar, Udo; Zeng, Haoyu; Levesque, Paul; Lu, Hua-Rong; Guillon, Jean-Michel; Wu, Joseph C; Li, Yingxin; Luerman, Greg; Anson, Blake; Guo, Liang; Clements, Mike; Abassi, Yama A; Ross, James; Pierson, Jennifer; Gintant, Gary

2018-04-27

Recent in vitro cardiac safety studies demonstrate the ability of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to detect electrophysiologic effects of drugs. However, variability contributed by unique approaches, procedures, cell lines and reagents across laboratories makes comparisons of results difficult, leading to uncertainty about the role of hiPSC-CMs in defining proarrhythmic risk in drug discovery and regulatory submissions. A blinded pilot study was conducted to evaluate the electrophysiologic effects of eight well-characterized drugs on four cardiomyocyte lines using a standardized protocol across three microelectrode array (MEA) platforms (18 individual studies). Drugs were selected to define assay sensitivity of prominent repolarizing currents (E-4031 for IKr, JNJ303 for IKs) and depolarizing currents (nifedipine for ICaL, mexiletine for INa) as well as drugs affecting multi-channel block (flecainide, moxifloxacin, quinidine, and ranolazine). Inclusion criteria for final analysis was based on demonstrated sensitivity to IKr block (20% prolongation with E-4031) and L-type calcium current block (20% shortening with nifedipine). Despite differences in baseline characteristics across cardiomyocyte lines, multiple sites and instrument platforms, 10 of 18 studies demonstrated adequate sensitivity to IKr block with E-4031 and ICaL block with nifedipine for inclusion in the final analysis. Concentration-dependent effects on repolarization were observed with this qualified dataset consistent with known ionic mechanisms of single and multi-channel blocking drugs. hiPSC-CMs can detect repolarization effects elicited by single and multi-channel blocking drugs after defining pharmacologic sensitivity to IKr and ICaL block, supporting further validation efforts using hiPSC-CMs for cardiac safety studies.

Patent foramen ovale and asymptomatic brain lesions in military fighter pilots.

PubMed

Kang, Kyung Wook; Kim, Joon-Tae; Choi, Won-Ho; Park, Won-Ju; Shin, Young Ho; Choi, Kang-Ho

2014-10-01

Previous studies have reported higher incidence of white matter lesions (WMLs) in military pilots. The anti-gravity straining maneuver, which fighter military pilots perform numerously during a flight is identical to the valsalva maneuver. We sought to investigate the prevalence of right-to-left shunt (RLS) associated with WMLs in military pilots. A prospective study was performed involving military pilots who visited the Airomedical Center. The pilots underwent brain magnetic resonance imaging (MRI) scan and transcranial Doppler (TCD) with intravenous injection of agitated saline solution for the detection of RLS. Periventricular WMLs (PVWMLs) on MRI were graded using Fazeka's scale, and deep WMLs (DWMLs) were graded using Scheltens's scale. This study included 81 military pilots. RLS on TCD was observed less frequently in non-fighter pilots than in fighter pilots (35.5% vs. 64.5%, p=0.011). Fighter pilot was an independently associated factor with RLS on the TCD. DWMLs were independently associated with RLSs through a patent foramen ovale (PFO) (OR 3.507, 95% CI 1.223-10.055, p=0.02). The results suggest that DWMLs in military pilots may significantly be associated with RLS via PFO. Additional investigations are warranted. Copyright © 2014 Elsevier B.V. All rights reserved.

Intrapulmonary percussive ventilation improves lung function in cystic fibrosis patients chronically colonized with Pseudomonas aeruginosa: a pilot cross-over study.

PubMed

Dingemans, Jozef; Eyns, Hanneke; Willekens, Julie; Monsieurs, Pieter; Van Houdt, Rob; Cornelis, Pierre; Malfroot, Anne; Crabbé, Aurélie

2018-06-01

High levels of shear stress can prevent and disrupt Pseudomonas aeruginosa biofilm formation in vitro. Intrapulmonary percussive ventilation (IPV) could be used to introduce shear stress into the lungs of cystic fibrosis (CF) patients to disrupt biofilms in vivo. We performed a first-of-its-kind pilot clinical study to evaluate short-term IPV therapy at medium (200 bursts per minute, bpm) and high frequency (400 bpm) as compared to autogenic drainage (AD) on lung function and the behavior of P. aeruginosa in the CF lung in four patients who are chronically colonized by P. aeruginosa. A significant difference between the three treatment groups was observed for both the forced expiratory volume in 1 s (FEV1) and the forced vital capacity (FVC) (p < 0.05). More specifically, IPV at high frequency significantly increased FEV1 and FVC compared to AD (p < 0.05) and IPV at medium frequency (p < 0.001). IPV at high frequency enhanced the expression levels of P. aeruginosa planktonic marker genes, which was less pronounced with IPV at medium frequency or AD. In conclusion, IPV at high frequency could potentially alter the behavior of P. aeruginosa in the CF lung and improve lung function. The trail was retrospectively registered at the ISRCTN registry on 6 June 2013, under trial registration number ISRCTN75391385.

Expertise and responsibility effects on pilots' reactions to flight deck alerts in a simulator.

PubMed

Zheng, Yiyuan; Lu, Yanyu; Yang, Zheng; Fu, Shan

2014-11-01

Flight deck alerts provide system malfunction information designed to lead corresponding pilot reactions aimed at guaranteeing flight safety. This study examined the roles of expertise and flight responsibility and their relationship to pilots' reactions to flight deck alerts. There were 17 pilots composing 12 flight crews that were assigned into pairs according to flight hours and responsibilities. The experiment included 9 flight scenarios and was carried out in a CRJ-200 flight simulator. Pilot performance was recorded by a wide angle video camera, and four kinds of reactions to alerts were defined for analysis. Pilots tended to have immediate reactions to uninterrupted cautions, with a turning off rate as high as 75%. However, this rate decreased sharply when pilots encountered interrupted cautions and warnings; they also exhibited many wrong reactions to warnings. Pilots with more expertise had more reactions to uninterrupted cautions than those with less expertise, both as pilot flying and pilot monitoring. Meanwhile, the pilot monitoring, regardless of level of expertise, exhibited more reactions than the pilot flying. In addition, more experienced pilots were more likely to have wrong reactions to warnings while acting as the monitoring pilot. These results suggest that both expertise and flight responsibility influence pilots' reactions to alerts. Considering crew pairing strategy, when a pilot flying is a less experienced pilot, a more experience pilot is suggested to be the monitoring pilot. The results of this study have implications for understanding pilots' behaviors to flight deck alerts, calling for specialized training and design of approach alarms on the flight deck.

Human factors in aviation crashes involving older pilots.

PubMed

Li, Guohua; Baker, Susan P; Lamb, Margaret W; Grabowski, Jurek G; Rebok, George W

2002-02-01

Pilot errors are recognized as a contributing factor in as many as 80% of aviation crashes. Experimental studies using flight simulators indicate that due to decreased working memory capacity, older pilots are outperformed by their younger counterparts in communication tasks and flight summary scores. This study examines age-related differences in crash circumstances and pilot errors in a sample of pilots who flew commuter aircraft or air taxis and who were involved in airplane or helicopter crashes. A historical cohort of 3306 pilots who in 1987 flew commuter aircraft or air taxis and were 45-54 yr of age was constructed using the Federal Aviation Administration's airmen information system. Crash records of the study subjects for the years 1983-1997 were obtained from the National Transportation Safety Board (NTSB) by matching name and date of birth. NTSB's investigation reports were reviewed to identify pilot errors and other contributing factors. Comparisons of crash circumstances and human factors were made between pilots aged 40-49 yr and pilots aged 50-63 yr. A total of 165 crash records were studied, with 52% of these crashes involving pilots aged 50-63 yr. Crash circumstances, such as time and location of crash, type and phase of flight, and weather conditions, were similar between the two age groups. Pilot error was a contributing factor in 73% of the crashes involving younger pilots and in 69% of the crashes involving older pilots (p = 0.50). Age-related differences in the pattern of pilot errors were statistically insignificant. Overall, 23% of pilot errors were attributable to inattentiveness, 20% to flawed decisions, 18% to mishandled aircraft kinetics, and 18% to mishandled wind/runway conditions. Neither crash circumstances nor the prevalence and patterns of pilot errors appear to change significantly as age increases from the 40s to the 50s and early 60s.

Evaluation of anti-plaque microbial activity of Azadirachta indica (neem oil) in vitro: A pilot study

PubMed Central

Elavarasu, Sugumari; Abinaya, P.; Elanchezhiyan, S.; Thangakumaran; Vennila, K.; Naziya, K. B.

2012-01-01

Background: Probably microbial plaque is the main etiology for periodontal tissue inflammation. Various chemical agents have been evaluated over the years with respect to their antimicrobial effects in the oral cavity. However, all are associated with side effects that prohibit regular long-term use. Therefore, the effectiveness of Azadirachta indica (neem) against plaque formation is considered to be vital, with lesser side effects. The aim of the present study is to evaluate and prove the antimicrobial activity of neem using plaque samples. Materials and Methods: Culture was prepared using brain heart infusion broth reagent. Dental plaque samples were used for that. Kirby–Bauer antimicrobial susceptibility test procedure was carried away with the sample. Neem oil was kept in the agar plate with culture and the diameter of inhibition zones was calculated. Results: Results showed inhibition zones on the agar plate around neem oil. Conclusion: Study shows definite antiplaque activity of neem oil. PMID:23066297

Bacteriocins from lactic acid bacteria: production, purification, and food applications.

PubMed

De Vuyst, Luc; Leroy, Frédéric

2007-01-01

In fermented foods, lactic acid bacteria (LAB) display numerous antimicrobial activities. This is mainly due to the production of organic acids, but also of other compounds, such as bacteriocins and antifungal peptides. Several bacteriocins with industrial potential have been purified and characterized. The kinetics of bacteriocin production by LAB in relation to process factors have been studied in detail through mathematical modeling and positive predictive microbiology. Application of bacteriocin-producing starter cultures in sourdough (to increase competitiveness), in fermented sausage (anti-listerial effect), and in cheese (anti-listerial and anti-clostridial effects), have been studied during in vitro laboratory fermentations as well as on pilot-scale level. The highly promising results of these studies underline the important role that functional, bacteriocinogenic LAB strains may play in the food industry as starter cultures, co-cultures, or bioprotective cultures, to improve food quality and safety. In addition, antimicrobial production by probiotic LAB might play a role during in vivo interactions occurring in the human gastrointestinal tract, hence contributing to gut health.

Human adipose-derived mesenchymal stem cells for osteoarthritis: a pilot study with long-term follow-up and repeated injections.

PubMed

Song, Yang; Du, Hui; Dai, Chengxiang; Zhang, Li; Li, Suke; Hunter, David J; Lu, Liangjing; Bao, Chunde

2018-04-01

This study aimed to evaluate the safety and therapeutic potential of autologous human adipose-derived mesenchymal stem cells (haMSCs) in patients with osteoarthritis. Safety and efficacy of haMSCs were preclinically assessed in vitro and in BALB/c-nu nude mice. 18 patients were enrolled and divided into three dose groups: the low-dose, mid-dose and high-dose group (1 × 10 7 , 2 × 10 7 and 5 × 10 7 cells, respectively), provided three injections and followed up for 96 weeks. The preclinical study established the safety and efficacy of haMSCs. Intra-articular injections of haMSCs were safe and improved pain, function and cartilage volume of the knee joint, rendering them a promising novel treatment for knee osteoarthritis. The dosage of 5 × 10 7 haMSCs exhibited the highest improvement (ClinicalTrials.gov Identifier: NCT01809769).

The psychophysiological assessment method for pilot's professional reliability.

PubMed

Zhang, L M; Yu, L S; Wang, K N; Jing, B S; Fang, C

1997-05-01

Previous research has shown that a pilot's professional reliability depends on two relative factors: the pilot's functional state and the demands of task workload. The Psychophysiological Reserve Capacity (PRC) is defined as a pilot's ability to accomplish additive tasks without reducing the performance of the primary task (flight task). We hypothesized that the PRC was a mirror of the pilot's functional state. The purpose of this study was to probe the psychophysiological method for evaluating a pilot's professional reliability on a simulator. The PRC Comprehensive Evaluating System (PRCCES) which was used in the experiment included four subsystems: a) quantitative evaluation system for pilot's performance on simulator; b) secondary task display and quantitative estimating system; c) multiphysiological data monitoring and statistical system; and d) comprehensive evaluation system for pilot PRC. Two studies were performed. In study one, 63 healthy and 13 hospitalized pilots participated. Each pilot performed a double 180 degrees circuit flight program with and without secondary task (three digit operation). The operator performance, score of secondary task and cost of physiological effort were measured and compared by PRCCES in the two conditions. Then, each pilot's flight skill in training was subjectively scored by instructor pilot ratings. In study two, 7 healthy pilots volunteered to take part in the experiment on the effects of sleep deprivation on pilot's PRC. Each participant had PRC tested pre- and post-8 h sleep deprivation. The results show that the PRC values of a healthy pilot was positively correlated with abilities of flexibility, operating and correcting deviation, attention distribution, and accuracy of instrument flight in the air (r = 0.27-0.40, p < 0.05), and negatively correlated with emotional anxiety in flight (r = -0.40, p < 0.05). The values of PRC in healthy pilots (0.61 +/- 0.17) were significantly higher than that of hospitalized pilots (0.43 +/- 0.15) (p < 0.05). The PRC value after 8 h sleep loss (0.50 +/- 0.17) was significantly lower than those before sleep loss (0.70 +/- 0.15) (p < 0.05). We conclude that a pilot's PRC, which was closely related to flight ability and functional state, could partly represent the pilot's professional reliability. It is worthwhile to further research using a pilot's PRC as a predictor of mental workload in aircraft design.

Adjunctive therapy (whole body hyperthermia versus lonidamine) to total body irradiation for the treatment of favorable B-cell neoplasms: a report of two pilot clinical trials and laboratory investigations.

PubMed

Robins, H I; Longo, W L; Steeves, R A; Cohen, J D; Schmitt, C L; Neville, A J; O'Keefe, S; Lagoni, R; Riggs, C

1990-04-01

Based on earlier clinical and preclinical investigations, we designed two different pilot trials for patients with nodular lymphoma or chronic lymphocytic leukemia. These studies evaluated the use of either 41.8 degrees C whole body hyperthermia (WBH), or the nonmyelosuppressive chemotherapeutic drug, lonidamine (LON), as an adjunct to total body irradiation (TBI) (12.5 cGy twice a week, every other week for a planned total dose of 150 cGy). Whole body hyperthermia was initiated approximately 10 min after total body irradiation; lonidamine was administered orally (420 mg/m2) on a daily basis. Although entry to the studies was nonrandomized, the two patient populations were accrued during the same time frame and were comparable in terms of histology, stage of disease, performance status, and prior therapy. Of 8 patients entered on the TBI/WBH study, we observed 3 complete responses (CR), 4 partial responses (PR), and 1 improvement (i.e., a 48% decrease in tumor burden). Of 10 patients entered in the TBI/LON study, there was 1 CR and 4 PR. For the TBI/WBH study, myelosuppression was not treatment-limiting; there were no instances of infection or bleeding and platelet support was never required. The median survival time for the TBI/WBH study is 52.5 months based on Kaplan Meir estimates. Two patients remain in a CR. The median time to treatment failure (MTTF) is 9.4 months (90% confidence interval = 7-15.4 months). In the TBI/LON study, 50% of patients receiving TBI required treatment modification due to platelet-count depression during therapy, but there were no instances of infection or bleeding. Frequently observed LON-related toxicities included myalgias, testicular pain, photophobia and ototoxicity. For the TBI/LON study, median survival is 7.6 months; MTTF was 2.4 months. In analyzing the results of these pilot studies, our subjective clinical impressions lead to the hypothesis that WBH protected against TBI-induced thrombocytopenia during therapy, whereas LON had no effect on TBI-induced myelosuppression. This speculation was tested and confirmed in a series of in vitro and in vivo experiments.

Prevention of bacterial colonization of contact lenses with covalently attached selenium and effects on the rabbit cornea.

PubMed

Mathews, Steven M; Spallholz, Julian E; Grimson, Mark J; Dubielzig, Richard R; Gray, Tracy; Reid, Ted W

2006-08-01

Although silicone hydrogel materials have produced many corneal health benefits to patients wearing contact lenses, bacteria that cause acute red eye or corneal ulcers are still a concern. A coating that inhibits bacterial colonization while not adversely affecting the cornea should improve the safety of contact lens wear. A covalent selenium (Se) coating on contact lenses was evaluated for safety using rabbits and prevention of bacterial colonization of the contact lenses in vitro. Contact lenses coated with Se were worn on an extended-wear schedule for up to 2 months by 10 New Zealand White rabbits. Corneal health was evaluated with slit-lamp biomicroscopy, pachymetry, electron microscopy, and histology. Lenses worn by the rabbits were analyzed for protein and lipid deposits. In addition, the ability of Se to block bacterial colonization was tested in vitro by incubating lenses in a Pseudomonas aeruginosa broth followed by scanning electron microscopy of the contact lens surface. The covalent Se coating decreased bacterial colonization in vitro while not adversely affecting the corneal health of rabbits in vivo. The Se coating produced no noticeable negative effects as observed with slit-lamp biomicroscopy, pachymetry, electron microscopy, and histology. The Se coating did not affect protein or lipid deposition on the contact lenses. The data from this pilot study suggest that a Se coating on contact lenses might reduce acute red eye and bacterial ulceration because of an inhibition of bacterial colonization. In addition, our safety tests suggest that this positive effect can be produced without an adverse effect on corneal health.

Characterization of cavitational activity in lithotripsy fields using a robust electromagnetic probe.

PubMed

Pye, S D; Dineley, J A

1999-03-01

A robust electromagnetic probe has been used to investigate cavitational activity in vitro in the fields of two extracorporeal lithotripters and one intracorporeal lithotripter. Some aspects of the electromagnetic probe design and characteristics are described. A series of experiments have been carried out with results indicating that the probe head moves in response to the pressure gradient generated by radial motion of cavitation bubbles. Empirical expressions have been derived for the cavitational force acting on the probe head, and for the low-frequency sawtooth pressure wave generated by inertial cavitation. This is the first time that the existence of a low-frequency sawtooth wave produced by inertial cavitation has been described. A linear relationship exists between the negative pressure amplitude of the sawtooth wave and the lifetime of the bubbles. Close to the cavitation site, substantial negative pressure is maintained throughout bubble expansion. This can easily exceed the tensile strength of urinary calculi, and may be considered to be an important mechanism for disintegrating these relatively weak structures. A pilot study has also been carried out involving three patients treated by extracorporeal lithotripsy. Signals similar to those recorded during the in vitro cavitation experiments were detected. We conclude that the electromagnetic probe is capable of detecting and quantifying aspects of cavitational activity in vitro, and potentially also in vivo. The observation that the probe responds directly to the motion of cavitation bubbles, coupled with its ability to detect cavitation at a distance, give it the potential for use in a range of medical and industrial applications.

Radiofrequency volumetric reduction of the tongue. A porcine pilot study for the treatment of obstructive sleep apnea syndrome.

PubMed

Powell, N B; Riley, R W; Troell, R J; Blumen, M B; Guilleminault, C

1997-05-01

To investigate, in an animal model, the feasibility of radiofrequency (RF) volumetric tongue reduction for the future purpose of determining its clinical applications in obstructive sleep apnea syndrome (OSAS). The study was performed in three stages, one in vitro bovine stage and two in vivo porcine stages. The last stage was a prospective investigation with histologic and volumetric analyses to establish outcomes. Laboratory and operating room of veterinary research center. A homogeneous population of porcine animal models, including seven in stage 2 and 12 in stage 3. RF energy was delivered by a custom-fabricated needle electrode and RF generator to the tongue tissue of both the in vitro and in vivo models. Microultransonic crystals were used to measure three-dimensional changes (volumetric reduction). Lesion size correlated well with increasing RF energy delivery (Sperman correlation coefficient of 0.986; p = 0.0003). Histologic assessments done serially over time (1 h through 3 weeks) showed a well-circumscribed lesion with a normal healing progression and no peripheral damage to nerves. Volumetric analysis documented a very mild initial edematous response that promptly tapered at 24 h. At 10 days after RF, a 26.3% volume reduction was documented at the treatment site (circumscribed by the microultrasonic crystals). RF, in a porcine animal model, can safely reduce tongue volume in a precise and controlled manner. Further studies will validate the use of RF in the treatment of OSAS.

Arab-American adolescent tobacco use: four pilot studies.

PubMed

Rice, Virginia Hill; Templin, Thomas; Kulwicki, Anahid

2003-11-01

Four pilot studies were conducted to determine the (1) current tobacco use patterns and predictors among 14- to 18-year-old Arab-American youths; (2) psychometric properties of study measures (English and Arabic); (3) cultural appropriateness of Project Toward No Tobacco (TNT) for intervention; (4) accessible population for a longitudinal study. Three studies were descriptive and one used a pretest-posttest design. From four Pilot Focus groups (N = 28 smokers) key tobacco use themes emerged along with information on study measures and the Project TNT intervention; Pilot Intervention tested the tailored Project TNT intervention with 9 Arab-American teens; Pilot Clinic (N = 44) determined the characteristics of the accessible teen health clinic population; and Pilot School (N = 119) obtained tobacco use data only. From Pilot Focus seven themes (being cool, "nshar ma'a al shabab" [hanging out with the guys], present [time] orientation, smoking feels and tastes good, keeps your mind off trouble, easy to get, and (many) "barriers to quitting") emerged from the data. In the Pilot Intervention a 37.5% cessation rate was found. In the Pilot Clinic study, 24% males and 17% females smoked. The current smoking rate in the Pilot School (N = 119) sample was 17%; 34% admitted to having ever smoked (even a puff). Significant predictors for current tobacco use included poor grades, stress, having many family members and peers who smoke, being exposed to many hours of smoking each day, receiving offers of tobacco products, advertising and mail, and believing that tobacco can help one to make friends. The four pilots contributed unique and essential knowledge for designing a longitudinal clinical trial on tobacco use by Arab-American adolescents.

Associations between IVF outcomes and essential trace elements measured in follicular fluid and urine: a pilot study.

PubMed

Ingle, Mary E; Bloom, Michael S; Parsons, Patrick J; Steuerwald, Amy J; Kruger, Pamela; Fujimoto, Victor Y

2017-02-01

A hypothesis-generating pilot study exploring associations between essential trace elements measured in follicular fluid (FF) and urine and in vitro fertilization (IVF) endpoints. We recruited 58 women undergoing IVF between 2007 and 2008, and measured cobalt, chromium, copper, manganese, molybdenum, and zinc in FF (n = 46) and urine (n = 45) by inductively coupled plasma mass spectrometry (ICP-MS). We used multivariable regression models to assess the impact of FF and urine trace elements on IVF outcomes, adjusted for age, body mass index, race, and cigarette smoking. Trace elements were mostly present at lower concentrations in FF than in urine. The average number of oocytes retrieved was positively associated with higher urine cobalt, chromium, copper, and molybdenum concentrations. FF chromium and manganese were negatively associated with the proportion of mature oocytes, yet urine manganese had a positive association. FF zinc was inversely associated with average oocyte fertilization. Urine trace elements were significant positive predictors for the total number of embryos generated. FF copper predicted lower embryo fragmentation while urine copper was associated with higher embryo cell number and urine manganese with higher embryo fragmentation. No associations were detected for implantation, pregnancy, or live birth. Our results suggest the importance of trace elements in both FF and urine for intermediate, although not necessarily clinical, IVF endpoints. The results differed using FF or urine biomarkers of exposure, which may have implications for the design of clinical and epidemiologic investigations. These initial findings will form the basis of a more definitive future study.

LumenRECON Guidewire: Pilot Study of a Novel, Nonimaging Technology for Accurate Vessel Sizing and Delivery of Therapy in Femoropopliteal Disease.

PubMed

Nair, Pradeep K; Carr, Jeffrey G; Bigelow, Brian; Bhatt, Deepak L; Berwick, Zachary C; Adams, George

2018-01-01

Proper vessel sizing during endovascular interventions is crucial to avoid adverse procedural and clinical outcomes. LumenRECON (LR) is a novel, nonimaging, 0.035-inch wire-based technology that uses the physics-based principle of Ohm's law to provide a simple, real-time luminal size while also providing a platform for therapy delivery. This study evaluated the accuracy, reliability, and safety of the LR system in patients presenting for a femoropopliteal artery intervention. This multicenter, prospective pilot study of 24 patients presenting for peripheral intervention compared LR measurements of femoropopliteal artery size to angiographic visual estimation, duplex ultrasound, quantitative angiography, and intravascular ultrasound. The primary effectiveness and safety end point was comparison against core laboratory adjudicated intravascular ultrasound values and major adverse events, respectively. Additional preclinical studies were also performed in vitro and in vivo in swine to determine the accuracy of the LR guidewire system. No intra- or postprocedure device-related adverse events occurred. A balloon or stent was successfully delivered in 12 patients (50%) over the LR wire. Differences in repeatability between successive LR measurements was 2.5±0.40% ( R 2 =0.96) with no significant bias. Differences in measurements of LR to other modalities were 0.5±1.7%, 5.0±1.8%, -1.5±2.0%, and 6.8±3.4% for intravascular ultrasound core laboratory, quantitative angiography, angiographic, and duplex ultrasound, respectively. This study demonstrates that through a physics-based principle, LR provides a real-time, safe, reproducible, and accurate vessel size of the femoropopliteal artery during intervention and can additionally serve as a conduit for therapy delivery over its wire-based platform. © 2018 American Heart Association, Inc.

Secretion of angiogenic proteins by human multipotent mesenchymal stromal cells and their clinical potential in the treatment of avascular osteonecrosis.

PubMed

Müller, I; Vaegler, M; Holzwarth, C; Tzaribatchev, N; Pfister, S M; Schütt, B; Reize, P; Greil, J; Handgretinger, R; Rudert, M

2008-11-01

Osteonecrosis is a frequent complication after treatment for childhood leukemia and other steroid-based therapies. The success rate of core decompression surgery is limited. Therefore, we evaluated relevant biological characteristics of human multipotent mesenchymal stromal cells (MSCs) in vitro. MSCs cultured under low-oxygen tensions showed decreased proliferation and differentiation into bone. However, these MSCs secreted significant amounts of vascular endothelial-derived factor in the presence of interferon-gamma. These in vitro results with potential effects on neovascularization and bone regeneration as well as findings in animal models prompted us to treat five patients with steroid-induced osteonecrosis of the femur by core decompression surgery and instillation of expanded autologous MSCs. Within 3 weeks of culture, sufficient numbers of MSCs were generated using animal protein-free culture conditions. No chromosomal aberrations were detected by matrix-based comparative genomic hybridization. Application of MSCs during core decompression was feasible and safe. Median follow-up is 16 months and the patients in this pilot study reported clinical improvement. Formation of mineralized bone in the osteonecrotic cavity was proven by computed tomography. Taken together, MSCs display biological properties that may add to the efficiency of surgical treatment in osteonecrosis and should be evaluated in larger patient cohorts.

Influence of irradiation on release of endothelial microparticles (EMP) in vitro.

PubMed

Neuber, Christin; Pufe, Johanna; Pietzsch, Jens

2015-01-01

Survivors of Hodgkin's disease as well as of breast and lung cancer are at risk of radiation-associated cardiovascular disease. Recent studies demonstrated a correlation between cardiovascular risk factors and circulating endothelial microparticles (EMP) and thereby suggest increased EMP levels in circulation to be an early biomarker of endothelial dysfunction and cardiovascular risk. This prompted us to analyze the amount of EMP released by human aortic endothelial cells (HAEC) after exposure to different doses of X-ray (0.4, 2, 4, 6, and 20 Gy) using antibodies against the endothelial cell markers CD31, CD144, and CD146 by flow cytometry. In this pilot experiment only CD146 proved appropriate for quantification of HAEC-derived EMP. Exposure of HAEC to different doses of X-ray did not significantly influence formation of CD146-positive EMP. However, low doses (0.4 Gy) tended to decrease EMP formation, whereas higher doses (2 or 4 Gy) slightly increased release of CD146-positive EMP. By contrast, inflammatory activation of HAEC by TPA significantly increased EMP release about 15-fold (P <  0.01). In conclusion, under the present experimental conditions EMP did not prove a suitable biomarker for radiation-induced endothelial dysfunction in vitro.

Unique proteomic signature for radiation sensitive patients; a comparative study between normo-sensitive and radiation sensitive breast cancer patients.

PubMed

Skiöld, Sara; Azimzadeh, Omid; Merl-Pham, Juliane; Naslund, Ingemar; Wersall, Peter; Lidbrink, Elisabet; Tapio, Soile; Harms-Ringdahl, Mats; Haghdoost, Siamak

2015-06-01

Radiation therapy is a cornerstone of modern cancer treatment. Understanding the mechanisms behind normal tissue sensitivity is essential in order to minimize adverse side effects and yet to prevent local cancer reoccurrence. The aim of this study was to identify biomarkers of radiation sensitivity to enable personalized cancer treatment. To investigate the mechanisms behind radiation sensitivity a pilot study was made where eight radiation-sensitive and nine normo-sensitive patients were selected from a cohort of 2914 breast cancer patients, based on acute tissue reactions after radiation therapy. Whole blood was sampled and irradiated in vitro with 0, 1, or 150 mGy followed by 3 h incubation at 37°C. The leukocytes of the two groups were isolated, pooled and protein expression profiles were investigated using isotope-coded protein labeling method (ICPL). First, leukocytes from the in vitro irradiated whole blood from normo-sensitive and extremely sensitive patients were compared to the non-irradiated controls. To validate this first study a second ICPL analysis comparing only the non-irradiated samples was conducted. Both approaches showed unique proteomic signatures separating the two groups at the basal level and after doses of 1 and 150 mGy. Pathway analyses of both proteomic approaches suggest that oxidative stress response, coagulation properties and acute phase response are hallmarks of radiation sensitivity supporting our previous study on oxidative stress response. This investigation provides unique characteristics of radiation sensitivity essential for individualized radiation therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

78 FR 23941 - Pilot Program for Early Feasibility Study Investigational Device Exemption Applications...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-23

...] Pilot Program for Early Feasibility Study Investigational Device Exemption Applications; Extending the... 13343), FDA terminated the acceptance of applications into the program and extended the pilot program for the nine accepted sponsors until May 8, 2013. The pilot program will be further extended for the...

Effects of Açai (Euterpe oleracea Mart.) berry preparation on metabolic parameters in a healthy overweight population: a pilot study.

PubMed

Udani, Jay K; Singh, Betsy B; Singh, Vijay J; Barrett, Marilyn L

2011-05-12

The purpose of this study was to evaluate the effect of açai fruit pulp on risk factors for metabolic disorders in overweight subjects. The açaí palm (Euterpe oleracea Mart.), which is native to South America, produces a small, black-purple fruit which is edible. The fruit has recently become popular as a functional food due to its antioxidant potential. Although several studies have been conducted in vitro and with animals, little is known about the potential health benefits in humans aside from an increase in plasma anti-oxidant capacity. Metabolic syndrome is a condition which is defined by a cluster of risk factors for cardiovascular disease and/or type-2 diabetes. Preliminary studies indicate that a reduction in reactive oxygen species can assist in the normalization of the metabolic pathways involved in this syndrome. This was an open label pilot study conducted with 10 overweight adults (BMI ≥ 25 kg/m² and ≤ 30 kg/m²) who took 100 g açai pulp twice daily for 1 month. The study endpoints included levels of fasting plasma glucose, insulin, cholesterol, triglycerides, exhaled (breath) nitric oxide metabolites (eNO) and plasma levels of high sensitivity C-reactive protein (hs-CRP). The response of blood glucose, blood pressure and eNO to a standardized meal was determined at baseline and following the 30 day treatment. Compared to baseline, there were reductions in fasting glucose and insulin levels following the 30 day treatment (both p < 0.02). There was also a reduction in total cholesterol (p = 0.03), as well as borderline significant reductions in LDL-cholesterol and the ratio of total cholesterol to HDL-cholesterol (both p = 0.051). Compared to baseline, treatment with açai ameliorated the post-prandial increase in plasma glucose following the standardized meal, measured as the area under the curve (p = 0.047). There was no effect on blood pressure, hs-CRP or eNO. In this uncontrolled pilot study, consumption of açai fruit pulp reduced levels of selected markers of metabolic disease risk in overweight adults, indicating that further studies are warranted.

Effects of Açai (Euterpe oleracea Mart.) berry preparation on metabolic parameters in a healthy overweight population: A pilot study

PubMed Central

2011-01-01

Background The purpose of this study was to evaluate the effect of açai fruit pulp on risk factors for metabolic disorders in overweight subjects. The açaí palm (Euterpe oleracea Mart.), which is native to South America, produces a small, black-purple fruit which is edible. The fruit has recently become popular as a functional food due to its antioxidant potential. Although several studies have been conducted in vitro and with animals, little is known about the potential health benefits in humans aside from an increase in plasma anti-oxidant capacity. Metabolic syndrome is a condition which is defined by a cluster of risk factors for cardiovascular disease and/or type-2 diabetes. Preliminary studies indicate that a reduction in reactive oxygen species can assist in the normalization of the metabolic pathways involved in this syndrome. Methods This was an open label pilot study conducted with 10 overweight adults (BMI ≥ 25 kg/m2 and ≤ 30 kg/m2) who took 100 g açai pulp twice daily for 1 month. The study endpoints included levels of fasting plasma glucose, insulin, cholesterol, triglycerides, exhaled (breath) nitric oxide metabolites (eNO) and plasma levels of high sensitivity C-reactive protein (hs-CRP). The response of blood glucose, blood pressure and eNO to a standardized meal was determined at baseline and following the 30 day treatment. Results Compared to baseline, there were reductions in fasting glucose and insulin levels following the 30 day treatment (both p < 0.02). There was also a reduction in total cholesterol (p = 0.03), as well as borderline significant reductions in LDL-cholesterol and the ratio of total cholesterol to HDL-cholesterol (both p = 0.051). Compared to baseline, treatment with açai ameliorated the post-prandial increase in plasma glucose following the standardized meal, measured as the area under the curve (p = 0.047). There was no effect on blood pressure, hs-CRP or eNO. Conclusion In this uncontrolled pilot study, consumption of açai fruit pulp reduced levels of selected markers of metabolic disease risk in overweight adults, indicating that further studies are warranted. PMID:21569436

Defining Feasibility and Pilot Studies in Preparation for Randomised Controlled Trials: Development of a Conceptual Framework.

PubMed

Eldridge, Sandra M; Lancaster, Gillian A; Campbell, Michael J; Thabane, Lehana; Hopewell, Sally; Coleman, Claire L; Bond, Christine M

2016-01-01

We describe a framework for defining pilot and feasibility studies focusing on studies conducted in preparation for a randomised controlled trial. To develop the framework, we undertook a Delphi survey; ran an open meeting at a trial methodology conference; conducted a review of definitions outside the health research context; consulted experts at an international consensus meeting; and reviewed 27 empirical pilot or feasibility studies. We initially adopted mutually exclusive definitions of pilot and feasibility studies. However, some Delphi survey respondents and the majority of open meeting attendees disagreed with the idea of mutually exclusive definitions. Their viewpoint was supported by definitions outside the health research context, the use of the terms 'pilot' and 'feasibility' in the literature, and participants at the international consensus meeting. In our framework, pilot studies are a subset of feasibility studies, rather than the two being mutually exclusive. A feasibility study asks whether something can be done, should we proceed with it, and if so, how. A pilot study asks the same questions but also has a specific design feature: in a pilot study a future study, or part of a future study, is conducted on a smaller scale. We suggest that to facilitate their identification, these studies should be clearly identified using the terms 'feasibility' or 'pilot' as appropriate. This should include feasibility studies that are largely qualitative; we found these difficult to identify in electronic searches because researchers rarely used the term 'feasibility' in the title or abstract of such studies. Investigators should also report appropriate objectives and methods related to feasibility; and give clear confirmation that their study is in preparation for a future randomised controlled trial designed to assess the effect of an intervention.

Open PHACTS computational protocols for in silico target validation of cellular phenotypic screens: knowing the knowns† †The authors declare no competing interests. ‡ ‡Electronic supplementary information (ESI) available: Pipeline Pilot protocols, xls file with the output of the Pipeline Pilot protocols, KNIME workflows, and supplementary figures showing the Pipeline Pilot protocols. See DOI: 10.1039/c6md00065g Click here for additional data file.

PubMed Central

Zdrazil, B.; Neefs, J.-M.; Van Vlijmen, H.; Herhaus, C.; Caracoti, A.; Brea, J.; Roibás, B.; Loza, M. I.; Queralt-Rosinach, N.; Furlong, L. I.; Gaulton, A.; Bartek, L.; Senger, S.; Chichester, C.; Engkvist, O.; Evelo, C. T.; Franklin, N. I.; Marren, D.; Ecker, G. F.

2016-01-01

Phenotypic screening is in a renaissance phase and is expected by many academic and industry leaders to accelerate the discovery of new drugs for new biology. Given that phenotypic screening is per definition target agnostic, the emphasis of in silico and in vitro follow-up work is on the exploration of possible molecular mechanisms and efficacy targets underlying the biological processes interrogated by the phenotypic screening experiments. Herein, we present six exemplar computational protocols for the interpretation of cellular phenotypic screens based on the integration of compound, target, pathway, and disease data established by the IMI Open PHACTS project. The protocols annotate phenotypic hit lists and allow follow-up experiments and mechanistic conclusions. The annotations included are from ChEMBL, ChEBI, GO, WikiPathways and DisGeNET. Also provided are protocols which select from the IUPHAR/BPS Guide to PHARMACOLOGY interaction file selective compounds to probe potential targets and a correlation robot which systematically aims to identify an overlap of active compounds in both the phenotypic as well as any kinase assay. The protocols are applied to a phenotypic pre-lamin A/C splicing assay selected from the ChEMBL database to illustrate the process. The computational protocols make use of the Open PHACTS API and data and are built within the Pipeline Pilot and KNIME workflow tools. PMID:27774140

Study to determine the IFR operational profile and problems of the general aviation single pilot

NASA Technical Reports Server (NTRS)

Weislogel, G. S.

1983-01-01

General aviation single pilot operating under instrument flight rules (GA SPIFR) was studied. The objectives of the study were to (1) develop a GA SPIFR operational profile, (2) identify problems experienced by the GA SPIFR pilot, and (3) identify research tasks which have the potential for eliminating or reducing the severity of the problems. To obtain the information necessary to accomplish these objectives, a mail questionnaire survey of instrument rated pilots was conducted. The general aviation IFR single pilot operational profile and selected data analysis examples are presented.

Piloted studies of Enhanced or Synthetic Vision display parameters

NASA Technical Reports Server (NTRS)

Harris, Randall L., Sr.; Parrish, Russell V.

1992-01-01

This paper summarizes the results of several studies conducted at Langley Research Center over the past few years. The purposes of these studies were to investigate parameters of pictorial displays and imaging sensors that affect pilot approach and landing performance. Pictorial displays have demonstrated exceptional tracking performance and improved the pilots' spatial awareness. Stereopsis cueing improved pilot flight performance and reduced pilot stress. Sensor image parameters such as increased field-of-view. faster image update rate, and aiding symbology improved flare initiation. Finer image resolution and magnification improved attitude control performance parameters.

Alzheimer's lymphocytes are resistant to ultraviolet B-induced apoptosis.

PubMed

Zana, Marianna; Juhász, Anna; Rimanóczy, Agnes; Bjelik, Annamária; Baltás, Eszter; Ocsovszki, Imre; Boda, Krisztina; Penke, Botond; Dobozy, Attila; Kemény, Lajos; Janka, Zoltán; Kálmán, János

2006-06-01

In the present pilot investigation, the susceptibility of T-lymphocytes from Alzheimer's disease (AD) subjects (n=22) and aged-matched, non-demented controls (CNT) (n=12) was examined with ultraviolet (UV) B light-induced apoptosis in vitro. The basal apoptotic ratios were similar in both groups. However, the AD lymphocytes displayed significantly (p<0.0001) lower apoptotic levels than those of the CNT lymphocytes at all of the applied UVB exposure doses (100, 200 and 300 mJ/cm(2)). These observations indicate that AD lymphocytes are more resistant than CNT lymphocytes to UVB irradiation.

PILOT STUDY: THE TAMPA ASTHMATIC CHILDREN'S STUDY (TACS)

EPA Science Inventory

The Tampa Asthmatic Children's Study (TACS) was a pilot research study that focused on developing and evaluating air pollution exposure assessment methods and participant recruiting tools for children in the age range of 1-5 years old. The pilot study focused on (a) simple, cost-...

Field-Scale Evaluation of Monitored Natural Attenuation for Dissolved Chlorinated Solvent Plumes

DTIC Science & Technology

2009-04-01

biological in-situ treatment, an air sparging pilot study, and a phytoremediation study. The innovative technology studies were conducted within the source... phytoremediation (June to September 1997), reductive anaerobic biological in-situ treatment technology (RABITT; 1998), and groundwater recirculation wells...u g / L ) Measured Concentrations in 1381MWS09 Air Sparge Pilot Test (1996/1997) Phytoremediation Pilot Test (1997) RABITT Pilot Test (1998

The Necessity of ASEAN Community in Producing Pilots

ERIC Educational Resources Information Center

Saowaros, Thanoo; Puncreobutr, Vichian

2016-01-01

The main objectives of this study are to identify the reasons for the shortage of pilots; the necessity of producing Pilots and the obstacles and problems faced by ASEAN Community in producing pilots. The study is conducted by official documents, observations, in-depth interview from personnel who are working for Airports Authority of Thailand,…

SPEEDIER Project. Preliminary Report on Social Studies Pilot Projects.

ERIC Educational Resources Information Center

Myers, Charles B.; And Others

This preliminary report describes five social studies pilot programs in the counties of Dauphin, Lancaster, Lebanon, and York, Pennsylvania. It is expected that these pilot endeavors will affect educators in the counties served by SPEEDIER as follows: 1) increase understanding of the newer content, ideas, and strategies in the pilot programs; 2)…

Pilot Study: Foam Wedge Chin Support Static Tolerance Testing

DTIC Science & Technology

2017-10-24

AFRL-SA-WP-SR-2017-0026 Pilot Study : Foam Wedge Chin Support Static Tolerance Testing Austin M. Fischer, BS1; William W...COVERED (From – To) April – October 2017 4. TITLE AND SUBTITLE Pilot Study : Foam Wedge Chin Support Static Tolerance Testing 5a. CONTRACT NUMBER...prototype to mitigate the increase in helmet weight and forward center of gravity. The purpose of this pilot study was to determine the feasibility and

The Partnership and Coping Enhancement Programme for couples undergoing in vitro fertilization treatment: the development of a complex intervention in China.

PubMed

Ying, Liying; Chen, Xiaomin; Wu, Lai Har; Shu, Jing; Wu, Xiangli; Loke, Alice Yuen

2017-01-01

Couples as dyads suffer from the diagnosis of infertility and related treatment. These couples commonly experience emotional and physical pain and tension in their marital lives. The purpose of this study is to report on the process of developing a potentially feasible and effective complex intervention for couples undergoing in vitro fertilization treatment in China. The Medical Research Council (MRC) framework for developing and evaluating the complex intervention was adopted to guide the development of the Partnership and Coping Enhancement Programme (PCEP). In developing the PCEP, three steps were taken, namely, (1) identifying evidence by conducting literature reviews, a concept analysis and a qualitative study; (2) identifying/developing a theory-in this case, a preliminary Endurance with Partnership Conceptual Framework (P-EPCF) was proposed; and (3) modelling the process and outcomes of the PCEP. The PCEP that was developed is targeted mainly at the domains of the partnership mediators of stress in the P-EPCF. It consists of two sections-partnership and coping-and will be delivered to infertile couples on the day of embryo transfer. The main focuses of the programme are to facilitate mutual sharing and support in infertile couples, and to improve their individual and dyadic coping strategies while undergoing IVF treatment, especially in the period when they are waiting for the results of a pregnancy test and after the disclosure of a negative treatment outcome. The programme is couple-based, consisting of experience sharing, psychoeducation, meditation exercise, skill practise and supplemental written materials. The Partnership and Coping Enhancement Programme (PCEP) for couples undergoing in vitro fertilization treatment was developed according to the guideline of the MRC framework. It is recommended that a pilot study be conducted to evaluate its feasibility and to model the process and outcomes of the programme.

An analytical study of aircraft lateral-directional handling qualities using pilot models

NASA Technical Reports Server (NTRS)

Adams, J. J.; Moore, F. L.

1976-01-01

A procedure for predicting lateral-directional pilot ratings on the basis of the characteristics of the pilot model and the closed-loop system characteristics is demonstrated. A correlation is shown to exist between experimentally obtained pilot ratings and the computed pilot ratings.

Dynamic Tunnel Usability Study: Format Recommendations for Synthetic Vision System Primary Flight Displays

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Kramer, Lynda J.; Bailey, Randall E.

2006-01-01

A usability study evaluating dynamic tunnel concepts has been completed under the Aviation Safety and Security Program, Synthetic Vision Systems Project. The usability study was conducted in the Visual Imaging Simulator for Transport Aircraft Systems (VISTAS) III simulator in the form of questionnaires and pilot-in-the-loop simulation sessions. Twelve commercial pilots participated in the study to determine their preferences via paired comparisons and subjective rankings regarding the color, line thickness and sensitivity of the dynamic tunnel. The results of the study showed that color was not significant in pilot preference paired comparisons or in pilot rankings. Line thickness was significant for both pilot preference paired comparisons and in pilot rankings. The preferred line/halo thickness combination was a line width of 3 pixels and a halo of 4 pixels. Finally, pilots were asked their preference for the current dynamic tunnel compared to a less sensitive dynamic tunnel. The current dynamic tunnel constantly gives feedback to the pilot with regard to path error while the less sensitive tunnel only changes as the path error approaches the edges of the tunnel. The tunnel sensitivity comparison results were not statistically significant.

Effects of alcohol on pilot performance in simulated flight

NASA Technical Reports Server (NTRS)

Billings, C. E.; Demosthenes, T.; White, T. R.; O'Hara, D. B.

1991-01-01

Ethyl alcohol's known ability to produce reliable decrements in pilot performance was used in a study designed to evaluate objective methods for assessing pilot performance. Four air carrier pilot volunteers were studied during eight simulated flights in a B727 simulator. Total errors increased linearly and significantly with increasing blood alcohol. Planning and performance errors, procedural errors and failures of vigilance each increased significantly in one or more pilots and in the group as a whole.

An experimental study of the effect of a pilot flame on technically pre-mixed, self-excited combustion instabilities

NASA Astrophysics Data System (ADS)

O'Meara, Bridget C.

Combustion instabilities are a problem facing the gas turbine industry in the operation of lean, pre-mixed combustors. Secondary flames known as "pilot flames" are a common passive control strategy for eliminating combustion instabilities in industrial gas turbines, but the underlying mechanisms responsible for the pilot flame's stabilizing effect are not well understood. This dissertation presents an experimental study of a pilot flame in a single-nozzle, swirl-stabilized, variable length atmospheric combustion test facility and the effect of the pilot on combustion instabilities. A variable length combustor tuned the acoustics of the system to excite instabilities over a range of operating conditions without a pilot flame. The inlet velocity was varied from 25 -- 50 m/s and the equivalence ratio was varied from 0.525 -- 0.65. This range of operating conditions was determined by the operating range of the combustion test facility. Stability at each operating condition and combustor length was characterized by measurements of pressure oscillations in the combustor. The effect of the pilot flame on the magnitude and frequency of combustor stability was then investigated. The mechanisms responsible for the pilot flame effect were studied using chemiluminescence flame images of both stable and unstable flames. Stable flame structure was investigated using stable flame images of CH* chemiluminescence emission. The effect of the pilot on stable flame metrics such as flame length, flame angle, and flame width was investigated. In addition, a new flame metric, flame base distance, was defined to characterize the effect of the pilot flame on stable flame anchoring of the flame base to the centerbody. The effect of the pilot flame on flame base anchoring was investigated because the improved stability with a pilot flame is usually attributed to improved flame anchoring through the recirculation of hot products from the pilot to the main flame base. Chemiluminescence images of unstable flames were used to identify several instability mechanisms and infer how these mechanisms are affected by the pilot flame. Flame images of cases in which the pilot flame did not eliminate the instability were investigated to understand why the pilot flame is not effective in certain cases. The phase of unstable pilot flame oscillations was investigated to determine how the phase of pilot flame oscillations may affect its ability to interfere with instability mechanisms in the main flame. A forced flame response study was conducted to determine the effect of inlet velocity oscillation amplitude on the pilot flame. The flame response was characterized by measurements of velocity oscillations in the injector and chemiluminescence intensity oscillations determined from flame images. As the forcing amplitude increases, the pilot flame's effect on the flame transfer function magnitude becomes weaker. Flame images show that as the forcing amplitude increases, the pilot flame oscillations increase, leading to an ineffective pilot. The results of the flame response portion of this study highlight the effect of instability amplitude on the ability of a pilot flame to eliminate a combustion instability.

Pilot study of Alteplase (tissue plasminogen activator) for treatment of urinary clot retention in an in vitro model.

PubMed

Ritch, Chad R; Ordonez, Maria A; Okhunov, Zhamshid; Araujo, Juan; Walsh, Rhonda; Baudin, Vania; Lee, Daniel; Badani, Ketan K; Gupta, Mantu; Landman, Jaime

2009-08-01

The management of urinary clot retention and hematuria involves manual irrigation with sterile water or normal saline via a Foley catheter followed by continuous bladder irrigation. Irrigation may become difficult because of the formation of dense blood clots. Tissue plasminogen activator (t-PA/Alteplase) may be a useful pharmacological agent to improve the efficacy of manual irrigation of large, dense clots. The goal of the current study was to compare t-PA to sterile water for clot irrigation in an in vitro model. In vitro models of clot retention were created using 500-cc urinary leg bags each filled with 80 cc of unpreserved whole blood from a healthy volunteer. Each model was incubated at 25 degrees C for 24 hours to allow clot formation. Four models each with 25 mL solution of t-PA at concentrations of 2, 1, 0.5, and 0.25 mg/mL were evaluated and compared to a control (25 mL sterile water). Models were instilled with solution (t-PA or control) and incubated for 30 minutes at 37 degrees C, and then irrigated with sterile water via 18F Foley by a blinded investigator. Three separate experiments were conducted, and statistical analysis was performed comparing various irrigation parameters. Clot evacuation with 25 mL of t-PA at a concentration of 2 mg/mL (50 mg) was significantly easier (p = 0.05) and faster (p < 0.05) than the sterile water control. The mean time for clot evacuation in this model was 2.7 minutes for t-PA solution 2 mg/mL versus 7.3 minutes for the control (p < 0.05). Compared to the control, irrigation with t-PA solution 2 mg/mL also required less irrigant (180 mL vs. 500 mL) (p < 0.05) for complete evacuation. There was a similar trend in efficacy for the lower doses of t-PA, but this was not statistically significant. In this in vitro study, a single 25 mL instillation of t-PA solution 2 mg/mL is significantly better than sterile water alone for clot evacuation. In vivo animal studies are pending.

Ingestion of onion soup high in quercetin inhibits platelet aggregation and essential components of the collagen-stimulated platelet activation pathway in man: a pilot study.

PubMed

Hubbard, Gary P; Wolffram, Siegfried; de Vos, Ric; Bovy, Arnaud; Gibbins, Jonathan M; Lovegrove, Julie A

2006-09-01

Epidemiological data suggest that those who consume a diet rich in quercetin-containing foods may have a reduced risk of CVD. Furthermore, in vitro and ex vivo studies have observed the inhibition of collagen-induced platelet activation by quercetin. The aim of the present study was to investigate the possible inhibitory effects of quercetin ingestion from a dietary source on collagen-stimulated platelet aggregation and signalling. A double-blind randomised cross-over pilot study was undertaken. Subjects ingested a soup containing either a high or a low amount of quercetin. Plasma quercetin concentrations and platelet aggregation and signalling were assessed after soup ingestion. The high-quercetin soup contained 69 mg total quercetin compared with the low-quercetin soup containing 5 mg total quercetin. Plasma quercetin concentrations were significantly higher after high-quercetin soup ingestion than after low-quercetin soup ingestion and peaked at 2.59 (sem 0.42) mumol/l. Collagen-stimulated (0.5 mug/ml) platelet aggregation was inhibited after ingestion of the high-quercetin soup in a time-dependent manner. Collagen-stimulated tyrosine phosphorylation of a key component of the collagen-signalling pathway via glycoprotein VI, Syk, was significantly inhibited by ingestion of the high-quercetin soup. The inhibition of Syk tyrosine phosphorylation was correlated with the area under the curve for the high-quercetin plasma profile. In conclusion, the ingestion of quercetin from a dietary source of onion soup could inhibit some aspects of collagen-stimulated platelet aggregation and signalling ex vivo. This further substantiates the epidemiological data suggesting that those who preferentially consume high amounts of quercetin-containing foods have a reduced risk of thrombosis and potential CVD risk.

Controlling road rage : a literature review and pilot study

DOT National Transportation Integrated Search

1999-06-01

This report discusses results of a literature review and pilot study on how to prevent aggressive driving and road rage. The study "Controlling Road Rage: A Literature Review and Pilot Study" defines road rage as "an incident in which an angry or imp...

Physiological studies on air tanker pilots flying forest fire retardant missions.

DOT National Transportation Integrated Search

1968-10-01

Pre-flight and post-flight studies were carried out on five air tanker pilots; in-flight studies were carried out on four of these five pilots. Pre- and post-flight studies consisted of a questionnaire and determinations of blood pressure, psychomoto...

Effects of culinary spices and psychological stress on postprandial lipemia and lipase activity: results of a randomized crossover study and in vitro experiments.

PubMed

McCrea, Cindy E; West, Sheila G; Kris-Etherton, Penny M; Lambert, Joshua D; Gaugler, Trent L; Teeter, Danette L; Sauder, Katherine A; Gu, Yeyi; Glisan, Shannon L; Skulas-Ray, Ann C

2015-01-16

Data suggest that culinary spices are a potent, low-calorie modality for improving physiological responses to high fat meals. In a pilot study (N = 6 healthy adults), we showed that a meal containing a high antioxidant spice blend attenuated postprandial lipemia by 30% compared to a low spice meal. Our goal was to confirm this effect in a larger sample and to consider the influence of acute psychological stress on fat metabolism. Further, we used in vitro methods to evaluate the inhibitory effect of spices on digestive enzymes. In a 2 x 2, randomized, 4-period crossover design, we compared the effects of 14.5 g spices (black pepper, cinnamon, cloves, garlic, ginger, oregano, paprika, rosemary, and turmeric) vs. placebo incorporated into a high fat meal (1000 kcal, 45 g fat), followed by psychological stress (Trier Social Stress Test) vs. rest on postprandial metabolism in 20 healthy but overweight adults. Blood was sampled at baseline and at 105, 140, 180, and 210 minutes for analysis of triglycerides, glucose, and insulin. Additional in vitro analyses examined the effect of the spice blend and constituent spices on the activity of pancreatic lipase (PL) and secreted phospholipase A₂ (PLA₂). Mixed models were used to model the effects of spices and stress (SAS v9.3). Serum triglycerides, glucose and insulin were elevated following the meal (p < 0.01). Spices reduced post-meal triglycerides by 31% when the meal was followed by the rest condition (p = 0.048), but this effect was not present during stress. There was no effect of the spice blend on glucose or insulin; however, acute stress significantly increased both of these measures (p < 0.01; mean increase of 47% and 19%, respectively). The spice blend and several of the individual spices dose-dependently inhibited PL and PLA2 activity in vitro. Inclusion of spices may attenuate postprandial lipemia via inhibition of PL and PLA₂. However, the impact of psychological stress negates any influence of the spice blend on triglycerides, and further, increases blood glucose and insulin. ClinicalTrials.gov as NCT00954902 .

Lessons from a One-to-One Laptop Pilot

ERIC Educational Resources Information Center

Peterson, Lana; Scharber, Cassandra

2017-01-01

The purpose of this study was to document the process one district used to design, develop, and implement a one-to-one pilot at its high school as part of its broader commitment to contemporary learning. Specifically, this qualitative case study (a) outlines the process of the laptop pilot, (b) describes the pilot implementation experience for…

Pilot Non-Conformance to Alerting System Commands

NASA Technical Reports Server (NTRS)

Pritchett, Amy R.; Hansman, R. John

1997-01-01

Instances of pilot non-conformance to alerting system commands have been identified in previous studies. Pilot non-conformance changes the final behavior of the system, and therefore may reduce actual performance from that anticipated. A simulator study has examined pilot non-conformance, using the task of collision avoidance during closely spaced parallel approaches as a case study. Consonance between the display and the alerting system was found to significantly improve subject agreement with automatic alerts. Based on these results, a more general discussion of the factors involved in pilot conformance is given, and design guidelines for alerting systems are given.

Pilot error in air carrier accidents: does age matter?

PubMed

Li, Guohua; Grabowski, Jurek G; Baker, Susan P; Rebok, George W

2006-07-01

The relationship between pilot age and safety performance has been the subject of research and controversy since the "Age 60 Rule" became effective in 1960. This study aimed to examine age-related differences in the prevalence and patterns of pilot error in air carrier accidents. Investigation reports from the National Transportation Safety Board for accidents involving Part 121 operations in the United States between 1983 and 2002 were reviewed to identify pilot error and other contributing factors. Accident circumstances and the presence and type of pilot error were analyzed in relation to pilot age using Chi-square tests. Of the 558 air carrier accidents studied, 25% resulted from turbulence, 21% from mechanical failure, 16% from taxiing events, 13% from loss of control at landing or takeoff, and 25% from other causes. Accidents involving older pilots were more likely to be caused by turbulence, whereas accidents involving younger pilots were more likely to be taxiing events. Pilot error was a contributing factor in 34%, 38%, 35%, and 34% of the accidents involving pilots ages 25-34 yr, 35-44 yr, 45-54 yr, and 55-59 yr, respectively (p = 0.87). The patterns of pilot error were similar across age groups. Overall, 26% of the pilot errors identified were inattentiveness, 22% flawed decisions, 22% mishandled aircraft kinetics, and 11% poor crew interactions. The prevalence and patterns of pilot error in air carrier accidents do not seem to change with pilot age. The lack of association between pilot age and error may be due to the "safe worker effect" resulting from the rigorous selection processes and certification standards for professional pilots.

77 FR 13343 - Pilot Program for Early Feasibility Study Investigational Device Exemption Applications...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-06

...] Pilot Program for Early Feasibility Study Investigational Device Exemption Applications; Termination of... acceptance of nominations for the Early Feasibility Study Investigational Device Exemption (IDE) Applications... technologies to participate in a pilot program for early feasibility study IDE applications. FDA is also...

Placental Growth Factor Levels in Populations with High Versus Low Risk for Cardiovascular Disease and Stressful Physiological Environments such as Microgravity: A Pilot Study

NASA Astrophysics Data System (ADS)

Sundaresan, Alamelu; Mehta, Satish K.; Schlegel, Todd. T.; Russomano, Thais; Pierson, Duane L.; Mann, Vivek; Mansoor, Elvedina; Olamigoke, Loretta; Okoro, Elvis

2017-02-01

This pilot study compared placental growth factor (PIGF) levels in populations with high versus low risk for cardiovascular disease. Previous experiments from our laboratory (Sundaresan et al. 2005, 2009) revealed that the angiogenic factor PIGF was up regulated in modeled microgravity conditions in human lymphocytes leading to possible atherogenesis and pathogenesis in microgravity. Since the findings came from microgravity analog experiments, there is a strong link to its usefulness in the microgravity field as a biomarker. It is important to understand, that these findings came from both studies on expression levels of this cardiovascular marker in human lymphocytes in microgravity ( in vitro microgravity analog), and a follow up gene expression study in hind limb suspended mice ( in vivo microgravity analog). The relevance is enhanced because in life on earth, PIGF is an inflammatory biomarker for cardiovascular disease. Studies on the levels of PIGF would help to reduce the risk and prevention of heart failures in astronauts. If we can use this marker to predict and reduce the risk of cardiac events in astronauts and pilots, it would significantly help aerospace medicine operations. The investigations here confirmed that in a cardiovascular stressed population such as coronary artery disease (CAD) and acute coronary syndrome (ACS) patients, PIGF could be overexpressed. We desired to re-evaluate this marker in patients with cardiovascular disease in our own study. PIGF is a marker of inflammation and a predictor of short-term and long-term adverse outcome in ACS. In addition, elevated PIGF levels may be associated with increased risk for CAD.PIGF levels were determined in thirty-one patients undergoing cardiovascular catheterization for reasons other than ACS and in thirty-three low-risk asymptomatic subjects. Additional data on traditional cardiovascular risk factors for both populations were also compiled and compared. We found that PIGF levels were significantly higher in the high-risk population as compared to low-risk population. Also we were able to ascertain that PIGF levels were inversely correlated with HDL-cholesterol but directly correlated with the triglyceride levels. With further validation, PIGF may prove a useful addition to the armamentarium of noninvasive biomarkers for cardiovascular disease including a new area of stressful physiological conditions such as microgravity.

Autogenic Feedback Training Exercise and pilot performance: enhanced functioning under search-and-rescue flying conditions.

PubMed

Cowings, P S; Kellar, M A; Folen, R A; Toscano, W B; Burge, J D

2001-01-01

Studies have shown that autonomous mode behavior is one cause of aircraft fatalities due to pilot error. In such cases, the pilot is in a high state of psychological and physiological arousal and tends to focus on one problem, while ignoring more critical information. This study examined the effect of training in physiological self-recognition and regulation, as a means of improving crew cockpit performance. Seventeen pilots were assigned to the treatment and control groups matched for accumulated flight hours. The treatment group contained 4 pilots from HC-130 Hercules aircraft and 4 HH-65 Dolphin helicopter pilots; the control group contained 3 pilots of HC-130s and 6 helicopter pilots. During an initial flight, physiological data were recorded on each crewmember and an instructor pilot rated individual crew performance. Eight crewmembers were then taught to regulate their own physiological response levels using Autogenic-Feedback Training Exercise (AFTE). The remaining participants received no training. During a second flight, treatment participants showed significant improvement in performance (rated by the same instructor pilot as in pretests) while controls did not improve. The results indicate that AFTE management of high states of physiological arousal may improve pilot performance during emergency flying conditions.

Autogenic Feedback Training Exercise and pilot performance: enhanced functioning under search-and-rescue flying conditions

NASA Technical Reports Server (NTRS)

Cowings, P. S.; Kellar, M. A.; Folen, R. A.; Toscano, W. B.; Burge, J. D.

2001-01-01

Studies have shown that autonomous mode behavior is one cause of aircraft fatalities due to pilot error. In such cases, the pilot is in a high state of psychological and physiological arousal and tends to focus on one problem, while ignoring more critical information. This study examined the effect of training in physiological self-recognition and regulation, as a means of improving crew cockpit performance. Seventeen pilots were assigned to the treatment and control groups matched for accumulated flight hours. The treatment group contained 4 pilots from HC-130 Hercules aircraft and 4 HH-65 Dolphin helicopter pilots; the control group contained 3 pilots of HC-130s and 6 helicopter pilots. During an initial flight, physiological data were recorded on each crewmember and an instructor pilot rated individual crew performance. Eight crewmembers were then taught to regulate their own physiological response levels using Autogenic-Feedback Training Exercise (AFTE). The remaining participants received no training. During a second flight, treatment participants showed significant improvement in performance (rated by the same instructor pilot as in pretests) while controls did not improve. The results indicate that AFTE management of high states of physiological arousal may improve pilot performance during emergency flying conditions.

X-Ray Psoralen Activated Cancer Therapy (X-PACT)

PubMed Central

Oldham, Mark; Yoon, Paul; Fathi, Zak; Beyer, Wayne F.; Adamson, Justus; Liu, Leihua; Alcorta, David; Xia, Wenle; Osada, Takuya; Liu, Congxiao; Yang, Xiao Y.; Dodd, Rebecca D.; Herndon, James E.; Meng, Boyu; Kirsch, David G.; Lyerly, H. Kim; Dewhirst, Mark W.; Fecci, Peter; Walder, Harold; Spector, Neil L.

2016-01-01

This work investigates X-PACT (X-ray Psoralen Activated Cancer Therapy): a new approach for the treatment of solid cancer. X-PACT utilizes psoralen, a potent anti-cancer therapeutic with current application to proliferative disease and extracorporeal photopheresis (ECP) of cutaneous T Cell Lymphoma. An immunogenic role for light-activated psoralen has been reported, contributing to long-term clinical responses. Psoralen therapies have to-date been limited to superficial or extracorporeal scenarios due to the requirement for psoralen activation by UVA light, which has limited penetration in tissue. X-PACT solves this challenge by activating psoralen with UV light emitted from novel non-tethered phosphors (co-incubated with psoralen) that absorb x-rays and re-radiate (phosphoresce) at UV wavelengths. The efficacy of X-PACT was evaluated in both in-vitro and in-vivo settings. In-vitro studies utilized breast (4T1), glioma (CT2A) and sarcoma (KP-B) cell lines. Cells were exposed to X-PACT treatments where the concentrations of drug (psoralen and phosphor) and radiation parameters (energy, dose, and dose rate) were varied. Efficacy was evaluated primarily using flow cell cytometry in combination with complimentary assays, and the in-vivo mouse study. In an in-vitro study, we show that X-PACT induces significant tumor cell apoptosis and cytotoxicity, unlike psoralen or phosphor alone (p<0.0001). We also show that apoptosis increases as doses of phosphor, psoralen, or radiation increase. Finally, in an in-vivo pilot study of BALBc mice with syngeneic 4T1 tumors, we show that the rate of tumor growth is slower with X-PACT than with saline or AMT + X-ray (p<0.0001). Overall these studies demonstrate a potential therapeutic effect for X-PACT, and provide a foundation and rationale for future studies. In summary, X-PACT represents a novel treatment approach in which well-tolerated low doses of x-ray radiation are delivered to a specific tumor site to generate UVA light which in-turn unleashes both short- and potentially long-term antitumor activity of photo-active therapeutics like psoralen. PMID:27583569

EXPOSURE ASSESSMENT METHODS DEVELOPMENT PILOTS FOR THE NATIONAL CHILDREN'S STUDY

EPA Science Inventory

Accurate exposure classification tools are needed to link exposure with health effects. EPA began methods development pilot studies in 2000 to address general questions about exposures and outcome measures. Selected pilot studies are highlighted in this poster. The “Literature Re...

Antifungal Activity of Denture Soft Lining Material Modified by Silver Nanoparticles—A Pilot Study

PubMed Central

Chladek, Grzegorz; Mertas, Anna; Barszczewska-Rybarek, Izabela; Nalewajek, Teresa; Żmudzki, Jarosław; Król, Wojciech; Łukaszczyk, Jan

2011-01-01

Soft liner materials in oral cavity environments are easily colonized both by fungi and dental plaque. These factors are the cause of mucosal infections. The microorganism that most frequently colonizes soft liner materials is Candida albicans. Colonization occurs on the surface of materials and within materials. A solution to this problem might involve modification of soft liner materials with silver nanoparticles (AgNPs). In this article, we present results showing the antifungal efficacy of silicone soft lining materials modified with AgNPs. The modification process was conducted by dissolving both material components (base and catalyst) in a colloidal solution of AgNPs and evaporating the solvent. Composites with various AgNP concentrations (10, 20, 40, 80, 120 and 200 ppm) were examined. The in vitro antifungal efficacy (AFE) of composite samples was 16.3% to 52.5%. PMID:21845108

Prevalence of fatigue in a group of airline pilots.

PubMed

Reis, Cátia; Mestre, Catarina; Canhão, Helena

2013-08-01

Fatigue is a common phenomenon in airline pilots that can impair alertness and ability of crewmembers to safely operate an aircraft and perform safety related tasks. Fatigue can increase the risk of an incident or even an accident. This study provides the first prevalence values for clinically significant fatigue in Portuguese airline pilots. The hypothesis that medium/short-haul pilots may currently present different levels of fatigue than long-haul pilots was also tested. A survey was conducted by requesting Portuguese airline pilots to complete questionnaires placed in the pilots' personal lockers from 1 April until 15 May 2012. The questionnaire included the self-response Fatigue Severity Scale (FSS) to measure subjective fatigue and some additional questions concerning perception of fatigue by pilots. The prevalence values for total and mental fatigue achieved in the Portuguese airline pilots were: 89.3% (FSS > or = 4) and 94.1% (FSS > or = 4) when splitting the sample in two subsamples, long- and medium/short-haul pilots. Levels of total and mental fatigue were higher for medium/short-haul pilots. The analysis of fatigue levels in each type of aviator showed that medium/short-haul pilots presented the highest levels of total and mental fatigue. This study produced the first prevalence values of total and mental fatigue among Portuguese airline pilots, which represents a great step to understanding and addressing this critical phenomenon.

76 FR 12367 - Proposed Information Collection; Visibility Valuation Survey Pilot Study

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-07

... Survey Pilot Study AGENCY: National Park Service, U.S. Department of the Interior. ACTION: Notice... Code of Federal Regulations). Updated estimates of visibility benefits are required because the studies... a pilot study to test the survey instrument and implementation procedures prior to the full survey...

Pre-Study Walkthrough with a Commercial Pilot for a Preliminary Single Pilot Operations Experiment

NASA Technical Reports Server (NTRS)

O'Connor-Dreher, Ryan; Roberts, Z.; Ziccardi, J.; Vu, K-P. L.; Strybel, T.; Koteskey, Robert William; Lachter, Joel B.; Vi Dao, Quang; Johnson, Walter W.; Battiste, V.

2013-01-01

The number of crew members in commercial flights has decreased to two members, down from the five-member crew required 50 years ago. One question of interest is whether the crew should be reduced to one pilot. In order to determine the critical factors involved in safely transitioning to a single pilot, research must examine whether any performance deficits arise with the loss of a crew member. With a concrete understanding of the cognitive and behavioral role of a co-pilot, aeronautical technologies and procedures can be developed that make up for the removal of the second aircrew member. The current project describes a pre-study walkthrough process that can be used to help in the development of scenarios for testing future concepts and technologies for single pilot operations. Qualitative information regarding the tasks performed by the pilots can be extracted with this technique and adapted for future investigations of single pilot operations.

Preanalytical considerations in detection of colorectal cancer in blood serum using Raman molecular imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Treado, Patrick J.; Stewart, Shona D.; Smith, Aaron; Kirschner, Heather; Post, Christopher; Overholt, Bergein F.

2016-03-01

Colorectal cancer (CRC) is the third most common cancer in men and women in the United States. Raman Molecular Imaging (RMI) is an effective technique to evaluate human tissue, cells and bodily fluids, including blood serum for disease diagnosis. ChemImage Corporation, in collaboration with clinicians, has been engaged in development of an in vitro diagnostic Raman assay focused on CRC detection. The Raman Assay for Colorectal Cancer (RACC) exploits the high specificity of Raman imaging to distinguish diseased from normal dried blood serum droplets without additional reagents. Pilot Study results from testing of hundreds of biobank patient samples have demonstrated that RACC detects CRC with high sensitivity and specificity. However, expanded clinical trials, which are ongoing, are revealing a host of important preanalytical considerations associated with sample collection, sample storage and stability, sample shipping, sample preparation and sample interferents, which impact detection performance. Results from recent clinical studies will be presented.

Improving FHWA's Ability to Assess Highway Infrastructure Health : Pilot Study Report

DOT National Transportation Integrated Search

2012-07-01

This report documents the results of a pilot study conducted as part of a project on improving FHWAs ability to assess highway infrastructure health. As part of the pilot study, a section of Interstate 90 through South Dakota, Minnesota, and Wisco...

Recommendations for Planning Pilot Studies in Clinical and Translational Research

PubMed Central

Moore, Charity G.; Carter, Rickey E.; Nietert, Paul J.; Stewart, Paul W.

2011-01-01

Abstract  Advances in clinical and translation science are facilitated by building on prior knowledge gained through experimentation and observation. In the context of drug development, preclinical studies are followed by a progression of phase I through phase IV clinical trials. At each step, the study design and statistical strategies are framed around research questions that are prerequisites for the next phase. In other types of biomedical research, pilot studies are used for gathering preliminary support for the next research step. However, the phrase “pilot study” is liberally applied to projects with little or no funding, characteristic of studies with poorly developed research proposals, and usually conducted with no detailed thought of the subsequent study. In this article, we present a rigorous definition of a pilot study, offer recommendations for the design, analysis and sample size justification of pilot studies in clinical and translational research, and emphasize the important role that well‐designed pilot studies play in the advancement of science and scientific careers. Clin Trans Sci 2011; Volume 4: 332–337 PMID:22029804

Piloted simulation study of an ILS approach of a twin-pusher business/commuter turboprop aircraft configuration

NASA Technical Reports Server (NTRS)

Riley, Donald R.; Brandon, Jay M.; Glaab, Louis J.

1994-01-01

A six-degree-of-freedom nonlinear simulation of a twin-pusher, turboprop business/commuter aircraft configuration representative of the Cessna ATPTB (Advanced turboprop test bed) was developed for use in piloted studies with the Langley General Aviation Simulator. The math models developed are provided, simulation predictions are compared with with Cessna flight-test data for validation purposes, and results of a handling quality study during simulated ILS (instrument landing system) approaches and missed approaches are presented. Simulated flight trajectories, task performance measures, and pilot evaluations are presented for the ILS approach and missed-approach tasks conducted with the vehicle in the presence of moderate turbulence, varying horizontal winds and engine-out conditions. Six test subjects consisting of two research pilots, a Cessna test pilot, and three general aviation pilots participated in the study. This effort was undertaken in cooperation with the Cessna Aircraft Company.

Study to determine the IFR operational profile and problems to the general aviation pilot

NASA Technical Reports Server (NTRS)

Weislogel, S.

1983-01-01

A study of the general aviation single pilot operating under instrument flight rules (GA SPIFR) has been conducted for NASA Langley Research Center. The objectives of the study were to (1) develop a GA SPIFR operational profile, (2) identify problems experienced by the GA SPIFR pilot, and (3) identify research tasks which have the potential for eliminating or reducing the severity of the problems. To obtain the information necessary to accomplish these objectives, a mail questionnaire survey of instrument rated pilots was conducted. Complete questionnaire data is reported in NASA CR-165805, "Statistical Summary: Study to Determine the IFR Operational Profile and Problems of the General Aviation Single Pilot'-Based upon the results of the GA SPIFR survey, this final report presents the general aviation IFR single pilot operational profile, illustrates selected data analysis, examples, identifies the problems which he is experiencing, and recommends further research.

A comparison between r-LH and urinary supplements containing LH activity in patients undergoing the microdose GnRH agonist flare protocol for in-vitro fertilization: a pilot study.

PubMed

Shavit, Tal; Agdi, Mohammed; Son, Weon Y; Hasson, Josseph; Dahan, Michael H

2016-08-01

The aim of this study was to compare pregnancy rates and stimulation parameters in patients with diminished ovarian reserve, who were treated with recombinant human luteinizing hormone (r-LH) or menopausal gonadotropins (hMG), as part of a microdose flare protocol. A retrospective cohort study was performed. Comparisons between the group that was stimulated with r-LH plus follicle stimulating hormone (FSH) to those treated with hMG and FSH, were performed. Measurements included: medication doses, number of oocyte collected, number of embryos obtained, pregnancy and clinical pregnancy rates. Patients in the r-LH group (N.=40) had significant higher clinical pregnancy rates (33% vs. 14%; P=0.04) and used lower dose of LH (1938 IU vs. 2807 IU; P=0.02) compared to patients that were stimulated with hMG (N.=39). r-LH may offer advantages for the treatment of diminished ovarian reserve when performing a microdose flare protocol when compared to hMG. Both larger and prospective studies should be carried out to confirm these findings.

Reflecting on the Germanwings Disaster: A Systematic Review of Depression and Suicide in Commercial Airline Pilots.

PubMed

Pasha, Terouz; Stokes, Paul R A

2018-01-01

The 2015 Germanwings Flight 9525 disaster, in which 150 people were killed after the co-pilot may have intentionally crashed the plane in a suicide attempt, highlights the importance of better understanding the mental health of commercial airline pilots. However, there have been few systematic reviews investigating the topic of mental health in commercial aviation. This systematic review aims to identify the types and prevalence of mental health disorders that commercial airline pilots experience with a focus on mood disorders and suicide risk. A systematic literature search was performed using PubMed, EMBASE, and PsycINFO databases. Eligible studies were assessed and data was extracted and analyzed. 20 studies were identified. The prevalence of depression experienced by commercial airline pilots in this review ranged from 1.9% to 12.6%. Factors that negatively impacted the mental health of pilots included substance abuse, experiencing verbal or sexual abuse, disruption in sleep circadian rhythms and fatigue. This systematic review identifies that commercial airline pilots may experience depression at least as frequently as the general population. Commercial airline pilots experience occupational stressors, such as disrupted circadian rhythms and fatigue which may increase risks of developing mood disorders. Most studies identified in this review were cross-sectional in nature with substantial limitations. There is a clear need for further higher quality longitudinal studies to better understand the mental health of commercial airline pilots.

A study on aircraft map display location and orientation. [effects of map display location on manual piloting performance

NASA Technical Reports Server (NTRS)

Baty, D. L.; Wempe, T. E.; Huff, E. M.

1973-01-01

Six airline pilots participated in a fixed-base simulator study to determine the effects of two Horizontal Situation Display (HSD/map) panel locations relative to the Vertical Situation Display (VSD), and of three map orientations on manual piloting performance. Pilot comments and opinions were formally obtained. Significant performance differences were found between wind conditions, and among pilots, but not between map locations and orientations. The results also illustrate the potential tracking accuracy of such a display. Recommendations concerning display location and map orientation are made.

Unrecoverable bi-products of drilling titanium alloy and tantalum metal implants: a pilot study.

PubMed

Skowronek, Paweł; Olszewski, Paweł; Święszkowski, Wojciech; Synder, Marek; Sibiński, Marcin; Mazek, Jacek

2018-05-01

Trabecular metal implants with a porous architecture that allows for the incorporation of bone into the implant during healing are gaining popularity in alloplastic revision procedures. The bi-products of drilling titanium alloy (Ti) and tantalum (Ta) implants have not been previously assessed. Four holes were drilled in each of two spatially porous trabecular implants, one Ta and the other Ti alloy (Ti-6Al-7Nb), for this pilot in vitro study. The particles were flushed out with a continuous flow of saline. The particles' weight and the volume were then measured using a Radwag XA 110/2X (USA) laboratory balance. The total volume of the obtained metal fines was measured by titration using a 10 mm 3 measurement system. A cobalt carbide bit was used since the holes could not be made with a standard bone drill. Each Ti and Ta implant lost 1.26 g and 2.48 g of mass, respectively. The volume of free particles recovered after each stage was 280 mm 3 and 149 mm 3 , respectively. Approximately 0.6% of the total implant mass was not recovered after drilling (roughly 2% of the mass of the particles created by drilling), despite the use of 5 µm filters. It is technically difficult to drill holes in Ti and Ta implants using standard surgical tools. The drilling process creates a considerable amount of metal particles, which cannot be recovered despite intensive flushing. This may have an adverse influence on the bio-functionality (survival) of the endoprosthesis and present deleterious systemic consequences.

Development of a completely autologous valved conduit with the sinus of Valsalva using in-body tissue architecture technology: a pilot study in pulmonary valve replacement in a beagle model.

PubMed

Yamanami, Masashi; Yahata, Yuki; Uechi, Masami; Fujiwara, Megumi; Ishibashi-Ueda, Hatsue; Kanda, Keiichi; Watanabe, Taiji; Tajikawa, Tsutomu; Ohba, Kenkichi; Yaku, Hitoshi; Nakayama, Yasuhide

2010-09-14

We developed autologous prosthetic implants by simple and safe in-body tissue architecture technology. We present the first report on the development of autologous valved conduit with the sinus of Valsalva (BIOVALVE) by using this unique technology and its subsequent implantation in the pulmonary valves in a beagle model. A mold of BIOVALVE organization was assembled using 2 types of specially designed silicone rods with a small aperture in a trileaflet shape between them. The concave rods had 3 projections that resembled the protrusions of the sinus of Valsalva. The molds were placed in the dorsal subcutaneous spaces of beagle dogs for 4 weeks. The molds were covered with autologous connective tissues. BIOVALVEs with 3 leaflets in the inner side of the conduit with the sinus of Valsalva were obtained after removing the molds. These valves had adequate burst strength, similar to that of native valves. Tight valvular coaptation and sufficient open orifice area were observed in vitro. These BIOVALVEs were implanted to the main pulmonary arteries as allogenic conduit valves (n=3). Postoperative echocardiography demonstrated smooth movement of the leaflets with trivial regurgitation. Histological examination of specimens obtained at 84 days showed that the surface of the leaflet was covered by endothelial cells and neointima, including an elastin fiber network, and was formed at the anastomosis sides on the luminal surface of the conduit. We developed the first completely autologous BIOVALVE and successfully implanted these BIOVALVEs in a beagle model in a pilot study.

Intermittent therapy with terbinafine and nail abrasion for dermatophyte toe onychomycosis: a pilot study.

PubMed

Succi, Isabella B; Bernardes-Engemann, Andréa R; Orofino-Costa, Rosane

2013-05-01

Onychomycosis constitutes up to 50% of all nail disorders. Toenails are generally affected, mostly due to dermatophytes. Terbinafine is the most potent antifungal agent in vitro against dermatophytes. There are few randomised controlled trials using a non-continuous dose of terbinafine. The aim of this open-label pilot study was to reduce the total drug amount, the collateral effects and, specially, the costs; albeit maintaining the same efficacy of the standard regimens. Compare the outcomes of two different intermittent regimens with the same total amount of the medication (42 tablets in 6 months). Forty-one patients were divided into the following groups: terbinafine 250 mg day(-1) , for 7 days, monthly or terbinafine 500 mg day(-1) , once daily, for 7 days, every 2 months, both plus nail abrasion during 6 months. The efficacy was evaluated at months 6, 12 and 18 using the disease free nail criteria. Total cure = group I: eight patients (44.4%) and group II: eight patients (44.4%). Partial cure = group I: five patients (27.8%) and group II: four patients (22.2%). Treatment failure = group I: five patients (27.8%) and group II: three patients (16.7%). Recurrence = group I: zero patients (0.0%) and group II: three patients (16.7%). Two intermittent dosing regimens of terbinafine plus nail abrasion proved to be an alternative statistically effective, safe and with reduced drug costs for dermatophytes toenail onychomycosis. © 2012 Blackwell Verlag GmbH.

The effectiveness of choline citrate infusions monitored by lymphocyte transformation test (LTT) in multiple sclerosis. A new approach to the diagnosis and treatment of the disease.

PubMed

Muss, Claus; Stejskal, Vera; Titel, Ekkehard

2009-01-01

The efficacy of intravenous choline citrate infusions was investigated in 34 patients with multiple sclerosis (MS) by clinical evaluation and by monitoring of lymphocyte proliferation in vitro against fragments of myelin basic protein (MOG-35-55, MBP15-31, PLP 39-15) over a period of 12 weeks. Patients have been diagnosed with MS at least one year before entering the study and suffered from mild relapsing/remitting course to long-term chronic progressive disease. Twenty one patients exhibited positive lymphocyte proliferation to myelin fragments prior to treatment and were therefore selected for further studies. Choline citrate was administered with a dosage of 1200mg/ 2x week for a period of 3 months. This treatment resulted in a significant decrease of lymphocyte proliferation to neural fragments (MOG- 35-55, MBP15-31) in lymphocyte transformation test (LTT). There was no significant SI change of PLP Peptide (PLP 39-15) LTT found after treatment with choline citrate. During the 3 mo observation period, patients remained stable and no side-effects of the treatment were observed. In addition, some patients reported long-lasting improvement (less paresthesia and increase of muscle strength in lower extremities) which was demonstrated up to 3 years later. In one spectacular case a commercial pilot was able to return to duty again after treatment. This pilot was allowed back in to his position as a commercial flying cockpit member and is on duty for more than 4 yrs now.

78 FR 48715 - Proposed Information Collection; Comment Request: NPS Study of Value of Natural Sounds: A Pilot...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-09

....NS0000] Proposed Information Collection; Comment Request: NPS Study of Value of Natural Sounds: A Pilot Study AGENCY: National Park Service, Interior. ACTION: Notice; request for comments. SUMMARY: We.... This is a new collection. Title: NPS Study of Value of Natural Sounds: A Pilot Study. Type of Request...

Evaluation of Silicon Phthalocyanine 4 Photodynamic Therapy Against Human Cervical Cancer Cells In Vitro and in Mice

PubMed Central

Gadzinski, Jill A.; Guo, Jianxia; Philips, Brian J.; Basse, Per; Craig, Ethan K.; Bailey, Lisa; Comerci, John T.; Eiseman, Julie L.

2017-01-01

Background Cervical cancer is the second most common cancer in women worldwide [1]. Photodynamic therapy has been used for cervical intraepithelial neoplasia with good responses, but few studies have used newer phototherapeutics. We evaluated the effectiveness of photodynamic therapy using Pc 4 in vitro and in vivo against human cervical cancer cells. Methods CaSki and ME-180 cancer cells were grown as monolayers and spheroids. Cell growth and cytotoxicity were measured using a methylthiazol tetrazolium assay. Pc 4 cellular uptake and intracellular distrubtion were determined. For in vitro Pc 4 photodynamic therapy cells were irradiated at 667nm at a fluence of 2.5 J/cm2 at 48 h. SCID mice were implanted with CaSki and ME-180 cells both subcutaneously and intracervically. Forty-eight h after Pc 4 photodynamic therapy was administered at 75 and 150 J/cm2. Results The IC50s for Pc 4 and Pc 4 photodynamic therapy for CaSki and ME-180 cells as monolayers were, 7.6μM and 0.016μM and >10μM and 0.026μM; as spheroids, IC50s of Pc 4 photodynamic therapy were, 0.26μM and 0.01μM. Pc 4 was taken up within cells and widely distributed in tumors and tissues. Intracervical photodynamic therapy resulted in tumor death, however mice died due to gastrointestinal toxicity. Photodynamic therapy resulted in subcutaneous tumor death and growth delay. Conclusions Pc 4 photodynamic therapy caused death within cervical cancer cells and xenografts, supporting development of Pc 4 photodynamic therapy for treatment of cervical cancer. Support: P30-CA47904, CTSI BaCCoR Pilot Program. PMID:28890844

Prediction of aircraft handling qualities using analytical models of the human pilot

NASA Technical Reports Server (NTRS)

Hess, R. A.

1982-01-01

The optimal control model (OCM) of the human pilot is applied to the study of aircraft handling qualities. Attention is focused primarily on longitudinal tasks. The modeling technique differs from previous applications of the OCM in that considerable effort is expended in simplifying the pilot/vehicle analysis. After briefly reviewing the OCM, a technique for modeling the pilot controlling higher order systems is introduced. Following this, a simple criterion for determining the susceptibility of an aircraft to pilot-induced oscillations (PIO) is formulated. Finally, a model-based metric for pilot rating prediction is discussed. The resulting modeling procedure provides a relatively simple, yet unified approach to the study of a variety of handling qualities problems.

Prediction of aircraft handling qualities using analytical models of the human pilot

NASA Technical Reports Server (NTRS)

Hess, R. A.

1982-01-01

The optimal control model (OCM) of the human pilot is applied to the study of aircraft handling qualities. Attention is focused primarily on longitudinal tasks. The modeling technique differs from previous applications of the OCM in that considerable effort is expended in simplifying the pilot/vehicle analysis. After briefly reviewing the OCM, a technique for modeling the pilot controlling higher order systems is introduced. Following this, a simple criterion for determining the susceptibility of an aircraft to pilot induced oscillations is formulated. Finally, a model based metric for pilot rating prediction is discussed. The resulting modeling procedure provides a relatively simple, yet unified approach to the study of a variety of handling qualities problems.

An analytical approach for predicting pilot induced oscillations

NASA Technical Reports Server (NTRS)

Hess, R. A.

1981-01-01

The optimal control model (OCM) of the human pilot is applied to the study of aircraft handling qualities. Attention is focused primarily on longitudinal tasks. The modeling technique differs from previous applications of the OCM in that considerable effort is expended in simplifying the pilot/vehicle analysis. After briefly reviewing the OCM, a technique for modeling the pilot controlling higher order systems is introduced. Following this, a simple criterion or determining the susceptability of an aircraft to pilot induced oscillations (PIO) is formulated. Finally, a model-based metric for pilot rating prediction is discussed. The resulting modeling procedure provides a relatively simple, yet unified approach to the study of a variety of handling qualities problems.

Numerical and flight simulator test of the flight deterioration concept

NASA Technical Reports Server (NTRS)

Mccarthy, J.; Norviel, V.

1982-01-01

Manned flight simulator response to theoretical wind shear profiles was studied in an effort to calibrate fixed-stick and pilot-in-the-loop numerical models of jet transport aircraft on approach to landing. Results of the study indicate that both fixed-stick and pilot-in-the-loop models overpredict the deleterious effects of aircraft approaches when compared to pilot performance in the manned simulator. Although the pilot-in-the-loop model does a better job than does the fixed-stick model, the study suggests that the pilot-in-the-loop model is suitable for use in meteorological predictions of adverse low-level wind shear along approach and departure courses to identify situations in which pilots may find difficulty. The model should not be used to predict the success or failure of a specific aircraft. It is suggested that the pilot model be used as part of a ground-based Doppler radar low-level wind shear detection and warning system.

Mandibular position influence on pilots' postural balance analyzed under dynamic conditions.

PubMed

Baldini, Alberto; Nota, Alessandro; Cioffi, Clementina; Ballanti, Fabiana; Tecco, Simona

2017-11-01

The aim of this study is to evaluate the influence of the mandibular position on the postural stability in a sample of civilian and military pilots. Twenty military pilots (males, mean age 35.15 ± 3.14 years) and 17 civilian pilots (males, mean 34.91 ± 2.15 years) were enrolled in this study and underwent a Sensory Organization Test (SOT) using the EquiTest® (NeuroCom International Inc., Clackamas, OR, USA) computerized dynamic posturography. The composite parameter was recorded and analyzed. The equilibrium score (ES) recorded in centric occlusion is slightly higher than the ES recorded in mandibular rest position; civilian pilots showed ESs slightly higher than military pilots. The two-way ANOVA analysis shows these differences are not statistically significant. The findings of this study seem to suggest that the composite parameter of the SOT is not sensitive in analyzing the influence of the stomatognathic system on the postural balance of civilian and military pilots.

Pilot age and error in air taxi crashes.

PubMed

Rebok, George W; Qiang, Yandong; Baker, Susan P; Li, Guohua

2009-07-01

The associations of pilot error with the type of flight operations and basic weather conditions are well documented. The correlation between pilot characteristics and error is less clear. This study aims to examine whether pilot age is associated with the prevalence and patterns of pilot error in air taxi crashes. Investigation reports from the National Transportation Safety Board for crashes involving non-scheduled Part 135 operations (i.e., air taxis) in the United States between 1983 and 2002 were reviewed to identify pilot error and other contributing factors. Crash circumstances and the presence and type of pilot error were analyzed in relation to pilot age using Chi-square tests. Of the 1751 air taxi crashes studied, 28% resulted from mechanical failure, 25% from loss of control at landing or takeoff, 7% from visual flight rule conditions into instrument meteorological conditions, 7% from fuel starvation, 5% from taxiing, and 28% from other causes. Crashes among older pilots were more likely to occur during the daytime rather than at night and off airport than on airport. The patterns of pilot error in air taxi crashes were similar across age groups. Of the errors identified, 27% were flawed decisions, 26% were inattentiveness, 23% mishandled aircraft kinetics, 15% mishandled wind and/or runway conditions, and 11% were others. Pilot age is associated with crash circumstances but not with the prevalence and patterns of pilot error in air taxi crashes. Lack of age-related differences in pilot error may be attributable to the "safe worker effect."

75 FR 80827 - Compliance Policy Guide; Radiofrequency Identification Feasibility Studies and Pilot Programs for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-23

... Identification (RFID) Feasibility Studies and Pilot Programs for Drugs'' to December 31, 2012. FOR FURTHER... Sec. 400.210 entitled ``Radiofrequency Identification (RFID) Feasibility Studies and Pilot Programs... FR 65750, November 23, 2007; 73 FR 78371, December 22, 2008). FDA has identified RFID as a promising...

Autogenic-feedback training improves pilot performance during emergency flying conditions

NASA Technical Reports Server (NTRS)

Kellar, Michael A.; Folen, Raymond A.; Cowings, Patricia S.; Toscano, William B.; Hisert, Glen L.

1994-01-01

Studies have shown that autonomous mode behavior is one cause of aircraft fatalities due to pilot error. In such cases, the pilot is in a high state of psychological and physiological arousal and tends to focus on one problem, while ignoring more critical information. This study examined the effect of training in physiological self-recognition and regulation, as a means of improving crew cockpit performance. Seventeen pilots were assigned to the treatment and control groups matched for accumulated flight hours. The treatment group comprised three pilots of HC-130 Hercules aircraft and four HH-65 Dolphin helicopter pilots; the control group comprised three pilots of HC-130's and six Dolphin helicopter pilots. During an initial flight, physiological data were recorded for each crew member and individual crew performance was rated by an instructor pilot. Eight crewmembers were then taught to regulate their own physiological response levels using Autogenic-Feedback Training (AFT). The remaining subjects received no training. During a second flight, treatment subjects showed significant improvement in performance, while controls did not improve. The results indicate that AFT management of high states of physiological arousal may improve pilot performance during emergency flying conditions.

Using Motivational Enhancement Among OIF / OEF Veterans Returning to the Community

DTIC Science & Technology

2014-10-01

than veterans who receive treatment as usual. During this year the pilot study for the project was completed. The purpose of the pilot study group was...pilot group members could not be used. The veterans in the pilot study were notified of the lapse and were re-consented. During the year the team...Veterans must not be currently in counseling to participate in the project. To combat this, one idea proposed is to allow veterans who live outside of

Review of immunomodulation by photopheresis: treatment of cutaneous T-cell lymphoma, autoimmune disease, and allograft rejection.

PubMed

Wolfe, J T; Lessin, S R; Singh, A H; Rook, A H

1994-12-01

Photopheresis is an apheresis-based therapy that is currently available at approximately 70 medical centers worldwide. Recent evidence indicates that extracorporeal photopheresis can significantly prolong life as well as induce a 60-75% response rate among individuals with advanced cutaneous T-cell lymphoma (CTCL). Moreover, a 10-15% cure rate, in response to photopheresis alone, or in combination with interferon-alpha, has been obtained at our institution. These complete responses have been characterized by the complete disappearance of morphologically atypical cells from the skin and blood. Southern blot analysis of peripheral blood specimens has also confirmed the indefinite disappearance of the malignant T-cell clone from the blood of patients with complete responses. Current immunological data obtained from in vitro human studies and from animal models suggest that the basis for the responses of CTCL patients are related to activation of treated macrophages resulting in release of cytokines, including substantial levels of tumor necrosis factor alpha (TNF-alpha), and perhaps, to the induction of anticlonotypic immunity directed against pathogenic clones of T lymphocytes. In addition to the treatment of CTCL, a potential role for photopheresis in the therapy of autoimmune disease has been suggested by recent pilot studies of pemphigus vulgaris, rheumatoid arthritis, and systemic lupus erythematosus. Furthermore, a randomized, single-blinded trial involving 79 patients with early onset, aggressive systemic sclerosis suggested that photopheresis could benefically affect the course of the cutaneous thickening in this form of the disease. Lastly, two independent pilot studies of cardiac transplantation have indicated that photopheresis can reverse acute cardiac allograft rejection and potentially suppress ongoing chronic rejection. Randomized, controlled trials for these new indications for photopheresis therapy are currently in the early stages of implementation.

In-vitro antibacterial study of zinc oxide nanostructures on Streptococcus sobrinus

NASA Astrophysics Data System (ADS)

Bakhori, Siti Khadijah Mohd; Mahmud, Shahrom; Ann, Ling Chuo; Sirelkhatim, Amna; Hasan, Habsah; Mohamad, Dasmawati; Masudi, Sam'an Malik; Seeni, Azman; Rahman, Rosliza Abd

2014-10-01

Zinc oxide nanostructures were prepared using a pilot plant of zinc oxide boiling furnace. Generally, it produced two types of nanostructures different in morphology; one is rod-like shaped (ZnO-1) and a plate-like shape (ZnO-2). The properties of ZnO were studied by structural, optical and morphological using XRD, PL and FESEM respectively. The XRD patterns confirmed the wurtzite structures of ZnO with the calculated crystallite size of 41 nm (ZnO-1) and 42 nm (ZnO-2) using Scherrer formula. The NBE peaks were determined by photoluminescence spectra which reveal peak at 3.25 eV and 3.23 eV for ZnO-1 and ZnO-2 respectively. Prior to that, the morphologies for both ZnO-1 and ZnO-2 were demonstrated from FESEM micrographs. Subsequently the antibacterial study was conducted using in-vitro broth dilution technique towards a gram positive bacterium Streptococcus sobrinus (ATCC 33478) to investigate the level of antibacterial effect of zinc oxide nanostructures as antibacterial agent. Gradual increment of ZnO concentrations from 10-20 mM affected the inhibition level after twenty four hours of incubation. In conjunction with concentration increment of ZnO, the percentage inhibition towards Streptococcus sobrinus was also increased accordingly. The highest inhibition occurred at 20 mM of ZnO-1 and ZnO-2 for 98% and 77% respectively. It showed that ZnO has good properties as antibacterial agent and relevancy with data presented by XRD, PL and FESEM were determined.

Compensation for time delay in flight simulator visual-display systems

NASA Technical Reports Server (NTRS)

Crane, D. F.

1983-01-01

A piloted aircraft can be viewed as a closed-loop, man-machine control system. When a simulator pilot is performing a precision maneuver, a delay in the visual display of aircraft response to pilot-control input decreases the stability of the pilot-aircraft system. The less stable system is more difficult to control precisely. Pilot dynamic response and performance change as the pilot attempts to compensate for the decrease in system stability, and these changes bias the simulation results by influencing the pilot's rating of the handling qualities of the simulated aircraft. Delay compensation, designed to restore pilot-aircraft system stability, was evaluated in several studies which are reported here. The studies range from single-axis, tracking-task experiments (with sufficient subjects and trials to establish statistical significance of the results) to a brief evaluation of compensation of a computer-generated-imagery (CGI) visual display system in a full six-degree-of-freedom simulation. The compensation was effective - improvements in pilot performance and workload or aircraft handling-qualities rating (HQR) were observed. Results from recent aircraft handling-qualities research literature which support the compensation design approach are also reviewed.

NORTHWEST ORGEON PILOT STUDY AREA (USA): THE USE OF LANDSCAPE SCIENCE FOR ENVIRONMENTAL ASSESSMENT PILOT STUDY

EPA Science Inventory

The Northwest Oregon Pilot Study Area encompasses approximately 59,167 km2 and varies in elevation from sea level to 3,200 m. Annual precipitation varies with elevation and meridian and ranges from 25 - 460cm. The study area comprises a mixture of federal, state, and privately ow...

An imidazopyridine anxiolytic alters glucose tolerance in patients: a pilot investigation.

PubMed

Bottaï, T; Cartault, F; Pouget, R; Blayac, J P; Petit, P

1995-02-01

We have recently shown that compounds with high affinity for peripheral-type benzodiazepine receptors inhibited glucose-induced insulin secretion in vitro. We therefore performed an oral glucose tolerance test in anxious inpatients treated with the imidazopyridine derivative alpidem, which has been shown to display high affinity for these binding sites. The test was performed before and after 1 week of daily administration of the drug. As compared with pretreatment values, a significant alteration of the insulin response to glucose was observed. It is suggested that daily administration of alpidem, at therapeutically effective doses for the treatment of anxiety, may alter glucose tolerance.

Pilot Comments From the Boeing High Speed Research Aircraft, Cycle 3, Simulation Study of the Effects of Aeroservoelasticity (LaRC.3)

NASA Technical Reports Server (NTRS)

Bailey, Melvin L. (Editor)

2000-01-01

This is a compilation of pilot comments from the Boeing High Speed Research Aircraft, Cycle 3, simulation study (LaRC.3) of the effects of aeroservoelasticity, conducted from October to December 1997 at NASA Langley Research Center. This simulation study was conducted using the Visual Motion Simulator. The comments are from direct tape transcriptions and have been edited for spelling only. These comments were made on tape following the completion of each flight card, immediately after the pilot was satisfied with his practice and data recording runs. Six pilots were used in the evaluation and they are identified as pilots A through F.

The use of total simulator training in transitioning air-carrier pilots: A field evaluation

NASA Technical Reports Server (NTRS)

Randle, R. J., Jr.; Tanner, T. A.; Hamerman, J. A.; Showalter, T. H.

1981-01-01

A field study was conducted in which the performance of air carrier transitioning pilots who had landing training in a landing maneuver approved simulator was compared with the performance of pilots who had landing training in the aircraft. Forty-eight trainees transitioning to the B-727 aircraft and eighty-seven trainees transitioning to the DC-10 were included in the study. The study results in terms of both objectively measured performance indicants and observer and check-pilot ratings did not demonstrate a clear distinction between the two training groups. The results suggest that, for these highly skilled transitioning pilots, a separate training module in the aircraft may be of dubious value.

Oregon department of transportation small business group twice-monthly payments pilot project : summary report.

DOT National Transportation Integrated Search

2008-07-01

Oregon Department of Transportation (ODOT) recently completed a pilot study on small business payment practices. In the study, three pilot projects were tested where payments to small business contractors were changed from a monthly payment to twice-...

Modeling human pilot cue utilization with applications to simulator fidelity assessment.

PubMed

Zeyada, Y; Hess, R A

2000-01-01

An analytical investigation to model the manner in which pilots perceive and utilize visual, proprioceptive, and vestibular cues in a ground-based flight simulator was undertaken. Data from a NASA Ames Research Center vertical motion simulator study of a simple, single-degree-of-freedom rotorcraft bob-up/down maneuver were employed in the investigation. The study was part of a larger research effort that has the creation of a methodology for determining flight simulator fidelity requirements as its ultimate goal. The study utilized a closed-loop feedback structure of the pilot/simulator system that included the pilot, the cockpit inceptor, the dynamics of the simulated vehicle, and the motion system. With the exception of time delays that accrued in visual scene production in the simulator, visual scene effects were not included in this study. Pilot/vehicle analysis and fuzzy-inference identification were employed to study the changes in fidelity that occurred as the characteristics of the motion system were varied over five configurations. The data from three of the five pilots who participated in the experimental study were analyzed in the fuzzy-inference identification. Results indicate that both the analytical pilot/vehicle analysis and the fuzzy-inference identification can be used to identify changes in simulator fidelity for the task examined.

A queueing model of pilot decision making in a multi-task flight management situation

NASA Technical Reports Server (NTRS)

Walden, R. S.; Rouse, W. B.

1977-01-01

Allocation of decision making responsibility between pilot and computer is considered and a flight management task, designed for the study of pilot-computer interaction, is discussed. A queueing theory model of pilot decision making in this multi-task, control and monitoring situation is presented. An experimental investigation of pilot decision making and the resulting model parameters are discussed.

Lunar Analog

NASA Technical Reports Server (NTRS)

Cromwell, Ronita L.

2009-01-01

In this viewgraph presentation, a ground-based lunar analog is developed for the return of manned space flight to the Moon. The contents include: 1) Digital Astronaut; 2) Bed Design; 3) Lunar Analog Feasibility Study; 4) Preliminary Data; 5) Pre-pilot Study; 6) Selection of Stockings; 7) Lunar Analog Pilot Study; 8) Bed Design for Lunar Analog Pilot.

Study of occupational stress among railway engine pilots

PubMed Central

Kumar, Devesh; Singh, Jai Vir; Kharwar, Poonam S.

2011-01-01

Background: Traffic volume and speed is going to be increased in Indian Railways successively, leading to higher stress in staff connected with train operations. The jobs of railway engine pilots come under the category of high-strain jobs, necessitating a need to conduct multicentric study to unfold the factors associated with occupational stress and organizational strategies. Materials and Methods: Present study covered 185 railway engine pilots and office clerks working in various railway zones by incidental method. Occupational Stress Index (OSI) test developed by Srivastva and Singh, questionnaire of specific stressors constructed by authors and laboratory test battery for psychological screening of high-speed train pilots were used as tools. Results: Means of OSI and all the 12 occupational stressors of railway engine pilots were found significantly higher to that of office clerks. Means of OSI and occupational stressors of goods train pilots were significantly higher in comparison to high-speed train pilots and passenger train pilots. Study revealed positive correlation of speed perception and complex reaction time tests and negative correlation of other constituent tests of laboratory test battery to OSI test. Highest subgroup of stressor observedwas role overload followed by role conflict. Conclusions: These findings provide a prima facie evidence of higher occupational stress among railway engine pilots because of identified specific stressors prevalent in their job and explore the possible intervention strategies for its reduction. Significant correlation is noticed between OSI and laboratory test results, indicating its relevant utility in preliminary psychological screening. PMID:21808497

A simulator evaluation of an automatic terminal approach system

NASA Technical Reports Server (NTRS)

Hinton, D. A.

1983-01-01

The automatic terminal approach system (ATAS) is a concept for improving the pilot/machine interface with cockpit automation. The ATAS can automatically fly a published instrument approach by using stored instrument approach data to automatically tune airplane avionics, control the airplane's autopilot, and display status information to the pilot. A piloted simulation study was conducted to determine the feasibility of an ATAS, determine pilot acceptance, and examine pilot/ATAS interaction. Seven instrument-rated pilots each flew four instrument approaches with a base-line heading select autopilot mode. The ATAS runs resulted in lower flight technical error, lower pilot workload, and fewer blunders than with the baseline autopilot. The ATAS status display enabled the pilots to maintain situational awareness during the automatic approaches. The system was well accepted by the pilots.

Urinary metabolites from mango (Mangifera indica L. cv. Keitt) galloyl derivatives and in vitro hydrolysis of gallotannins in physiological conditions.

PubMed

Barnes, Ryan C; Krenek, Kimberly A; Meibohm, Bernd; Mertens-Talcott, Susanne U; Talcott, Stephen T

2016-03-01

The absorption, metabolism, and excretion of mango galloyl derivatives (GD) has not yet been investigated in humans, and studies investigating repeated dosages of polyphenols are limited. In this human pilot trial, healthy volunteers (age = 21-38 y, n = 11) consumed 400 g/day of mango-pulp (cv. Keitt) for 10 days, and seven metabolites of gallic acid (GA) were characterized and quantified in urine excreted over a 12 h period. Pyrogallol-O-sulfate and deoxypyrogallol-O-sulfate were found to be significantly more excreted between days 1 and 10 (p < 0.05) from 28.5 to 55.4 mg and 23.6 to 47.7 mg, respectively. Additionally, the in vitro hydrolysis of gallotannins (GTs) was monitored at physiological pH and temperature conditions, and after 4 h a significant (p < 0.05) shift in composition from relativity high to low molecular weight GTs was observed. Seven metabolites of GA were identified in the urine of healthy volunteers, and two microbial metabolites were found to be significantly more excreted following 10 days of mango consumption. Mango GTs were also found to release free GA in conditions similar to the intestines. GTs may serve as a pool of pro-GA compounds that can be absorbed or undergo microbial metabolism. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Monitoring brain temperature by time-resolved near-infrared spectroscopy: pilot study

NASA Astrophysics Data System (ADS)

Bakhsheshi, Mohammad Fazel; Diop, Mamadou; St. Lawrence, Keith; Lee, Ting-Yim

2014-05-01

Mild hypothermia (HT) is an effective neuroprotective strategy for a variety of acute brain injuries. However, the wide clinical adaptation of HT has been hampered by the lack of a reliable noninvasive method for measuring brain temperature, since core measurements have been shown to not always reflect brain temperature. The goal of this work was to develop a noninvasive optical technique for measuring brain temperature that exploits both the temperature dependency of water absorption and the high concentration of water in brain (80%-90%). Specifically, we demonstrate the potential of time-resolved near-infrared spectroscopy (TR-NIRS) to measure temperature in tissue-mimicking phantoms (in vitro) and deep brain tissue (in vivo) during heating and cooling, respectively. For deep brain tissue temperature monitoring, experiments were conducted on newborn piglets wherein hypothermia was induced by gradual whole body cooling. Brain temperature was concomitantly measured by TR-NIRS and a thermocouple probe implanted in the brain. Our proposed TR-NIRS method was able to measure the temperature of tissue-mimicking phantoms and brain tissues with a correlation of 0.82 and 0.66 to temperature measured with a thermometer, respectively. The mean difference between the TR-NIRS and thermometer measurements was 0.15°C±1.1°C for the in vitro experiments and 0.5°C±1.6°C for the in vivo measurements.

Should we isolate human preantral follicles before or after cryopreservation of ovarian tissue?

PubMed

Vanacker, Julie; Luyckx, Valérie; Amorim, Christiani; Dolmans, Marie-Madeleine; Van Langendonckt, Anne; Donnez, Jacques; Camboni, Alessandra

2013-04-01

To evaluate the survival and growth potential of human preantral follicles isolated before and after cryopreservation. Pilot study. Gynecology research unit in a university hospital. Six women aged 27 to 32 years. Six ovarian biopsy samples were cut into two equal parts, half subjected to slow-freezing followed by follicle isolation (cryo-iso group) and alginate-matrigel embedding, and half immediately processed for follicle isolation and alginate-matrigel embedding followed by slow-freezing (iso-cryo group) or used as fresh controls (fresh group). Follicle number, viability, diameter, and morphology. After 1,134 preantral follicles had been isolated from fresh biopsy samples and 1,132 from frozen specimens, the three groups were compared before and after 7 days of in vitro culture (IVC) in alginate-matrigel beads. No statistically significant differences in viability were found between the three groups before or after IVC, but follicle diameter increased in all three groups after IVC. Morphology analysis revealed well-preserved follicles in both the iso-cryo and cryo-iso groups after IVC. Human preantral follicles can be successfully cryopreserved before or after isolation without impairing their ability to survive and grow in vitro. This could lead to development of new protocols for follicle cryopreservation, IVC, and grafting in clinical and research settings for fertility preservation. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

A pilot study investigating lactic acid bacterial symbionts from the honeybee in inhibiting human chronic wound pathogens.

PubMed

Butler, Éile; Oien, Rut F; Lindholm, Christina; Olofsson, Tobias C; Nilson, Bo; Vásquez, Alejandra

2016-10-01

Treatment and management of chronic wounds is a large burden on the health sector and causes substantial suffering for the patients. We believe that 13 lactic acid bacteria (LAB) symbionts isolated from the honey crop of the honeybee are important players in the antimicrobial action of honey, by producing antimicrobial substances and can be used in combination with heather honey as an effective treatment in wound management. A total of 22 patients with chronic ulcers were included; culture-dependent and molecular-based (MALDI-MS and 16S rRNA gene sequencing) techniques were used to identify bacteria from chronic wounds. These clinical isolates were used for in vitro antimicrobial testing with standardised viable LAB and sterilised heather honey mixture. Twenty of the patients' wounds were polymicrobial and 42 different species were isolated. Patient isolates that were tested in vitro were inhibited by the LAB and honey combination with inhibitory zones comparable with different antibiotics. LAB and heather honey in combination presents a new topical option in chronic wound management because of the healing properties of honey, antimicrobial metabolite production from the LAB and their bactericidal effect on common chronic wound pathogens. This new treatment may be a stepping stone towards an alternative solution to antibiotics. © 2014 The Authors. International Wound Journal © 2014 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Treatment of textile wastewater by submerged membrane bioreactor: In vitro bioassays for the assessment of stress response elicited by raw and reclaimed wastewater.

PubMed

Friha, Inès; Bradai, Mohamed; Johnson, Daniel; Hilal, Nidal; Loukil, Slim; Ben Amor, Fatma; Feki, Firas; Han, Junkuy; Isoda, Hiroko; Sayadi, Sami

2015-09-01

The performance of a pilot-scale membrane bioreactor (MBR) system for the treatment of textile wastewater was investigated. The MBR was continuously operated for 7 months. Very high treatment efficiencies were achieved (color, 100%; chemical oxygen demand (COD), 98%; biochemical oxygen demand (BOD5), 96%; suspended solids (SS), 100%). Furthermore, the MBR treatment efficiency was analyzed from a toxicological-risk assessment point of view, via different In vitro bioassays using Caco-2 cells, a widely used cell model in toxicological studies. Results showed that MBR treatment significantly reduced the raw textile wastewater (RTWW) cytotoxicity on Caco-2 cells by 53% for a hydraulic retention time (HRT) of 2 days. Additionally, the RTWW-induced disruption in the barrier function (BF) of the Caco-2 cell monolayer was also significantly reduced after MBR treatment under a HRT of 2 days (no disruption of BF was observed). Moreover, the effect of RTWW and treated wastewater on stress response was investigated using different stress genes: AHSA1, HSPD1, HSPA1A, HSPA5 and HSPA8. The cell exposure to RTWW significantly increased the expression of all used stress genes; interestingly, the treated wastewater (HRT 2 days) did not show any significant modulation of the stress genes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Revised NEO Personality Inventory profiles of male and female U.S. Air Force pilots.

PubMed

Callister, J D; King, R E; Retzlaff, P D; Marsh, R W

1999-12-01

The study of pilot personality characteristics has a long and controversial history. Personality characteristics seem to be fairly poor predictors of training outcome; however, valid personality assessment is essential to clinical psychological evaluations. Therefore, the personality characteristics of pilots must be studied to ensure valid clinical assessment. This paper describes normative personality characteristics of U.S. Air Force pilots based on the Revised NEO Personality Inventory profiles of 1,301 U.S. Air Force student pilots. Compared with male adult norms, male student pilots had higher levels of extraversion and lower levels of agreeableness. Compared with female adult norms, female student pilots had higher levels of extraversion and openness and lower levels of agreeableness. Descriptive statistics and percentile tables for the five domain scores and 30 facet scores are provided for clinical use, and a case vignette is provided as an example of the clinical utility of these U.S. Air Force norms.

Head positioning for high +Gz loads: an analysis of the techniques used by F/A-18 pilots.

PubMed

Newman, D G

1997-08-01

A study was undertaken among Royal Australian Air Force fighter pilots to determine whether, as an occupational group, they had developed any particular protective head positioning strategies in order to minimize their risk of sustaining a +Gz-induced neck injury during air combat maneuvering. There were 42 F/A-18 Hornet pilots who responded to an anonymous questionnaire which asked about head positioning strategies. Of these, 29 pilots reported using a protective strategy. Several pilots reported using several different techniques. The most popular strategy reported was positioning the head prior to the application of +Gz (13 respondents). Eleven pilots reported using aircraft structures to wedge or brace their heads against. The results of this study show that fighter pilots who are regularly exposed to high +Gz forces develop an individualized approach to protecting their cervical spines from +Gz-induced injury.

Effects of hydration on cognitive function of pilots.

PubMed

Lindseth, Paul D; Lindseth, Glenda N; Petros, Thomas V; Jensen, Warren C; Caspers, Julie

2013-07-01

The objective of this study was to examine the effect of fluid intake and possible dehydration on cognitive flight performance of pilots. A repeated-measures, counterbalanced, mixed study design was used to examine differences in working memory, spatial orientation, and cognitive flight performance of 40 randomly selected healthy pilots after having high and low fluid intakes. Serial weights were also analyzed to determine differences in cognitive flight performance of the dehydrated (1-3% weight loss) and hydrated study participants. Results showed flight performance and spatial cognition test scores were significantly (p < 0.05) poorer for pilots who had low fluid intakes and experienced dehydration in comparison to the hydrated pilots. These findings indicate fluid intake differences resulting in dehydration may have safety implications because peak cognitive performance among pilots is critical for flight safety. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

Pilot Age and Error in Air-Taxi Crashes

PubMed Central

Rebok, George W.; Qiang, Yandong; Baker, Susan P.; Li, Guohua

2010-01-01

Introduction The associations of pilot error with the type of flight operations and basic weather conditions are well documented. The correlation between pilot characteristics and error is less clear. This study aims to examine whether pilot age is associated with the prevalence and patterns of pilot error in air-taxi crashes. Methods Investigation reports from the National Transportation Safety Board for crashes involving non-scheduled Part 135 operations (i.e., air taxis) in the United States between 1983 and 2002 were reviewed to identify pilot error and other contributing factors. Crash circumstances and the presence and type of pilot error were analyzed in relation to pilot age using Chi-square tests. Results Of the 1751 air-taxi crashes studied, 28% resulted from mechanical failure, 25% from loss of control at landing or takeoff, 7% from visual flight rule conditions into instrument meteorological conditions, 7% from fuel starvation, 5% from taxiing, and 28% from other causes. Crashes among older pilots were more likely to occur during the daytime rather than at night and off airport than on airport. The patterns of pilot error in air-taxi crashes were similar across age groups. Of the errors identified, 27% were flawed decisions, 26% were inattentiveness, 23% mishandled aircraft kinetics, 15% mishandled wind and/or runway conditions, and 11% were others. Conclusions Pilot age is associated with crash circumstances but not with the prevalence and patterns of pilot error in air-taxi crashes. Lack of age-related differences in pilot error may be attributable to the “safe worker effect.” PMID:19601508

Human risk factors associated with pilots in runway excursions.

PubMed

Chang, Yu-Hern; Yang, Hui-Hua; Hsiao, Yu-Jung

2016-09-01

A breakdown analysis of civil aviation accidents worldwide indicates that the occurrence of runway excursions represents the largest portion among all aviation occurrence categories. This study examines the human risk factors associated with pilots in runway excursions, by applying a SHELLO model to categorize the human risk factors and to evaluate the importance based on the opinions of 145 airline pilots. This study integrates aviation management level expert opinions on relative weighting and improvement-achievability in order to develop four kinds of priority risk management strategies for airline pilots to reduce runway excursions. The empirical study based on experts' evaluation suggests that the most important dimension is the liveware/pilot's core ability. From the perspective of front-line pilots, the most important risk factors are the environment, wet/containment runways, and weather issues like rain/thunderstorms. Finally, this study develops practical strategies for helping management authorities to improve major operational and managerial weaknesses so as to reduce the human risks related to runway excursions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of the use of a nonlinear, rate limited, filter on pilot control signals

NASA Technical Reports Server (NTRS)

Adams, J. J.

1977-01-01

The use of a filter on the pilot's control output could improve the performance of the pilot-aircraft system. What is needed is a filter with a sharp high frequency cut-off, no resonance peak, and a minimum of lag at low frequencies. The present investigation studies the usefulness of a nonlinear, rate limited, filter in performing the needed function. The nonlinear filter is compared with a linear, first order filter, and no filter. An analytical study using pilot models and a simulation study using experienced test pilots was performed. The results showed that the nonlinear filter does promote quick, steady maneuvering. It is shown that the nonlinear filter attenuates the high frequency remnant and adds less phase lag to the low frequency signal than does the linear filter. It is also shown that the rate limit in the nonlinear filter can be set to be too restrictive, causing an unstable pilot-aircraft system response.

Airplane pilot mental health and suicidal thoughts: a cross-sectional descriptive study via anonymous web-based survey.

PubMed

Wu, Alexander C; Donnelly-McLay, Deborah; Weisskopf, Marc G; McNeely, Eileen; Betancourt, Theresa S; Allen, Joseph G

2016-12-15

The Germanwings Flight 9525 crash has brought the sensitive subject of airline pilot mental health to the forefront in aviation. Globally, 350 million people suffer from depression-a common mental disorder. This study provides further information on this important topic regarding mental health especially among female airline pilots. This is the first study to describe airline pilot mental health-with a focus on depression and suicidal thoughts-outside of the information derived from aircraft accident investigations, regulated health examinations, or identifiable self-reports, which are records protected by civil aviation authorities and airline companies. This is a descriptive cross-sectional study via an anonymous web-based survey administered between April and December 2015. Pilots were recruited from unions, airline companies, and airports via convenience sampling. Data analysis included calculating absolute number and prevalence of health characteristics and depression scores. One thousand eight hundred thirty seven (52.7%) of the 3485 surveyed pilots completed the survey, with 1866 (53.5%) completing at least half of the survey. 233 (12.6%) of 1848 airline pilots responding to the Patient Health Questionnaire 9 (PHQ-9), and 193 (13.5%) of 1430 pilots who reported working as an airline pilot in the last seven days at time of survey, met depression threshold-PHQ-9 total score ≥ 10. Seventy-five participants (4.1%) reported having suicidal thoughts within the past two weeks. We found a significant trend in proportions of depression at higher levels of use of sleep-aid medication (trend test z = 6.74, p < 0.001) and among those experiencing sexual harassment (z = 3.18, p = 0.001) or verbal harassment (z = 6.13, p < 0.001). Hundreds of pilots currently flying are managing depressive symptoms perhaps without the possibility of treatment due to the fear of negative career impacts. This study found 233 (12.6%) airline pilots meeting depression threshold and 75 (4.1%) pilots reporting having suicidal thoughts. Although results have limited generalizability, there are a significant number of active pilots suffering from depressive symptoms. We recommend airline organizations increase support for preventative mental health treatment. Future research will evaluate additional risk factors of depression such as sleep and circadian rhythm disturbances.

Identification of Centella asiatica's Effective Ingredients for Inducing the Neuronal Differentiation.

PubMed

Jiang, Hui; Zheng, Guoshuai; Lv, Junwei; Chen, Heyu; Lin, Jinjin; Li, Yiyang; Fan, Guorong; Ding, Xianting

2016-01-01

Centella asiatica, commonly known as Gotu kola, has been widely used as a traditional herb for decades. Yet, the study on which compounds or compound combinations actually lead to its brain benefits remains scarce. To study the neuroprotection effects of Centella asiatica, neuronal differentiation of PC12 cells was applied. In our pilot study, we isolated 45 Centella asiatica fractions and tested their abilities for inducing neuronal differentiation on PC12 cells. The most effective fraction showed robust induction in neurite outgrowth and neurofilament expression. LC-MS fingerprint analysis of this fraction revealed asiatic acid and madecassic acid as the dominant components. A further investigation on the pure combination of these two compounds indicated that the combination of these two compounds extensively promoted nerve differentiation in vitro. Application of PD98059, a protein MEK inhibitor, attenuated combination-induced neurofilament expression, indicating the combination-induced nerve differentiation through activation of MEK signaling pathway. Our results support the use of combination of asiatic acid and madecassic acid as an effective mean to intervene neurodegenerative diseases in which neurotrophin deficiency is involved.

Identification of Centella asiatica's Effective Ingredients for Inducing the Neuronal Differentiation

PubMed Central

Jiang, Hui; Zheng, Guoshuai; Lv, Junwei; Chen, Heyu; Lin, Jinjin; Li, Yiyang; Fan, Guorong

2016-01-01

Centella asiatica, commonly known as Gotu kola, has been widely used as a traditional herb for decades. Yet, the study on which compounds or compound combinations actually lead to its brain benefits remains scarce. To study the neuroprotection effects of Centella asiatica, neuronal differentiation of PC12 cells was applied. In our pilot study, we isolated 45 Centella asiatica fractions and tested their abilities for inducing neuronal differentiation on PC12 cells. The most effective fraction showed robust induction in neurite outgrowth and neurofilament expression. LC-MS fingerprint analysis of this fraction revealed asiatic acid and madecassic acid as the dominant components. A further investigation on the pure combination of these two compounds indicated that the combination of these two compounds extensively promoted nerve differentiation in vitro. Application of PD98059, a protein MEK inhibitor, attenuated combination-induced neurofilament expression, indicating the combination-induced nerve differentiation through activation of MEK signaling pathway. Our results support the use of combination of asiatic acid and madecassic acid as an effective mean to intervene neurodegenerative diseases in which neurotrophin deficiency is involved. PMID:27446228

Pilot Convective Weather Decision Making in En Route Airspace

NASA Technical Reports Server (NTRS)

Wu, Shu-Chieh; Gooding, Cary L.; Shelley, Alexandra E.; Duong, Constance G.; Johnson, Walter W.

2012-01-01

The present research investigates characteristics exhibited in pilot convective weather decision making in en route airspace. In a part-task study, pilots performed weather avoidance under various encounter scenarios. Results showed that the margins of safety that pilots maintain from storms are as fluid as deviation decisions themselves.

Pilot age and expertise predict flight simulator performance: a 3-year longitudinal study.

PubMed

Taylor, Joy L; Kennedy, Quinn; Noda, Art; Yesavage, Jerome A

2007-02-27

Expert knowledge may compensate for age-related declines in basic cognitive and sensory-motor abilities in some skill domains. We investigated the influence of age and aviation expertise (indexed by Federal Aviation Administration pilot ratings) on longitudinal flight simulator performance. Over a 3-year period, 118 general aviation pilots aged 40 to 69 years were tested annually, in which their flight performance was scored in terms of 1) executing air-traffic controller communications; 2) traffic avoidance; 3) scanning cockpit instruments; 4) executing an approach to landing; and 5) a flight summary score. More expert pilots had better flight summary scores at baseline and showed less decline over time. Secondary analyses revealed that expertise effects were most evident in the accuracy of executing aviation communications, the measure on which performance declined most sharply over time. Regarding age, even though older pilots initially performed worse than younger pilots, over time older pilots showed less decline in flight summary scores than younger pilots. Secondary analyses revealed that the oldest pilots did well over time because their traffic avoidance performance improved more vs younger pilots. These longitudinal findings support previous cross-sectional studies in aviation as well as non-aviation domains, which demonstrated the advantageous effect of prior experience and specialized expertise on older adults' skilled cognitive performances.

Feasibility and Pilot Studies in Palliative Care Research: A Systematic Review.

PubMed

Jones, Terry A; Olds, Timothy S; Currow, David C; Williams, Marie T

2017-07-01

Feasibility and pilot study designs are common in palliative care research. Finding standard guidelines on the structure and reporting of these study types is difficult. In feasibility and pilot studies in palliative care research, to determine 1) how commonly a priori feasibility are criteria reported and whether results are subsequently reported against these criteria? and 2) how commonly are participants' views on acceptability of burden of the study protocol assessed? Four databases (OVID Medline, EMBASE, CINAHL, and PubMed via caresearch.com.au.) were searched. Search terms included palliative care, terminal care, advance care planning, hospice, pilot, feasibility, with a publication date between January 1, 2012 and December 31, 2013. Articles were selected and appraised by two independent reviewers. Fifty-six feasibility and/or pilot studies were included in this review. Only three studies had clear a priori criteria to measure success. Sixteen studies reported participant acceptability or burden with measures. Forty-eight studies concluded feasibility. The terms "feasibility" and "pilot" are used synonymously in palliative care research when describing studies that test for feasibility. Few studies in palliative care research outline clear criteria for success. The assessment of participant acceptability and burden is uncommon. A gold standard for feasibility study design in palliative care research that includes both clear criteria for success and testing of the study protocol for participant acceptability and burden is needed. Such a standard would assist with consistency in the design, conduct and reporting of feasibility and pilot studies. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Intelligent Pilot Aids for Flight Re-Planning in Emergencies

NASA Technical Reports Server (NTRS)

Pritchett, Amy R.; Ockerman, Jennifer

2005-01-01

Effective and safe control of an aircraft may be difficult or nearly impossible for a pilot following an unexpected system failure. Without prior training, the pilot must ascertain on the fly those changes in both manual control technique and procedures that will lead to a safe landing of the aircraft. Sophisticated techniques for determining the required control techniques are now available. Likewise, a body of literature on pilot decision making provides formalisms for examining how pilots approach discrete decisions framed as the selection between options. However, other aspects of behavior, such as the task of route planning and guidance, are not as well studied. Not only is the pilot faced with possible performance changes to the aircraft dynamics, but he or she is also tasked to create a plan of actions that will effectively take the aircraft down to a safe landing. In this plan, the many actions that the pilot can perform are closely intertwined with the trajectory of the aircraft, making it difficult to accurately predict the final outcome. Coupled with the vast number of potential actions to be taken, this problem may seem intractable. This is reflected in the lack of a pre-specified procedure capable of giving pilots the ability to find a resolution for this task. This report summarizes a multi-year effort to examine methods to aid pilots in planning an approach and arrival to an airport following an aircraft systems failure. Ultimately, we hypothesize that automatic assistance to pilots can be provided in real-time in the form of improving pilot control of a damaged aircraft and providing pilots with procedural directives suitable for critical flight conditions; such systems may also benefit pilot training and procedure design. To achieve this result, a systematic, comprehensive research program was followed, building on prior research. This approach included a pencil-and-paper study with airline pilots examining methods of representing a flight route in an immediately understandable manner, and in a manner that would allow the pilot to modify an automatically-generated route and/or detect any inappropriate elements in an automatically-generated route. Likewise, a flight simulator study examined different cockpit systems for the relative merits of providing pilots with any of a variety of automated functions for emergency flight planning. The results provide specific guidance for the design of such systems.

Airline Pilot Cosmic Radiation and Circadian Disruption Exposure Assessment from Logbooks and Company Records

PubMed Central

Grajewski, Barbara; Waters, Martha A.; Yong, Lee C.; Tseng, Chih-Yu; Zivkovich, Zachary; Cassinelli II, Rick T.

2011-01-01

Objectives: US commercial airline pilots, like all flight crew, are at increased risk for specific cancers, but the relation of these outcomes to specific air cabin exposures is unclear. Flight time or block (airborne plus taxi) time often substitutes for assessment of exposure to cosmic radiation. Our objectives were to develop methods to estimate exposures to cosmic radiation and circadian disruption for a study of chromosome aberrations in pilots and to describe workplace exposures for these pilots. Methods: Exposures were estimated for cosmic ionizing radiation and circadian disruption between August 1963 and March 2003 for 83 male pilots from a major US airline. Estimates were based on 523 387 individual flight segments in company records and pilot logbooks as well as summary records of hours flown from other sources. Exposure was estimated by calculation or imputation for all but 0.02% of the individual flight segments’ block time. Exposures were estimated from questionnaire data for a comparison group of 51 male university faculty. Results: Pilots flew a median of 7126 flight segments and 14 959 block hours for 27.8 years. In the final study year, a hypothetical pilot incurred an estimated median effective dose of 1.92 mSv (absorbed dose, 0.85 mGy) from cosmic radiation and crossed 362 time zones. This study pilot was possibly exposed to a moderate or large solar particle event a median of 6 times or once every 3.7 years of work. Work at the study airline and military flying were the two highest sources of pilot exposure for all metrics. An index of work during the standard sleep interval (SSI travel) also suggested potential chronic sleep disturbance in some pilots. For study airline flights, median segment radiation doses, time zones crossed, and SSI travel increased markedly from the 1990s to 2003 (Ptrend < 0.0001). Dose metrics were moderately correlated with records-based duration metrics (Spearman’s r = 0.61–0.69). Conclusions: The methods developed provided an exposure profile of this group of US airline pilots, many of whom have been exposed to increasing cosmic radiation and circadian disruption from the 1990s through 2003. This assessment is likely to decrease exposure misclassification in health studies. PMID:21610083

Airline pilot cosmic radiation and circadian disruption exposure assessment from logbooks and company records.

PubMed

Grajewski, Barbara; Waters, Martha A; Yong, Lee C; Tseng, Chih-Yu; Zivkovich, Zachary; Cassinelli, Rick T

2011-06-01

US commercial airline pilots, like all flight crew, are at increased risk for specific cancers, but the relation of these outcomes to specific air cabin exposures is unclear. Flight time or block (airborne plus taxi) time often substitutes for assessment of exposure to cosmic radiation. Our objectives were to develop methods to estimate exposures to cosmic radiation and circadian disruption for a study of chromosome aberrations in pilots and to describe workplace exposures for these pilots. Exposures were estimated for cosmic ionizing radiation and circadian disruption between August 1963 and March 2003 for 83 male pilots from a major US airline. Estimates were based on 523 387 individual flight segments in company records and pilot logbooks as well as summary records of hours flown from other sources. Exposure was estimated by calculation or imputation for all but 0.02% of the individual flight segments' block time. Exposures were estimated from questionnaire data for a comparison group of 51 male university faculty. Pilots flew a median of 7126 flight segments and 14 959 block hours for 27.8 years. In the final study year, a hypothetical pilot incurred an estimated median effective dose of 1.92 mSv (absorbed dose, 0.85 mGy) from cosmic radiation and crossed 362 time zones. This study pilot was possibly exposed to a moderate or large solar particle event a median of 6 times or once every 3.7 years of work. Work at the study airline and military flying were the two highest sources of pilot exposure for all metrics. An index of work during the standard sleep interval (SSI travel) also suggested potential chronic sleep disturbance in some pilots. For study airline flights, median segment radiation doses, time zones crossed, and SSI travel increased markedly from the 1990s to 2003 (P(trend) < 0.0001). Dose metrics were moderately correlated with records-based duration metrics (Spearman's r = 0.61-0.69). The methods developed provided an exposure profile of this group of US airline pilots, many of whom have been exposed to increasing cosmic radiation and circadian disruption from the 1990s through 2003. This assessment is likely to decrease exposure misclassification in health studies.

Early Maladaptive Schemas in a Sample of Airline Pilots seeking Residential Substance Use Treatment: An Initial Investigation

PubMed Central

Shorey, Ryan C.; Brasfield, Hope; Anderson, Scott; Stuart, Gregory L.

2014-01-01

Background Recent research has begun to examine the early maladaptive schemas of substance abusers, as it is believed that targeting these core beliefs in treatment may result in improved substance use outcomes. One special population that has received scant attention in the research literature, despite high levels of substance use, is airline pilots. Aims The current study examined the early maladaptive schemas of a sample of airline pilots (n = 64) who were seeking residential treatment for alcohol dependence and whether they differed in early maladaptive schemas from non-pilot substance abusers who were also seeking residential treatment for alcohol dependence (n = 45). Method Pre-existing medical records from patients of a residential substance abuse treatment facility were reviewed for the current study. Results Of the 18 early maladaptive schemas, results demonstrated that pilots scored higher than non-pilots on the early maladaptive schema of unrelenting standards (high internalized standards of behavior), whereas non-pilots scored higher on insufficient self-control (low frustration tolerance and self-control). Conclusions Early maladaptive schemas may be a relevant treatment target for substance abuse treatment seeking pilots and non-pilots. PMID:24701252

Report of ejections in the Spanish Air Force, 1979-1995: an epidemiological and comparative study.

PubMed

Moreno Vázquez, J M; Durán Tejeda, M R; García Alcón, J L

1999-07-01

Ejection seats have saved many lives with more than 80% of pilots having survived an ejection. Nevertheless, ejection injuries are seen in all modern air forces. An epidemiological study has been carried out on the 48 ejections made by the Spanish Air Force (SpAF) from 1979-1995. From data facilitated by the Flight Safety Section of the SpAF Staff, by the Flight Safety Section of Squadrons, and from personal reports of pilots who survived ejections a form was created. Relationships between data concerning aeronautical parameters, pilot data and injuries have been found, and a comparative study was made between these results and data shown by air forces of other countries. Of 48 pilots who ejected, 7 died, 25 had severe injuries, 11 had minor injuries and 5 had no injuries. The reason for the ejections included 35 cases of technical failure, and 13 cases of human error. Of 43 surviving pilots, 23 were injured only at the egress phase, 1 1 only at landing, and 9 cases at both moments. None of the five pilots who ejected outside the ejection envelope were able to adopt the correct position. However, of 43 pilots who ejected within the envelope, 19 were seated in good position. Of 13 pilots who maintained control of the airplane, 9 were able to adopt a correct position. Of 35 pilots who effected the ejection without control of the aircraft, 25 were not able to achieve a correct seated position. The pilot position in the ejection seat, plane control, ejection inside the envelope, the pilot's training in how to assume the necessary body position at both egress and landing phases are determining factors for successful ejections.

Wound-healing potential of human umbilical cord blood-derived mesenchymal stromal cells in vitro--a pilot study.

PubMed

You, Hi-Jin; Namgoong, Sik; Han, Seung-Kyu; Jeong, Seong-Ho; Dhong, Eun-Sang; Kim, Woo-Kyung

2015-11-01

Our previous studies demonstrated that human bone marrow-derived mesenchymal stromal cells have great potential for wound healing. However, it is difficult to clinically utilize cultured stem cells. Recently, human umbilical cord blood-derived mesenchymal stromal cells (hUCB-MSCs) have been commercialized for cartilage repair as a first cell therapy product that uses allogeneic stem cells. Should hUCB-MSCs have a superior effect on wound healing as compared with fibroblasts, which are the main cell source in current cell therapy products for wound healing, they may possibly replace fibroblasts. The purpose of this in vitro study was to compare the wound-healing activity of hUCB-MSCs with that of fibroblasts. This study was particularly designed to compare the effect of hUCB-MSCs on diabetic wound healing with those of allogeneic and autologous fibroblasts. Healthy (n = 5) and diabetic (n = 5) fibroblasts were used as the representatives of allogeneic and autologous fibroblasts for diabetic patients in the control group. Human UCB-MSCs (n = 5) were used in the experimental group. Cell proliferation, collagen synthesis and growth factor (basic fibroblast growth factor, vascular endothelial growth factor and transforming growth factor-β) production were compared among the three cell groups. Human UCB-MSCs produced significantly higher amounts of vascular endothelial growth factor and basic fibroblast growth factor when compared with both fibroblast groups. Human UCB-MSCs were superior to diabetic fibroblasts but not to healthy fibroblasts in collagen synthesis. There were no significant differences in cell proliferation and transforming growth factor-β production. Human UCB-MSCs may have greater capacity for diabetic wound healing than allogeneic or autologous fibroblasts, especially in angiogenesis. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Cardiac responses to long duration and high magnitude +Gz exposure in pilots: an observational study.

PubMed

Öztürk, Cengiz; İlbasmış, M Savaş; Akın, Ahmet

2012-12-01

In military aviation, high performance aircraft pilots are exposed to +Gz acceleration at longer durations and higher magnitude than transport/helicopter pilots. The purpose of this study was to reveal the negative or positive cardiac responses to this occupational high +Gz exposure. Our study design was cross-sectional and observational. We have evaluated 21 echocardiographic parameters of 63 pilots who applied for aircrew periodic medical examination. Of 63 pilots, 33 were grouped as high performance aircraft pilots group (Group A) and 30 were grouped as control group (Group B) whose aircraft type was transport or helicopter. Means of demographic and echocardiography parameters between two groups were compared statistically with Student's t-test, Mann- Whitney U or Chi-square test as appropriate. Among all echocardiographic parameters, mean TV A (tricuspid valve peak velocity during late diastolic filling) was significantly higher and TV E (peak velocity during early diastolic filling)/ A ratio was significantly lower for Group A pilots (p<0.05). In Group A pilots, mean TV A and TV E/A ratio were (52.12 ± 13.85) and (1.36 ± 0.30) respectively. In Group B pilots, mean TV A and TV E/A ratio were (42.61 ± 6.42) and (1.53 ± 0.20) respectively (p=0.001 for TVA and p=0.005 for TV E/A). Mean pulmonary artery pressure (PAP) of Group A pilots (32.04 ± 9.09) was higher than Group B pilots (28.76 ± 7.9) but it was not statistically significant (p>0.05). We conclude that according to the results of our study, long term +Gz exposure has no effects on cardiac morphologic and systolic functions but has effects on right ventricular diastolic functions. We have considered that these effects may be a result of chronic +Gz adaptation or high PAP levels.

Dietary Effects on Cognition and Pilots' Flight Performance.

PubMed

Lindseth, Glenda N; Lindseth, Paul D; Jensen, Warren C; Petros, Thomas V; Helland, Brian D; Fossum, Debra L

2011-01-01

The purpose of this study was to investigate the effects of diet on cognition and flight performance of 45 pilots. Based on a theory of self-care, this clinical study used a repeated-measure, counterbalanced crossover design. Pilots were randomly rotated through 4-day high-carbohydrate, high-protein, high-fat, and control diets. Cognitive flight performance was evaluated using a GAT-2 full-motion flight simulator. The Sternberg short-term memory test and Vandenberg's mental rotation test were used to validate cognitive flight test results. Pilots consuming a high-protein diet had significantly poorer ( p < .05) overall flight performance scores than pilots consuming high-fat and high-carbohydrate diets.

Where have all the pilot studies gone? A follow-up on 30 years of pilot studies in Clinical Rehabilitation

PubMed Central

Kaur, Navaldeep; Figueiredo, Sabrina; Bouchard, Vanessa; Moriello, Carolina; Mayo, Nancy

2017-01-01

Introduction: Pilot studies are meritorious for determining the feasibility of a definitive clinical trial in terms of conduct and potential for efficacy, but their possible applications for planning a future trial are not always fully realized. The purpose of this review was to estimate the extent to which pilot/feasibility studies: (i) addressed needed objectives; (ii) led to definitive trials; and (iii) whether the subsequent undertaking of a definitive trial was influenced by the strength of the evidence of outcome improvement. Methods: Trials published in the journal Clinical Rehabilitation, since its inception, were eligible if the word ‘pilot’ or ‘feasibility’ was specified somewhere in the article. A total of 191 studies were reviewed, results were summarized descriptively, and between-group effect sizes were computed. Results: The specific purposes of piloting were stated in only 58% (n = 110) of the studies. The most frequent purpose was to estimate the potential for efficacy (85%), followed by testing the feasibility of the intervention (60%). Only 12% of the studies were followed by a definitive trial; <4% of studies had a main study underway or a published study protocol. There was no relationship between observed effect size and follow-up of pilot studies, although the confidence intervals were very wide owing to small number of trials that followed on. Discussion: Labelling and reporting of pilot studies needs to be improved to be concordant with the recently issued CONSORT guidelines. Feasibility needs to be fully tested and demonstrated prior to committing considerable human and monetary resources. PMID:28786333

Pilot Decision-Making in Irreversible Emergencies

ERIC Educational Resources Information Center

Winter, Scott R.

2013-01-01

The purpose of this study was to determine if a reflexive learning treatment utilizing select case studies could enhance the decision-making of pilots who encounter an irreversible emergency. Participants, who consisted of members of the subject university's professional pilot program, were divided into either a control or experimental group and…

77 FR 69658 - Agency Information Collection Activities; Proposed Collection; Comment Request: Generic Clearance...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-20

... Activities; Proposed Collection; Comment Request: Generic Clearance for Cognitive, Pilot and Field Studies...) Title of the Form/Collection: BJS Generic Clearance for Cognitive, Pilot, and Field Test Studies. (3... respondents will be involved in exploratory, field test, pilot, cognitive, and focus group work conducted...

A Study of Longitudinal Control Problems at Low and Negative Damping and Stability with Emphasis on Effects of Motion Cues

NASA Technical Reports Server (NTRS)

Sadoff, Melvin; McFadden, Norman M.; Heinle, Donovan R.

1961-01-01

As part of a general investigation to determine the effects of simulator motions on pilot opinion and task performance over a wide range of vehicle longitudinal dynamics, a cooperative NASA-AMAL program was conducted on the centrifuge at Johnsville, Pennsylvania. The test parameters and measurements for this program duplicated those of earlier studies made at Ames Research Center with a variable-stability airplane and with a pitch-roll chair flight simulator. Particular emphasis was placed on the minimum basic damping and stability the pilots would accept and on the minimum dynamics they considered controllable in the event of stability-augmentation system failure. Results of the centrifuge-simulator program indicated that small positive damping was required by the pilots over most of the frequency range covered for configurations rated acceptable for emergency conditions only (e.g., failure of a pitch damper). It was shown that the pilot's tolerance for unstable dynamics was dependent primarily on the value of damping. For configurations rated acceptable for emergency operation only, the allowable instability and damping corresponded to a divergence time to double amplitude of about 1 second. Comparisons were made of centrifuge, pitch-chair and fixed-cockpit simulator tests with flight tests. Pilot ratings indicated that the effects of incomplete or spurious motion cues provided by these three modes of simulation were important only for high-frequency, lightly damped dynamics or unstable, moderately damped dynamics. The pitch- chair simulation, which provided accurate angular-acceleration cues to the pilot, compared most favorably with flight. For the centrifuge simulation, which furnished accurate normal accelerations but spurious pitching and longitudinal accelerations, there was a deterioration of pilots' opinion relative to flight results. Results of simulator studies with an analog pilot replacing the human pilot illustrated the adaptive capability of human pilots in coping with the wide range of vehicle dynamics and the control problems covered in this study. It was shown that pilot-response characteristics, deduced by the analog-pilot method, could be related to pilot opinion. Possible application of these results for predicting flight-control problems was illustrated by means of an example control-problem analysis. The results of a brief evaluation of a pencil-type side-arm controller in the centrifuge showed a considerable improvement in the pilots' ability to cope with high-frequency, low-damping dynamics, compared to results obtained with the center stick. This improvement with the pencil controller was attributed primarily to a marked reduction in the adverse effects of large and exaggerated pitching and longitudinal accelerations on pilot control precision.

Field Collection Methods for an EPA Pilot Study Evaluating Personal, Housing, and Community Factors Influencing Children’s Potential Exposures to Indoor Contaminants at Various Lifestages (EPA Pilot Study Add-On to the GreenHousing Study)

EPA Science Inventory

This compilation of field collection standard operating procedures (SOPs) was assembled for the U.S. Environmental Protection Agency’s (EPA) Pilot Study add-on to the Green Housing Study (GHS). A detailed description of this add-on study can be found in the peer reviewed research...

Effects of malicious ocular laser exposure in commercial airline pilots.

PubMed

Palakkamanil, Mathew M; Fielden, Michael P

2015-12-01

Intentional malicious laser strikes on commercial pilots are committed by individuals who target a laser into airplane cockpits during takeoff and landing. Because laser exposure to pilots is a relatively new but growing occurrence, our study investigates the ocular effect of this laser exposure in pilots. Retrospective chart review by a single ophthalmologist. All commercial airline pilots (58 male, 3 female) who experienced a laser strike while flying between April 2012 and November 2014 who presented to our clinic were included. A retrospective chart review was performed in a retinal specialist's practice. Ocular assessment was performed within 3 days of laser exposure. A complete ophthalmic evaluation was conducted, including Early Treatment Diabetic Retinopathy Study visual acuity, colour vision, visual fields, intraocular pressure, slit-lamp examination, dilated fundus examination, colour fundus photographs, and ocular coherence tomography. Sixty-four laser strike incidents involving commercial pilots were included. All pilots in the study experienced some degree of immediate ocular irritation or light sensitivity. No definite cases of ocular damage were attributed to laser strikes. No pilot had any functional ocular deficits. Our study revealed that laser strikes on aircraft did not result in permanent visual functional or structural deficits. However, laser strikes cause immediate visual effects, including glare, flash blindness, and ocular irritation that can interfere with a pilot's visual function. Given the widespread accessibility of high-power lasers and the rapid increase in incidents, laser strikes threaten to jeopardize aviation safety unless effective preventative measures are put in place. Copyright © 2015 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

Neo-Institutional Analysis on Response Patterns of Pilot Schools

ERIC Educational Resources Information Center

Shin, Chol-Kyun

2016-01-01

This study examines response patterns of pilot schools in the neo-institutional perspective to make improvements on the pilot school systematic framework. In order to achieve this goal, in-depth interviews were conducted to obtain qualitative data. The results show that pilot schools either (a) actively adopt or (b) ceremonially adopt an education…

Pilot-Reported Beta-Blockers Identified by Forensic Toxicology Analysis of Postmortem Specimens.

PubMed

Canfield, Dennis V; Dubowski, Kurt M; Whinnery, James M; Forster, Estrella M

2018-01-01

This study compared beta-blockers reported by pilots with the medications found by postmortem toxicology analysis of specimens received from fatal aviation accidents between 1999 and 2015. Several studies have compared drugs using the standard approach: Compare the drug found by toxicology analysis with the drug reported by the pilot. This study uniquely examined first the pilot-reported medication and then compared it to that detected by toxicology analysis. This study will serve two purposes: (i) to determine the capability of a toxicology laboratory to detect reported medications, and (ii) to identify pilots with medications below detectable limits. All information required for this study was extracted from the Toxicology Data Base system and was searched using ToxFlo or SQL Server Management Studio. The following information was collected and analyzed: pilot-reported trade and/or generic drug, date specimens received, time of accident, type of aviation operations (CFR), state, pilot level, age, class of medical, specimen type, specimen concentration, dose reported, frequency reported associated with the accident, quantity reported, National Transportation Safety Board (NTSB) accident event number, and all NTSB reports. There were 319 pilots that either reported taking a beta-blocker or were found to be taking a beta-blocker by postmortem toxicology analysis. Time of death, therapeutic concentration and specimen type were found to be factors in the ability of the laboratory to detect beta-blockers. Beta-blockers taken by pilots will, in most cases, be found by a competent postmortem forensic toxicology laboratory at therapeutic concentrations. The dose taken by the pilot was not found to be a factor in the ability of the laboratory to identify beta-blockers. Time of dose, route of administration, specimen tested and therapeutic concentration of the drug were found to be factors in the ability of the laboratory to identify beta-blockers in postmortem specimens. Published by Oxford University Press 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Relationship between day 1 and day 2 Vancomycin area under the curve values and emergence of heterogeneous Vancomycin-intermediate Staphylococcus aureus (hVISA) by Etest® macromethod among patients with MRSA bloodstream infections: a pilot study.

PubMed

Martirosov, Dmitriy M; Bidell, Monique R; Pai, Manjunath P; Scheetz, Marc H; Rosenkranz, Susan L; Faragon, Corey; Malik, M; Mendes, R E; Jones, R N; McNutt, Louise-Anne; Lodise, Thomas P

2017-08-02

In vitro data suggests that suboptimal initial vancomycin exposure may select for heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) infections. However, no clinical studies have evaluated the relationship between initial vancomycin exposure and emergence of hVISA. This pilot study seeks to assess the relationship between day 1 and day 2 vancomycin area under the curve (AUC) and emergence of hVISA bloodstream infections (BSIs) by Etest® macromethod among patients with a non-hVISA BSI at baseline. This was a retrospective cohort study of patients with methicillin-resistant Staphylococcus aureus (MRSA) BSIs at Albany Medical Center Hospital (AMCH) between January 2005 and June 2009. The vancomycin AUC exposure variables on day 1 (AUC 0-24h ) and day 2 (AUC 24-48h ) were estimated using the maximal a posteriori probability (MAP) procedure in ADAPT 5. There were 238 unique episodes of MRSA BSIs during the study period, 119 of which met inclusion criteria. Overall, hVISA emerged in 7/119 (5.9%) of patients. All 7 cases of hVISA involved patients who did not achieve area under the curve over broth microdilution minimum inhibitory concentration (AUC 0-24h /MIC BMD ) ratio of 521 or an AUC 24-48h /MIC BMD ratio of 650. No associations between other day 1 and day 2 AUC variables and emergence of hVISA were noted. Although more data are needed to draw definitive conclusions, these findings suggest that hVISA emergence among patients with non-hVISA MRSA BSIs at baseline may be partially explained by suboptimal exposure to vancomycin in the first 1 to 2 days of therapy. At a minimum, these findings support further study of the relationship between initial vancomycin exposure and hVISA emergence among patients with MRSA BSIs in a well-powered, multi-center, prospective trial.

Cosmic Radiation and Cataracts in Airline Pilots

NASA Astrophysics Data System (ADS)

Rafnsson, V.; Olafsdottir, E.; Hrafnkelsson, J.; de Angelis, G.; Sasaki, H.; Arnarson, A.; Jonasson, F.

Nuclear cataracts have been associated with ionising radiation exposure in previous studies. A population based case-control study on airline pilots has been performed to investigate whether employment as a commercial pilot and consequent exposure to cosmic radiation were associated to lens opacification, when adjusted for known risk factors for cataracts. Cases of opacification of the ocular lens were found in surveys among pilots and a random sample of the Icelandic population. Altogether 445 male subjects underwent a detailed eye examination and answered a questionnaire. Information from the airline company on the 79 pilots employment time, annual hours flown per aircraft type, the timetables and the flight profiles made calculation of individual cumulated radiation dose (mSv) possible. Lens opacification were classified and graded according to WHO simplified cataracts grading system using slit lamp. The odds ratio from logistic regression of nuclear cataracts risk among cases and controls was 3.02 (95% CI 1.44 to 6.35) for pilots compared with non-pilots, adjusted for age, smoking and sunbathing habits, whereas that of cortical cataracts risk among cases and controls was lower than unity (non significant) for pilots compared with non-pilots in a logistic regression analysis adjusted for same factors. Length of employment as a pilot and cumulated radiation dose (mSv) were significantly related to the risk of nuclear cataracts. So the association between radiation exposure of pilots and the risk of nuclear cataracts, adjusted for age, smoking and sunbathing habits, indicates that cosmic radiation may be cause of nuclear cataract among commercial pilots.

Defining Feasibility and Pilot Studies in Preparation for Randomised Controlled Trials: Development of a Conceptual Framework

PubMed Central

Eldridge, Sandra M.; Lancaster, Gillian A.; Campbell, Michael J.; Thabane, Lehana; Hopewell, Sally; Coleman, Claire L.; Bond, Christine M.

2016-01-01

We describe a framework for defining pilot and feasibility studies focusing on studies conducted in preparation for a randomised controlled trial. To develop the framework, we undertook a Delphi survey; ran an open meeting at a trial methodology conference; conducted a review of definitions outside the health research context; consulted experts at an international consensus meeting; and reviewed 27 empirical pilot or feasibility studies. We initially adopted mutually exclusive definitions of pilot and feasibility studies. However, some Delphi survey respondents and the majority of open meeting attendees disagreed with the idea of mutually exclusive definitions. Their viewpoint was supported by definitions outside the health research context, the use of the terms ‘pilot’ and ‘feasibility’ in the literature, and participants at the international consensus meeting. In our framework, pilot studies are a subset of feasibility studies, rather than the two being mutually exclusive. A feasibility study asks whether something can be done, should we proceed with it, and if so, how. A pilot study asks the same questions but also has a specific design feature: in a pilot study a future study, or part of a future study, is conducted on a smaller scale. We suggest that to facilitate their identification, these studies should be clearly identified using the terms ‘feasibility’ or ‘pilot’ as appropriate. This should include feasibility studies that are largely qualitative; we found these difficult to identify in electronic searches because researchers rarely used the term ‘feasibility’ in the title or abstract of such studies. Investigators should also report appropriate objectives and methods related to feasibility; and give clear confirmation that their study is in preparation for a future randomised controlled trial designed to assess the effect of an intervention. PMID:26978655

A study on aircraft map display location and orientation

NASA Technical Reports Server (NTRS)

Baty, D. L.; Wempe, T.; Huff, E.

1973-01-01

Six airline pilots participated in a fixed-based simulator study to determine the effects of two horizontal situation display (HSD/map) panel locations relative to the vertical situation display (VSD), and of three map orientations on manual piloting performance. Pilot comments and opinions were formally obtained. Significant performance differences were found between wind conditions and among pilots but not between map locations and orientations. The results also illustrate the potential tracking accuracy of such a display. Recommendations concerning display location and map orientation are made.

Visual cues to geographical orientation during low-level flight

NASA Technical Reports Server (NTRS)

Battiste, Vernol; Delzell, Suzanne

1991-01-01

A field study of an operational Emergency Medical Service (EMS) unit was conducted to investigate the relationships among geographical orientation, pilot decision making, and workload in EMS flights. The map data collected during this study were compared to protocols gathered in the laboratory, where pilots viewed a simulated flight over different types of unfamiliar terrain and verbally identified the features utilized to maintain geographical orientation. The EMS pilot's questionnaire data were compared with data from non-EMS helicopter pilots with comparable flight experience.

A study on aircraft map display location and orientation

NASA Technical Reports Server (NTRS)

Baty, D. L.; Wempe, T. E.; Huff, E. M.

1974-01-01

Six airline pilots participated in a fixed-base simulator study to determine the effects of two horizontal situation display (HSD/map) panel locations relative to the vertical situation display (VSD), and of three map orientations on manual piloting performance. Pilot comments and opinions were formally obtained. Significant performance differences were found between wind conditions and among pilots, but not between map locations and orientations. The results also illustrate the potential tracking accuracy of such a display. Recommendations concerning display location and map orientation are made.

The Internet and Some International Regulatory Issues Relating to Content: A Pilot Comparative Study.

ERIC Educational Resources Information Center

Australian Broadcasting Authority.

In December 1996 UNESCO commissioned the Australian Broadcasting Authority to conduct a pilot study which considered a range of online issues; this report outlines the findings of the pilot study, based on data collected between February and May 1997 and updated in July 1997. The objective is to identify the main types of Internet content which…

Assessing five pilot carbon trading programs in China from a perspective of efficiency analysis

NASA Astrophysics Data System (ADS)

Yu, Xianyu; Shi, Guo; Wang, Jinghan

2018-02-01

In order to overcome the challenge of growing carbon emissions in China, the pilot carbon emissions trading systems (ETSs) serve as precursors of the national carbon ETS. Five province-level pilot ETSs in Beijing, Tianjin, Shanghai, Guangdong and Hubei are assessed from the view of carbon emission efficiency analysis in this study. Firstly, both the environmental production technology and the Malmquist index are adopted to evaluate the carbon emission efficiency of 28 provinces in China. Then, the regression significance analysis of carbon emission efficiency and the operational information evaluation for pilot ETSs are combined to develop an integrated approach for assessing five considered pilot ETSs. The Efficiency analysis of carbon emissions indicate that the effect of ETS in Beijing is significant, the effect of ETS in Tianjin is weak significant, and those of the other three pilot ETSs are not significant. Based on the operational information for pilot ETSs, the evaluating results of pilot ETSs in Beijing and Hubei are better than those of other pilot ETSs. This study highlights two main findings. First, the pilot ETS in Beijing has better performance than the other considered pilot ETSs, and its operational experience should be promoted throughout the country to improve the construction of national carbon ETS. Second, the successful cooperation between the ETSs in Beijing and Tianjin implies that the regional cooperation among neighbouring ETSs should be encouraged and further implemented to enhance the overall performance of the regional ETSs.

Flight Simulator Visual-Display Delay Compensation

NASA Technical Reports Server (NTRS)

Crane, D. Francis

1981-01-01

A piloted aircraft can be viewed as a closed-loop man-machine control system. When a simulator pilot is performing a precision maneuver, a delay in the visual display of aircraft response to pilot-control input decreases the stability of the pilot-aircraft system. The less stable system is more difficult to control precisely. Pilot dynamic response and performance change as the pilot attempts to compensate for the decrease in system stability. The changes in pilot dynamic response and performance bias the simulation results by influencing the pilot's rating of the handling qualities of the simulated aircraft. The study reported here evaluated an approach to visual-display delay compensation. The objective of the compensation was to minimize delay-induced change in pilot performance and workload, The compensation was effective. Because the compensation design approach is based on well-established control-system design principles, prospects are favorable for successful application of the approach in other simulations.

The size of a pilot study for a clinical trial should be calculated in relation to considerations of precision and efficiency.

PubMed

Sim, Julius; Lewis, Martyn

2012-03-01

To investigate methods to determine the size of a pilot study to inform a power calculation for a randomized controlled trial (RCT) using an interval/ratio outcome measure. Calculations based on confidence intervals (CIs) for the sample standard deviation (SD). Based on CIs for the sample SD, methods are demonstrated whereby (1) the observed SD can be adjusted to secure the desired level of statistical power in the main study with a specified level of confidence; (2) the sample for the main study, if calculated using the observed SD, can be adjusted, again to obtain the desired level of statistical power in the main study; (3) the power of the main study can be calculated for the situation in which the SD in the pilot study proves to be an underestimate of the true SD; and (4) an "efficient" pilot size can be determined to minimize the combined size of the pilot and main RCT. Trialists should calculate the appropriate size of a pilot study, just as they should the size of the main RCT, taking into account the twin needs to demonstrate efficiency in terms of recruitment and to produce precise estimates of treatment effect. Copyright © 2012 Elsevier Inc. All rights reserved.

Pilots' monitoring strategies and performance on automated flight decks: an empirical study combining behavioral and eye-tracking data.

PubMed

Sarter, Nadine B; Mumaw, Randall J; Wickens, Christopher D

2007-06-01

The objective of the study was to examine pilots' automation monitoring strategies and performance on highly automated commercial flight decks. A considerable body of research and operational experience has documented breakdowns in pilot-automation coordination on modern flight decks. These breakdowns are often considered symptoms of monitoring failures even though, to date, only limited and mostly anecdotal data exist concerning pilots' monitoring strategies and performance. Twenty experienced B-747-400 airline pilots flew a 1-hr scenario involving challenging automation-related events on a full-mission simulator. Behavioral, mental model, and eye-tracking data were collected. The findings from this study confirm that pilots monitor basic flight parameters to a much greater extent than visual indications of the automation configuration. More specifically, they frequently fail to verify manual mode selections or notice automatic mode changes. In other cases, they do not process mode annunciations in sufficient depth to understand their implications for aircraft behavior. Low system observability and gaps in pilots' understanding of complex automation modes were shown to contribute to these problems. Our findings describe and explain shortcomings in pilot's automation monitoring strategies and performance based on converging behavioral, eye-tracking, and mental model data. They confirm that monitoring failures are one major contributor to breakdowns in pilot-automation interaction. The findings from this research can inform the design of improved training programs and automation interfaces that support more effective system monitoring.

An investigation into pilot and system response to critical in-flight events. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

Rockwell, T. H.; Griffin, W. C.

1981-01-01

Critical in-flight events (CIFE) that threaten the aircraft were studied. The scope of the CIFE was described and defined with emphasis on characterizing event development, detection and assessment; pilot information requirements, sources, acquisition, and interpretation, pilot response options, decision processed, and decision implementation and event outcome. Detailed scenarios were developed for use in simulators and paper and pencil testing for developing relationships between pilot performance and background information as well as for an analysis of pilot reaction decision and feedback processes. Statistical relationships among pilot characteristics and observed responses to CIFE's were developed.

Operational problems experienced by single pilots in instrument meteorological conditions

NASA Technical Reports Server (NTRS)

Weislogel, S.

1981-01-01

The development and implementation of a search strategy to extract pertinent reports from the Aviation Safety Reporting System-2 (ASRS-2) database are described. For any particular occurence to be pertinent to the study, it must have satisfied the following conditions: the aircraft must be of the type usually flown by a single pilot; operation on an IFR flight plan in instrument meteorological conditions; pilot experienced an operational problem. The occurances consist of reports by the pilot about his own performance, by the pilot about the system performance, or by an air traffic controller about a pilot's performance.

75 FR 75725 - Financial Management Service; Proposed Collection of Information: Tax Time Card Account Pilot...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-06

... Information: Tax Time Card Account Pilot, Screening, Focus Groups, and Study AGENCY: Financial Management... general public and other Federal agencies to take this opportunity to comment on a continuing information... Account Pilot Screening, Focus Groups, and Study.'' DATES: Written comments should be received on or...

PILOT-SCALE STUDIES ON THE EFFECT OF BROMINE ADDITION ON THE EMISSIONS OF CHLORINATED ORGANIC COMBUSTION BY-PRODUCTS

EPA Science Inventory

The paper reports on a study to evaluate organic combustion by-product emissions while feeding varying amounts of bromine (Br) and chlorine (Cl) into a pilot-scale incinerator burning surrogate waste materials. (NOTE: Adding brominated organic compounds to a pilot-scale incinerat...

Final Report of NATO/SPS Pilot Study on Clean Products and Processes (Phase I and II)

EPA Science Inventory

Early in 1998 the NATO Committee for Challenges to Modern Society (SPS) (Science for Peace and Security) approved the Pilot Study on Clean Products and Processes for an initial period of five years. The pilot was to provide a forum for member country representatives to discuss t...

Fixed-Base Simulator Studies of the Ability of the Human Pilot to Provide Energy Management Along Abort and Deep-Space Entry Trajectories

NASA Technical Reports Server (NTRS)

Young, J. W.; Goode, M. W.

1962-01-01

A simulation study has been made to determine a pilot's ability to control a low L/D vehicle to a desired point on the earth with initial conditions ranging from parabolic orbits to abort conditions along the boost phase of a deep-space mission. The program was conducted to develop procedures which would allow the pilot to perform the energy management functions required while avoiding the high deceleration or skipout region and to determine the information display required to aid the pilot in flying these procedures. The abort conditions studied extend from a region of relatively high flight-path angles at suborbital velocities while leaving the atmosphere to a region between orbital and near-escape velocity outside the atmosphere. The conditions studied included guidance from suborbital and superorbital aborts as well as guidance following return from a deepspace mission. In this paper, the role of the human pilot?s ability to combine safe return abort procedures with guidance procedures has been investigated. The range capability from various abort and entry conditions is also presented.

Manpower Projections, Recruitment Needs and Training Requirements for Commercial Airline Pilots in the United States 1968-1979.

ERIC Educational Resources Information Center

Simons, Robert Marchand

This study evaluated the reported airline pilot shortage in relation to certified air carriers; recruitment needs for qualified applicants; training requirements as recommended by air carriers, airline captains, and flight officers; and airline pilot supply and demand during 1968-79. A literature review on foreign and domestic pilot shortages was…

THE EFFECTIVENESS OF PILOT PROGRAMS COMPARED TO OTHER PROGRAMS OF VOCATIONAL AGRICULTURE IN TENNESSEE.

ERIC Educational Resources Information Center

LEGG, OTTO

THE OBJECTIVE OF THIS COMPARATIVE STUDY WAS TO EVALUATE THE RELATIVE EFFECTIVENESS OF TENNESSEE VOCATIONAL AGRICULTURE PROGRAMS IN FOUR CATEGORIES -- (1) PILOT SCHOOLS, (2) LIKE-PILOT SCHOOLS OR SCHOOLS RESEMBLING PILOT SCHOOLS, (3) STUDENT TEACHING CENTERS, AND (4) NEGRO SCHOOLS. THE RANDOM SAMPLE INCLUDED 800 STUDENTS FROM 20 SCHOOLS DIVIDED…

Investigating the impact of the properties of pilot points on calibration of groundwater models: case study of a karst catchment in Rote Island, Indonesia

NASA Astrophysics Data System (ADS)

Klaas, Dua K. S. Y.; Imteaz, Monzur Alam

2017-09-01

A robust configuration of pilot points in the parameterisation step of a model is crucial to accurately obtain a satisfactory model performance. However, the recommendations provided by the majority of recent researchers on pilot-point use are considered somewhat impractical. In this study, a practical approach is proposed for using pilot-point properties (i.e. number, distance and distribution method) in the calibration step of a groundwater model. For the first time, the relative distance-area ratio ( d/ A) and head-zonation-based (HZB) method are introduced, to assign pilot points into the model domain by incorporating a user-friendly zone ratio. This study provides some insights into the trade-off between maximising and restricting the number of pilot points, and offers a relative basis for selecting the pilot-point properties and distribution method in the development of a physically based groundwater model. The grid-based (GB) method is found to perform comparably better than the HZB method in terms of model performance and computational time. When using the GB method, this study recommends a distance-area ratio of 0.05, a distance-x-grid length ratio ( d/ X grid) of 0.10, and a distance-y-grid length ratio ( d/ Y grid) of 0.20.

The impact of transition training on adapting to Technically Advanced Aircraft at regional airlines: Perceptions of pilots and instructor pilots

NASA Astrophysics Data System (ADS)

di Renzo, John Carl, Jr.

Scope and method of study. The purpose of this study was to test a hypothesis about pilot and instructor pilot perceptions of how effectively pilots learn and use new technology, found in Technically Advanced Aircraft (TAA), given initial type of instrumentation training. New aviation technologies such as Glass Cockpits in technically advanced aircraft are complex and can be difficult to learn and use. The research questions focused on the type of initial instrumentation training to determine the differences among pilots trained using various types of instrumentation ranging from aircraft equipped with traditional analog instrumentation to aircraft equipped with glass cockpits. A convenience sample of Pilots in Training (PT) and Instructor Pilots (IP) was selected from a regional airline. The research design used a mixed methodology. Pilots in training completed a thirty-two question quantitative questionnaire and instructor pilots completed a five question qualitative questionnaire. Findings and conclusions. This investigation failed to disprove the null hypothesis. The type of instrumentation training has no significant effect on newly trained regional airline pilot perceived ability to adapt to advanced technology cockpits. Therefore, no evidence exists from this investigation to support the early introduction and training of TAA. While the results of this investigation were surprising, they are nonetheless, instructive. Even though it would seem that there would be a relationship between exposure to and use of technically advanced instrumentation, apparently there was no perceived relationship for this group of airline transport pilots. However, a point of interest is that these pilots were almost evenly divided in their opinion of whether or not their previous training had prepared them for transition to TAA. The majority also believed that the type of initial instrumentation training received does make a difference when transitioning to TAA. Pilots believed that TAA made them safer pilots, but were not convinced it made them better pilots. The results of this investigation raise many new questions and provide a number of ideas for future research projects.

A mixed method pilot study: the researchers' experiences.

PubMed

Secomb, Jacinta M; Smith, Colleen

2011-08-01

This paper reports on the outcomes of a small well designed pilot study. Pilot studies often disseminate limited or statistically meaningless results without adding to the body knowledge on the comparative research benefits. The design a pre-test post-test group parallel randomised control trial and inductive content analysis of focus group transcripts was tested specifically to increase outcomes in a proposed larger study. Strategies are now in place to overcome operational barriers and recruitment difficulties. Links between the qualitative and quantitative arms of the proposed larger study have been made; it is anticipated that this will add depth to the final report. More extensive reporting on the outcomes of pilot studies would assist researchers and increase the body of knowledge in this area.

Successful implementation of clinical practice guidelines for pressure risk management in a home nursing setting.

PubMed

Kapp, Suzanne

2013-10-01

This paper reports an initiative which promoted evidence-based practice in pressure risk assessment and management among home nursing clients in Melbourne, Australia. The aim of this study was to evaluate the introduction and uptake of the Australian Wound Management Association Guidelines for the Prediction and Prevention of Pressure Ulcers. In 2007 a pilot study was conducted. Nurse perspectives (n=21) were obtained via survey and a client profile (n=218) was generated. Audit of the uptake and continued use of the pressure risk screening tool, during the pilot study and later once implemented as standard practice organizational wide, was conducted. Nurses at the pilot site successfully implemented the practice guidelines, pressure risk screening was adopted and supporting resources were well received. Most clients were at low risk of pressure ulcer development. The pilot site maintained and extended their pilot study success, ensuring more than 90% of clients were screened for pressure risk over the 18 months which followed. All other sites performed less well initially, however subsequently improved, meeting the pilot sites success after 18 months. Two years later, the organization continues to screen more than 90% of all clients for pressure risk. Implementation of clinical practice guidelines was successful in the pilot project and pressure risk screening became a well-adopted practice. Success continued following organizational wide implementation. Pilot study findings suggest it may be prudent to monitor the pressure ulcer risk status of low risk clients so as to prevent increasing risk and pressure ulcer development among this group. © 2012 John Wiley & Sons Ltd.

Structural Differences in Gray Matter between Glider Pilots and Non-Pilots. A Voxel-Based Morphometry Study

PubMed Central

Ahamed, Tosif; Kawanabe, Motoaki; Ishii, Shin; Callan, Daniel E.

2014-01-01

Glider flying is a unique skill that requires pilots to control an aircraft at high speeds in three dimensions and amidst frequent full-body rotations. In the present study, we investigated the neural correlates of flying a glider using voxel-based morphometry. The comparison between gray matter densities of 15 glider pilots and a control group of 15 non-pilots exhibited significant gray matter density increases in left ventral premotor cortex, anterior cingulate cortex, and the supplementary eye field. We posit that the identified regions might be associated with cognitive and motor processes related to flying, such as joystick control, visuo-vestibular interaction, and oculomotor control. PMID:25506339

Analysis of aircraft longitudinal handling qualities

NASA Technical Reports Server (NTRS)

Hess, R. A.

1981-01-01

The optimal control model (OCM) of the human pilot is applied to the study of aircraft handling qualities. Attention is focused primarily on longitudinal tasks. The modeling technique differs from previous applications of the OCM in that considerable effort is expended in simplifying the pilot/vehicle analysis. After briefly reviewing the OCM, a technique for modeling the pilot controlling higher order systems is introduced. Following this, a simple criterion for determining the susceptibility of an aircraft to pilot induced oscillations (PIO) is formulated. Finally, a model-based metric for pilot rating prediction is discussed. The resulting modeling procedure provides a relatively simple, yet unified approach to the study of a variety of handling qualities problems.

[Adaptive process in Vietnamese military pilots during the flights on modern Russian aircraft].

PubMed

Ushakov, I V; Pham Xuan, Nihn; Bukhtiaiarov, I V; Ushakov, B N

2013-04-01

Study on health status of 156 Vietnamese military pilots on Russian modern jet planes (Su-22, Su-27, Su-30, MiG-21B). The results showed that unprofitable factors in working environment (acceleration, radiation, high temperature, humidity, noise) have an impact on the health of pilots during the flight, leading to deterioration of professional health and physiological functions (cardiovascular, respiratory and nervous system) and obesity of pilots after 35 years old. Basing on the studies, we suggested some measures for health protecting, safety of flight and prolonging flight-activity of pilots (training in decompression chamber, vestibular training) and balance in food ration for prevention of professional diseases.

Structural Differences in Gray Matter between Glider Pilots and Non-Pilots. A Voxel-Based Morphometry Study.

PubMed

Ahamed, Tosif; Kawanabe, Motoaki; Ishii, Shin; Callan, Daniel E

2014-01-01

Glider flying is a unique skill that requires pilots to control an aircraft at high speeds in three dimensions and amidst frequent full-body rotations. In the present study, we investigated the neural correlates of flying a glider using voxel-based morphometry. The comparison between gray matter densities of 15 glider pilots and a control group of 15 non-pilots exhibited significant gray matter density increases in left ventral premotor cortex, anterior cingulate cortex, and the supplementary eye field. We posit that the identified regions might be associated with cognitive and motor processes related to flying, such as joystick control, visuo-vestibular interaction, and oculomotor control.

Pilot interaction with cockpit automation - Operational experiences with the Flight Management System

NASA Technical Reports Server (NTRS)

Sarter, Nadine B.; Woods, David D.

1992-01-01

Results are presented of two studies on the potential effect of cockpit automation on the pilot's performance, which provide data on pilots' difficulties with understanding and operating one of the core systems of cockpit automation, the Flight Management System (FMS). The results of both studies indicate that, although pilots do become proficient in standard FMS operations through ground training and subsequent flight experience, they still have difficulties tracking the FMS status and behavior in certain flight contexts and show gaps in the understanding of the functional structure of the system. The results suggest that design-related factors such as opaque interfaces contribute to these difficulties, which can affect the pilot's situation awareness.

Training General Aviation Pilots for Convective Weather Situations.

PubMed

Blickensderfer, Elizabeth L; Lanicci, John M; Vincent, Michael J; Thomas, Robert L; Smith, MaryJo; Cruit, Jessica K

2015-10-01

Over the past 10-15 yr, considerable research has occurred for the development, testing, and fielding of real-time Datalink weather products for general aviation (GA) pilots to use before and during flight. As is the case with the implementation of most new technologies, work is needed to ensure that the users (in this case, the pilots) understand both the capabilities and limitations of the new technologies as well as how to use the new systems to improve their task performance. The purpose of this study was to replicate and extend a previous study on training pilots how and when to use these new weather technologies. This field study used a quasi-experimental design (pre- vs. post-test with a control group). There were 91 GA pilots from the Midwest, Northeastern, and Southeastern United States who participated in a 2-h short course or a control activity. The lecture-based short course covered radar basics, Next Generation Weather Radar (NEXRAD), NEXRAD specifics/limitations, thunderstorm basics, radar products, and decision making. The pilots who participated in the course earned higher knowledge test scores, improved at applying the concepts in paper-based flight scenarios, had higher self-efficacy in post-training assessments as compared to pre-training assessments, and also performed better than did control subjects on post-test knowledge and skills assessments. GA pilots lack knowledge about real-time Datalink weather technology. This study indicates that a relatively short training program was effective for fostering Datalink weather-related knowledge and skills in GA pilots.

Occupational Stress and Hypertension among Railway Loco Pilots and Section Controllers.

PubMed

Jayakumar, Devasigamoney

2017-01-01

A cross-sectional study on occupational stress was conducted on loco pilots in 2008, in view of loco pilots being one of the high strain jobs in Indian Railways. Subsequently, a comparative cross-sectional study on occupational stress was conducted among section controllers in 2011, which is another high strain job of Indian Railways. The studies were conducted to analyze and compare occupational stress and hypertension. A cross-sectional study on occupational stress and hypertension was conducted among 230 loco pilots in 2008, and subsequently, a comparative cross-sectional study was conducted among 82 section controllers in 2011. A closed end 24 item questionnaire on occupational stress was administered. Systolic blood pressure above 140 mmHg and diastolic blood pressure above 90 mmHg were considered as hypertension as per the VII Joint National Committee. Chi-square test and t -test were used for testing significance at P < 0.05. The mean stress score was 8.56 in loco pilots and 7.32 in section controllers. The number of loco pilots with more than 12 stress factors was 49 (21.3%) and the number of section controllers with more than 12 stress factors was 7 (8.5%). The number employees with more than 12 stress factors in different categories of loco pilots were 30 (32%) in the goods category, 12 (12%) in the mail/passenger category, and 7 (19%) in the shunter category, and 3 (11%) in the supervisory category and 4 (7%) in the on-board category of section controllers. The prevalence of hypertension in loco pilots was 36.52% (84) and in the section controllers was 53.66% (44). The prevalence of hypertension in the category with more than 12 stress factors was 30.61% (15) in the loco pilots and 28.57% (2) in the section controllers. The prevalence of hypertension in the both the study groups were higher in the older age, with a family history of hypertension, and with a body mass index of more than 25 kg/m 2 . The mean occupational stress and employees with more than 12 stress factors were higher in the loco pilots group. The goods category of loco pilots had highest stress factors. The prevalence of hypertension was high in the category with risk factors such as older age, family history of hypertension and BMI above 25 kg/m 2 .

Fighting Off Wound Pathogens in Horses with Honeybee Lactic Acid Bacteria.

PubMed

Olofsson, Tobias C; Butler, Éile; Lindholm, Christina; Nilson, Bo; Michanek, Per; Vásquez, Alejandra

2016-10-01

In the global perspective of antibiotic resistance, it is urgent to find potent topical antibiotics for the use in human and animal infection. Healing of equine wounds, particularly in the limbs, is difficult due to hydrostatic factors and exposure to environmental contaminants, which can lead to heavy bio-burden/biofilm formation and sometimes to infection. Therefore, antibiotics are often prescribed. Recent studies have shown that honeybee-specific lactic acid bacteria (LAB), involved in honey production, and inhibit human wound pathogens. The aim of this pilot study was to investigate the effects on the healing of hard-to-heal equine wounds after treatment with these LAB symbionts viable in a heather honey formulation. For this, we included ten horses with wound duration of >1 year, investigated the wound microbiota, and treated wounds with the novel honeybee LAB formulation. We identified the microbiota using MALDI-TOF mass spectrometry and DNA sequencing. In addition, the antimicrobial properties of the honeybee LAB formulation were tested against all wound isolates in vitro. Our results indicate a diverse wound microbiota including fifty-three bacterial species that showed 90 % colonization by at least one species of Staphylococcus. Treatment with the formulation promoted wound healing in all cases already after the first application and the wounds were either completely healed (n = 3) in less than 20 days or healing was in progress. Furthermore, the honeybee LAB formulation inhibited all pathogens when tested in vitro. Consequently, this new treatment option presents as a powerful candidate for the topical treatment of hard-to-heal wounds in horses.

Prenatal Exposure to Urban Air Nanoparticles in Mice Causes Altered Neuronal Differentiation and Depression-Like Responses

PubMed Central

Godar, Sean C.; Sander, Thomas K.; Iwata, Nahoko; Pakbin, Payam; Shih, Jean C.; Berhane, Kiros; McConnell, Rob; Sioutas, Constantinos

2013-01-01

Emerging evidence suggests that excessive exposure to traffic-derived air pollution during pregnancy may increase the vulnerability to neurodevelopmental alterations that underlie a broad array of neuropsychiatric disorders. We present a mouse model for prenatal exposure to urban freeway nanoparticulate matter (nPM). In prior studies, we developed a model for adult rodent exposure to re-aerosolized urban nPM which caused inflammatory brain responses with altered neuronal glutamatergic functions. nPMs are collected continuously for one month from a local freeway and stored as an aqueous suspension, prior to re-aerosolization for exposure of mice under controlled dose and duration. This paradigm was used for a pilot study of prenatal nPM impact on neonatal neurons and adult behaviors. Adult C57BL/6J female mice were exposed to re-aerosolized nPM (350 µg/m3) or control filtered ambient air for 10 weeks (3×5 hour exposures per week), encompassing gestation and oocyte maturation prior to mating. Prenatal nPM did not alter litter size, pup weight, or postnatal growth. Neonatal cerebral cortex neurons at 24 hours in vitro showed impaired differentiation, with 50% reduction of stage 3 neurons with long neurites and correspondingly more undifferentiated neurons at Stages 0 and 1. Neuron number after 24 hours of culture was not altered by prenatal nPM exposure. Addition of exogenous nPM (2 µg/ml) to the cultures impaired pyramidal neuron Stage 3 differentiation by 60%. Adult males showed increased depression-like responses in the tail-suspension test, but not anxiety-related behaviors. These pilot data suggest that prenatal exposure to nPM can alter neuronal differentiation with gender-specific behavioral sequelae that may be relevant to human prenatal exposure to urban vehicular aerosols. PMID:23734187

Pilot Biofeedback Training in the Cognitive Awareness Training Study (CATS)

NASA Technical Reports Server (NTRS)

Uenking, M.

2000-01-01

One of the ongoing problems that pilots face today is a diminished state of awareness such as boredom, sleepiness, or fatigue during cruise conditions that could result in various pilot errors. This study utilized a cognitive training exercise to sharpen the pilot's awareness during simulated flight thereby providing them with a means to overcome these diminished states of awareness. This study utilizes psychophysiological methods in an attempt to assess a pilot's state of awareness more directly. In turn, the pilots will be able to train themselves to recognize these states of awareness and be more mentally sharp during mundane tasks such as those experienced in cruise conditions. The use of these measurement tools may be beneficial for researchers working within the NASA Aviation Safety Program. This paper will provide the reader with some background information concerning the motivation for the study, a brief description of the experimental setup and design matrix, the dependent and independent variables that were employed, and some preliminary findings based on some of the subjective and objective data that was collected. These preliminary findings are of part of an ongoing study being conducted at the NASA Langley Research Center in Hampton, Virginia.

Occupational cosmic radiation exposure in Portuguese airline pilots: study of a possible correlation with oxidative biological markers.

PubMed

Silva, Rodrigo; Folgosa, Filipe; Soares, Paulo; Pereira, Alice S; Garcia, Raquel; Gestal-Otero, Juan Jesus; Tavares, Pedro; Gomes da Silva, Marco D R

2013-05-01

Several studies have sought to understand the health effects of occupational exposure to cosmic radiation. However, only few biologic markers or associations with disease outcomes have so far been identified. In the present study, 22 long- and 26 medium-haul male Portuguese airline pilots and 36 factory workers who did not fly regularly were investigated. The two groups were comparable in age and diet, were non-smokers, never treated with ionizing radiation and other factors. Cosmic radiation exposure in pilots was quantified based on direct monitoring of 51 flights within Europe, and from Europe to North and South America, and to Africa. Indirect dose estimates in pilots were performed based on the SIEVERT (Système informatisé d'évaluation par vol de l'exposition au rayonnement cosmique dans les transports aériens) software for 6,039 medium- and 1,366 long-haul flights. Medium-haul pilots had a higher cosmic radiation dose rate than long-haul pilots, that is, 3.3 ± 0.2 μSv/h and 2.7 ± 0.3 μSv/h, respectively. Biological tests for oxidative stress on blood and urine, as appropriate, at two time periods separated by 1 year, included measurements of antioxidant capacity, total protein, ferritin, hemoglobin, creatinine and 8-hydroxy-2-deoxyguanosine (8OHdG). Principal components analysis was used to discriminate between the exposed and unexposed groups based on all the biological tests. According to this analysis, creatinine and 8OHdG levels were different for the pilots and the unexposed group, but no distinctions could be made among the medium- and the long-haul pilots. While hemoglobin levels seem to be comparable between the studied groups, they were directly correlated with ferritin values, which were lower for the airline pilots.

Cross-sectional study of neck pain and cervical sagittal alignment in air force pilots.

PubMed

Moon, Bong Ju; Choi, Kyong Ho; Yun, Chul; Ha, Yoon

2015-05-01

There is a high prevalence of neck pain in air force pilots; however, the causes are not clear and are considered work-related. Kyphotic changes in the cervical spine have been known to cause neck pain. In this study, we investigated the association between neck pain and cervical kyphosis in air force pilots. This is a cross-sectional study of 63 Republic of South Korea Air Force pilots. We examined the C2-7 absolute rotation angle (ARA) using the posterior tangent method and other radiologic parameters on whole spine lateral radiographs. We divided the participants into a neck pain group (N = 32) and no neck pain group (N = 31), and subsequently analyzed the difference in radiographic parameters and clinical data between the two groups. There were no significant differences found in age, body mass index, total flight time, or aerobic or anaerobic exercise between the neck pain and control groups. The fighter pilots had higher 1-yr prevalence of neck pain than nonfighter pilots (84.4% vs. 15.6%). The lower C2-7 ARA (OR = 0.91, 95% CI 0.846, 0.979) and fighter type aircrafts (OR = 3.93, 95% CI 1.104, 13.989) were associated with neck pain. Fighter pilots experienced neck pain more frequently than the nonfighter pilots. Those fighter pilots suffering from neck pain were shown to have more kyphotic changes in the cervical spine than control pilots through evaluation of whole spine lateral radiographs using the posterior tangent method. These key findings suggest that the forces involved in flying a fighter type aircraft may affect cervical alignment and neck pain.

A Pilot Trial of the Combination of Vemurafenib with Adoptive Cell Therapy in Patients with Metastatic Melanoma

PubMed Central

Deniger, Drew C.; Kwong, Mei Li M.; Pasetto, Anna; Dudley, Mark E.; Wunderlich, John R.; Langhan, Michelle M.; Lee, Chyi-Chia Richard; Rosenberg, Steven A.

2016-01-01

Purpose This pilot feasibility clinical trial evaluated the co-administration of vemurafenib, a small molecule antagonist of BRAFV600 mutations, and tumor infiltrating lymphocytes (TIL) for the treatment of metastatic melanoma. Experimental Design A metastatic tumor was resected for growth of TIL and patients were treated with vemurafenib for 2 weeks followed by resection of a second lesion. Patients then received a non-myeloablative pre-conditioning regimen, infusion of autologous TIL and high-dose interleukin-2 administration. Vemurafenib was restarted at the time of TIL infusion and was continued for 2 years or until disease progression. Clinical responses were evaluated by RECIST 1.0. Metastases resected prior to and after two weeks of vemurafenib were compared using TCRB deep sequencing, immunohistochemistry, proliferation and recognition of autologous tumor. Results The treatment was well tolerated and had a safety profile similar to that of TIL or vemurafenib alone. Seven of 11 patients (64%) experienced an objective clinical response and 2 patients (18%) had a complete response for 3 years (one response is ongoing at 46 months). Proliferation and viability of infusion bag TIL and peripheral blood T cells were inhibited in vitro by vemurafenib (PLX4032) when approaching the maximum serum concentration of vemurafenib. TCRB repertoire (clonotypes numbers, clonality and frequency) did not significantly change between pre- and post-vemurafenib lesions. Recognition of autologous tumor by T cells was similar between TIL grown from pre- and post-vemurafenib metastases. Conclusions Co-administration of vemurafenib and TIL was safe, feasible and generated objective clinical responses in this small pilot clinical trial. PMID:28093487

The effects of pilot stress factors on handling quality assessments during US/German helicopter agility flight tests

NASA Technical Reports Server (NTRS)

Pausder, H. J.; Gerdes, R. M.

1982-01-01

Flight tests were conducted with two helicopters to study and evaluate the effects of helicopter characteristics and pilot and task demands on performance in nap-of-the-Earth flight. Different, low-level slalom courses were set up and were flown by three pilots with different levels of flight experience. A pilot rating questionnaire was used to obtain redundant information and to gain more insight into factors that influence pilot ratings. The flight test setups and procedures are described, and the pilot ratings are summarized and interpreted in close connection with the analyzed test data. Pilot stress is discussed. The influence of demands on the pilot, of the helicopter characteristics, and of other stress factors are outlined with particular emphasis on how these factors affect handling-qualities assessment.

Improved oral bioavailability in rats of SR13668, a novel anti-cancer agent.

PubMed

Green, Carol E; Swezey, Robert; Bakke, James; Shinn, Walter; Furimsky, Anna; Bejugam, Naveen; Shankar, Gita N; Jong, Ling; Kapetanovic, Izet M

2011-05-01

SR13668, a bis-indole with potent activity in vitro and in vivo against various cancers and promising cancer chemopreventive activity, was found to have very low oral bioavailability, <1%, in rats during pilot pharmacokinetic studies. The objective of these studies was to better understand the source of low oral exposure and to develop a formulation that could be used in preclinical development studies. An automated screening system for determining solubility in lipid-based vehicles, singly and in combination, was used to identify formulations that might enhance absorption by improving solubility of SR13668, and these results were confirmed in vivo using Sprague-Dawley rats. Pharmacokinetics of SR13668 was then determined in male and female Sprague-Dawley rats administered 1 mg/kg iv, 1, 10, and 30 mg/kg po formulated in PEG400:Labrasol (1:1 v/v). Blood was collected at time points through 24 h and the concentration of SR13668 determined using HPLC with UV and fluorescence detection. SR13668 was found to be resistant to plasma esterases in vitro and relatively stable to rat and human liver microsomal metabolism. SR13668 concentrates in tissues as indicated by significantly higher levels in lung compared to blood, blood concentrations ~2.5-fold higher than plasma levels, and apparent volume of distribution (V) of ~5 l/kg. A marked sex difference was observed in exposure to SR13668 with area under the curve (AUC) significantly higher and clearance (CL) lower for female compared to male rats, after both iv and oral administration. The oral bioavailability (F) of SR13668 was 25.4 ± 3.8 and 27.7 ± 3.9% (30 mg/kg), for males and females, respectively. A putative metabolite (M1), molecular weight of 445 in the negative ion mode (i.e., SR13668 + 16), was identified in blood samples from both the iv and po routes, as well as in vitro microsomal samples. In summary, while SR13668 does undergo metabolism, probably by the liver, the oral bioavailability of SR13668 in rats was dramatically improved by the use of formulation that contained permeation enhancers and promoted better solubilization of the drug.

Enhancing pilot situational awareness of the airport surface movement area

NASA Technical Reports Server (NTRS)

Jones, D. R.; Young, S. D.

1994-01-01

Two studies are being conducted to address airport surface movement area safety and capacity issues by providing enhanced situational awareness information to pilots. One study focuses on obtaining pilot opinion of the Runway Status Light System (RSLS). This system has been designed to reduce the likelihood of runway incursions by informing pilots when a runway is occupied. The second study is a flight demonstration of an rate integrated system consisting of an electronic moving map in the cockpit and display of the aircraft identification to the controller. Taxi route and hold warning information will be sent to the aircraft data link for display on the electronic moving map. This paper describes the plans for the two studies.

The Pilot Training Study: A Cost-Estimating Model for Advanced Pilot Training (APT).

ERIC Educational Resources Information Center

Knollmeyer, L. E.

The Advanced Pilot Training Cost Model is a statement of relationships that may be used, given the necessary inputs, for estimating the resources required and the costs to train pilots in the Air Force formal flying training schools. Resources and costs are computed by weapon system on an annual basis for use in long-range planning or sensitivity…

The Relationship of a Pilot's Educational Background, Aeronautical Experience and Recency of Experience to Performance In Initial Training at a Regional Airline

NASA Astrophysics Data System (ADS)

Shane, Nancy R.

The purpose of this study was to determine how a pilot's educational background, aeronautical experience and recency of experience relate to their performance during initial training at a regional airline. Results show that variables in pilots' educational background, aeronautical experience and recency of experience do predict performance in training. The most significant predictors include years since graduation from college, multi-engine time, total time and whether or not a pilot had military flying experience. Due to the pilot shortage, the pilots entering regional airline training classes since August 2013 have varied backgrounds, aeronautical experience and recency of experience. As explained by Edward Thorndike's law of exercise and the law of recency, pilots who are actively using their aeronautical knowledge and exercising their flying skills should exhibit strong performance in those areas and pilots who have not been actively using their aeronautical knowledge and exercising their flying skills should exhibit degraded performance in those areas. Through correlation, chi-square and multiple regression analysis, this study tests this theory as it relates to performance in initial training at a regional airline.

An Assessment of Teacher Education Students' Perceptions and Satisfaction of Their Learning Experiences in a Summer Pilot Program

ERIC Educational Resources Information Center

Hicks, Terence; Lewis, Leontye; Munn, Geraldine; Jordon, Earlyn; Charles, Kelly

2010-01-01

This study assessed teacher education students' perceptions and satisfaction of their learning experiences concerning an accelerated summer pilot program. In addition, the study provided information on the impact and teaching effectiveness of the accelerated teacher education summer pilot program on participating students. Results from this study…

Supporting Parents to Facilitate Communication and Joint Attention in Their Young Children with Autism Spectrum Disorders: Two Pilot Studies

ERIC Educational Resources Information Center

Prelock, Patricia A.; Calhoun, James; Morris, Hope; Platt, Gretchen

2011-01-01

This article describes 2 pilot studies partnering early interventionists and families in targeting social communication and joint attention abilities for young children with autism spectrum disorders. Both parent-intervention trainings involved opportunities for interventionists to partner with families. One pilot utilized "More than Words" (MTW;…

Testing Telephone and Web Surveys for Studying Men's Sexual Assault Perpetration Behaviors

ERIC Educational Resources Information Center

DiNitto, Diana M.; Busch-Armendariz, Noel Bridget; Bender, Kimberly; Woo, Hyeyoung; Tackett-Gibson, Melissa; Dyer, James

2008-01-01

Three pilot studies were conducted to obtain information about sexual assault perpetration from adult men in the United States. Each used the same random digit-dial sampling and recruitment strategy. One pilot was administered by telephone and two via the Web. Response rates in all pilots were low. Although results cannot be generalized beyond the…

An Exploration of the Importance of Piloting and Access as Action Research

ERIC Educational Resources Information Center

Gudmundsdottir, Greta Bjork; Brock-Utne, Birgit

2010-01-01

In this article we illustrate how the piloting process has influenced two widely different studies within the educational sciences. These studies differ in design but have as a common denominator that they used piloting methods in their preparatory process. They are also similar in the intention of the main researchers of conducting research with…

Evaluation of oral keratinocyte progenitor and T-lymphocite cells response during early healing after augmentation of keratinized gingiva with a 3D collagen matrix - a pilot study.

PubMed

Rusu, Darian; Calenic, Bogdan; Greabu, Maria; Kralev, Alexander; Boariu, Marius; Bojin, Florina; Anghel, Simona; Paunescu, Virgil; Vela, Octavia; Calniceanu, Horia; Stratul, Stefan-Ioan

2016-07-07

The aim of the present study is to analyze the behavior of selected populations of oral keratinocytes and T-lymphocytes, responsible for re-constructing and maintaining the oral epithelial tissue architecture, following augmentation of the keratinized oral mucosa using a 3D-collagen matrix. Different groups of oral keratinocytes were isolated from biopsies harvested from 3 patients before the surgical procedure, as well as 7 and 14 days after the augmentation procedure. T-lymphocytes were isolated from peripheral blood at same timepoints. Keratinocytes were characterized for stem and differentiation markers, such as p63, cytokeratin 10 and 14, and in vitro parameters, such as cell viability, cell size and colony-forming efficiency. T-lymphocytes were analyzed for viability and the expression of various cluster of differentiation markers. The methods included magnetic separation of cell populations, immunofluorescence, flow cytometry, and histology of oral biopsies. Both at 7 and 14 days, the majority of cells that repopulate the matrix were actively proliferating/progenitor oral keratinocytes with the phenotype integrin alfa6beta4 + CD71+. These cells display in vitro characteristics similar to the progenitor cells analyzed before the matrix placement. T-lymphocytes expressed CD8 and CD69 markers, while CD25 was absent. The study shows that two weeks after the collagen membrane placement, the healing process appeared to be histologically complete, with no abnormal immune response induced by the matrix, however, with a higher than usual content of active proliferating cells, the majority of keratinocytes being characterized as transit amplifying cells.

Potential Effects of Aerobic Exercise on the Expression of Perilipin 3 in the Adipose Tissue of Women with Polycystic Ovary Syndrome: A Pilot Study

PubMed Central

Covington, Jeffrey D.; Bajpeyi, Sudip; Moro, Cedric; Tchoukalova, Yourka D.; Ebenezer, Philip J.; Burk, David H.; Ravussin, Eric; Redman, Leanne M.

2014-01-01

Objective Polycystic Ovary Syndrome (PCOS) is associated with reduced adipose tissue lipolysis that can be rescued by aerobic exercise. We aimed to identify differences in gene expression of perilipins and associated targets in adipose tissue in women with PCOS before and after exercise. Design and Methods We conducted a cross-sectional study in 8 women with PCOS and 8 women matched for BMI and age with normal cycles. Women with PCOS also completed a 16-week prospective aerobic exercise-training study. Abdominal subcutaneous adipose tissue biopsies were collected, and primary adipose-derived stromal/stem cell cultures were established from women with PCOS before 16 weeks of aerobic exercise training (n=5) and controls (n=5). Gene expression was measured using real time PCR, in vitro lipolysis was measured using radiolabeled oleate, and PLIN3 protein content was measured by western blotting. Results The expression of PLIN1, PLIN3, and PLIN5, along with coatomers ARF1, ARFRP1, and βCOP were ~80% lower in women with PCOS (all p<0.05). Following exercise training, PLIN3 was the only perilipin to increase significantly (p<0.05), along with coatomers ARF1, ARFRP1, βCOP, and Sec23a (all p<0.05). Furthermore, PLIN3 protein expression was undetectable in the cell cultures from women with PCOS vs. controls. Following exercise training, in vitro adipose oleate oxidation, glycerol secretion, and PLIN3 protein expression were increased, along with reductions in triglyceride content and absence of large lipid droplet morphology. Conclusions These findings suggest that PLIN3 and coatomer GTPases are important regulators of lipolysis and triglyceride storage in the adipose tissue of women with PCOS. PMID:25342854

Clinical Efficacy of a Specifically Targeted Antimicrobial Peptide Mouth Rinse: Targeted Elimination of Streptococcus mutans and Prevention of Demineralization

PubMed Central

Sullivan, R.; Santarpia, P.; Lavender, S.; Gittins, E.; Liu, Z.; Anderson, M.H.; He, J.; Shi, W.; Eckert, R.

2011-01-01

Background/Aims Streptococcus mutans, the major etiological agent of dental caries, has a measurable impact on domestic and global health care costs. Though persistent in the oral cavity despite conventional oral hygiene, S. mutans can be excluded from intact oral biofilms through competitive exclusion by other microorganisms. This suggests that therapies capable of selectively eliminating S. mutans while limiting the damage to the normal oral flora might be effective long-term interventions to fight cariogenesis. To meet this challenge, we designed C16G2, a novel synthetic specifically targeted antimicrobial peptide with specificity for S. mutans. C16G2 consists of a S. mutans-selective ‘targeting region’ comprised of a fragment from S. mutans competence stimulation peptide (CSP) conjoined to a ‘killing region’ consisting of a broad-spectrum antimicrobial peptide (G2). In vitro studies have indicated that C16G2 has robust efficacy and selectivity for S. mutans, and not other oral bacteria, and affects targeted bacteria within seconds of contact. Methods In the present study, we evaluated C16G2 for clinical utility in vitro, followed by a pilot efficacy study to examine the impact of a 0.04% (w/v) C16G2 rinse in an intra-oral remineralization/demineralization model. Results and Conclusions C16G2 rinse usage was associated with reductions in plaque and salivary S. mutans, lactic acid production, and enamel demineralization. The impact on total plaque bacteria was minimal. These results suggest that C16G2 is effective against S. mutans in vivo and should be evaluated further in the clinic. PMID:21860239

FMP study of pilot workload. Qualification of workload via instrument scan

NASA Technical Reports Server (NTRS)

Tolel, J. R.; Vivaudou, M.; Harris, R. L., Sr.; Ephrath, A.

1982-01-01

Various methods of measuring a pilot's mental workload are discussed. Scanning the various flight instruments with good scan pattern and other verbal tasks during instrument landings is given special attention for measuring pilot workload.

A Piloted Simulator Evaluation of Transport Aircraft Rudder Pedal Force/Feel Characteristics

NASA Technical Reports Server (NTRS)

Stewart, Eric C.

2008-01-01

A piloted simulation study has been conducted in a fixed-base research simulator to assess the directional handling qualities for various rudder pedal feel characteristics for commercial transport airplanes. That is, the effects of static pedal force at maximum pedal travel, breakout force, and maximum pedal travel on handling qualities were studied. An artificial maneuver with a severe lateral wind shear and requiring runway tracking at an altitude of 50 feet in a crosswind was used to fully exercise the rudder pedals. Twelve active airline pilots voluntarily participated in the study and flew approximately 500 maneuvers. The pilots rated the maneuver performance with various rudder pedal feel characteristics using the Cooper- Harper rating scale. The test matrix had 15 unique combinations of the 3 static pedal feel characteristics. A 10-term, second-order equation for the Cooper-Harper pilot rating as a function of the 3 independent pedal feel parameters was fit to the data. The test matrix utilized a Central Composite Design that is very efficient for fitting an equation of this form. The equation was used to produce contour plots of constant pilot ratings as a function of two of the parameters with the third parameter held constant. These contour plots showed regions of good handling qualities as well as regions of degraded handling qualities. In addition, a numerical equation solver was used to predict the optimum parameter values (those with the lowest pilot rating). Quantitative pilot performance data were also analyzed. This analysis found that the peak values of the cross power spectra of the pedal force and heading angle could be used to quantify the tendency toward directional pilot induced oscillations (PIO). Larger peak values of the cross power spectra were correlated with larger (degraded) Cooper-Harper pilot ratings. Thus, the subjective data (Cooper-Harper pilot ratings) were consistent with the objective data (peak values of the cross power spectra).

Visual/motion cue mismatch in a coordinated roll maneuver

NASA Technical Reports Server (NTRS)

Shirachi, D. K.; Shirley, R. S.

1981-01-01

The effects of bandwidth differences between visual and motion cueing systems on pilot performance for a coordinated roll task were investigated. Visual and motion cue configurations which were acceptable and the effects of reduced motion cue scaling on pilot performance were studied to determine the scale reduction threshold for which pilot performance was significantly different from full scale pilot performance. It is concluded that: (1) the presence or absence of high frequency error information in the visual and/or motion display systems significantly affects pilot performance; and (2) the attenuation of motion scaling while maintaining other display dynamic characteristics constant, affects pilot performance.

Techniques for Improving Pilot Recovery from System Failures

NASA Technical Reports Server (NTRS)

Pritchett, Amy R.

2001-01-01

This project examined the application of intelligent cockpit systems to aid air transport pilots at the tasks of reacting to in-flight system failures and of planning and then following a safe four dimensional trajectory to the runway threshold during emergencies. Two studies were conducted. The first examined pilot performance with a prototype awareness/alerting system in reacting to on-board system failures. In a full-motion, high-fidelity simulator, Army helicopter pilots were asked to fly a mission during which, without warning or briefing, 14 different failures were triggered at random times. Results suggest that the amount of information pilots require from such diagnostic systems is strongly dependent on their training; for failures they are commonly trained to react to with a procedural response, they needed only an indication of which failure to follow, while for 'un-trained' failures, they benefited from more intelligent and informative systems. Pilots were also found to over-rely on the system in conditions were it provided false or mis-leading information. In the second study, a proof-of-concept system was designed suitable for helping pilots replan their flights in emergency situations for quick, safe trajectory generation. This system is described in this report, including: the use of embedded fast-time simulation to predict the trajectory defined by a series of discrete actions; the models of aircraft and pilot dynamics required by the system; and the pilot interface. Then, results of a flight simulator evaluation with airline pilots are detailed. In 6 of 72 simulator runs, pilots were not able to establish a stable flight path on localizer and glideslope, suggesting a need for cockpit aids. However, results also suggest that, to be operationally feasible, such an aid must be capable of suggesting safe trajectories to the pilot; an aid that only verified plans entered by the pilot was found to have significantly detrimental effects on performance and pilot workload. Results also highlight that the trajectories suggested by the aid must capture the context of the emergency; for example, in some emergencies pilots were willing to violate flight envelope limits to reduce time in flight - in other emergencies the opposite was found.

LAM Pilot Study with Imatinib Mesylate (LAMP-1)

DTIC Science & Technology

2015-10-01

AD______________ AWARD NUMBER: W81XWH-14-1-0132 TITLE: LAM Pilot Study with Imatinib Mesylate (LAMP-1) PRINCIPAL INVESTIGATOR: Charlie...AND SUBTITLE LAM Pilot Study with Imatinib Mesylate (LAMP-1) 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-14-1-0132 5c. PROGRAM ELEMENT...designed to generate short-term safety and efficacy data regarding imatinib mesylate (imatinib) in the treatment of Lymphangioleiomyomatosis ( LAM

Pilot Domain Task Experience in Night Fatal Helicopter Emergency Medical Service Accidents.

PubMed

Aherne, Bryan B; Zhang, Chrystal; Newman, David G

2016-06-01

In the United States, accident and fatality rates in helicopter emergency medical service (HEMS) operations increase significantly under nighttime environmentally hazardous operational conditions. Other studies have found pilots' total flight hours unrelated to HEMS accident outcomes. Many factors affect pilots' decision making, including their experience. This study seeks to investigate whether pilot domain task experience (DTE) in HEMS plays a role against likelihood of accidents at night when hazardous operational conditions are entered. There were 32 flights with single pilot nighttime fatal HEMS accidents between 1995 and 2013 with findings of controlled flight into terrain (CFIT) and loss of control (LCTRL) due to spatial disorientation (SD) identified. The HEMS DTE of the pilots were compared with industry survey data. Of the pilots, 56% had ≤2 yr of HEMS experience and 9% had >10 yr of HEMS experience. There were 21 (66%) accidents that occurred in non-visual flight rules (VFR) conditions despite all flights being required to be conducted under VFR. There was a statistically significant increase in accident rates in pilots with <2 and <4 yr HEMS DTE and a statistically significant decrease in accident rates in pilots with >10 yr HEMS DTE. HEMS DTE plays a preventive role against the likelihood of a night operational accident. Pilots with limited HEMS DTE are more likely to make a poor assessment of hazardous conditions at night, and this will place HEMS flight crew at high risk in the VFR night domain.

Variations Among Pilots from Different Flight Operations in Party Line Information Requirements for Situation Awareness

NASA Technical Reports Server (NTRS)

Pritchett, Amy; Hansman, John

1997-01-01

Current air traffic control communications use shared VHF voice frequencies from which pilots can obtain 'party line' information (PLI) by overhearing communications addressed to other aircraft. Previous studies have shown that pilots perceive PLI to be important. There is concern that some critical PLI may be lost in the proposed data link environment, where communications will be discretely addressed. Different types of flight operations will be equipped with data link equipment at different times, generating a mixed environment in which some pilots will rely on PLI, while others will receive their information by data link. To research the importance, availability, and accuracy of PLI and to query pilots on the information they feel is necessary for global situation awareness, a survey was distributed to pilots. The pilots were selected from four flight operation groups to study the variations in PLI requirements in the mixed data link environment. Pilots perceived PLI to be important overall, with specific traffic and weather information elements identified as critical. Most PLI elements followed a pattern of higher perceived importance during terminal area operations, final approach, and landing. Pilots from the different flight operation groups identified some elements as particularly important. In a free-response question designed to identify the information requirements for global situation awareness, pilots frequently indicated a need for traffic and weather information. The results of this survey reveal specific concerns to be addressed when implementing data link communications.

Recent advances in the cryopreservation of shoot-derived germplasm of economically important fruit trees of Actinidia, Diospyros, Malus, Olea, Prunus, Pyrus and Vitis.

PubMed

Benelli, Carla; De Carlo, Anna; Engelmann, Florent

2013-01-01

This paper presents the advances made over the last decade in cryopreservation of economically important vegetatively propagated fruit trees. Cryopreservation protocols have been established using both dormant buds sampled on field-grown plants and shoot tips sampled on in vitro plantlets. In the case of dormant buds, scions are partially dehydrated by storage at -5 °C, and then cooled slowly to -30 °C using low cooling rates (c.a. 1 °C/h) before immersion in liquid nitrogen. After slow rewarming and rehydration of samples, regrowth takes place either through grafting of buds on rootstocks or excision of apices and inoculation in vitro. In the case of shoot tips of in vitro plantlets, the cryopreservation techniques employed are the following: controlled rate cooling procedures involving slow prefreezing followed by immersion in liquid nitrogen or vitrification-based procedures including encapsulation-dehydration, vitrification, encapsulation-vitrification and droplet-vitrification. The current status of cryopreservation for a series of fruit tree species including Actinidia, Diospyros, Malus, Olea, Prunus, Pyrus and Vitis is presented. Routine application of cryopreservation for long-term germplasm storage in genebanks is currently limited to apple and pear, for which large cryopreserved collections have been established at NCGRP, Fort Collins (USA), using dormant buds and in vitro shoot tips, respectively. However, there are a growing number of examples of pilot scale testing experiments under way for different species in various countries. Progress in the further development and application of cryopreservation techniques will be made through a better understanding of the mechanisms involved in the induction of tolerance to dehydration and cryopreservation in frozen explants. Copyright © 2012 Elsevier Inc. All rights reserved.

Assessment of sleepiness, fatigue, and depression among Gulf Cooperation Council commercial airline pilots.

PubMed

Aljurf, Tareq M; Olaish, Awad H; BaHammam, Ahmed S

2018-05-01

No studies have assessed the prevalence of fatigue, depression, sleepiness, and the risk of obstructive sleep apnea (OSA) among commercial airlines pilots in the Gulf Cooperation Council (GCC). This was a quantitative cross-sectional study conducted among pilots who were on active duty and had flown during the past 6 months for one of three commercial airline companies. We included participants with age between 20 and 65 years. Data were collected using a predesigned electronic questionnaire composed of questions related to demographic information in addition to the Fatigue Severity Scale (FSS), the Berlin Questionnaire, the Epworth Sleepiness Scale (ESS), and the Hospital Anxiety and Depression Scale (HADS). The study included 328 pilots with a mean age ± standard deviation of 41.4 ± 9.7 years. Overall, 224 (68.3%) pilots had an FSS score ≥ 36 indicating severe fatigue and 221 (67.4%) reported making mistakes in the cockpit because of fatigue. One hundred and twelve (34.1%) pilots had an ESS score ≥ 10 indicating excessive daytime sleepiness and 148 (45.1%) reported falling asleep at the controls at least once without previously agreeing with their colleagues. One hundred and thirteen (34.5%) pilots had an abnormal HADS depression score (≥ 8), and 96 (29.3%) pilots were at high risk for OSA requiring further assessment. Fatigue, sleepiness, risk of OSA, and depression are prevalent among GCC commercial airline pilots. Regular assessment by aviation authorities is needed to detect and treat these medical problems.

A unique in vivo approach for investigating antimicrobial materials utilizing fistulated animals

NASA Astrophysics Data System (ADS)

Berean, Kyle J.; Adetutu, Eric M.; Zhen Ou, Jian; Nour, Majid; Nguyen, Emily P.; Paull, David; McLeod, Jess; Ramanathan, Rajesh; Bansal, Vipul; Latham, Kay; Bishop-Hurley, Greg J.; McSweeney, Chris; Ball, Andrew S.; Kalantar-Zadeh, Kourosh

2015-06-01

Unique in vivo tests were conducted through the use of a fistulated ruminant, providing an ideal environment with a diverse and vibrant microbial community. Utilizing such a procedure can be especially invaluable for investigating the performance of antimicrobial materials related to human and animal related infections. In this pilot study, it is shown that the rumen of a fistulated animal provides an excellent live laboratory for assessing the properties of antimicrobial materials. We investigate microbial colonization onto model nanocomposites based on silver (Ag) nanoparticles at different concentrations into polydimethylsiloxane (PDMS). With implantable devices posing a major risk for hospital-acquired infections, the present study provides a viable solution to understand microbial colonization with the potential to reduce the incidence of infection through the introduction of Ag nanoparticles at the optimum concentrations. In vitro measurements were also conducted to show the validity of the approach. An optimal loading of 0.25 wt% Ag is found to show the greatest antimicrobial activity and observed through the in vivo tests to reduce the microbial diversity colonizing the surface.

Convection-enhanced delivery of cetuximab conjugated iron-oxide nanoparticles for treatment of spontaneous canine intracranial gliomas.

PubMed

Freeman, A Courtenay; Platt, Simon R; Holmes, Shannon; Kent, M; Robinson, Kelsey; Howerth, Elizabeth; Eagleson, Joe; Bouras, Alexandros; Kaluzova, Milota; Hadjipanayis, Constantinos G

2018-05-01

Cetuximab conjugated iron-oxide nanoparticles (cetuximab-IONPs) have shown both in-vitro and in-vivo anti-tumor efficacy against gliomas. The purpose of this pilot study was to evaluate the safety and potential efficacy of cetuximab-IONPs for treatment of spontaneously occurring intracranial gliomas in canines after convection-enhanced delivery (CED). The use of CED allowed for direct infusion of the cetuximab-IONPs both intratumorally and peritumorally avoiding the blood brain barrier (BBB) and limiting systemic effects. A total of eight dogs participated in the study and only two developed mild post-operative complications, which resolved with medical therapy. All canines underwent a single CED treatment of the cetuximab-IONPs over 3 days and did not receive any further adjuvant treatments. Volumetric analysis showed a median reduction in tumor size of 54.9% by MRI at 1-month (4-6 weeks) follow-up. Five dogs were euthanized due to recurrence of neurological signs other than seizures, two due to recurrent seizures, and one dog died in his sleep. Median survival time after surgery was 248 days (mean 367 days).

Impact characteristics for high-pressure large-flow water-based emulsion pilot operated check valve reverse opening

NASA Astrophysics Data System (ADS)

Liu, Lei; Huang, Chuanhui; Yu, Ping; Zhang, Lei

2017-10-01

To improve the dynamic characteristics and cavitation characteristics of large-flow pilot operated check valve, consider the pilot poppet as the research object, analyses working principle and design three different kinds of pilot poppets. The vibration characteristics and impact characteristics are analyzed. The simulation model is established through flow field simulation software. The cavitation characteristics of large-flow pilot operated check valve are studied and discussed. On this basis, high-pressure large-flow impact experimental system is used for impact experiment, and the cavitation index is discussed. Then optimal structure is obtained. Simulation results indicate that the increase of pilot poppet half cone angle can effectively reduce the cavitation area, reducing the generation of cavitation. Experimental results show that the pressure impact is not decreasing with increasing of pilot poppet half cone angle in process of unloading, but the unloading capacity, response speed and pilot poppet half cone angle are positively correlated. The impact characteristics of 60° pilot poppet, and its cavitation index is lesser, which indicates 60° pilot poppet is the optimal structure, with the theory results are basically identical.

A simulation evaluation of a pilot interface with an automatic terminal approach system

NASA Technical Reports Server (NTRS)

Hinton, David A.

1987-01-01

The pilot-machine interface with cockpit automation is a critical factor in achieving the benefits of automation and reducing pilot blunders. To improve this interface, an automatic terminal approach system (ATAS) was conceived that can automatically fly a published instrument approach by using stored instrument approach data to automatically tune airplane radios and control an airplane autopilot and autothrottle. The emphasis in the ATAS concept is a reduction in pilot blunders and work load by improving the pilot-automation interface. A research prototype of an ATAS was developed and installed in the Langley General Aviation Simulator. A piloted simulation study of the ATAS concept showed fewer pilot blunders, but no significant change in work load, when compared with a baseline heading-select autopilot mode. With the baseline autopilot, pilot blunders tended to involve loss of navigational situational awareness or instrument misinterpretation. With the ATAS, pilot blunders tended to involve a lack of awareness of the current ATAS mode state or deficiencies in the pilots' mental model of how the system operated. The ATAS display provided adequate approach status data to maintain situational awareness.

Symptoms of fatigue and coping strategies in maritime pilotage.

PubMed

Chambers, Timothy P; Main, Luana C

2015-01-01

Little is known regarding the symptoms of fatigue that maritime pilots experience during shift work. Moreover, the strategies these individuals use to cope with the onset of fatigue are also unknown. The current study explored the symptoms of fatigue and coping strategies experienced by maritime pilots when on-shift. Fifty maritime pilots were recruited via an advertisement in the national association's quarterly newsletter (Mage = 51.42; SD = 9.81). Participants responded to a modified version of the questionnaire used with aviation pilots that assessed overall fatigue, and the symptoms pilots associated with fatigue on duty. Methods pilots used to cope with fatigue before shift and when on the bridge were also assessed. There were significant effects for pilot vitality on 4 categories of fatigue: cognitive dysfunction; emotional disturbance; mean physical effects; and sleepiness. There were no significant effects for vitality on any of the self-reported coping strategy factors. The findings indicated that maritime pilots experience a variety of physical, behavioural, and cognitive fatigue symptoms when on shift. Some of these symptoms are similar to those reported by aviation pilots. However, unlike aviation pilots, maritime pilots reported utilising self-sufficient coping strategies to deal with the experience of fatigue.

The effects of pilot stress factors on handling quality assessments during US/German helicopter agility flight tests

NASA Technical Reports Server (NTRS)

Pausder, H.-J.; Gerdes, R. M.

1982-01-01

Flight tests were conducted with two helicopters to study and evaluate the effects of helicopter characteristics and pilot and task demands on performance in nap-of-the-earth flight. Different, low-level slalom courses were set up and were flown by three pilots with different levels of flight experience. A pilot rating questionnaire was used to obtain redundant information and to gain more insight into factors that influence pilot ratings. The flight test setups and procedures are described, and the pilot ratings are summarized and interpreted in close connection with the analyzed test data. Pilot stress is discussed. The influence of demands on the pilot, of the helicopter characteristics, and of other stress factors are outlined with particular emphasis on how these factors affect handling-qualities assessment. Previously announced in STAR as N83-13114

Safety and efficacy of intravenous infusion of allogeneic cryopreserved mesenchymal stem cells for treatment of chronic kidney disease in cats: results of three sequential pilot studies

PubMed Central

2013-01-01

Introduction Administration of mesenchymal stem cells (MSCs) has been shown to improve renal function in rodent models of chronic kidney disease (CKD), in part by reducing intrarenal inflammation and suppressing fibrosis. CKD in cats is characterized by tubulointerstitial inflammation and fibrosis, and thus treatment with MSCs might improve renal function and urinary markers of inflammation in this disease. Therefore, a series of pilot studies was conducted to assess the safety and efficacy of intravenous administration of allogeneic adipose-derived MSCs (aMSCs) in cats with naturally occurring CKD. Methods Cats enrolled in these studies received an intravenous infusion of allogeneic aMSCs every 2 weeks collected from healthy, young, specific pathogen-free cats. Cats in pilot study 1 (six cats) received 2 × 106 cryopreserved aMSCs per infusion, cats in pilot study 2 (five cats) received 4 × 106 cryopreserved aMSCs per infusion, and cats in pilot study 3 (five cats) received 4 × 106 aMSCs cultured from cryopreserved adipose. Serum biochemistry, complete blood count, urinalysis, urine protein, glomerular filtration rate, and urinary cytokine concentrations were monitored during the treatment period. Changes in clinical parameters were compared statistically by means of repeated measures analysis of variance (ANOVA) followed by Bonferroni’s correction. Results Cats in pilot study 1 had few adverse effects from the aMSC infusions and there was a statistically significant decrease in serum creatinine concentrations during the study period, however the degree of decrease seems unlikely to be clinically relevant. Adverse effects of the aMSC infusion in cats in pilot study 2 included vomiting (2/5 cats) during infusion and increased respiratory rate and effort (4/5 cats). Cats in pilot study 3 did not experience any adverse side effects. Serum creatinine concentrations and glomerular filtration rates did not change significantly in cats in pilot studies 2 and 3. Conclusions Administration of cryopreserved aMSCs was associated with significant adverse effects and no discernible clinically relevant improvement in renal functional parameters. Administration of aMSCs cultured from cryopreserved adipose was not associated with adverse effects, but was also not associated with improvement in renal functional parameters. PMID:23632128

Spectroscopic Detection of Caries Lesions

PubMed Central

Ruohonen, Mika; Palo, Katri; Alander, Jarmo

2013-01-01

Background. A caries lesion causes changes in the optical properties of the affected tissue. Currently a caries lesion can be detected only at a relatively late stage of development. Caries diagnosis also suffers from high interobserver variance. Methods. This is a pilot study to test the suitability of an optical diffuse reflectance spectroscopy for caries diagnosis. Reflectance visible/near-infrared spectroscopy (VIS/NIRS) was used to measure caries lesions and healthy enamel on extracted human teeth. The results were analysed with a computational algorithm in order to find a rule-based classification method to detect caries lesions. Results. The classification indicated that the measured points of enamel could be assigned to one of three classes: healthy enamel, a caries lesion, and stained healthy enamel. The features that enabled this were consistent with theory. Conclusions. It seems that spectroscopic measurements can help to reduce false positives at in vitro setting. However, further research is required to evaluate the strength of the evidence for the method's performance. PMID:27006907

Development and pilot testing of daily Interactive Voice Response (IVR) calls to support antiretroviral adherence in India: A mixed-methods pilot study

PubMed Central

Swendeman, Dallas; Jana, Smarajit; Ray, Protim; Mindry, Deborah; Das, Madhushree; Bhakta, Bhumi

2015-01-01

This two-phase pilot study aimed to design, pilot, and refine an automated Interactive Voice Response (IVR) intervention to support antiretroviral adherence for people living with HIV (PLH), in Kolkata, India. Mixed-methods formative research included a community advisory board (CAB) for IVR message development, one-month pre-post pilot, post-pilot focus groups, and further message development. Two IVR calls are made daily, timed to patients’ dosing schedules, with brief messages (<1-minute) on strategies for self-management of three domains: medical (adherence, symptoms, co-infections), mental health (social support, stress, positive cognitions), and nutrition and hygiene (per PLH preferences). Three ART appointment reminders are also sent each month. One-month pilot results (n=46, 80% women, 60% sex workers) found significant increases in self-reported ART adherence, both within past three days (p=0.05) and time since missed last dose (p=0.015). Depression was common. Messaging content and assessment domains were expanded for testing in a randomized trial is currently underway. PMID:25638037

Development and Pilot Testing of Daily Interactive Voice Response (IVR) Calls to Support Antiretroviral Adherence in India: A Mixed-Methods Pilot Study.

PubMed

Swendeman, Dallas; Jana, Smarajit; Ray, Protim; Mindry, Deborah; Das, Madhushree; Bhakta, Bhumi

2015-06-01

This two-phase pilot study aimed to design, pilot, and refine an automated interactive voice response (IVR) intervention to support antiretroviral adherence for people living with HIV (PLH), in Kolkata, India. Mixed-methods formative research included a community advisory board for IVR message development, 1-month pre-post pilot, post-pilot focus groups, and further message development. Two IVR calls are made daily, timed to patients' dosing schedules, with brief messages (<1-min) on strategies for self-management of three domains: medical (adherence, symptoms, co-infections), mental health (social support, stress, positive cognitions), and nutrition and hygiene (per PLH preferences). Three ART appointment reminders are also sent each month. One-month pilot results (n = 46, 80 % women, 60 % sex workers) found significant increases in self-reported ART adherence, both within past three days (p = 0.05) and time since missed last dose (p = 0.015). Depression was common. Messaging content and assessment domains were expanded for testing in a randomized trial currently underway.

Understanding Teachers' Pedagogical Knowledge: Report on an International Pilot Study. OECD Education Working Papers, No. 159

ERIC Educational Resources Information Center

Sonmark, Kristina; Révai, Nóra; Gottschalk, Francesca; Deligiannidi, Karolina; Burns, Tracey

2017-01-01

What is the nature of teachers' pedagogical knowledge? The Innovative Teaching for Effective Learning Teacher Knowledge Survey (ITEL TKS) set out to answer this question in a pilot study that ran in five countries: Estonia, Greece, Hungary Israel, and the Slovak Republic. Using convenience samples, the pilot assessed the pedagogical knowledge base…

2012 Preschool Pilot Study of PBS KIDS Transmedia Mathematics Content: A Report to the CPB-PBS "Ready to Learn Initiative"

ERIC Educational Resources Information Center

Pasnik, Shelley; Llorente, Carlin

2012-01-01

The 2012 Preschool Pilot Study of PBS KIDS Transmedia Mathematics Content (Preschool Pilot) is an important part of the authors' multiyear "Ready To Learn" (RTL) summative evaluation initiative. Through this initiative funded by the Corporation for Public Broadcasting (CPB) and Public Broadcasting Service (PBS), it was the responsibility…

A Pilot Systematic Review and Meta-Analysis on the Effectiveness of Problem Based Learning.

ERIC Educational Resources Information Center

Newman, Mark

This paper reports on the development and piloting of a systematic review and meta analysis of research on the effectiveness of problem based learning (PBL). The systematic review protocol was pilot tested with a sample of studies cited as providing "evidence" about the effectiveness of PBL. From the 5 studies mentioned in the sample of reviews,…

Pilots using selective serotonin reuptake inhibitors compared to other fatally injured pilots.

PubMed

Rogers, Paul; Hileman, Christy; Salazar, Guillermo; Cliburn, Kacey; Paskoff, Lawrence; Hathaway, William; Gildea, Kevin; Tejera Villalaz, Victor Hugo

2017-10-01

Selective Serotonin Reuptake Inhibitors (SSRI) were a disqualifying medication for U.S. civil pilots before April 5, 2010. After this date, a Federal Aviation Administration policy was created that allowed airmen, on select SSRIs, a pathway to hold a valid medical certificate. The purpose of this study was to provide a detailed look at SSRIs in the U.S. pilot population since the inception of this new policy. We examined the toxicology results from fatally injured airmen in addition to outcomes concerning pilots who are participating in the program. This study examined data from the Civil Aerospace Medical Institute's Bioaeronautical Sciences Research Laboratory in conjunction with the Medical Analysis Tracking Registry and the Document Imaging and Workflow System. A count-based regression model quantified the relationships between positive SSRI findings with additional factors of interest. These factors included pilot rating, ethanol, and first generation antihistamines. There were 1484 fatally injured airmen over the six year study period, of which 44-tested positive for an SSRI. First-generation antihistamines were statistically associated with positive findings of SSRIs. Published by Elsevier Ltd.

Investigating gender differences under conditions of fatigue in a simulated high G aerial combat environment.

PubMed

Chelette, T L

1997-06-01

Advances in technology have equipped high-performance combat aircraft with the capability of delivering higher and higher sustained acceleration or G-forces on the pilots flying them. While the physiological effects of increased g-forces on the human body continue to be investigated, studies examining the effects of acceleration on the cognitive abilities of high-performance aircraft pilots remain sparse. Additionally, as higher technology is making its way into the cockpit, so are female pilots. With even fewer studies investigating women's physiological and cognitive tolerances to the stressors in the high-performance cockpit and flight environment, Dr. Chelette's study aimed to investigate these issues. Examining pilot workload, flight task abilities, and the effects of sleeplessness on both male and female pilots, Dr. Chelette's results revealed findings that will make their way into the high-performance cockpit of the future.

Alcohol rehabilitation of airline pilots.

DOT National Transportation Integrated Search

1985-10-01

This study involves a survey of medical records for over 500 airline pilots who have been medically certified by the FAA after a diagnosis of alcoholism. The program demonstrates an 85% rate of success since 1976. If a pilot experiences a relapse, he...

Reconstructing Cell Lineages from Single-Cell Gene Expression Data: A Pilot Study

DTIC Science & Technology

2016-08-30

Reconstructing cell lineages from single- cell gene expression data: a pilot study The goal of this pilot study is to develop novel mathematical...methods, by leveraging tools developed in the bifurcation theory, to infer the underlying cell -state dynamics from single- cell gene expression data. Our...proposed method contains two steps. The first step is to reconstruct the temporal order of the cells from gene expression data, whereas the second

Service Quality, User Satisfaction and Net-Benefits' Effect on e-School Success: The Case of NEPAD's e-School Pilot in Kenya

ERIC Educational Resources Information Center

Nyagowa, Hesbon O.; Ocholla, Dennis N.; Mutula, Stephen M.

2013-01-01

This study was conducted to determine the effect of a set of dimensions on e-School success in a cross-sectional study of NEPAD's e-School pilot in Kenya. All of the six e-Schools participating in the NEPAD's e-School pilot in Kenya were selected. The study used survey methodology. Students and teachers in those schools formed the study…

The effects of workload on respiratory variables in simulated flight: a preliminary study.

PubMed

Karavidas, Maria Katsamanis; Lehrer, Paul M; Lu, Shou-En; Vaschillo, Evgeny; Vaschillo, Bronya; Cheng, Andrew

2010-04-01

In this pilot study, we investigated respiratory activity and end-tidal carbon dioxide (P(et)CO(2)) during exposure to varying levels of work load in a simulated flight environment. Seven pilots (age: 34-60) participated in a one-session test on the Boeing 737-800 simulator. Physiological data were collected while pilots wore an ambulatory multi-channel recording device. Respiratory variables, including inductance plethysmography (respiratory pattern) and pressure of end-tidal carbon dioxide (P(et)CO(2)), were collected demonstrating change in CO(2) levels proportional to changes in flight task workload. Pilots performed a set of simulation flight tasks. Pilot performance was rated for each task by a test pilot; and self-report of workload was taken using the NASA-TLX scale. Mixed model analysis revealed that respiration rate and minute ventilation are significantly associated with workload levels and evaluator scores controlling for "vanilla baseline" condition. Hypocapnia exclusively occurred in tasks where pilots performed more poorly. This study was designed as a preliminary investigation in order to develop a psychophysiological assessment methodology, rather than to offer conclusive findings. The results show that the respiratory system is very reactive to high workload conditions in aviation and suggest that hypocapnia may pose a flight safety risk under some circumstances. Copyright © 2010 Elsevier B.V. All rights reserved.

Use of a Data-Linked Weather Information Display and Effects on Pilot Navigation Decision Making in a Piloted Simulation Study

NASA Technical Reports Server (NTRS)

Yuchnovicz, Daniel E.; Novacek, Paul F.; Burgess, Malcolm A.; Heck, Michael L.; Stokes, Alan F.

2001-01-01

This study provides recommendations to the FAA and to prospective manufacturers based on an exploration of the effects of data link weather displays upon pilot decision performance. An experiment was conducted with twenty-four current instrument rated pilots who were divided into two equal groups and presented with a challenging but realistic flight scenario involving weather containing significant embedded convective activity. All flights were flown in a full-mission simulation facility within instrument meteorological conditions. The inflight weather display depicted NexRad images, graphical METARs and textual METARs. The objective was to investigate the potential for misuse of a weather display, and incorporate recommendations for the design and use of these displays. The primary conclusion of the study found that the inflight weather display did not improve weather avoidance decision making. Some of the reasons to support this finding include: the pilot's inability to easily perceive their proximity to the storms, increased workload and difficulty in deciphering METAR textual data. The compelling nature of a graphical weather display caused many pilots to reduce their reliance on corroborating weather information from other sources. Minor changes to the weather display could improve the ability of a pilot to make better decisions on hazard avoidance.

Impact of a daily 10-minute strength and flexibility program in a manufacturing plant.

PubMed

Pronk, S J; Pronk, N P; Sisco, A; Ingalls, D S; Ochoa, C

1995-01-01

In summary, employees' flexibility and mood showed modest improvements following the implementation of a plant-wide, 10-minute, daily flexibility and strength program. The initial six-week pilot study, administered prior to the plant-wide program implementation, successfully assessed program feasibility, assessed the efficiency of program implementation, identified administrative and logistical concerns, and generated pilot data needed to secure managerial support. Despite the noted significant increases in grip strength in the pilot study, no increases were observed following the six months of plant-wide implementation. This may be related to the differences in low average pretest grip strength for the pilot study compared to the higher scores for the main study population. The pilot study subjects may have received a sufficient exercise stimulus to increase grip strength over the course of six weeks. In contrast, this may not have been the case for the main study subjects due to their higher initial mean grip strength. An increased number of exercises designed to directly impact grip strength may be needed to improve this parameter.

Review of performance, medical, and operational data on pilot aging issues

NASA Technical Reports Server (NTRS)

Stoklosa, J. H.

1992-01-01

An extensive review of the literature and studies relating to performance, medical, operational, and legal data regarding pilot aging issues was performed in order to determine what evidence there is, if any, to support mandatory pilot retirement. Popular misconceptions about aging, including the failure to distinguish between the normal aging process and disease processes that occur more frequently in older individuals, continue to contribute to much of the misunderstanding and controversy that surround this issue. Results: Review of medical data related to the pilot aging issue indicate that recent improvement in medical diagnostics and treatment technology have made it possible to identify to a high degree individuals who are at risk for developing sudden incapacitating illness and for treating those with disqualifying medical conditions. Performance studies revealed that after controlling for the presence of disease states, older pilots are able to perform as well as younger pilots on many performance tasks. Review of accident data showed that older, healthy pilots do not have higher accident rates than younger pilots, and indeeed, evidence suggests that older pilots have an advantage in the cockpit due to higher experience levels. The Man-Machine-Mission-Environment interface of factors can be managed through structured, supervised, and enhanced operations, maintenance, flight reviews, and safety procedures in order to ensure safe and productive operations by reducing the margin of error and by increasing the margin of safety. Conclusions: There is no evidence indicating any specific age as an arbitrary cut-off point for pilots to perform their fight duties. A combination of regular medical screening, performance evaluation, enhanced operational maintenance, and safety procedures can most effectively ensure a safe pilot population than can a mandatory retirement policy based on arbitrary age restrictions.

A pilot study to evaluate mindfulness as a strategy to improve inpatient nurse and patient experiences.

PubMed

Horner, Janice K; Piercy, Brigit S; Eure, Lois; Woodard, Elizabeth K

2014-08-01

The purpose of the Mindful Nursing Pilot Study was to explore the impact of mindfulness training for nursing staff on levels of mindfulness, compassion satisfaction, burnout, and stress. In addition, the study attempted to determine the impact on patient satisfaction scores. The pilot was designed as a quasi-experimental research study; staff on one nursing unit participated in the 10-week mindfulness training program while another, similar nursing unit served as the control group. The intervention group showed improvement in levels of mindfulness, burnout, and stress as well as patient satisfaction while the control group remained largely the same. This pilot provides encouraging results that suggest that replication and further study of mindfulness in the workplace would be beneficial. Copyright © 2014 Elsevier Inc. All rights reserved.

A Methodology for Evaluating the Fidelity of Ground-Based Flight Simulators

NASA Technical Reports Server (NTRS)

Zeyada, Y.; Hess, R. A.

1999-01-01

An analytical and experimental investigation was undertaken to model the manner in which pilots perceive and utilize visual, proprioceptive, and vestibular cues in a ground-based flight simulator. The study was part of a larger research effort which has the creation of a methodology for determining flight simulator fidelity requirements as its ultimate goal. The study utilized a closed-loop feedback structure of the pilot/simulator system which included the pilot, the cockpit inceptor, the dynamics of the simulated vehicle and the motion system. With the exception of time delays which accrued in visual scene production in the simulator, visual scene effects were not included in this study. The NASA Ames Vertical Motion Simulator was used in a simple, single-degree of freedom rotorcraft bob-up/down maneuver. Pilot/vehicle analysis and fuzzy-inference identification were employed to study the changes in fidelity which occurred as the characteristics of the motion system were varied over five configurations i The data from three of the five pilots that participated in the experimental study were analyzed in the fuzzy inference identification. Results indicate that both the analytical pilot/vehicle analysis and the fuzzyinference identification can be used to reflect changes in simulator fidelity for the task examined.

A Methodology for Evaluating the Fidelity of Ground-Based Flight Simulators

NASA Technical Reports Server (NTRS)

Zeyada, Y.; Hess, R. A.

1999-01-01

An analytical and experimental investigation was undertaken to model the manner in which pilots perceive and utilize visual, proprioceptive, and vestibular cues in a ground-based flight simulator. The study was part of a larger research effort which has the creation of a methodology for determining flight simulator fidelity requirements as its ultimate goal. The study utilized a closed-loop feedback structure of the pilot/simulator system which included the pilot, the cockpit inceptor, the dynamics of the simulated vehicle and the motion system. With the exception of time delays which accrued in visual scene production in the simulator, visual scene effects were not included in this study. The NASA Ames Vertical Motion Simulator was used in a simple, single-degree of freedom rotorcraft bob-up/down maneuver. Pilot/vehicle analysis and fuzzy-inference identification were employed to study the changes in fidelity which occurred as the characteristics of the motion system were varied over five configurations. The data from three of the five pilots that participated in the experimental study were analyzed in the fuzzy-inference identification. Results indicate that both the analytical pilot/vehicle analysis and the fuzzy-inference identification can be used to reflect changes in simulator fidelity for the task examined.

Influence of Cultural, Organizational, and Automation Capability on Human Automation Trust: A Case Study of Auto-GCAS Experimental Test Pilots

NASA Technical Reports Server (NTRS)

Koltai, Kolina; Ho, Nhut; Masequesmay, Gina; Niedober, David; Skoog, Mark; Cacanindin, Artemio; Johnson, Walter; Lyons, Joseph

2014-01-01

This paper discusses a case study that examined the influence of cultural, organizational and automation capability upon human trust in, and reliance on, automation. In particular, this paper focuses on the design and application of an extended case study methodology, and on the foundational lessons revealed by it. Experimental test pilots involved in the research and development of the US Air Force's newly developed Automatic Ground Collision Avoidance System served as the context for this examination. An eclectic, multi-pronged approach was designed to conduct this case study, and proved effective in addressing the challenges associated with the case's politically sensitive and military environment. Key results indicate that the system design was in alignment with pilot culture and organizational mission, indicating the potential for appropriate trust development in operational pilots. These include the low-vulnerability/ high risk nature of the pilot profession, automation transparency and suspicion, system reputation, and the setup of and communications among organizations involved in the system development.

Occupational exposure to noise and hypertension in pilots.

PubMed

Tomei, Francesco; De Sio, Simone; Tomao, Enrico; Anzelmo, Vincenza; Baccolo, Tiziana Paola; Ciarrocca, Manuela; Cherubini, Emilia; Valentini, Valentina; Capozzella, Assunta; Rosati, Maria Valeria

2005-04-01

The role of occupational exposure to noise as a hypertension risk factor has not been established sufficiently. The aim of the study is to evaluate whether chronic exposure to different levels of noise in two groups of pilots, operating with two types of aircraft, could be a risk for hypertension, what relevance the parameters (intensity, duration and type) of exposure can have and, lastly, whether there are any links between hearing impairment and hypertension. After excluding pilots with confounding factors, a study was made of 77 male pilots of turboprop planes (group A) and 224 male pilots of jet aircraft (group B), matched by age and working life. Blood pressure (supine and standing positions) and heart rate were measured. Electrocardiogram, stress tests on a cycle ergometer, sound-level measurement and audiometric tests were also done. Pilots of group A were exposed to Leq of 93 dBA while pilots of group B were exposed to the Leq of 79 dBA. Significant results in group A compared to group B were found between heart rate, blood pressure, drop in blood pressure, parameters (intensity, duration and type) of exposure to noise and between hearing damage and hypertension. The findings suggest that chronic exposure to noise is a risk factor for blood hypertension in pilots exposed to high noise levels, and that the drop in blood pressure may be a sign of more sensitive effect of noise on blood pressure, according to other studies in literature.

Occupational Stress and Hypertension among Railway Loco Pilots and Section Controllers

PubMed Central

Jayakumar, Devasigamoney

2017-01-01

Introduction: A cross-sectional study on occupational stress was conducted on loco pilots in 2008, in view of loco pilots being one of the high strain jobs in Indian Railways. Subsequently, a comparative cross-sectional study on occupational stress was conducted among section controllers in 2011, which is another high strain job of Indian Railways. Objective: The studies were conducted to analyze and compare occupational stress and hypertension. Setting and Design: A cross-sectional study on occupational stress and hypertension was conducted among 230 loco pilots in 2008, and subsequently, a comparative cross-sectional study was conducted among 82 section controllers in 2011. Materials and Methods: A closed end 24 item questionnaire on occupational stress was administered. Systolic blood pressure above 140 mmHg and diastolic blood pressure above 90 mmHg were considered as hypertension as per the VII Joint National Committee. Chi-square test and t-test were used for testing significance at P < 0.05. Results: The mean stress score was 8.56 in loco pilots and 7.32 in section controllers. The number of loco pilots with more than 12 stress factors was 49 (21.3%) and the number of section controllers with more than 12 stress factors was 7 (8.5%). The number employees with more than 12 stress factors in different categories of loco pilots were 30 (32%) in the goods category, 12 (12%) in the mail/passenger category, and 7 (19%) in the shunter category, and 3 (11%) in the supervisory category and 4 (7%) in the on-board category of section controllers. The prevalence of hypertension in loco pilots was 36.52% (84) and in the section controllers was 53.66% (44). The prevalence of hypertension in the category with more than 12 stress factors was 30.61% (15) in the loco pilots and 28.57% (2) in the section controllers. The prevalence of hypertension in the both the study groups were higher in the older age, with a family history of hypertension, and with a body mass index of more than 25 kg/m2. The mean occupational stress and employees with more than 12 stress factors were higher in the loco pilots group. The goods category of loco pilots had highest stress factors. The prevalence of hypertension was high in the category with risk factors such as older age, family history of hypertension and BMI above 25 kg/m2. PMID:29391744

New iron-oxide particles for magnetic nanoparticle hyperthermia: an in-vitro and in-vivo pilot study

NASA Astrophysics Data System (ADS)

Hedayati, Mohammad; Attaluri, Anilchandra; Bordelon, David; Goh, R.; Armour, Michael; Zhou, Haoming; Cornejo, Christine; Wabler, Michele; Zhang, Yonggang; DeWeese, Theodore; Ivkov, Robert

2013-02-01

Magnetic nanoparticle hyperthermia (mNHP) is regarded as a promising minimally invasive procedure. These nanoparticles generate heat when exposed to alternating magnetic fields (AMFs) and thus have shown a potential for selective delivery of heat to a target such as a cancer cell. Despite the great promise however, successful clinical translation has been limited in part by technical challenges of selectively delivering heat only to the target tissue. Interaction of AMF with tissues also deposits heat through Joule heating via eddy currents. Considerations of patient safety thus constrain the choice of AMF power and frequency to values that are insufficient to produce desirable heating from available nanoparticle formulations. Therefore, considerable effort must be directed to the design of particles and the AMF device to maximize the specific delivery of heat to the intended target while minimizing the unintended and non-specific heating. We have recently developed new iron-oxide nanoparticles (IONPs) having much higher heating capability at the clinically relevant amplitudes and frequencies than other formulations. Here, we utilize a new rectangular coil designed for treating multi well tissue culture plate and show that these particles are superior to two commercially available IONPs for hyperthermia of DU145 prostate cancer cells in culture. We report results of pilot in-vivo experiments using the DU145 human prostate xenograft model in nude male mouse. AMF treatment yielded an intratumor temperature rise > 10 °C in <10 min heating (AMF amplitude 29 kA/m @160 kHz) with ~4 mg nanoparticle /g tumor while maintaining rectal (core) temperature well within physiological range.

Cognitive engineering in aerospace application: Pilot interaction with cockpit automation

NASA Technical Reports Server (NTRS)

Sarter, Nadine R.; Woods, David D.

1993-01-01

Because of recent incidents involving glass-cockpit aircraft, there is growing concern with cockpit automation and its potential effects on pilot performance. However, little is known about the nature and causes of problems that arise in pilot-automation interaction. The results of two studies that provide converging, complementary data on pilots' difficulties with understanding and operating one of the core systems of cockpit automation, the Flight Management System (FMS) is reported. A survey asking pilots to describe specific incidents with the FMS and observations of pilots undergoing transition training to a glass cockpit aircraft served as vehicles to gather a corpus on the nature and variety of FMS-related problems. The results of both studies indicate that pilots become proficient in standard FMS operations through ground training and subsequent line experience. But even with considerable line experience, they still have difficulties tracking FMS status and behavior in certain flight contexts, and they show gaps in their understanding of the functional structure of the system. The results suggest that design-related factors such as opaque interfaces contribute to these difficulties which can affect pilots' situation awareness. The results of this research are relevant for both the design of cockpit automation and the development of training curricula specifically tailored to the needs of glass cockpits.

Experimental models for contamination of titanium surfaces and disinfection protocols.

PubMed

Sousa, Vanessa; Mardas, Nikos; Spratt, David; Boniface, David; Dard, Michel; Donos, Nikolaos

2016-10-01

The aim of this pilot study was to describe an in vitro model of peri-implantitis microcosm for contamination of titanium surfaces and an in vivo model for evaluating different disinfection strategies of titanium surfaces. Biofilms were grown in vitro for 30 days on sandblasted large-grit acid-etched (SLA) Ti discs (n = 69) in a constant depth film fermentor (CDFF) associated with peri-implantitis conditions. Four Swedish loop rabbits were randomly allocated in three test groups (T 1 , T 2 , T 3 ) and one control group (C). In group C, two sterile SLA Ti discs were implanted/fixed in each tibia. In the test groups (to evaluate the potential of different surface disinfection techniques), one sterile and three previously disinfected SLA Ti discs were placed following different disinfection protocols: group T 1 : the discs were treated with a titanium brush - TiB; group T 2 : the discs were treated with the combination of TiB and photodynamic therapy; and group T 3 : the discs were treated with TiB and 1%NaOCl plus 0.2%CHX. Tensile strength test and qualitative histological analysis were performed on all 16 discs after 4 weeks of healing. Thirty days following CDFF emulating peri-implantitis microcosm, all SLA Ti discs had a mean total viable aerobes and facultative anaerobes count of 8.06 log 10  CFU/biofilm and anaerobes 8.32 log 10  CFU/biofilm. Before implantation/fixation on the tibia, differences of log 10  CFU/biofilm counts between control and test groups after post hoc adjustment were highly significant (P < 0.001). In the in vivo analysis, group C exhibited the highest tensile strength (67.60 N [25.64-127.02]) and the histological sections revealed the presence of dense mature bone in direct contact with the disc surface. The analysis at the test groups showed that T 2 presented with the highest tensile strength in comparison with the other two test groups. The in vitro model used in this study provides a valuable and reproducible tool for evaluating the in vitro dynamics of the peri-implantitis microcosm biofilm and for contaminating in a reproducible manner titanium surfaces. At the same time, the in vivo model used in this study provides a standardised mode of evaluating disinfection modalities of previously infected titanium surfaces. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Evaluative Priming in the Pronunciation Task.

PubMed

Klauer, Karl Christoph; Becker, Manuel; Spruyt, Adriaan

2016-01-01

We replicated and extended a study by Spruyt and Hermans (2008) in which picture primes engendered an evaluative-priming effect on the pronunciation of target words. As preliminary steps, we assessed data reproducibility of the original study, conducted Pilot Study I to identify highly semantically related prime-target pairs, reanalyzed the original data excluding such pairs, conducted Pilot Study II to demonstrate that we can replicate traditional associative priming effects in the pronunciation task, and conducted Pilot Study III to generate relatively unrelated sets of prime pictures and target words. The main study comprised three between-participants conditions: (1) a close replication of the original study, (2) the same condition excluding highly related prime-target pairs, and (3) a condition based on the relatively unrelated sets of prime pictures and target words developed in Pilot Study III. There was little evidence for an evaluative priming effect independent of semantic relatedness.

Pilot interaction with cockpit automation 2: An experimental study of pilots' model and awareness of the Flight Management System

NASA Technical Reports Server (NTRS)

Sarter, Nadine B.; Woods, David D.

1994-01-01

Technological developments have made it possible to automate more and more functions on the commercial aviation flight deck and in other dynamic high-consequence domains. This increase in the degrees of freedom in design has shifted questions away from narrow technological feasibility. Many concerned groups, from designers and operators to regulators and researchers, have begun to ask questions about how we should use the possibilities afforded by technology skillfully to support and expand human performance. In this article, we report on an experimental study that addressed these questions by examining pilot interaction with the current generation of flight deck automation. Previous results on pilot-automation interaction derived from pilot surveys, incident reports, and training observations have produced a corpus of features and contexts in which human-machine coordination is likely to break down (e.g., automation surprises). We used these data to design a simulated flight scenario that contained a variety of probes designed to reveal pilots' mental model of one major component of flight deck automation: the Flight Management System (FMS). The events within the scenario were also designed to probe pilots' ability to apply their knowledge and understanding in specific flight contexts and to examine their ability to track the status and behavior of the automated system (mode awareness). Although pilots were able to 'make the system work' in standard situations, the results reveal a variety of latent problems in pilot-FMS interaction that can affect pilot performance in nonnormal time critical situations.

Informing efficient randomised controlled trials: exploration of challenges in developing progression criteria for internal pilot studies.

PubMed

Avery, Kerry N L; Williamson, Paula R; Gamble, Carrol; O'Connell Francischetto, Elaine; Metcalfe, Chris; Davidson, Peter; Williams, Hywel; Blazeby, Jane M

2017-02-17

Designing studies with an internal pilot phase may optimise the use of pilot work to inform more efficient randomised controlled trials (RCTs). Careful selection of preagreed decision or 'progression' criteria at the juncture between the internal pilot and main trial phases provides a valuable opportunity to evaluate the likely success of the main trial and optimise its design or, if necessary, to make the decision not to proceed with the main trial. Guidance on the appropriate selection and application of progression criteria is, however, lacking. This paper outlines the key issues to consider in the optimal development and review of operational progression criteria for RCTs with an internal pilot phase. A structured literature review and exploration of stakeholders' opinions at a Medical Research Council (MRC) Hubs for Trials Methodology Research workshop. Key stakeholders included triallists, methodologists, statisticians and funders. There is considerable variation in the use of progression criteria for RCTs with an internal pilot phase, although 3 common issues predominate: trial recruitment, protocol adherence and outcome data. Detailed and systematic reporting around the decision-making process for stopping, amending or proceeding to a main trial is uncommon, which may hamper understanding in the research community about the appropriate and optimal use of RCTs with an internal pilot phase. 10 top tips for the development, use and reporting of progression criteria for internal pilot studies are presented. Systematic and transparent reporting of the design, results and evaluation of internal pilot trials in the literature should be encouraged in order to facilitate understanding in the research community and to inform future trials. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Informing efficient randomised controlled trials: exploration of challenges in developing progression criteria for internal pilot studies

PubMed Central

Williamson, Paula R; Gamble, Carrol; O'Connell Francischetto, Elaine; Metcalfe, Chris; Davidson, Peter; Williams, Hywel; Blazeby, Jane M

2017-01-01

Objectives Designing studies with an internal pilot phase may optimise the use of pilot work to inform more efficient randomised controlled trials (RCTs). Careful selection of preagreed decision or ‘progression’ criteria at the juncture between the internal pilot and main trial phases provides a valuable opportunity to evaluate the likely success of the main trial and optimise its design or, if necessary, to make the decision not to proceed with the main trial. Guidance on the appropriate selection and application of progression criteria is, however, lacking. This paper outlines the key issues to consider in the optimal development and review of operational progression criteria for RCTs with an internal pilot phase. Design A structured literature review and exploration of stakeholders' opinions at a Medical Research Council (MRC) Hubs for Trials Methodology Research workshop. Key stakeholders included triallists, methodologists, statisticians and funders. Results There is considerable variation in the use of progression criteria for RCTs with an internal pilot phase, although 3 common issues predominate: trial recruitment, protocol adherence and outcome data. Detailed and systematic reporting around the decision-making process for stopping, amending or proceeding to a main trial is uncommon, which may hamper understanding in the research community about the appropriate and optimal use of RCTs with an internal pilot phase. 10 top tips for the development, use and reporting of progression criteria for internal pilot studies are presented. Conclusions Systematic and transparent reporting of the design, results and evaluation of internal pilot trials in the literature should be encouraged in order to facilitate understanding in the research community and to inform future trials. PMID:28213598

The Effects of Aviation Weather Information Systems on General Aviation Weather Information Systems on General Pilots' Workload

NASA Technical Reports Server (NTRS)

Scerbo, Mark; Coyne, Joseph; Burt, Jennifer L. (Technical Monitor)

2002-01-01

My work at NASA Langley has focused around Aviation Weather Information CAWING displays. The majority of my time at LYRIC has been spent on the Workload and Relative Position (WaRP) Study. The goal of this project is to determine how an AWIN display at various positions within the cockpit affects pilot performance and workload. The project is being conducted in Languages Cessna 206H research aircraft. During the past year the design of the experiment was finalized and approved. Despite facing several delays the data collection was completed in early February. Alter the completion of the data collection an extensive data entry task began. This required recording air speed, altitude, course heading, bank angle, and vertical speed information from videos of the primary flight displays. This data was then used to determine root mean square error (RMSE) for each experimental condition. In addition to the performance data (RMSE) taken from flight path deviation, the study also collected data on pilot;s accuracy in reporting weather information, and a subjective rating of workload from the pilot. The data for this experiment is currently being analyzed. Overall the current experiment should help to determine potential costs and benefits associated with AWIN displays. The data will be used to determine if a private pilot can safely fly a general aviation aircraft while operating a weather display. Clearly a display that adds to the pilot#s already heavy workload represents a potential problem. The study will compare the use of an AWIN display to conventional means of acquiring weather data. The placement of the display within the cockpit (i.e., either on the yoke, kneeboard, or panel) will be also compared in terms of workload, performance, and pilot preference.

Integrating Research-Informed Teaching within an Undergraduate Level 4 (Year 1) Diagnostic Radiography Curriculum: A Pilot Study

ERIC Educational Resources Information Center

Higgins, Robert; Hogg, Peter; Robinson, Leslie

2013-01-01

This article discusses the piloting and evaluation of the Research-informed Teaching experience (RiTe) project. The aim of RiTe was to link teaching and learning with research within an undergraduate diagnostic radiography curriculum. A preliminary pilot study of RiTe was undertaken with a group of level 4 (year 1) volunteer BSc (Hons) diagnostic…

Burnout among pilots: psychosocial factors related to happiness and performance at simulator training.

PubMed

Demerouti, Evangelia; Veldhuis, Wouter; Coombes, Claire; Hunter, Rob

2018-06-18

In this study among airline pilots, we aim to uncover the work characteristics (job demands and resources) and the outcomes (job crafting, happiness and simulator training performance) that are related to burnout for this occupational group. Using a large sample of airline pilots, we showed that 40% of the participating pilots experience high burnout. In line with Job Demands-Resources theory, job demands were detrimental for simulator training performance because they made pilots more exhausted and less able to craft their job, whereas job resources had a favourable effect because they reduced feelings of disengagement and increased job crafting. Moreover, burnout was negatively related to pilots' happiness with life. These findings highlight the importance of psychosocial factors and health for valuable outcomes for both pilots and airlines. Practitioner Summary: Using an online survey among the members of a European pilots' professional association, we examined the relationship between psychosocial factors (work characteristics, burnout) and outcomes (simulator training performance, happiness). Forty per cent of the participating pilots experience high burnout. Job demands were detrimental, whereas job resources were favourable for simulator training performance/happiness. Twitter text: 40% of airline pilots experience burnout and psychosocial work factors and burnout relate to performance at pilots' simulator training.

Digestive functional symptoms among commercial pilots in relation to diet, insomnia, and lifestyle factors.

PubMed

Lindgren, Torsten; Runeson, Roma; Wahlstedt, Kurt; Wieslander, Gunilla; Dammström, Bo-Göran; Norbäck, Dan

2012-09-01

The aim of our study was to identify associations between digestive symptoms among pilots and diet, insomnia, and lifestyle factors. A standardized questionnaire was mailed to all Stockholm pilots on duty in a Swedish airline company: 354 pilots and 564 office workers from the same company participated. Associations were analyzed by multiple logistic regressions with mutual adjustment. Of the pilots, 9.9% reported poor appetite, 15.2% heartburn, 12.4% diarrhea, 62.1% bloating, 9.3% constipation, and 14.4% epigastralgia. Pilots reported more bloating and poor appetite compared with office workers. The prevalence of insomnia was 70.6% among pilots and 63.1% among office workers. Among pilots, insomnia was related to poor appetite, heartburn, diarrhea, bloating, constipation, and epigastralgia. There were no associations between insomnia and digestive symptoms among office workers. Among pilots, higher body mass index (BMI) was related to heartburn and smokers more often suffered from constipation. Frequent milk consumption was associated with heartburn and less constipation; female pilots suffered from more constipation. The number of years as an active pilot was negatively associated with epigastralgia and bloating. Insomnia and some digestive symptoms were more common among pilots than office workers. In addition to insomnia, BMI, smoking, female gender, and milk consumption were associated with some digestive symptoms. The strong association between insomnia and digestive symptoms among pilots, but not among office workers, suggests a stress component related to this occupation.

Modeling Pilot Pulse Control

NASA Technical Reports Server (NTRS)

Bachelder, Edward; Hess, Ronald; Godfroy-Cooper, Martine; Aponso, Bimal

2017-01-01

In this study, behavioral models are developed that closely reproduced pulsive control response of two pilots from the experimental pool using markedly different control techniques (styles) while conducting a tracking task. An intriguing find was that the pilots appeared to: 1) produce a continuous, internally-generated stick signal that they integrated in time; 2) integrate the actual stick position; and 3) compare the two integrations to issue and cease pulse commands. This suggests that the pilots utilized kinesthetic feedback in order to perceive and integrate stick position, supporting the hypothesis that pilots can access and employ the proprioceptive inner feedback loop proposed by Hess' pilot Structural Model. The Pulse Models used in conjunction with the pilot Structural Model closely recreated the pilot data both in the frequency and time domains during closed-loop simulation. This indicates that for the range of tasks and control styles encountered, the models captured the fundamental mechanisms governing pulsive and control processes. The pilot Pulse Models give important insight for the amount of remnant (stick output uncorrelated with the forcing function) that arises from nonlinear pilot technique, and for the remaining remnant arising from different sources unrelated to tracking control (i.e. neuromuscular tremor, reallocation of cognitive resources, etc.).

Autogenic-feedback training improves pilot performance during emergency flying conditions

NASA Technical Reports Server (NTRS)

Kellar, Michael A.; Folen, Raymond A.; Cowings, Patricia S.; Toscano, William B.; Hisert, Glen L.

1993-01-01

Studies have shown that autonomous mode behavior is one cause of aircraft fatalities due to pilot error. In such cases, the pilot is in a high state of psychological and physiological arousal and tends to focus on one problem, while ignoring more critical information. The effect of training in physiological self-recognition and regulation, as a means of improving crew cockpit performance was examined. Seventeen pilots were assigned to the treatment and control groups matched for accumulated flight hours. The treatment group comprised four pilots of HC-130 Hercules aircraft and four HH-65 Dolphin helicopter pilots; the control group comprised three pilots of HC-130's and six Dolphin helicopter pilots. During an initial flight physiological data were recorded for each crewmember and individual crew performance and rated by an instructor pilot. Eight crewmembers were then taught to regulate their own physiological response levels using Autogenic-Feedback Training (AFT). The remaining subjects received no training. During a second flight, treatment subjects showed significant improvement in performance, while controls did not improve. The results indicate that AFT management of high states of physiological arousal may improve pilot performance during emergency flying conditions.

Fatigue in trans-Atlantic airline operations: diaries and actigraphy for two- vs. three-pilot crews.

PubMed

Eriksen, Claire A; Akerstedt, Torbjörn; Nilsson, Jens P

2006-06-01

The aim was to compare intercontinental flights with two-pilot and three-pilot crews with respect to fatigue/sleepiness and sleep, as there is considerable economic pressure on the airlines to use two-pilot crews. Twenty pilots participated. Data were collected before, during, and after outbound and homebound flights using a sleep/wake diary (sleepiness ratings every 2-3 h) and wrist actigraphy. The duration of flights was approximately 8 h, and six time zones were crossed. The same pilots participated in both conditions. Napping during the outbound flight was 26 min for the two-pilot crew, and 48 min for the three-pilot crew. Napping during the homebound flight was 54 min and 1 h 6 min, respectively, and the difference was directly related to the time allotted for sleep. Subjective sleepiness was significantly higher for the two-pilot condition in both directions, peaking a few hours into the flight. Performance at top of descent for the two-pilot condition was rated as lower than the three-pilot condition. In the overall evaluation questionnaire there was a significant negative attitude toward two-crew operations. Sleep, sleepiness, subjective performance, boredom, mood, and layover sleep were assessed as having deteriorated in the two-pilot condition. The homebound flight was associated with considerably higher levels of sleepiness than the outbound flight. The study indicates that the reduction of crew size by one pilot is associated with moderately increased levels of sleepiness. It is also suggested that time allotted to sleep in the two-pilot condition might be somewhat extended to improve alertness.

A pilot evaluation of text display formats for weather information in the cockpit

DOT National Transportation Integrated Search

1995-10-01

This study focuses on the weather (WX) services portion of Data Link. A : two-phase evaluation was conducted with 16 air transport (ATP) and general : aviation (GA) pilots. The pilots evaluated four data formatting options and : four data entry metho...

Agricultural aviation versus other general aviation : toxicological findings in fatal accidents.

DOT National Transportation Integrated Search

1978-09-01

Results from the toxicological study of samples from 174 pilots killed while engaged in aerial application and samples from 2,449 other general aviation pilots are compared. The incidence of alcohol in specimens was similar for ag pilots and other ge...

Effect of motion cues during complex curved approach and landing tasks: A piloted simulation study

NASA Technical Reports Server (NTRS)

Scanlon, Charles H.

1987-01-01

A piloted simulation study was conducted to examine the effect of motion cues using a high fidelity simulation of commercial aircraft during the performance of complex approach and landing tasks in the Microwave Landing System (MLS) signal environment. The data from these tests indicate that in a high complexity MLS approach task with moderate turbulence and wind, the pilot uses motion cues to improve path tracking performance. No significant differences in tracking accuracy were noted for the low and medium complexity tasks, regardless of the presence of motion cues. Higher control input rates were measured for all tasks when motion was used. Pilot eye scan, as measured by instrument dwell time, was faster when motion cues were used regardless of the complexity of the approach tasks. Pilot comments indicated a preference for motion. With motion cues, pilots appeared to work harder in all levels of task complexity and to improve tracking performance in the most complex approach task.

Driving-while-intoxicated history as a risk marker for general aviation pilots.

PubMed

Li, Guohua; Baker, Susan P; Qiang, Yandong; Grabowski, Jurek G; McCarthy, Melissa L

2005-01-01

The Federal Aviation Administration conducts background checking for driving-while-intoxicated (DWI) convictions on all pilots. This study examined the association between DWI history and crash risk in a cohort of 335,672 general aviation pilots. These pilots were followed up from 1994 to 2000 through the aviation crash surveillance system of the National Transportation Safety Board. At baseline, 3.4% of the pilots had a DWI history. DWI history was associated with a 43% increased risk of crash involvement (adjusted relative risk: 1.43; 95% confidence interval: 1.15-1.77). The population-attributable risk fraction for DWI history was estimated as 1.4%. In addition to DWI history, male gender, older age, and inexperience were associated with significantly increased risk of crash involvement. The results of this study support DWI history as a valid risk marker for general aviation pilots. The safety benefit of background checking for DWI history needs to be further evaluated.

PRACA Enhancement Pilot Study Report: Engineering for Complex Systems Program (formerly Design for Safety), DFS-IC-0006

NASA Technical Reports Server (NTRS)

Korsmeyer, David; Schreiner, John

2002-01-01

This technology evaluation report documents the findings and recommendations of the Engineering for Complex Systems Program (formerly Design for Safety) PRACA Enhancement Pilot Study of the Space Shuttle Program's (SSP's) Problem Reporting and Corrective Action (PRACA) System. A team at NASA Ames Research Center (ARC) performed this Study. This Study was initiated as a follow-on to the NASA chartered Shuttle Independent Assessment Team (SIAT) review (performed in the Fall of 1999) which identified deficiencies in the current PRACA implementation. The Pilot Study was launched with an initial qualitative assessment and technical review performed during January 2000 with the quantitative formal Study (the subject of this report) started in March 2000. The goal of the PRACA Enhancement Pilot Study is to evaluate and quantify the technical aspects of the SSP PRACA systems and recommend enhancements to address deficiencies and in preparation for future system upgrades.

Piloted simulation study of two tilt-wing control concepts

NASA Technical Reports Server (NTRS)

Birckelbaw, Lourdes G.; Corliss, Lloyd D.

1994-01-01

A two-phase piloted simulation study was conducted to investigate alternative wing and flap controls for tilt-wing aircraft. The initial phase of the study compared the flying qualities of both a conventional (programmed) flap and an innovative geared flap. The second phase of the study introduced an alternate method of pilot control for the geared flap and further studied the flying qualities of the programmed flap, and two geared flap configurations. In general, the pilot rating showed little variation between the programmed flap and the geared flap control concepts. Some differences between the two concepts were noticed and are discussed in this paper. The addition of pitch attitude stabilization in the second phase of the study greatly enhanced the aircraft flying qualities. This paper describes the simulated tilt-wing aircraft and the flap control concepts and presents the results of both phases of the simulation study.

Are pilot trials useful for predicting randomisation and attrition rates in definitive studies: A review of publicly funded trials.

PubMed

Cooper, Cindy L; Whitehead, Amy; Pottrill, Edward; Julious, Steven A; Walters, Stephen J

2018-04-01

External pilot trials are recommended for testing the feasibility of main or confirmatory trials. However, there is little evidence that progress in external pilot trials actually predicts randomisation and attrition rates in the main trial. To assess the use of external pilot trials in trial design, we compared randomisation and attrition rates in publicly funded randomised controlled trials with rates in their pilots. Randomised controlled trials for which there was an external pilot trial were identified from reports published between 2004 and 2013 in the Health Technology Assessment Journal. Data were extracted from published papers, protocols and reports. Bland-Altman plots and descriptive statistics were used to investigate the agreement of randomisation and attrition rates between the full and external pilot trials. Of 561 reports, 41 were randomised controlled trials with pilot trials and 16 met criteria for a pilot trial with sufficient data. Mean attrition and randomisation rates were 21.1% and 50.4%, respectively, in the pilot trials and 16.8% and 65.2% in the main. There was minimal bias in the pilot trial when predicting the main trial attrition and randomisation rate. However, the variation was large: the mean difference in the attrition rate between the pilot and main trial was -4.4% with limits of agreement of -37.1% to 28.2%. Limits of agreement for randomisation rates were -47.8% to 77.5%. Results from external pilot trials to estimate randomisation and attrition rates should be used with caution as comparison of the difference in the rates between pilots and their associated full trial demonstrates high variability. We suggest using internal pilot trials wherever appropriate.

Are pilot trials useful for predicting randomisation and attrition rates in definitive studies: A review of publicly funded trials

PubMed Central

Whitehead, Amy; Pottrill, Edward; Julious, Steven A; Walters, Stephen J

2018-01-01

Background/aims: External pilot trials are recommended for testing the feasibility of main or confirmatory trials. However, there is little evidence that progress in external pilot trials actually predicts randomisation and attrition rates in the main trial. To assess the use of external pilot trials in trial design, we compared randomisation and attrition rates in publicly funded randomised controlled trials with rates in their pilots. Methods: Randomised controlled trials for which there was an external pilot trial were identified from reports published between 2004 and 2013 in the Health Technology Assessment Journal. Data were extracted from published papers, protocols and reports. Bland–Altman plots and descriptive statistics were used to investigate the agreement of randomisation and attrition rates between the full and external pilot trials. Results: Of 561 reports, 41 were randomised controlled trials with pilot trials and 16 met criteria for a pilot trial with sufficient data. Mean attrition and randomisation rates were 21.1% and 50.4%, respectively, in the pilot trials and 16.8% and 65.2% in the main. There was minimal bias in the pilot trial when predicting the main trial attrition and randomisation rate. However, the variation was large: the mean difference in the attrition rate between the pilot and main trial was −4.4% with limits of agreement of −37.1% to 28.2%. Limits of agreement for randomisation rates were −47.8% to 77.5%. Conclusion: Results from external pilot trials to estimate randomisation and attrition rates should be used with caution as comparison of the difference in the rates between pilots and their associated full trial demonstrates high variability. We suggest using internal pilot trials wherever appropriate. PMID:29361833

Development and validation of Aviation Causal Contributors for Error Reporting Systems (ACCERS).

PubMed

Baker, David P; Krokos, Kelley J

2007-04-01

This investigation sought to develop a reliable and valid classification system for identifying and classifying the underlying causes of pilot errors reported under the Aviation Safety Action Program (ASAP). ASAP is a voluntary safety program that air carriers may establish to study pilot and crew performance on the line. In ASAP programs, similar to the Aviation Safety Reporting System, pilots self-report incidents by filing a short text description of the event. The identification of contributors to errors is critical if organizations are to improve human performance, yet it is difficult for analysts to extract this information from text narratives. A taxonomy was needed that could be used by pilots to classify the causes of errors. After completing a thorough literature review, pilot interviews and a card-sorting task were conducted in Studies 1 and 2 to develop the initial structure of the Aviation Causal Contributors for Event Reporting Systems (ACCERS) taxonomy. The reliability and utility of ACCERS was then tested in studies 3a and 3b by having pilots independently classify the primary and secondary causes of ASAP reports. The results provided initial evidence for the internal and external validity of ACCERS. Pilots were found to demonstrate adequate levels of agreement with respect to their category classifications. ACCERS appears to be a useful system for studying human error captured under pilot ASAP reports. Future work should focus on how ACCERS is organized and whether it can be used or modified to classify human error in ASAP programs for other aviation-related job categories such as dispatchers. Potential applications of this research include systems in which individuals self-report errors and that attempt to extract and classify the causes of those events.

Simulation Evaluation of Pilot Inputs for Real Time Modeling During Commercial Flight Operations

NASA Technical Reports Server (NTRS)

Martos, Borja; Ranaudo, Richard; Oltman, Ryan; Myhre, Nick

2017-01-01

Aircraft dynamics characteristics can only be identified from flight data when the aircraft dynamics are excited sufficiently. A preliminary study was conducted into what types and levels of manual piloted control excitation would be required for accurate Real-Time Parameter IDentification (RTPID) results by commercial airline pilots. This includes assessing the practicality for the pilot to provide this excitation when cued, and to further understand if pilot inputs during various phases of flight provide sufficient excitation naturally. An operationally representative task was evaluated by 5 commercial airline pilots using the NASA Ice Contamination Effects Flight Training Device (ICEFTD). Results showed that it is practical to use manual pilot inputs only as a means of achieving good RTPID in all phases of flight and in flight turbulence conditions. All pilots were effective in satisfying excitation requirements when cued. Much of the time, cueing was not even necessary, as just performing the required task provided enough excitation for accurate RTPID estimation. Pilot opinion surveys reported that the additional control inputs required when prompted by the excitation cueing were easy to make, quickly mastered, and required minimal training.

Conflict Resolution Automation and Pilot Situation Awareness

NASA Technical Reports Server (NTRS)

Dao, Arik-Quang V.; Brandt, Summer L.; Bacon, Paige; Kraut, Josh; Nguyen, Jimmy; Minakata, Katsumi; Raza, Hamzah; Rozovski, David; Johnson, Walter W.

2010-01-01

This study compared pilot situation awareness across three traffic management concepts. The Concepts varied in terms of the allocation of traffic avoidance responsibility between the pilot on the flight deck, the air traffic controllers, and a conflict resolution automation system. In Concept 1, the flight deck was equipped with conflict resolution tools that enable them to fully handle the responsibility of weather avoidance and maintaining separation between ownship and surrounding traffic. In Concept 2, pilots were not responsible for traffic separation, but were provided tools for weather and traffic avoidance. In Concept 3, flight deck tools allowed pilots to deviate for weather, but conflict detection tools were disabled. In this concept pilots were dependent on ground based automation for conflict detection and resolution. Situation awareness of the pilots was measured using online probes. Results showed that individual situation awareness was highest in Concept 1, where the pilots were most engaged, and lowest in Concept 3, where automation was heavily used. These findings suggest that for conflict resolution tasks, situation awareness is improved when pilots remain in the decision-making loop.

Pilot Alcohol Violations Reported in U.S. Newspapers, 1990–2006

PubMed Central

Kraus, Chadd K.; Li, Guohua

2009-01-01

Introduction Alcohol violations by airline pilots are rare yet remain a public concern. Such incidents often generate widespread news coverage. This study examines the frequency and characteristics of alcohol violation incidents involving airline pilots reported in U.S. newspapers. Methods The database of Lexis-Nexis™, which contains full-text articles for over 350 newspapers, was searched to identify alcohol violation incidents involving airline pilots in the U.S. between January 1990 and June 2006. Information pertaining to the pilot, flight, blood alcohol concentration (BAC), and consequence was ascertained for each incident based on the newspaper coverage. Results During the study period, newspapers reported on a total of 13 incidents of alcohol violations involving 17 pilots. All but two of the incidents occurred during January 2002 through June 2006. The majority (85%) of the incidents were first identified by airport personnel, such as security screeners, based on suspicion of alcohol use by the pilot. Subsequent alcohol testing revealed a mean BAC of 90 mg/dL (ranging from 10 mg · dL−1 to 182 mg · dL−1). Of the 17 pilots, 6 were known to be prosecuted criminally, including 5 who were sentenced to jail terms. Discussion Incidents of alcohol violations by airline pilots reported in U.S. newspapers have increased in recent years. This increase is likely due in part to increased detection resulting from enhanced aviation security and enforcement following the September 2001 terrorist attacks. PMID:17183928

Hunner's Ulcers

MedlinePlus

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Bladder Retraining

MedlinePlus

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Portable Weather Applications for General Aviation Pilots.

PubMed

Ahlstrom, Ulf; Ohneiser, Oliver; Caddigan, Eamon

2016-09-01

The objective of this study was to examine the potential benefits and impact on pilot behavior from the use of portable weather applications. Seventy general aviation (GA) pilots participated in the study. Each pilot was randomly assigned to an experimental or a control group and flew a simulated single-engine GA aircraft, initially under visual meteorological conditions (VMC). The experimental group was equipped with a portable weather application during flight. We recorded measures for weather situation awareness (WSA), decision making, cognitive engagement, and distance from the aircraft to hazardous weather. We found positive effects from the use of the portable weather application, with an increased WSA for the experimental group, which resulted in credibly larger route deviations and credibly greater distances to hazardous weather (≥30 dBZ cells) compared with the control group. Nevertheless, both groups flew less than 20 statute miles from hazardous weather cells, thus failing to follow current weather-avoidance guidelines. We also found a credibly higher cognitive engagement (prefrontal oxygenation levels) for the experimental group, possibly reflecting increased flight planning and decision making on the part of the pilots. Overall, the study outcome supports our hypothesis that portable weather displays can be used without degrading pilot performance on safety-related flight tasks, actions, and decisions as measured within the constraints of the present study. However, it also shows that an increased WSA does not automatically translate to enhanced flight behavior. The study outcome contributes to our knowledge of the effect of portable weather applications on pilot behavior and decision making. © 2016, Human Factors and Ergonomics Society.

Ball Powder Production Wastewater Biodegradation Support Studies - With Nitroglycerine

DTIC Science & Technology

1989-02-01

in the wastewater. Characterization of the ball powder wastewater stream showed an actual average NG inlet concentration of 192 mg/L. Pilot test...the first phase of pilot testing, the recommendation was made to conduct an additional pilot test phase to determine the effect of nitroglycerin (NG...NG by aerobic bacteria, a pilot program was undertaken with the following objectives: 1) to determine the concentration of NG in the ball powder

V/STOL tilt rotor aircraft study. Volume 9: Piloted simulator evaluation of the Boeing Vertol model 222 tilt rotor aircraft

NASA Technical Reports Server (NTRS)

Rosenstein, H.; Mcveigh, M. A.; Mollenkof, P. A.

1973-01-01

The results of a real time piloted simulation to investigate the handling qualities and performance of a tilting rotor aircraft design are presented. The aerodynamic configuration of the aircraft is described. The procedures for conducting the simulator evaluation are reported. Pilot comments of the aircraft handling qualities under various simulated flight conditions are included. The time histories of selected pilot maneuvers are shown.

TAMPA ASTHMATIC CHILDREN'S STUDY (TACS)

EPA Science Inventory

The Tampa Asthmatic Children's Study (TACS) was a pilot research study to assess methodologies and research instruments needed for including asthma as a health outcome in the National Children's Study (NCS). This was one of a series of pilot studies focusing on (a) simple, cos...

The Impact of Suggestive Maneuver Guidance on UAS Pilots Performing the Detect and Avoid Function

NASA Technical Reports Server (NTRS)

Rorie, Conrad; Fern, Lisa; Shively, Jay

2016-01-01

This presentation discusses the results of a recent UAS Integration into the NAS human-in-the-loop simulation. In the study, 16 active UAS pilots flew a UAS through civil airspace and were tasked with maintaining well clear from other aircraft in the area. Pilots performed the task with four different detect and avoid (DAA) traffic displays, each of which varied in the form of guidance it provided to pilots The present findings focus on how the different displays impacted pilots' measured response to scripted conflicts with their aircraft. Measured response is made up of several components, each of which help inform our understanding of the pilots' role in the overall detect and avoid task.

Applications of pilot scanning behavior to integrated display research

NASA Technical Reports Server (NTRS)

Waller, M. C.

1977-01-01

The oculometer is an electrooptical device designed to measure pilot scanning behavior during instrument approaches and landing operations. An overview of some results from a simulation study is presented to illustrate how information from the oculometer installed in a visual motion simulator, combined with measures of performance and control input data, can provide insight into the behavior and tactics of individual pilots during instrument approaches. Differences in measured behavior of the pilot subjects are pointed out; these differences become apparent in the way the pilots distribute their visual attention, in the amount of control activity, and in selected performance measures. Some of these measured differences have diagnostic implications, suggesting the use of the oculometer along with performance measures as a pilot training tool.

Impact of gender, age and experience of pilots on general aviation accidents.

PubMed

Bazargan, Massoud; Guzhva, Vitaly S

2011-05-01

General aviation (GA) accounts for more than 82% of all air transport-related accidents and air transport-related fatalities in the U.S. In this study, we conduct a series of statistical analyses to investigate the significance of a pilot's gender, age and experience in influencing the risk for pilot errors and fatalities in GA accidents. There is no evidence from the Chi-square tests and logistic regression models that support the likelihood of an accident caused by pilot error to be related to pilot gender. However, evidence is found that male pilots, those older than 60 years of age, and with more experience, are more likely to be involved in a fatal accident. Copyright © 2010 Elsevier Ltd. All rights reserved.

Functional aging in pilots : an examination of a mathematical model based on medical data on general aviation pilots.

DOT National Transportation Integrated Search

1982-06-01

The purpose of this study was to apply mathematical procedures to the Federal Aviation Administration (FAA) pilot medical data to examine the feasibility of devising a linear numbering system such that (1) the cumulative probability distribution func...

The influence of ATC message length and timing on pilot communication

NASA Technical Reports Server (NTRS)

Morrow, Daniel; Rodvold, Michelle

1993-01-01

Pilot-controller communication is critical to safe and efficient flight. It is often a challenging component of piloting, which is reflected in the number of incidents and accidents involving miscommunication. Our previous field study identified communication problems that disrupt routine communication between pilots and controllers. The present part-task simulation study followed up the field results with a more controlled investigation of communication problems. Pilots flew a simulation in which they were frequently vectored by Air Traffic Control (ATC), requiring intensive communication with the controller. While flying, pilots also performed a secondary visual monitoring task. We examined the influence of message length (one message with four commands vs. two messages with two commands each) and noncommunication workload on communication accuracy and length. Longer ATC messages appeared to overload pilot working memory, resulting in more incorrect or partial readbacks, as well as more requests to repeat the message. The timing between the two short messages also influenced communication. The second message interfered with memory for or response to the first short message when it was delivered too soon after the first message. Performing the secondary monitoring task did not influence communication. Instead, communication reduced monitoring accuracy.

Effects of False Tilt Cues on the Training of Manual Roll Control Skills

NASA Technical Reports Server (NTRS)

Zaal, Peter M. T.; Popovici, Alexandru; Zavala, Melinda A.

2015-01-01

This paper describes a transfer-of-training study performed in the NASA Ames Vertica lMotion Simulator. The purpose of the study was to investigate the effect of false tilt cues on training and transfer of training of manual roll control skills. Of specific interest were the skills needed to control unstable roll dynamics of a mid-size transport aircraft close to the stall point. Nineteen general aviation pilots trained on a roll control task with one of three motion conditions: no motion, roll motion only, or reduced coordinated roll motion. All pilots transferred to full coordinated roll motion in the transfer session. A novel multimodal pilot model identification technique was successfully applied to characterize how pilots' use of visual and motion cues changed over the course of training and after transfer. Pilots who trained with uncoordinated roll motion had significantly higher performance during training and after transfer, even though they experienced the false tilt cues. Furthermore, pilot control behavior significantly changed during the two sessions, as indicated by increasing visual and motion gains, and decreasing lead time constants. Pilots training without motion showed higher learning rates after transfer to the full coordinated roll motion case.

Comparison of Postural Responses to Galvanic Vestibular Stimulation between Pilots and the General Populace

PubMed Central

Yang, Yang; Pu, Fang; Lv, Xiaoning; Li, Shuyu; Li, Jing; Li, Deyu; Li, Minggao

2015-01-01

Galvanic vestibular stimulation (GVS) can be used to study the body's response to vestibular stimuli. This study aimed to investigate whether postural responses to GVS were different between pilots and the general populace. Bilateral bipolar GVS was applied with a constant-current profile to 12 pilots and 12 control subjects via two electrodes placed over the mastoid processes. Both GVS threshold and the center of pressure's trajectory (COP's trajectory) were measured. Position variability of COP during spontaneous body sway and peak displacement of COP during GVS-induced body sway were calculated in the medial-lateral direction. Spontaneous body sway was slight for all subjects, and there was no significant difference in the value of COP position variability between the pilots and controls. Both the GVS threshold and magnitude of GVS-induced body deviation were similar for different GVS polarities. GVS thresholds were similar between the two groups, but the magnitude of GVS-induced body deviation in the controls was significantly larger than that in the pilots. The pilots showed less GVS-induced body deviation, meaning that pilots may have a stronger ability to suppress vestibular illusions. PMID:25632395

Men and IC

MedlinePlus

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IC Associated Conditions

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General IC Symptoms

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Children and IC

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Statistical analysis plan of the head position in acute ischemic stroke trial pilot (HEADPOST pilot).

PubMed

Olavarría, Verónica V; Arima, Hisatomi; Anderson, Craig S; Brunser, Alejandro; Muñoz-Venturelli, Paula; Billot, Laurent; Lavados, Pablo M

2017-02-01

Background The HEADPOST Pilot is a proof-of-concept, open, prospective, multicenter, international, cluster randomized, phase IIb controlled trial, with masked outcome assessment. The trial will test if lying flat head position initiated in patients within 12 h of onset of acute ischemic stroke involving the anterior circulation increases cerebral blood flow in the middle cerebral arteries, as measured by transcranial Doppler. The study will also assess the safety and feasibility of patients lying flat for ≥24 h. The trial was conducted in centers in three countries, with ability to perform early transcranial Doppler. A feature of this trial was that patients were randomized to a certain position according to the month of admission to hospital. Objective To outline in detail the predetermined statistical analysis plan for HEADPOST Pilot study. Methods All data collected by participating researchers will be reviewed and formally assessed. Information pertaining to the baseline characteristics of patients, their process of care, and the delivery of treatments will be classified, and for each item, appropriate descriptive statistical analyses are planned with comparisons made between randomized groups. For the outcomes, statistical comparisons to be made between groups are planned and described. Results This statistical analysis plan was developed for the analysis of the results of the HEADPOST Pilot study to be transparent, available, verifiable, and predetermined before data lock. Conclusions We have developed a statistical analysis plan for the HEADPOST Pilot study which is to be followed to avoid analysis bias arising from prior knowledge of the study findings. Trial registration The study is registered under HEADPOST-Pilot, ClinicalTrials.gov Identifier NCT01706094.

Methods for Aiding Height Determination in Pseudolite-Based Reference Systems Using Batch Least-Squares Estimation

DTIC Science & Technology

2006-03-01

LocataLite Test Examples. LocataLites have been used in several experimental trials as pilot studies of the system. 1.7.5.1 BlueScope Steel. In this pilot...study, [2], the Locata system is shown to give centimeter level relative positioning precision in a severe multipath en- vironment. The BlueScope ...Using Locata: A pilot study at BlueScope Steel.” Proceedings of the 2004 Annual Meeting of the U.S. Institute of Navigation. Dayton, OH, June 2004. 3

Integrating Virtual Worlds with Tangible User Interfaces for Teaching Mathematics: A Pilot Study.

PubMed

Guerrero, Graciela; Ayala, Andrés; Mateu, Juan; Casades, Laura; Alamán, Xavier

2016-10-25

This article presents a pilot study of the use of two new tangible interfaces and virtual worlds for teaching geometry in a secondary school. The first tangible device allows the user to control a virtual object in six degrees of freedom. The second tangible device is used to modify virtual objects, changing attributes such as position, size, rotation and color. A pilot study on using these devices was carried out at the "Florida Secundaria" high school. A virtual world was built where students used the tangible interfaces to manipulate geometrical figures in order to learn different geometrical concepts. The pilot experiment results suggest that the use of tangible interfaces and virtual worlds allowed a more meaningful learning (concepts learnt were more durable).

Study of Synthetic Vision Systems (SVS) and Velocity-vector Based Command Augmentation System (V-CAS) on Pilot Performance

NASA Technical Reports Server (NTRS)

Liu, Dahai; Goodrich, Ken; Peak, Bob

2006-01-01

This study investigated the effects of synthetic vision system (SVS) concepts and advanced flight controls on single pilot performance (SPP). Specifically, we evaluated the benefits and interactions of two levels of terrain portrayal, guidance symbology, and control-system response type on SPP in the context of lower-landing minima (LLM) approaches. Performance measures consisted of flight technical error (FTE) and pilot perceived workload. In this study, pilot rating, control type, and guidance symbology were not found to significantly affect FTE or workload. It is likely that transfer from prior experience, limited scope of the evaluation task, specific implementation limitations, and limited sample size were major factors in obtaining these results.

Salivary alpha-amylase activity and stress in Japan air self-defense force cargo pilots involved in Iraq reconstruction.

PubMed

Iizuka, Naotaka; Awano, Shuji; Ansai, Toshihiro

2012-01-01

This study aimed to verify whether salivary α-amylase enzyme activity (Amy) is useful as a biomarker of stress in pilots working in a stressful environment. The subjects in this study were nine Japan air self-defense force pilots who participated in Iraq reconstruction support activity in Kuwait. Amy was measured using a portable salivary amylase monitor at preflight, postflight, and on stand-by day. In addition, the state-trait anxiety inventory was administered with state scores (STAI-S) compared to Amy levels. There were greater differences in Amy levels at baseline compared to STAI-S scores between subjects on the stand-by day. Amy levels at preflight tended to increase compared to those on stand-by day as did STAI-S. The change in Amy level at postflight varied among the pilots. The Amy levels of four subjects at postflight were elevated compared to levels at preflight, while the STAI-S scores for all pilots at postflight were lower than at preflight. This study suggests that the Amy level of pilots can reflect subtle individual differences in response to the psychological and physiological stress of a flight task. Thus, monitoring Amy level may be useful for stress evaluation of pilots working in a stressful environment, providing data that might be used as an impetus for addressing stress management for this population. Copyright © 2012 Wiley Periodicals, Inc.

OTEC riser cable system, Phase II: conceptual design

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

Not Available

1980-10-01

Studies are summarized of conceptual designs of riser cable systems for OTEC pilot plants of both the spar and plantship configurations located at sites off the southeast coast of Puerto Rico. The studies utilize a baseline pilot plant riser cable, the design of which has been developed and reported on in other reports. Baseline riser cable systems for OTEC pilot plants are identified, system hardware consistent with these designs are conceptualized, and comparisons of the various system concepts are provided. It is concluded that there are three riser cable systems feasible for a spar pilot plant platform at the Puntamore » Yeguas site, and two riser cable systems feasible at the plantship pilot plant at the Punta Tuna site. Recommendations for further investigations in the areas of materials, hardware design and pre-installation site surveys are also addressed.« less

Pilot performance

NASA Technical Reports Server (NTRS)

Nicholls, Jennifer

1988-01-01

For many years, the emphasis has been placed on the performance of the aircraft, rather than on those who fly the aircraft. This is largely due to the relative safety of flying. Just in the last few years there have been several major accidents that have shown that flying is not quite as safe as it was thought to be. Sixty-five percent of these accidents are a result of pilot performance decrements, and so it is obvious that there is a need to reduce that figure. A study has been mandated to evaluate the performance of pilots. This includes workload, circadium rhythms, jet lag, and any other factors which might affect a pilot's performance in the cockpit. The purpose of this study is to find out when and why the decrement in a pilot's performance occur and how to remedy the situation.

On the development of a new methodology in sub-surface parameterisation on the calibration of groundwater models

NASA Astrophysics Data System (ADS)

Klaas, D. K. S. Y.; Imteaz, M. A.; Sudiayem, I.; Klaas, E. M. E.; Klaas, E. C. M.

2017-10-01

In groundwater modelling, robust parameterisation of sub-surface parameters is crucial towards obtaining an agreeable model performance. Pilot point is an alternative in parameterisation step to correctly configure the distribution of parameters into a model. However, the methodology given by the current studies are considered less practical to be applied on real catchment conditions. In this study, a practical approach of using geometric features of pilot point and distribution of hydraulic gradient over the catchment area is proposed to efficiently configure pilot point distribution in the calibration step of a groundwater model. A development of new pilot point distribution, Head Zonation-based (HZB) technique, which is based on the hydraulic gradient distribution of groundwater flow, is presented. Seven models of seven zone ratios (1, 5, 10, 15, 20, 25 and 30) using HZB technique were constructed on an eogenetic karst catchment in Rote Island, Indonesia and their performances were assessed. This study also concludes some insights into the trade-off between restricting and maximising the number of pilot points and offers a new methodology for selecting pilot point properties and distribution method in the development of a physically-based groundwater model.

A piloted simulation investigation of yaw dynamics requirements for turreted gun use in low-level helicopter air combat

NASA Technical Reports Server (NTRS)

Decker, William A.; Morris, Patrick M.; Williams, Jeffrey N.

1988-01-01

A piloted, fixed-base simulation study was conducted to investigate the handling qualities requirements for helicopter air-to-air combat using turreted guns in the near-terrain environment. The study used a version of the helicopter air combat system developed at NASA Ames Research Center for one-on-one air combat. The study focused on the potential trade-off between gun angular movement capability and required yaw axis response. Experimental variables included yaw axis response frequency and damping and the size of the gun-movement envelope. A helmet position and sighting system was used for pilot control of gun aim. Approximately 340 simulated air combat engagements were evaluated by pilots from the Army and industry. Results from the experiment indicate that a highly-damped, high frequency yaw response was desired for Level I handling qualities. Pilot preference for those characteristics became more pronounced as gun turret movement was restricted; however, a stable, slow-reacting platform could be used with a large turret envelope. Most pilots preferred to engage with the opponent near the own-ship centerline. Turret elevation restriction affected the engagement more than azimuth restrictions.

Integration of Diagnostic and Interventional MRI for the Study of Persistent Prostate Cancer after External Beam Radiotherapy

DTIC Science & Technology

2009-10-01

1500 ms). A clinical pilot study reported equivalence between central gland (CG) and peripheral zone (PZ) T1 values (CG: 1321±45 ms, n=14; PZ: 1359...across variable TI, the period of longitudinal recovery is kept independent of TI selection for any TR. Central to T1prep is RF cycling of an...pilot study A clinical pilot study involved 15 patients with low or intermediate risk localized prostate cancer and no history of prior therapy. The

Conservative Management of Mechanical Neck Pain in a Helicopter Pilot.

PubMed

Alagha, Babak

2015-10-01

Acute and chronic spinal symptoms such as neck pain may limit flying performance significantly and disqualify the pilot from flight duty. Mechanical neck pain is very common among pilots because of their exposure to vibration, +GZ forces, helmet weight, poor neck posture during air combat maneuvers, previous neck injuries, and poor treatment plans for such injuries. Successful treatment of such injuries requires appropriate therapeutic procedures as well as an aeromedical assessment. The aim of this case study was to demonstrate the benefits of conservative procedures such as spinal manipulation and mobilization therapy (SMMT) and exercise therapy (ET) in treating chronic mechanical neck pain in an Iranian commercial helicopter pilot. A 36-yr-old male patient presented to the clinic with moderate, intermittent nonradicular chronic neck pain and limited range of motion over a 2-yr period. The patient was treated with cervical and upper thoracic SMMT followed by home ET for 5 wk. After this period, the patient reported significant recovery and improvement in range of motion in his neck. Mechanical neck pain is very common among helicopter pilots. Although Air Force and Navy waiver guides recommend nonsteroidal anti-inflammatory medications as well as SMMT and ET, there are currently very few published studies that examine the benefits of manual and exercise therapy for treating mechanical neck pain in commercial and military pilots. Based on the results of this study, it seems that SMMT and ET may be a safe and effective in treatment of uncomplicated mechanical neck pain in helicopter pilots. Alagha B. Conservative management of mechanical neck pain in a helicopter pilot.

An approach to the determination of aircraft handling qualities using pilot transfer functions

NASA Technical Reports Server (NTRS)

Adams, J. J.; Hatch, H. G., Jr.

1978-01-01

It was shown that a correlation exists between pilot-aircraft system closed-loop characteristics, determined by using analytical expressions for pilot response along with the analytical expression for the aircraft response, and pilot ratings obtained in many previous flight and simulation studies. Two different levels of preferred pilot response were used. These levels were: (1) a static gain and a second-order lag function with a lag time constant of 0.2 second; and (2) a static gain, a lead time constant of 1 second, and a 0.2-second lag time constant. If a system response with a pitch-angle time constant of 2.6 seconds and a stable oscillatory mode of motion with a period of 2.5 seconds could be achieved with the first-level pilot model, it was shown that the pilot rating will be satisfactory for that vehicle.

Interstitial Cystitis and Diet

MedlinePlus

... Epidemiology (RICE) Study Boston Area Community Health (BACH) Survey ICA Pilot Research Program Funding Opportunities Clinical Trial ... Epidemiology (RICE) Study Boston Area Community Health (BACH) Survey ICA Pilot Research Program Funding Opportunities Clinical Trial ...

IC Treatment: Surgical Procedures

MedlinePlus

... Epidemiology (RICE) Study Boston Area Community Health (BACH) Survey ICA Pilot Research Program Funding Opportunities Clinical Trial ... Epidemiology (RICE) Study Boston Area Community Health (BACH) Survey ICA Pilot Research Program Funding Opportunities Clinical Trial ...

IC: Frequently Asked Questions

MedlinePlus

... Epidemiology (RICE) Study Boston Area Community Health (BACH) Survey ICA Pilot Research Program Funding Opportunities Clinical Trial ... Epidemiology (RICE) Study Boston Area Community Health (BACH) Survey ICA Pilot Research Program Funding Opportunities Clinical Trial ...

Variations in Party Line Information Requirements for Flight Crew Situation Awareness in the Datalink Environment

NASA Technical Reports Server (NTRS)

Pritchett, Amy R.; Hansman, R. John

1994-01-01

Current Air Traffic Control communications use shared very high frequency (VHF) voice frequencies from which pilots can obtain 'Party Line' Information (PLI) by overhearing communications addressed to other aircraft. A prior study has shown pilots perceive this PLI to be important. There is concern that some critical PLI may be lost in the proposed datalink environment where communications will be discretely addressed. Different types of flight operations will be, equipped with datalink equipment at different times, generating a 'mixed environment' where some pilots may rely on PLI while others will receive their information by datalink. To research the importance, availability and accuracy of PLI and to query pilots on the information they feel is necessary, a survey was distributed to pilots. The pilots were selected from four flight operation groups to study the variations in PLI requirements in the mixed datalink environment. Pilots perceived PLI to be important overall. Specific information elements pertaining to traffic and weather information were identified as Critical. Most PLI elements followed a pattern of higher perceived importance during terminal area operations, final approach and landing. Pilots from the different flight operation groups identified some elements as particularly important. Pilots perceived PLI to be only moderately available and accurate overall. Several PLI elements received very low availability and accuracy ratings but are perceived as important. In a free response question designed to find the information requirements for global situation awareness, pilots frequently indicated a need for traffic and weather information. These elements were also frequently cited by them as information that could be presented by a datalink system. The results of this survey identify specific concerns to be addressed when implementing datalink communications.

A Pilot Trial of the Combination of Vemurafenib with Adoptive Cell Therapy in Patients with Metastatic Melanoma.

PubMed

Deniger, Drew C; Kwong, Mei Li M; Pasetto, Anna; Dudley, Mark E; Wunderlich, John R; Langhan, Michelle M; Lee, Chyi-Chia Richard; Rosenberg, Steven A

2017-01-15

This pilot feasibility clinical trial evaluated the coadministration of vemurafenib, a small-molecule antagonist of BRAF V600 mutations, and tumor-infiltrating lymphocytes (TIL) for the treatment of metastatic melanoma. A metastatic tumor was resected for growth of TILs, and patients were treated with vemurafenib for 2 weeks, followed by resection of a second lesion. Patients then received a nonmyeloablative preconditioning regimen, infusion of autologous TILs, and high-dose interleukin-2 administration. Vemurafenib was restarted at the time of TIL infusion and was continued for 2 years or until disease progression. Clinical responses were evaluated by Response Evaluation Criteria in Solid Tumors (RECIST) 1.0. Metastases resected prior to and after 2 weeks of vemurafenib were compared using TCRB deep sequencing, immunohistochemistry, proliferation, and recognition of autologous tumor. The treatment was well tolerated and had a safety profile similar to that of TIL or vemurafenib alone. Seven of 11 patients (64%) experienced an objective clinical response, and 2 patients (18%) had a complete response for 3 years (one response is ongoing at 46 months). Proliferation and viability of infusion bag TILs and peripheral blood T cells were inhibited in vitro by research-grade vemurafenib (PLX4032) when approaching the maximum serum concentration of vemurafenib. TCRB repertoire (clonotypes numbers, clonality, and frequency) did not significantly change between pre- and post-vemurafenib lesions. Recognition of autologous tumor by T cells was similar between TILs grown from pre- and post-vemurafenib metastases. Coadministration of vemurafenib and TILs was safe and feasible and generated objective clinical responses in this small pilot clinical trial. Clin Cancer Res; 23(2); 351-62. ©2016 AACRSee related commentary by Cogdill et al., p. 327. ©2016 American Association for Cancer Research.

Motivational Engineering for Pilot Training.

ERIC Educational Resources Information Center

Herzberg, Frederick I.; And Others

The study was an investigation of student pilot motivation for, and toward, the Air Training Command's undergraduate pilot training (UPT) program. The motivation hygiene approach was used to identify the motivational factors operating in the UPT program systematically. This approach has been used extensively in industry and with success in a…

The Pilot Staffing Conundrum: A Delphi Study

DTIC Science & Technology

2009-06-01

Project, AFIT/ GMO /LAL/98J-2. School of Logistics and Acquisition Management, Air Force Institute of Technology (AU), Wright Patterson AFB, OH, June...Kafer, John H. Relationship of Airline Pilot Demand and Air Force Pilot Retention. Graduate Research Project, AFIT/ GMO /LAL/98J-11. School of Logistics

GIS data for the Seaside, Oregon, Tsunami Pilot Study to modernize FEMA flood hazard maps

USGS Publications Warehouse

Wong, Florence L.; Venturato, Angie J.; Geist, Eric L.

2007-01-01

A Tsunami Pilot Study was conducted for the area surrounding the coastal town of Seaside, Oregon, as part of the Federal Emergency Management's (FEMA) Flood Insurance Rate Map Modernization Program (Tsunami Pilot Study Working Group, 2006). The Cascadia subduction zone extends from Cape Mendocino, California, to Vancouver Island, Canada. The Seaside area was chosen because it is typical of many coastal communities subject to tsunamis generated by far- and near-field (Cascadia) earthquakes. Two goals of the pilot study were to develop probabilistic 100-year and 500-year tsunami inundation maps using Probabilistic Tsunami Hazard Analysis (PTHA) and to provide recommendations for improving tsunami hazard assessment guidelines for FEMA and state and local agencies. The study was an interagency effort by the National Oceanic and Atmospheric Administration, U.S. Geological Survey, and FEMA, in collaboration with the University of Southern California, Middle East Technical University, Portland State University, Horning Geoscience, Northwest Hydraulics Consultants, and the Oregon Department of Geological and Mineral Industries. The pilot study model data and results are published separately as a geographic information systems (GIS) data report (Wong and others, 2006). The flood maps and GIS data are briefly described here.

The potential for dental plaque to protect against erosion using an in vivo-in vitro model--a pilot study.

PubMed

Cheung, A; Zid, Z; Hunt, D; McIntyre, J

2005-12-01

Tooth erosion is a problem for professional wine tasters (exogenous erosion from frequent exposure to wine acids) and for people with gastro oesophageal reflux disease (GORD) and bulimia who experience frequent reflux of gastric contents into the mouth (endogenous erosion from mainly HCl). The objective in this study was to determine whether plaque/pellicle could provide teeth with any protection from two common erosive acids, using an in vivo-in vitro technique. Tiles of human tooth enamel and root surfaces were prepared from six extracted, unerupted third molar teeth and sterilized. Mandibular stents were prepared for six volunteer subjects and the tiles bonded to the buccal flanges of these stents. They were worn initially for three days to permit a layer of pellicle and plaque to form over the tile surfaces, and for a further 10 days of experimentation. Following cleaning of the plaque/ pellicle layer from the tiles on the right side flange, all the tiles were submerged in either 0.06M HCl or white wine for an accumulated time of 600 and 1500 minutes, respectively. Depths of erosion were determined using light microscopy of sections of the enamel and root tiles. SEM of the lesion surfaces was carried out to investigate the nature of erosive damage and of plaque/pellicle remnants. Retained plaque was found to significantly inhibit dental erosion on enamel, from contact with both HCl and wine, compared with that resulting following its removal. However, it was found to provide no significant protection on root surfaces. SEM analysis of the tile surfaces revealed marked etching of enamel on the cleaned surfaces, and considerable alteration to the appearance of remaining plaque and pellicle on most surfaces. Within the limitations of numbers of specimens, dental plaque/pellicle provided a significant level of protection to tooth enamel against dental erosion from simulated gastric acids and from white wine, using an in vivo-in vitro model. It was unable to provide any significant protection to root surfaces from these erosive agents. Possible reasons for this difference are explored.

Cardiomyogenic Differentiation of Human Dental Follicle-derived Stem Cells by Suberoylanilide Hydroxamic Acid and Their In Vivo Homing Property.

PubMed

Sung, Iel-Yong; Son, Han-Na; Ullah, Imran; Bharti, Dinesh; Park, Ju-Mi; Cho, Yeong-Cheol; Byun, June-Ho; Kang, Young-Hoon; Sung, Su-Jin; Kim, Jong-Woo; Rho, Gyu-Jin; Park, Bong-Wook

2016-01-01

The purpose of the present study was to investigate the in vitro cardiomyogenic differentiation potential of human dental follicle-derived stem cells (DFCs) under the influence of suberoylanilide hydroxamic acid (SAHA), a member of the histone deacetylase inhibitor family, and analyze the in vivo homing capacity of induced cardiomyocytes (iCMs) when transplanted systemically. DFCs from extracted wisdom teeth showed mesenchymal stem cell (MSC) characteristics such as plate adherent growing, expression of MSC markers (CD44, CD90, and CD105), and mesenchymal lineage-specific differentiation potential. Adding SAHA to the culture medium induced the successful in vitro differentiation of DFCs into cardiomyocytes. These iCMs expressed cardiomyogenic markers, including alpha-smooth muscle actin (α-SMA), cardiac muscle troponin T (TNNT2), Desmin, and cardiac muscle alpha actin (ACTC1) , at both the mRNA and protein level. For the assessment of homing capacity, PKH26 labeled iCMs were intraperitoneally injected (1×10 6 cells in 100 µL of PBS) into the experimental mice, and the ratios of PKH26 positive cells to the total number of injected cells, in multiple organs were determined. The calculated homing ratios, 14 days after systemic cell transplantation, were 5.6 ± 1.0%, 3.6 ± 1.1%, and 11.6 ± 2.7% in heart, liver, and kidney respectively. There was no difference in the serum levels of interleukin-2 and interleukin-10 at 14 days after transplantation, between the experimental (iCM injected) and control (no injection or PBS injection) groups. These results demonstrate that DFCs can be an excellent source for cardiomyocyte differentiation and regeneration. Moreover, the iCMs can be delivered into heart muscle via systemic administration without eliciting inflammatory or immune response. This can serve as the pilot study for further investigations into the in vitro cardiomyogenic differentiation potential of DFCs under the influence of SAHA and the in vivo homing capacity of the iCMs into the heart muscle, when injected systemically.

In-vivo corneal pulsation in relation to in-vivo intraocular pressure and corneal biomechanics assessed in-vitro. An animal pilot study.

PubMed

Rogala, Maja M; Danielewska, Monika E; Antończyk, Agnieszka; Kiełbowicz, Zdzisław; Rogowska, Marta E; Kozuń, Marta; Detyna, Jerzy; Iskander, D Robert

2017-09-01

The aim was to ascertain whether the characteristics of the corneal pulse (CP) measured in-vivo in a rabbit eye change after short-term artificial increase of intraocular pressure (IOP) and whether they correlate with corneal biomechanics assessed in-vitro. Eight New Zealand white rabbits were included in this study and were anesthetized. In-vivo experiments included simultaneous measurements of the CP signal, registered with a non-contact method, IOP, intra-arterial blood pressure, and blood pulse (BPL), at the baseline and short-term elevated IOP. Afterwards, thickness of post-mortem corneas was determined and then uniaxial tensile tests were conducted leading to estimates of their Young's modulus (E). At the baseline IOP, backward stepwise regression analyses were performed in which successively the ocular biomechanical, biometric and cardiovascular predictors were separately taken into account. Results of the analysis revealed that the 3rd CP harmonic can be statistically significantly predicted by E and central corneal thickness (Models: R 2  = 0.662, p < 0.005 and R 2  = 0.832, p < 0.001 for the signal amplitude and power, respectively). The 1st CP harmonic can be statistically significantly predicted by the amplitude and power of the 1st BPL harmonic (Models: R 2  = 0.534, p = 0.015 and R 2  = 0.509, p < 0.018, respectively). For elevated IOP, non-parametric analysis indicated significant differences for the power of the 1st CP harmonic (Kruskal-Wallis test; p = 0.031) and for the mean, systolic and diastolic blood pressures (p = 0.025, p = 0.019, p = 0.033, respectively). In conclusion, for the first time, the association between parameters of the CP signal in-vivo and corneal biomechanics in-vitro was confirmed. In particular, spectral analysis revealed that higher amplitude and power of the 3rd CP harmonic indicates higher corneal stiffness, while the 1st CP harmonic correlates positively with the corresponding harmonic of the BPL signal. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enhanced Flight Vision Systems Operational Feasibility Study Using Radar and Infrared Sensors

NASA Technical Reports Server (NTRS)

Etherington, Timothy J.; Kramer, Lynda J.; Severance, Kurt; Bailey, Randall E.; Williams, Steven P.; Harrison, Stephanie J.

2015-01-01

Approach and landing operations during periods of reduced visibility have plagued aircraft pilots since the beginning of aviation. Although techniques are currently available to mitigate some of the visibility conditions, these operations are still ultimately limited by the pilot's ability to "see" required visual landing references (e.g., markings and/or lights of threshold and touchdown zone) and require significant and costly ground infrastructure. Certified Enhanced Flight Vision Systems (EFVS) have shown promise to lift the obscuration veil. They allow the pilot to operate with enhanced vision, in lieu of natural vision, in the visual segment to enable equivalent visual operations (EVO). An aviation standards document was developed with industry and government consensus for using an EFVS for approach, landing, and rollout to a safe taxi speed in visibilities as low as 300 feet runway visual range (RVR). These new standards establish performance, integrity, availability, and safety requirements to operate in this regime without reliance on a pilot's or flight crew's natural vision by use of a fail-operational EFVS. A pilot-in-the-loop high-fidelity motion simulation study was conducted at NASA Langley Research Center to evaluate the operational feasibility, pilot workload, and pilot acceptability of conducting straight-in instrument approaches with published vertical guidance to landing, touchdown, and rollout to a safe taxi speed in visibility as low as 300 feet RVR by use of vision system technologies on a head-up display (HUD) without need or reliance on natural vision. Twelve crews flew various landing and departure scenarios in 1800, 1000, 700, and 300 RVR. This paper details the non-normal results of the study including objective and subjective measures of performance and acceptability. The study validated the operational feasibility of approach and departure operations and success was independent of visibility conditions. Failures were handled within the lateral confines of the runway for all conditions tested. The fail-operational concept with pilot in the loop needs further study.

A simulator investigation of the use of digital data link for pilot/ATC communications in a single pilot operation

NASA Technical Reports Server (NTRS)

Hinton, David A.; Lohr, Gary W.

1988-01-01

Studies have shown that radio communications between pilots and air traffic control contribute to high pilot workload and are subject to various errors. These errors result from congestion on the voice radio channel, and missed and misunderstood messages. The use of digital data link has been proposed as a means of reducing this workload and error rate. A critical factor, however, in determining the potential benefit of data link will be the interface between future data link systems and the operator of those systems, both in the air and on the ground. The purpose of this effort was to evaluate the pilot interface with various levels of data link capability, in simulated general aviation, single-pilot instrument flight rule operations. Results show that the data link reduced demands on pilots' short-term memory, reduced the number of communication transmissions, and permitted the pilots to more easily allocate time to critical cockpit tasks while receiving air traffic control messages. The pilots who participated unanimously indicated a preference for data link communications over voice-only communications. There were, however, situations in which the pilot preferred the use of voice communications, and the ability for pilots to delay processing the data link messages, during high workload events, caused delays in the acknowledgement of messages to air traffic control.

Accident rates for novice glider pilots vs. pilots with experience.

PubMed

Jarvis, Steve; Harris, Don

2007-12-01

It is a popular notion in gliding that newly soloed pilots have a low accident rate. The intention of this study was to review the support for such a hypothesis from literature and to explore it using UK accident totals and measures of flying exposure. Log sheets from UK gliding clubs were used to estimate flying exposure for inexperienced glider pilots. This was used along with accident data and annual flight statistics for the period 2004-2006 in order to estimate accident rates that could be compared between the pilot groups. The UK accident rate for glider pilots from 2004-2006 was 1 accident in every 3534 launches and 1590 flying hours. The lowest estimated rate for pilots with up to 1 h of experience was 1 accident every 976 launches and 149 h flown. For pilots with up to 10 h of experience the figures were 1 accident in 1274 launches and 503 h. From 2004-2006 UK glider pilots with 10 h or less experience in command had twice the number of accidents per launch and three times as many accidents per hour flown than average for UK glider pilots. Pilots with only 1 h of experience or less were involved in at least 10 times the number of accidents per hour flown than the UK average and had more than 3.5 times the number of accidents per launch.

Multiplex transcriptional analysis of paraffin-embedded liver needle biopsy from patients with liver fibrosis

PubMed Central

2012-01-01

Background The possibility of extracting RNA and measuring RNA expression from paraffin sections can allow extensive investigations on stored paraffin samples obtained from diseased livers and could help with studies of the natural history of liver fibrosis and inflammation, and in particular, correlate basic mechanisms to clinical outcomes. Results To address this issue, a pilot study of multiplex gene expression using branched-chain DNA technology was conducted to directly measure mRNA expression in formalin-fixed paraffin-embedded needle biopsy samples of human liver. Twenty-five genes were selected for evaluation based on evidence obtained from human fibrotic liver, a rat BDL model and in vitro cultures of immortalized human hepatic stellate cells. The expression levels of these 25 genes were then correlated with liver fibrosis and inflammation activity scores. Statistical analysis revealed that three genes (COL3A1, KRT18, and TUBB) could separate fibrotic from non-fibrotic samples and that the expression of ten genes (ANXA2, TIMP1, CTGF, COL4A1, KRT18, COL1A1, COL3A1, ACTA2, TGFB1, LOXL2) were positively correlated with the level of liver inflammation activity. Conclusion This is the first report describing this multiplex technique for liver fibrosis and has provided the proof of concept of the suitability of RNA extracted from paraffin sections for investigating the modulation of a panel of proinflammatory and profibrogenic genes. This pilot study suggests that this technique will allow extensive investigations on paraffin samples from diseased livers and possibly from any other tissue. Using identical or other genes, this multiplex expression technique could be applied to samples obtained from extensive patient cohorts with stored paraffin samples in order to correlate gene expression with valuable clinically relevant information. This method could be used to provide a better understanding of the mechanisms of liver fibrosis and inflammation, its progression, and help development of new therapeutic approaches for this indication. PMID:23270325

Development and characterization of a novel C-terminal inhibitor of Hsp90 in androgen dependent and independent prostate cancer cells

PubMed Central

2011-01-01

Background The molecular chaperone, heat shock protein 90 (Hsp90) has been shown to be overexpressed in a number of cancers, including prostate cancer, making it an important target for drug discovery. Unfortunately, results with N-terminal inhibitors from initial clinical trials have been disappointing, as toxicity and resistance resulting from induction of the heat shock response (HSR) has led to both scheduling and administration concerns. Therefore, Hsp90 inhibitors that do not induce the heat shock response represent a promising new direction for the treatment of prostate cancer. Herein, the development of a C-terminal Hsp90 inhibitor, KU174, is described, which demonstrates anti-cancer activity in prostate cancer cells in the absence of a HSR and describe a novel approach to characterize Hsp90 inhibition in cancer cells. Methods PC3-MM2 and LNCaP-LN3 cells were used in both direct and indirect in vitro Hsp90 inhibition assays (DARTS, Surface Plasmon Resonance, co-immunoprecipitation, luciferase, Western blot, anti-proliferative, cytotoxicity and size exclusion chromatography) to characterize the effects of KU174 in prostate cancer cells. Pilot in vivo efficacy studies were also conducted with KU174 in PC3-MM2 xenograft studies. Results KU174 exhibits robust anti-proliferative and cytotoxic activity along with client protein degradation and disruption of Hsp90 native complexes without induction of a HSR. Furthermore, KU174 demonstrates direct binding to the Hsp90 protein and Hsp90 complexes in cancer cells. In addition, in pilot in-vivo proof-of-concept studies KU174 demonstrates efficacy at 75 mg/kg in a PC3-MM2 rat tumor model. Conclusions Overall, these findings suggest C-terminal Hsp90 inhibitors have potential as therapeutic agents for the treatment of prostate cancer. PMID:22039910

Continuous glucose monitoring in subcutaneous tissue using factory-calibrated sensors: a pilot study.

PubMed

Hoss, Udo; Jeddi, Iman; Schulz, Mark; Budiman, Erwin; Bhogal, Claire; McGarraugh, Geoffrey

2010-08-01

Commercial continuous subcutaneous glucose monitors require in vivo calibration using capillary blood glucose tests. Feasibility of factory calibration, i.e., sensor batch characterization in vitro with no further need for in vivo calibration, requires a predictable and stable in vivo sensor sensitivity and limited inter- and intra-subject variation of the ratio of interstitial to blood glucose concentration. Twelve volunteers wore two FreeStyle Navigator (Abbott Diabetes Care, Alameda, CA) continuous glucose monitoring systems for 5 days in parallel for two consecutive sensor wears (four sensors per subject, 48 sensors total). Sensors from a prototype sensor lot with a low variability in glucose sensitivity were used for the study. Median sensor sensitivity values based on capillary blood glucose were calculated per sensor and compared for inter- and intra-subject variation. Mean absolute relative difference (MARD) calculation and error grid analysis were performed using a single calibration factor for all sensors to simulate factory calibration and compared to standard fingerstick calibration. Sensor sensitivity variation in vitro was 4.6%, which increased to 8.3% in vivo (P < 0.0001). Analysis of variance revealed no significant inter-subject differences in sensor sensitivity (P = 0.134). Applying a single universal calibration factor retrospectively to all sensors resulted in a MARD of 10.4% and 88.1% of values in Clarke Error Grid Zone A, compared to a MARD of 10.9% and 86% of values in Error Grid Zone A for fingerstick calibration. Factory calibration of sensors for continuous subcutaneous glucose monitoring is feasible with similar accuracy to standard fingerstick calibration. Additional data are required to confirm this result in subjects with diabetes.

Effect of myo-inositol and alpha-lipoic acid on oocyte quality in polycystic ovary syndrome non-obese women undergoing in vitro fertilization: a pilot study.

PubMed

Rago, R; Marcucci, I; Leto, G; Caponecchia, L; Salacone, P; Bonanni, P; Fiori, C; Sorrenti, G; Sebastianelli, A

2015-01-01

The aim of the present study was to evaluate the effectiveness of the combined administration of myo-inositol and α-lipoic acid in polycystic ovary syndrome (PCOS) patients with normal body mass index (BMI), who had previously undergone intracytoplasmic sperm injection (ICSI) and received myo-inositol alone. Thirty-six of 65 normal-weight patients affected by PCOS who did not achieve pregnancy and one patient who had a spontaneous abortion were re-enrolled and given a cycle of treatment with myo-inositol and α-lipoic acid. For all female partners of the treated couples, the endocrine-metabolic and ultrasound parameters, ovarian volume, oocyte and embryo quality, and pregnancy rates were assessed before and after three months of treatment and compared with those of previous in vitro fertilization (IVF) cycle(s). After supplementation of myo-inositol with α-lipoic acid, insulin levels, BMI and ovarian volume were significantly reduced compared with myo-inositol alone. No differences were found in the fertilization and cleavage rate or in the mean number of transferred embryos between the two different treatments, whereas the number of grade 1 embryos was significantly increased, with a significant reduction in the number of grade 2 embryos treated with myo-inositol plus α-lipoic acid. Clinical pregnancy was not significantly different with a trend for a higher percentage for of myo-inositol and α-lipoic acid compared to the myo-inositol alone group. Our preliminary data suggest that the supplementation of myo-inositol and α-lipoic acid in PCOS patients undergoing an IVF cycle can help to improve their reproductive outcome and also their metabolic profiles, opening potential for their use in long-term prevention of PCOS.

Intact Cell MALDI-TOF MS on Sperm: A Molecular Test For Male Fertility Diagnosis.

PubMed

Soler, Laura; Labas, Valérie; Thélie, Aurore; Grasseau, Isabelle; Teixeira-Gomes, Ana-Paula; Blesbois, Elisabeth

2016-06-01

Currently, evaluation of sperm quality is primarily based on in vitro measures of sperm function such as motility, viability and/or acrosome reaction. However, results are often poorly correlated with fertility, and alternative diagnostic tools are therefore needed both in veterinary and human medicine. In a recent pilot study, we demonstrated that MS profiles from intact chicken sperm using MALDI-TOF profiles could detect significant differences between fertile/subfertile spermatozoa showing that such profiles could be useful for in vitro male fertility testing. In the present study, we performed larger standardized experimental procedures designed for the development of fertility- predictive mathematical models based on sperm cell MALDI-TOF MS profiles acquired through a fast, automated method. This intact cell MALDI-TOF MS-based method showed high diagnostic accuracy in identifying fertile/subfertile males in a large male population of known fertility from two distinct genetic lineages (meat and egg laying lines). We additionally identified 40% of the m/z peaks observed in sperm MS profiles through a top-down high-resolution protein identification analysis. This revealed that the MALDI-TOF MS spectra obtained from intact sperm cells contained a large proportion of protein degradation products, many implicated in important functional pathways in sperm such as energy metabolism, structure and movement. Proteins identified by our predictive model included diverse and important functional classes providing new insights into sperm function as it relates to fertility differences in this experimental system. Thus, in addition to the chicken model system developed here, with the use of appropriate models these methods should effectively translate to other animal taxa where similar tests for fertility are warranted. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Retention strength of impression materials to a tray material using different adhesive methods: an in vitro study.

PubMed

Marafie, Yousef; Looney, Stephen; Nelson, Steven; Chan, Daniel; Browning, William; Rueggeberg, Frederick

2008-12-01

A new self-stick adhesive system has been purported to eliminate the need to use chemical adhesives with plastic impression trays; however, no testing has confirmed the claim. The purpose of this study was to compare the in vitro retentive strength of impression materials to plastic substrates having conventional adhesive (CA) or the self-stick adhesive system, with and without mechanical retention. Three types of impression materials (irreversible hydrocolloid (IH), vinyl polysiloxane (VPS), and polyether (PE)) were applied to polystyrene disc-shaped surfaces (33.68 cm(2)) that were held on the arms of a universal testing machine. The appropriate CA or the self-stick adhesive system (Self-Stick Dots) (SSD) was applied to the plates, which had either no mechanical retention, or equally spaced mechanical perforations (n=4). An in vivo pilot test determined the appropriate rate of plate separation. Plates with impression material were lowered to provide 4 mm of space, the material set, and plates were separated using the appropriate speed. Force at first separation was divided by plate area (peak stress). Five replications per test condition were made, and results were analyzed using ANOVA and Bonferroni-adjusted t tests (alpha=.05). Within each impression material/test combination, stress using SSD was significantly lower than CA (P<.05). Mechanical retention did not always provide significantly greater strength. The combination of mechanical retention and CA yielded the highest strength within each material type, except for PE, for which nonmechanical and CA strength did not differ from that of mechanical and CA. Use of the self-stick adhesive system provided significantly lower retentive strength to plastic tray material than chemical adhesives for irreversible hydrocolloid, vinyl polysiloxane, and polyether.

Effect of an oxygenating agent on oral bacteria in vitro and on dental plaque composition in healthy young adults.

PubMed

Fernandez y Mostajo, Mercedes; van der Reijden, Wil A; Buijs, Mark J; Beertsen, Wouter; Van der Weijden, Fridus; Crielaard, Wim; Zaura, Egija

2014-01-01

Oral bacteria live in symbiosis with the host. Therefore, when mouthwashes are indicated, selective inhibition of taxa contributing to disease is preferred instead of broad-spectrum antimicrobials. The potential selectivity of an oxygenating mouthwash, Ardox-X® (AX), has not been assessed. The aim of this study was to determine the antimicrobial potential of AX and the effects of a twice-daily oral rinse on dental plaque composition. In vitro, 16 oral bacterial strains were tested using agar diffusion susceptibility, minimum inhibitory and minimum bactericidal concentration tests. A pilot clinical study was performed with 25 healthy volunteers. Clinical assessments and microbiological sampling of supragingival plaque were performed at 1 month before the experiment (Pre-exp), at the start of the experiment (Baseline) and after the one-week experimental period (Post-exp). During the experiment individuals used AX mouthwash twice daily in absence of other oral hygiene measures. The microbiological composition of plaque was assessed by 16S rRNA gene amplicon sequencing. AX showed high inter-species variation in microbial growth inhibition. The tested Prevotella strains and Fusobacterium nucleatum showed the highest sensitivity, while streptococci and Lactobacillus acidophilus were most resistant to AX. Plaque scores at Pre-exp and Baseline visits did not differ significantly (p = 0.193), nor did the microbial composition of plaque. During a period of 7-days non-brushing but twice daily rinsing plaque scores increased from 2.21 (0.31) at Baseline to 2.43 (0.39) Post-exp. A significant microbial shift in composition was observed: genus Streptococcus and Veillonella increased while Corynebacterium, Haemophilus, Leptotrichia, Cardiobacterium and Capnocytophaga decreased (p ≤ 0.001). AX has the potential for selective inhibition of oral bacteria. The shift in oral microbiome after 1 week of rinsing deserves further research.

Tocotrienol Treatment in Familial Dysautonomia: Open-Label Pilot Study.

PubMed

Cheishvili, David; Maayan, Channa; Holzer, Naama; Tsenter, Jeanna; Lax, Elad; Petropoulos, Sophie; Razin, Aharon

2016-07-01

Familial dysautonomia (FD) is an autosomal recessive congenital neuropathy, primarily presented in Ashkenazi Jews. The most common mutation in FD patients results from a single base pair substitution of an intronic splice site in the IKBKAP gene which disrupts normal mRNA splicing and leads to tissue-specific reduction of IKBKAP protein (IKAP). To date, treatment of FD patients remains preventative, symptomatic and supportive. Based on previous in vitro evidence that tocotrienols, members of the vitamin E family, upregulate transcription of the IKBKAP gene, we aimed to investigate whether a similar effects was observed in vivo. In the current study, we assessed the effects of tocotrienol treatment on FD patients' symptoms and IKBKAP expression in white blood cells. The initial daily doses of 50 or 100 mg tocotrienol, doubled after 3 months, was administered to 32 FD patients. Twenty-eight FD patients completed the 6-month study. The first 3 months of tocotrienol treatment was associated with a significant increase in IKBKAP expression level in FD patients' blood. Despite doubling the dose after the initial 3 months of treatment, IKBKAP expression level returned to baseline by the end of the 6-month treatment. Clinical improvement was noted in the reported clinical questionnaire (with regard to dizziness, bloching, sweating, number of pneumonia, cough episodes, and walking stability), however, no significant effect was observed in any clinical measurements (weight, height, oxygen saturation, blood pressure, tear production, histamine test, vibration threshold test, nerve conduction, and heart rate variability) following Tocotrienol treatment. In conclusion, tocotrienol treatment appears significantly beneficial by clinical evaluation for some FD patients in a few clinical parameters; however it was not significant by clinical measurements. This open-label study shows the complexity of effect of tocotrienol treatment on FD patients' clinical outcomes and on IKBKAP expression level compared to in vitro results. A longitudinal study with an increased sample size is required in the future to better understand tocotrienol affect on FD patients.

Pilot age and expertise predict flight simulator performance

PubMed Central

Kennedy, Quinn; Noda, Art; Yesavage, Jerome A.

2010-01-01

Background Expert knowledge may compensate for age-related declines in basic cognitive and sensory-motor abilities in some skill domains. We investigated the influence of age and aviation expertise (indexed by Federal Aviation Administration pilot ratings) on longitudinal flight simulator performance. Methods Over a 3-year period, 118 general aviation pilots aged 40 to 69 years were tested annually, in which their flight performance was scored in terms of 1) executing air-traffic controller communications; 2) traffic avoidance; 3) scanning cockpit instruments; 4) executing an approach to landing; and 5) a flight summary score. Results More expert pilots had better flight summary scores at baseline and showed less decline over time. Secondary analyses revealed that expertise effects were most evident in the accuracy of executing aviation communications, the measure on which performance declined most sharply over time. Regarding age, even though older pilots initially performed worse than younger pilots, over time older pilots showed less decline in flight summary scores than younger pilots. Secondary analyses revealed that the oldest pilots did well over time because their traffic avoidance performance improved more vs younger pilots. Conclusions These longitudinal findings support previous cross-sectional studies in aviation as well as non-aviation domains, which demonstrated the advantageous effect of prior experience and specialized expertise on older adults’ skilled cognitive performances. PMID:17325270

Conducting pilot and feasibility studies.

PubMed

Cope, Diane G

2015-03-01

Planning a well-designed research study can be tedious and laborious work. However, this process is critical and ultimately can produce valid, reliable study findings. Designing a large-scale randomized, controlled trial (RCT)-the gold standard in quantitative research-can be even more challenging. Even the most well-planned study potentially can result in issues with research procedures and design, such as recruitment, retention, or methodology. One strategy that may facilitate sound study design is the completion of a pilot or feasibility study prior to the initiation of a larger-scale trial. This article will discuss pilot and feasibility studies, their advantages and disadvantages, and implications for oncology nursing research. 
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The Impact of Integrated Maneuver Guidance Information on UAS Pilots Performing the Detect and Avoid Task

NASA Technical Reports Server (NTRS)

Rorie, Conrad; Fern, Lisa

2015-01-01

The integrated human-in-the-loop (iHITL) simulation examined the effect of four different Detect-and-Avoid (DAA) display concepts on unmanned aircraft system (UAS) pilots' ability to maintain safe separation. The displays varied in the type and amount of guidance they provided to pilots. The study's background and methodology are discussed, followed by the 'measured response' data (i.e., pilots' end-to-end response time in reacting to traffic alerts on their DAA display). Results indicate that display type had a significant impact on how long pilot's spent interacting with the interface (i.e., edit times).

An investigation of correlation between pilot scanning behavior and workload using stepwise regression analysis

NASA Technical Reports Server (NTRS)

Waller, M. C.

1976-01-01

An electro-optical device called an oculometer which tracks a subject's lookpoint as a time function has been used to collect data in a real-time simulation study of instrument landing system (ILS) approaches. The data describing the scanning behavior of a pilot during the instrument approaches have been analyzed by use of a stepwise regression analysis technique. A statistically significant correlation between pilot workload, as indicated by pilot ratings, and scanning behavior has been established. In addition, it was demonstrated that parameters derived from the scanning behavior data can be combined in a mathematical equation to provide a good representation of pilot workload.

Aircraft control forces and EMG activity: comparison of novice and experienced pilots during simulated rolls, loops and turns.

PubMed

Hewson, D J; McNair, P J; Marshall, R N

2000-08-01

Flying an aircraft requires a considerable degree of coordination, particularly during aerobatic activities such as rolls, loops and turns. Only one previous study has examined the magnitude of muscle activity required to fly an aircraft, and that was restricted to takeoff and landing maneuvers. The aim of this study was to examine the phasing of muscle activation and control forces of novice and experienced pilots during more complex simulated flight maneuvers. There were 12 experienced and 9 novice pilots who were tested on an Aermacchi flight simulator while performing a randomized set of rolling, looping, and turning maneuvers. Four different runaway trim settings were used to increase the difficulty of the turns (elevator-up, elevator-down, aileron-left, and aileron-right). Variables recorded included aircraft attitude, pilot applied forces, and electromyographic (EMG) activity. Discriminant function analysis was used to distinguish between novice and experienced pilots. Over all maneuvers, 70% of pilots were correctly classified as novice or experienced. Better levels of classification were achieved when maneuvers were analyzed individually (67-91%), although the maneuvers that required the greatest force application, elevator-up turns, were unable to discriminate between novice and experienced pilots. There were no differences in the phasing of muscle activity between experienced and novice pilots. The only consistent difference in EMG activity between novice and experienced pilots was the reduced EMG activity in the wrist extensors of experienced pilots (p < 0.05). The increased wrist extensor activity of the novice pilots is indicative of a distal control strategy, whereby distal muscles with smaller motor units are used to perform a task that requires precise control. Muscle activity sensors could be used to detect the onset of high G maneuvers prior to any change in aircraft attitude and control G-suit inflation accordingly.

The social context of the aeronautical education experience of African-American civilian, commercial, and military pilots

NASA Astrophysics Data System (ADS)

Walker, Taurean Mashawn

The purpose of this research is to explore the social context (the nature and cultural environment) of the aeronautical training experience of African-American civilian, commercial, and military pilots. This research highlights the challenges African-American pilots are exposed to in addition to drawing parallels between the social context and the obstacles they are subjected to along the way. This study is valuable for stakeholders, African-American pilot aspirants, aviation corporations, Federal Aviation Administration, flight schools - in the aviation industry in understanding ways to initiate a paradigm shift and increase awareness about representation and participation of African-American aviation professionals. The qualitative approach was selected to gather a better understanding of the sociological hurdles black aviators face while going through the journey of becoming a pilot. Hardiman (2010) states, "While quantitative research is valuable, qualitative research provides the researcher the ability to view real world situations as they naturally unfold" ( p. 25). According to OBAP (2014), less than 2% of pilots in the United States are African-American. The experiences shared by the participants can provide helpful insight of possible policy implications for the aeronautical industry. There were three research questions in the study: 1) What factors hindered pilot training? 2) What were the resilience factors experienced during pilot training? 3) What were the defining features of the social context surrounding pilot training? Semi-structured, face-to-face interviews were conducted of six professional pilots. A qualitative data analysis was conducted to illustrate the context of the social challenges during the course of pilot training. Three themes were revealed: 1) access, 2) perception of inferiority, and 3) support. Implications of the significance of providing social networks to expose African-Americans to aviation were discussed. Additional means of access and exposure of African-Americans to aviation is essential for further research.

The value of a pilot study in breast-feeding research.

PubMed

Carfoot, Sue; Williamson, Paula R; Dickson, Rumona

2004-06-01

To test the integrity of a protocol for a randomised controlled trial (RCT) to examine the effectiveness of skin-to-skin care compared to routine care on the initiation and duration of breast feeding and to provide data to be used in the power calculation for a proposed trial. Randomised pilot study. Warrington Hospital, Cheshire, UK. Women at 36 weeks' gestation with healthy singleton pregnancies, who intended to breast feed, who had 'booked' for care at Warrington Hospital and had given informed consent to participate. Twenty-eight women were randomised in the pilot study. Women were randomly allocated to receive either routine or skin-to-skin care following birth. The first breast feed was assessed using the Breast-feeding Assessment Tool (BAT). Mothers were followed up at discharge from hospital and again at four months to provide details of duration of breast feeding. 66 women were approached to participate in the trial and 44 consented (67% consent rate). Twenty-eight women were randomised in the study and 26 breast feeds were observed (93%). The pilot study identified procedural changes that were required in the design of the main study, provided an estimate of recruitment rates and confirmed the previously calculated sample size. The pilot study demonstrated that a large RCT of skin-to-skin versus routine care was feasible. This is an example of how a pilot study has the ability to identify unforeseen challenges in the conduct of the trial as well as allowing necessary changes to be made to the design that will increase the quality of the subsequent research.

Cognitive Workload and Psychophysiological Parameters During Multitask Activity in Helicopter Pilots.

PubMed

Gaetan, Sophie; Dousset, Erick; Marqueste, Tanguy; Bringoux, Lionel; Bourdin, Christophe; Vercher, Jean-Louis; Besson, Patricia

2015-12-01

Helicopter pilots are involved in a complex multitask activity, implying overuse of cognitive resources, which may result in piloting task impairment or in decision-making failure. Studies usually investigate this phenomenon in well-controlled, poorly ecological situations by focusing on the correlation between physiological values and either cognitive workload or emotional state. This study aimed at jointly exploring workload induced by a realistic simulated helicopter flight mission and emotional state, as well as physiological markers. The experiment took place in the helicopter full flight dynamic simulator. Six participants had to fly on two missions. Workload level, skin conductance, RMS-EMG, and emotional state were assessed. Joint analysis of psychological and physiological parameters associated with workload estimation revealed particular dynamics in each of three profiles. 1) Expert pilots showed a slight increase of measured physiological parameters associated with the increase in difficulty level. Workload estimates never reached the highest level and the emotional state for this profile only referred to positive emotions with low emotional intensity. 2) Non-Expert pilots showed increasing physiological values as the perceived workload increased. However, their emotional state referred to either positive or negative emotions, with a greater variability in emotional intensity. 3) Intermediate pilots were similar to Expert pilots regarding emotional states and similar to Non-Expert pilots regarding physiological patterns. Overall, high interindividual variability of these results highlight the complex link between physiological and psychological parameters with workload, and question whether physiology alone could predict a pilot's inability to make the right decision at the right time.

Acceleration effects on neck muscle strength: pilots vs. non-pilots.

PubMed

Seng, Kok-Yong; Lam, Pin-Min; Lee, Vee-Sin

2003-02-01

Conditioning of neck muscles, if any, due to repeated exposures to +Gz forces has received little research attention. This study was conducted to evaluate and compare the neck muscle strength of test volunteers representative of the general populations of fighter aircraft pilots and non-pilots. The tests were performed using a special attachment device on a computerized dynamometer. Ten pilots and ten non-pilots volunteered as test subjects. Each individual's maximal isometric neck muscle strength was evaluated in the extension, flexion, and left and right lateral bending directions in a single day. Peak values from the measurements were used for data analysis. Overall neck strength was calculated as the mean values for the four directions in each group. The overall muscular strength of the necks of pilots did not differ significantly from that of non-pilots, nor did exposure to +Gz forces lead to specific changes in isometric muscle strength across any of the four principal directions. Neck muscle strength in the four measured directions pooled across the two subgroups were statistically significant. The widespread practice of adopting protective head-positioning strategies to minimize neck strains, coupled with results from this research study, suggest that the neck muscles are subjected to reduced in-flight strengthening workouts during exposures to +Gz forces. To maximize in-flight performance and minimize +Gz-induced neck injuries, fighter pilots should be encouraged to perform on-land neck muscle strengthening exercise and in-flight head-positioning techniques. More research is needed to fine-tune this countermeasure strategy against cervical spine injury.

Well clear: General aviation and commercial pilots' perception of unmanned aerial vehicles in the national airspace system

NASA Astrophysics Data System (ADS)

Ott, Joseph T.

The purpose of this research was to determine how different pilot types perceived the subjective concept of the Well Clear Boundary (WCB) and to observe if that boundary changed when dealing with manned versus unmanned aircraft systems (UAS) as well as the effects of other variables. Pilots' perceptions of the WCB were collected objectively through simulator recordings and subjectively through questionnaires. Together, these metrics provided quantitative and qualitative data about pilot WCB perception. The objective results of this study showed significant differences in WCB perception between two different pilot types, as well as WCB significant differences when comparing two different intruder types (manned versus unmanned aircraft). These differences were dependent on other manipulated variables, including intruder approach angle, ownship speed, and background traffic levels. Subjectively, there were evident differences in WCB perception across pilot types; general aviation (GA) pilots appeared to trust UAS aircraft slightly more than did the more experienced Airline Transport Pilots (ATPs). Overall, it is concluded that pilots' mental models of the WCB are more easily perceived as time-based boundaries in front of ownship, while being more easily perceived as distance-based boundaries to the rear of ownship.

Estimation of Time-Varying Pilot Model Parameters

NASA Technical Reports Server (NTRS)

Zaal, Peter M. T.; Sweet, Barbara T.

2011-01-01

Human control behavior is rarely completely stationary over time due to fatigue or loss of attention. In addition, there are many control tasks for which human operators need to adapt their control strategy to vehicle dynamics that vary in time. In previous studies on the identification of time-varying pilot control behavior wavelets were used to estimate the time-varying frequency response functions. However, the estimation of time-varying pilot model parameters was not considered. Estimating these parameters can be a valuable tool for the quantification of different aspects of human time-varying manual control. This paper presents two methods for the estimation of time-varying pilot model parameters, a two-step method using wavelets and a windowed maximum likelihood estimation method. The methods are evaluated using simulations of a closed-loop control task with time-varying pilot equalization and vehicle dynamics. Simulations are performed with and without remnant. Both methods give accurate results when no pilot remnant is present. The wavelet transform is very sensitive to measurement noise, resulting in inaccurate parameter estimates when considerable pilot remnant is present. Maximum likelihood estimation is less sensitive to pilot remnant, but cannot detect fast changes in pilot control behavior.

Flight performance using a hyperstereo helmet-mounted display: aircraft handling

NASA Astrophysics Data System (ADS)

Jennings, Sion A.; Craig, Gregory L.; Stuart, Geoffrey W.; Kalich, Melvyn E.; Rash, Clarence E.; Harding, Thomas H.

2009-05-01

A flight study was conducted to assess the impact of hyperstereopsis on helicopter handling proficiency, workload and pilot acceptance. Three pilots with varying levels of night vision goggle and hyperstereo helmet-mounted display experience participated in the test. The pilots carried out a series of flights consisting of low-level maneuvers over a period of two weeks. Four of the test maneuvers, The turn around the tail, the hard surface landing, the hover height estimation and the tree-line following were analysed in detail. At the end of the testing period, no significant difference was observed in the performance data, between maneuvers performed with the TopOwl helmet and maneuvers performed with the standard night vision goggle. This study addressed only the image intensification display aspects of the TopOwl helmet system. The tests did not assess the added benefits of overlaid symbology or head slaved infrared camera imagery. These capabilities need to be taken into account when assessing the overall usefulness of the TopOwl system. Even so, this test showed that pilots can utilize the image intensification imagery displayed on the TopOwl to perform benign night flying tasks to an equivalent level as pilots using ANVIS. The study should be extended to investigate more dynamic and aggressive low level flying, slope landings and ship deck landings. While there may be concerns regarding the effect of hyperstereopsis on piloting, this initial study suggests that pilots can either adapt or compensate for hyperstereo effects with sufficient exposure and training. Further analysis and testing is required to determine the extent of training required.

Design of pilot studies to inform the construction of composite outcome measures.

PubMed

Edland, Steven D; Ard, M Colin; Li, Weiwei; Jiang, Lingjing

2017-06-01

Composite scales have recently been proposed as outcome measures for clinical trials. For example, the Prodromal Alzheimer's Cognitive Composite (PACC) is the sum of z-score normed component measures assessing episodic memory, timed executive function, and global cognition. Alternative methods of calculating composite total scores using the weighted sum of the component measures that maximize signal-to-noise of the resulting composite score have been proposed. Optimal weights can be estimated from pilot data, but it is an open question how large a pilot trial is required to calculate reliably optimal weights. In this manuscript, we describe the calculation of optimal weights, and use large-scale computer simulations to investigate the question of how large a pilot study sample is required to inform the calculation of optimal weights. The simulations are informed by the pattern of decline observed in cognitively normal subjects enrolled in the Alzheimer's Disease Cooperative Study (ADCS) Prevention Instrument cohort study, restricting to n=75 subjects age 75 and over with an ApoE E4 risk allele and therefore likely to have an underlying Alzheimer neurodegenerative process. In the context of secondary prevention trials in Alzheimer's disease, and using the components of the PACC, we found that pilot studies as small as 100 are sufficient to meaningfully inform weighting parameters. Regardless of the pilot study sample size used to inform weights, the optimally weighted PACC consistently outperformed the standard PACC in terms of statistical power to detect treatment effects in a clinical trial. Pilot studies of size 300 produced weights that achieved near-optimal statistical power, and reduced required sample size relative to the standard PACC by more than half. These simulations suggest that modestly sized pilot studies, comparable to that of a phase 2 clinical trial, are sufficient to inform the construction of composite outcome measures. Although these findings apply only to the PACC in the context of prodromal AD, the observation that weights only have to approximate the optimal weights to achieve near-optimal performance should generalize. Performing a pilot study or phase 2 trial to inform the weighting of proposed composite outcome measures is highly cost-effective. The net effect of more efficient outcome measures is that smaller trials will be required to test novel treatments. Alternatively, second generation trials can use prior clinical trial data to inform weighting, so that greater efficiency can be achieved as we move forward.

Pilot Evaluations of Runway Status Light System

NASA Technical Reports Server (NTRS)

Young, Steven D.; Wills, Robert W.; Smith, R. Marshall

1996-01-01

This study focuses on use of the Transport Systems Research Vehicle (TSRV) Simulator at the Langley Research Center to obtain pilot opinion and input on the Federal Aviation Administration's Runway Status Light System (RWSL) prior to installation in an operational airport environment. The RWSL has been designed to reduce the likelihood of runway incursions by visually alerting pilots when a runway is occupied. Demonstrations of the RWSL in the TSRV Simulator allowed pilots to evaluate the system in a realistic cockpit environment.

Prediction and measurement of human pilot dynamic characteristics

NASA Technical Reports Server (NTRS)

Hess, Ronald A.; Reedy, James T.

1988-01-01

An analytical and experimental study of human pilot control strategies in a manned rotorcraft simulation is described. The task simulated involves a low-speed, constant-altitude maneuvering task in which a head-down display is utilized to allow the pilot to track a moving hover point. The efficacy of the display law driving an 'acceleration symbol' is determined and the manner in which the prediction and measurement of pilot/vehicle dynamics can be made part of man/machine system evaluations is demonstrated.

Laboratory Study on Macro-Features of Wave Breaking Over Bars and Artificial Reefs

DTIC Science & Technology

1990-07-01

Prototype and Model Conditions of Case CE400 ( Pilot Test ) . 72 7 List of Design Parameters for Base Tests ... ........... . 72 8 List of Design Parameters...bar configurations, and the procedure was repeated. Pilot test 112. A pilot test was performed as a trial of the methodology and vali- dation of the...criterion on bar depth given by Larson and Kraus (1989) prior to actual testing . In this pilot test , the wave conditions and equilibrium bar formed in a

Reviewing and piloting methods for decreasing discount rates; someone, somewhere in time.

PubMed

Parouty, Mehraj B Y; Krooshof, Daan G M; Westra, Tjalke A; Pechlivanoglou, Petros; Postma, Maarten J

2013-08-01

There has been substantial debate on the need for decreasing discounting for monetary and health gains in economic evaluations. Next to the discussion on differential discounting, a way to identify the need for such discounting strategies is through eliciting the time preferences for monetary and health outcomes. In this article, the authors investigate the perceived time preference for money and health gains through a pilot survey on Dutch university students using methods on functional forms previously suggested. Formal objectives of the study were to review such existing methods and to pilot them on a convenience sample using a questionnaire designed for this specific purpose. Indeed, a negative relation between the time of delay and the variance of the discounting rate for all models was observed. This study was intended as a pilot for a large-scale population-based investigation using the findings from this pilot on wording of the questionnaire, interpretation, scope and analytic framework.

Pilot Perception of Electronic Flight Bags at Part 121 Air Carriers

NASA Astrophysics Data System (ADS)

Lytle, Donley

Electronic Flight Bags (EFBs) have been approved for use by pilots in flight operations at many Part 121 air carriers in the United States since 2010. As an automated device replacing paper in the cockpit, there are many human factor issues that relate to operation of the EFB. EFBs have been cited in accidents and incidents worldwide in large, transport category aircraft. While the EFB was not cited as the main cause of the accident/incident, it has been listed as a contributing factor. This study looks at pilot perception related to the safety aspect of the EFB in flight operations at Part 121 carriers in the United States. It surveys pilots that utilize the device in daily, routine flight operations to determine their perception of the EFB. The study is followed with a survey of a small group of pilots to help explain the results and any correlation between the variables.

Combining destination diversion decisions and critical in-flight event diagnosis in computer aided testing of pilots

NASA Technical Reports Server (NTRS)

Rockwell, T. H.; Giffin, W. C.; Romer, D. J.

1984-01-01

Rockwell and Giffin (1982) and Giffin and Rockwell (1983) have discussed the use of computer aided testing (CAT) in the study of pilot response to critical in-flight events. The present investigation represents an extension of these earlier studies. In testing pilot responses to critical in-flight events, use is made of a Plato-touch CRT system operating on a menu based format. In connection with the typical diagnostic problem, the pilot was presented with symptoms within a flight scenario. In one problem, the pilot has four minutes for obtaining the information which is needed to make a diagnosis of the problem. In the reported research, the attempt has been made to combine both diagnosis and diversion scenario into a single computer aided test. Tests with nine subjects were conducted. The obtained results and their significance are discussed.

[Personnel with poor vision at fighter pilot school].

PubMed

Corbé, C; Menu, J P

1997-10-01

The piloting of fighting aircraft, the navigation of space-shuttle, the piloting of an helicopter in tactical flight at an altitude of 50 metres require the use of all sensorial, ocular, vestibular, proprioceptive ... sensors. So, the selection and the follow-up of these aerial engines' pilots need a very complete study of medical parameters, in particular sensorial and notably visual system. The doctors and the expert researchers in Aeronautical and spatial Medicine of the Army Health Department, which have in charge the medical supervision of flight crew, should study, create, and improve tests of visual sensorial exploration developed from fundamental and applied research. These authenticated tests with military pilots were applied in ophthalmology for the estimation of normal and deficient vision. A proposition to change norms of World Health Organisation applied to the vision has been following these to low visual persons was equally introduced.

Pilot non dialysis chronic renal insufficiency study (P-ND-CRIS): a pilot study of an open prospective hospital-based French cohort.

PubMed

Massol, Jacques; Janin, Gérard; Bachot, Camille; Gousset, Christophe; Deville, Geoffroy Sainte-Claire; Chalopin, Jean-Marc

2017-02-01

Before establishing a prospective cohort, an initial pilot study is recommended. However, there are no precise guidelines on this subject. This paper reports the findings of a French regional pilot study carried out in three nephrology departments, before realizing a major prospective Non Dialysis Chronic Renal Insufficiency study (ND-CRIS). We carried out an internal pilot study. The objectives of this pilot study were to validate the feasibility (regulatory approval, providing patients with information, availability of variables, refusal rate of eligible patients) and quality criteria (missing data, rate of patients lost to follow-up, characteristics of the patients included and non-included eligible patients, quality control of the data gathered) and estimate the human resources necessary (number of clinical research associates required). The authorizations obtained (CCTIRS - CNIL) and the contracts signed with hospitals have fulfilled the regulatory requirements. After validating the information on the study provided to patients, 1849 of them were included in three centres (university hospital, intercommunal hospital, town hospital) between April 2012 and September 2015. The low refusal rate (51 patients) and the characteristics of non-included patients have confirmed the benefit for patients of participating in the study and provide evidence of the feasibility and representativeness of the population studied. The lack of missing data on the variables studied, the quality of the data analyzed and the low number of patients lost to follow-up are evidence of the quality of the study. By taking into account the time spent by CRAs to enter data and to travel, as well as the annual patient numbers in each hospital, we estimate that five CRAs will be required in total. With no specific guidelines on how to realize a pilot study before implementing a major prospective cohort, we considered it pertinent to report our experience of P-ND-CRIS. This experience confirms that i) feasibility, ii) quality of data and iii) evaluating the resources required must be validated before carrying out a large prospective cohort study such as ND-CRIS.

Integrating Virtual Worlds with Tangible User Interfaces for Teaching Mathematics: A Pilot Study

PubMed Central

Guerrero, Graciela; Ayala, Andrés; Mateu, Juan; Casades, Laura; Alamán, Xavier

2016-01-01

This article presents a pilot study of the use of two new tangible interfaces and virtual worlds for teaching geometry in a secondary school. The first tangible device allows the user to control a virtual object in six degrees of freedom. The second tangible device is used to modify virtual objects, changing attributes such as position, size, rotation and color. A pilot study on using these devices was carried out at the “Florida Secundaria” high school. A virtual world was built where students used the tangible interfaces to manipulate geometrical figures in order to learn different geometrical concepts. The pilot experiment results suggest that the use of tangible interfaces and virtual worlds allowed a more meaningful learning (concepts learnt were more durable). PMID:27792132

The Development, Test, and Evaluation of Three Pilot Performance Reference Scales.

ERIC Educational Resources Information Center

Horner, Walter R.; And Others

A set of pilot performance reference scales was developed based upon airborne Audio-Video Recording (AVR) of student performance in T-37 undergraduate Pilot Training. After selection of the training maneuvers to be studied, video tape recordings of the maneuvers were selected from video tape recordings already available from a previous research…

The Pilot Training Study: A Cost-Estimating Model for Undergraduate Pilot Training.

ERIC Educational Resources Information Center

Allison, S. L.

A means for estimating the resource requirements and attendant costs of any configuration of the undergraduate pilot training system (UPT) is described by inputs that are supplied by the user of the model. The inputs consist of data such as UPT graduate requirements, course syllabus requirements, instructor-student ratios, administrative and…

Pilot/vehicle model analysis of visual and motion cue requirements in flight simulation. [helicopter hovering

NASA Technical Reports Server (NTRS)

Baron, S.; Lancraft, R.; Zacharias, G.

1980-01-01

The optimal control model (OCM) of the human operator is used to predict the effect of simulator characteristics on pilot performance and workload. The piloting task studied is helicopter hover. Among the simulator characteristics considered were (computer generated) visual display resolution, field of view and time delay.

Treatment of the Cerro Prieto I brines for use in reinjection. 2. Results of the pilot plant tests

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

Hurtado J, R.; Mercado G, S.; Rocha C, E.

Silica removal experiments have been carried out both in the laboratory and in pilot scale tests. The results obtained to date are presented, with special emphasis on the pilot tests with or without the use of flocculants. Previous studies on brine treatment are described briefly.

Strong Results, High Demand: A Four-Year Study of Boston's Pilot High Schools

ERIC Educational Resources Information Center

Tung, Rosann; Ouimette, Monique

2007-01-01

New research from the Center for Collaborative Education finds that students in Boston's Pilot high schools outperform students from other non-exam Boston Public Schools on every standard measure of engagement and performance. This level of achievement holds for every racial, economic, and academic subgroup examined. Pilot high school students…

General Aviation Weather Encounter Case Studies

DOT National Transportation Integrated Search

2012-09-01

This study presents a compilation of 24 cases involving general aviation (GA) pilots weather encounters over the : continental U.S. The project team interviewed pilots who had experienced a weather encounter, and we : examined their backgrounds, f...

Manual flying of curved precision approaches to landing with electromechanical instrumentation. A piloted simulation study

NASA Technical Reports Server (NTRS)

Knox, Charles E.

1993-01-01

A piloted simulation study was conducted to examine the requirements for using electromechanical flight instrumentation to provide situation information and flight guidance for manually controlled flight along curved precision approach paths to a landing. Six pilots were used as test subjects. The data from these tests indicated that flight director guidance is required for the manually controlled flight of a jet transport airplane on curved approach paths. Acceptable path tracking performance was attained with each of the three situation information algorithms tested. Approach paths with both multiple sequential turns and short final path segments were evaluated. Pilot comments indicated that all the approach paths tested could be used in normal airline operations.

Dietary Effects on Cognition and Pilots’ Flight Performance

PubMed Central

Lindseth, Glenda N.; Lindseth, Paul D.; Jensen, Warren C.; Petros, Thomas V.; Helland, Brian D.; Fossum, Debra L.

2017-01-01

The purpose of this study was to investigate the effects of diet on cognition and flight performance of 45 pilots. Based on a theory of self-care, this clinical study used a repeated-measure, counterbalanced crossover design. Pilots were randomly rotated through 4-day high-carbohydrate, high-protein, high-fat, and control diets. Cognitive flight performance was evaluated using a GAT-2 full-motion flight simulator. The Sternberg short-term memory test and Vandenberg’s mental rotation test were used to validate cognitive flight test results. Pilots consuming a high-protein diet had significantly poorer (p < .05) overall flight performance scores than pilots consuming high-fat and high-carbohydrate diets. PMID:29353985

Using Visualization in Cockpit Decision Support Systems

NASA Technical Reports Server (NTRS)

Aragon, Cecilia R.

2005-01-01

In order to safely operate their aircraft, pilots must make rapid decisions based on integrating and processing large amounts of heterogeneous information. Visual displays are often the most efficient method of presenting safety-critical data to pilots in real time. However, care must be taken to ensure the pilot is provided with the appropriate amount of information to make effective decisions and not become cognitively overloaded. The results of two usability studies of a prototype airflow hazard visualization cockpit decision support system are summarized. The studies demonstrate that such a system significantly improves the performance of helicopter pilots landing under turbulent conditions. Based on these results, design principles and implications for cockpit decision support systems using visualization are presented.

A study of ASRS reports involving general aviation and weather encounters

NASA Technical Reports Server (NTRS)

Rockwell, T. H.; Roach, D. E.; Griffin, W. C.

1981-01-01

Consideration is given to the nature and characteristics of problems involving dissemination of weather information, use of this information by pilots, its adequacy for the purpose intended, the ability of the air traffic control system to cope with weather related incidents, and the various aspects of pilot behavior, aircraft equipment, and NAVAIDS affecting flights in which weather figures. It is concluded from the study that skill and training deficiencies of general aviation pilots are not major factors in weather related occurrences, nor is lack of aircraft equipment. Major problem causes are identified with timely and easily interpreted weather information, judgement and attitude factors of pilots, and the functioning of the air traffic control system.

I spy with my little eye: Analysis of airline pilots' gaze patterns in a manual instrument flight scenario.

PubMed

Haslbeck, Andreas; Zhang, Bo

2017-09-01

The aim of this study was to analyze pilots' visual scanning in a manual approach and landing scenario. Manual flying skills suffer from increasing use of automation. In addition, predominantly long-haul pilots with only a few opportunities to practice these skills experience this decline. Airline pilots representing different levels of practice (short-haul vs. long-haul) had to perform a manual raw data precision approach while their visual scanning was recorded by an eye-tracking device. The analysis of gaze patterns, which are based on predominant saccades, revealed one main group of saccades among long-haul pilots. In contrast, short-haul pilots showed more balanced scanning using two different groups of saccades. Short-haul pilots generally demonstrated better manual flight performance and within this group, one type of scan pattern was found to facilitate the manual landing task more. Long-haul pilots tend to utilize visual scanning behaviors that are inappropriate for the manual ILS landing task. This lack of skills needs to be addressed by providing specific training and more practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

Classification and prediction of pilot weather encounters: A discriminant function analysis.

PubMed

O'Hare, David; Hunter, David R; Martinussen, Monica; Wiggins, Mark

2011-05-01

Flight into adverse weather continues to be a significant hazard for General Aviation (GA) pilots. Weather-related crashes have a significantly higher fatality rate than other GA crashes. Previous research has identified lack of situational awareness, risk perception, and risk tolerance as possible explanations for why pilots would continue into adverse weather. However, very little is known about the nature of these encounters or the differences between pilots who avoid adverse weather and those who do not. Visitors to a web site described an experience with adverse weather and completed a range of measures of personal characteristics. The resulting data from 364 pilots were carefully screened and subject to a discriminant function analysis. Two significant functions were found. The first, accounting for 69% of the variance, reflected measures of risk awareness and pilot judgment while the second differentiated pilots in terms of their experience levels. The variables measured in this study enabled us to correctly discriminate between the three groups of pilots considerably better (53% correct classifications) than would have been possible by chance (33% correct classifications). The implications of these findings for targeting safety interventions are discussed.

Physiological Indices of Pilots' Abilities Under Varying Task Demands.

PubMed

Wang, Zhen; Zheng, Lingxiao; Lu, Yanyu; Fu, Shan

2016-04-01

This study investigated pilots' ability by examining the effects of flight experience and task demand on physiological reactions, and analyzing the diagnostic meanings underlying correlated parameters. A total of 12 experienced pilots and 12 less experienced pilots performed 4 simulated flight tasks, including normal and emergency situations. Fixation duration (FD), saccade rate (SR), blink rate (BR), heart rate (HR), respiration rate (RR), and respiration amplitude (RA) were measured during the tasks. More experienced pilots adapted their SR flexibly to changing task demands and had significantly lower SR than less experienced pilots during emergency tasks (29.6 ± 20.0 vs. 70.1 ± 67.1 saccades/min). BR, HR, and RR were affected by pilot experience but not by task demand. More experienced pilots had lower BR, HR, and RR than less experienced pilots during both normal tasks (BR: 14.3 ± 13.0 vs. 32.9 ± 25.8 blinks/min; HR: 72.7 ± 7.9 vs. 83.2 ± 7.2 bpm; RR: 15.4 ± 2.1 vs. 19.5 ± 5.2 breaths/min) and emergency tasks (BR: 10.2 ± 5.0 vs. 32.3 ± 20.8 blinks/min; HR: 73.3 ± 7.3 vs. 82.2 ± 11.6 bpm; RR: 15.6 ± 1.9 vs. 18.0 ± 3.2 breaths/min). FD and RA were not sensitive to either flight experience or task demand. Physiological reactions have the potential to reflect pilots' ability from different aspects. SR and BR could indicate pilots' differences in information access strategy. HR and RR could reflect a pilot's physical fitness. These findings are useful for understanding a pilot's ability.

Thoughts in flight: automation use and pilots' task-related and task-unrelated thought.

PubMed

Casner, Stephen M; Schooler, Jonathan W

2014-05-01

The objective was to examine the relationship between cockpit automation use and task-related and task-unrelated thought among airline pilots. Studies find that cockpit automation can sometimes relieve pilots of tedious control tasks and afford them more time to think ahead. Paradoxically, automation has also been shown to lead to lesser awareness. These results prompt the question of what pilots think about while using automation. A total of 18 airline pilots flew a Boeing 747-400 simulator while we recorded which of two levels of automation they used. As they worked, pilots were verbally probed about what they were thinking. Pilots were asked to categorize their thoughts as pertaining to (a) a specific task at hand, (b) higher-level flight-related thoughts (e.g.,planning ahead), or (c) thoughts unrelated to the flight. Pilots' performance was also measured. Pilots reported a smaller percentage of task-at-hand thoughts (27% vs. 50%) and a greater percentage of higher-level flight-related thoughts (56% vs. 29%) when using the higher level of automation. However, when all was going according to plan, using either level of automation, pilots also reported a higher percentage of task-unrelated thoughts (21%) than they did when in the midst of an unsuccessful performance (7%). Task-unrelated thoughts peaked at 25% when pilots were not interacting with the automation. Although cockpit automation may provide pilots with more time to think, it may encourage pilots to reinvest only some of this mental free time in thinking flight-related thoughts. This research informs the design of human-automation systems that more meaningfully engage the human operator.

RESULTS FROM EXPOSURE MONITORING PERFORMED DURING THE 1997 BALTIMORE PM PILOT STUDY

EPA Science Inventory

An eighteen day winter-time ambient and personal exposure monitoring study of particulate matter (PM) was conducted as part of an.integrated epidemiological-exposure pilot study of an aged population. Goals of the study were to determine the feasibility of performing active per...

International Safeguards Technology and Policy Education and Training Pilot Programs

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

Dreicer, M; Anzelon, G A; Essner, J T

2009-06-16

A major focus of the National Nuclear Security Administration-led Next Generation Safeguards Initiative (NGSI) is the development of human capital to meet present and future challenges to the safeguards regime. An effective university-level education in safeguards and related disciplines is an essential element in a layered strategy to rebuild the safeguards human resource capacity. NNSA launched two pilot programs in 2008 to develop university level courses and internships in association with James, Martin Center for Nonproliferation Studies (CNS) at the Monterey Institute of International Studies (MIIS) and Texas A&M University (TAMU). These pilot efforts involved 44 students in total andmore » were closely linked to hands-on internships at Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL). The Safeguards and Nuclear Material Management pilot program was a collaboration between TAMU, LANL, and LLNL. The LANL-based coursework was shared with the students undertaking internships at LLNL via video teleconferencing. A weeklong hands-on exercise was also conducted at LANL. A second pilot effort, the International Nuclear Safeguards Policy and Information Analysis pilot program was implemented at MIIS in cooperation with LLNL. Speakers from MIIS, LLNL, and other U.S. national laboratories (LANL, BNL) delivered lectures for the audience of 16 students. The majority of students were senior classmen or new master's degree graduates from MIIS specializing in nonproliferation policy studies. The two pilots programs concluded with an NGSI Summer Student Symposium, held at LLNL, where 20 students participated in LLNL facility tours and poster sessions. The value of bringing together the students from the technical and policy pilots was notable and will factor into the planning for the continued refinement of the two programs in the coming years.« less

Pilot behaviors in the face of adverse weather: A new look at an old problem.

PubMed

Batt, Richard; O'Hare, David

2005-06-01

Weather-related general aviation accidents remain one of the most significant causes for concern in aviation safety. Previous studies have typically compared accident and non-accident cases. In contrast, the current study does not concentrate on occurrence outcome. Instead, the emphasis is on the different behaviors that pilots exhibit in the face of adverse weather and, by inference, on the decision-making processes that underlie those behaviors. This study compares three weather-related behaviors that reflect different levels of risk: visual flight rules flight into instrument meteorological conditions ('VFR into IMC'); precautionary landing; and other significant weather avoidance actions. Occurrence data (n=491) were drawn from the Australian Transport Safety Bureau database of aviation occurrences, and included weather-related accidents, incidents, and 'normal operationsd.' There were few significant differences between the three weather-related behavior groups in terms of pilot demographics, aircraft characteristics, geographic or environmental factors, or absolute flight distances. The pattern of relative flight distances (a psychological construct) was markedly different for the three groups, with pilots in the weather avoidance group being distinguished by taking timely action. The relative distance results suggest that the mid-point of the flight can be a 'psychological turning point' for pilots, irrespective of the absolute flight distance involved. Hence, pilots' behavior was sometimes influenced by psychological factors not related to any particular operational aspect of the flight. The results of the weather avoidance group indicate that a safe pilot is a proactive pilot. Dealing with adverse weather is not a one-off decision but a continually evolving process. This aspect is discussed in terms of the concept of 'mindfulness'.

Acute spinal injury after centrifuge training in asymptomatic fighter pilots.

PubMed

Kang, Kyung-Wook; Shin, Young Ho; Kang, Seungcheol

2015-04-01

Many countries have hypergravity training centers using centrifuges for pilots to cope with a high gravity (G) environment. The high G training carries potential risk for the development of spinal injury. However, no studies evaluated the influence of centrifuge training on the spines of asymptomatic fighter pilots on a large scale. Study subjects were 991 male fighter pilots with high G training at one institution. Subject variables included information about physical characteristics, flight hours of pilots prior to the training, and G force exposure related factors during training. The two dependent variables were whether the pilots developed acute spinal injury after training and the severity of the injury (major/minor). The incidence of acute spinal injury after high G training was 2.3% (23 of 991 subjects). There were 19 subjects who developed minor injury and 4 subjects who developed a herniated intervertebral disc, which is considered a major injury. In multivariate analysis, only the magnitude of G force during training was significantly related to the development of acute spinal injury. However, there was no significant factor related to the severity of the injury. These results suggest that high G training could cause negative effects on fighter pilots' spines. The magnitude of G force during training seemed to be the most significant factor affecting the occurrence of acute spinal injury.

Use of platelet rich plasma for the treatment of bicipital tendinopathy in spinal cord injury:: a pilot study.

PubMed

Ibrahim, Victor M; Groah, Suzanne L; Libin, Alexander; Ljungberg, Inger H

2012-01-01

The purpose of study is to explore the efficacy and safety of platelet rich plasma (PRP) in the nonoperative management of shoulder tendinopathy amongst individuals with spinal cord injury. This objective was met by completing a pilot study on the effectiveness and safety of a PRP injection into the biceps tendon demonstrating clinical and ultrasonagraphic pathology. Recent analysis of the preliminary pilot data has demonstrated remarkably convincing results demonstrating both the safety and efficacy of this novel intervention.

A multifaceted intervention to reduce inappropriate polypharmacy in primary care: research co-creation opportunities in a pilot study.

PubMed

Anderson, Kristen; Foster, Michele M; Freeman, Christopher R; Scott, Ian A

2016-04-18

Co-creation (or co-design) represents the highest form of stakeholder engagement, but it can be infeasible to co-create with all stakeholders through all stages of a research project. The choice of stakeholders for co-design will depend on the study purpose and context of change. For this deprescribing pilot study, general practitioners were recognised as a critical gateway for co-creation, with patients' perspectives of the deprescribing process to be assessed in the evaluation of the pilot.

The effects of visual scenes on roll and pitch thresholds in pilots versus nonpilots.

PubMed

Otakeno, Shinji; Matthews, Roger S J; Folio, Les; Previc, Fred H; Lessard, Charles S

2002-02-01

Previous studies have indicated that, compared with nonpilots, pilots rely more on vision than "seat-of-the-pants" sensations when presented with visual-vestibular conflict. The objective of this study was to evaluate whether pilots and nonpilots differ in their thresholds for tilt perception while viewing visual scenes depicting simulated flight. This study was conducted in the Advanced Spatial Disorientation Demonstrator (ASDD) at Brooks AFB, TX. There were 14 subjects (7 pilots and 7 nonpilots) who recorded tilt detection thresholds in pitch and roll while exposed to sub-threshold movement in each axis. During each test run, subjects were presented with computer-generated visual scenes depicting accelerating forward flight by day or night, and a blank (control) condition. The only significant effect detected by an analysis of variance (ANOVA) was that all subjects were more sensitive to tilt in roll than in pitch [F (2,24) = 18.96, p < 0.001]. Overall, pilots had marginally higher tilt detection thresholds compared with nonpilots (p = 0.055), but the type of visual scene had no significant effect on thresholds. In this study, pilots did not demonstrate greater visual dominance over vestibular and proprioceptive cues than nonpilots, but appeared to have higher pitch and roll thresholds overall. The finding of significantly lower detection thresholds in the roll axis vs. the pitch axis was an incidental finding for both subject groups.

Virgil Gus Grissom's Visit to LaRC

NASA Image and Video Library

1963-02-22

Astronaut Virgil "Gus" Grissom at the controls of the Visual Docking Simulator. From A.W. Vogeley, "Piloted Space-Flight Simulation at Langley Research Center," Paper presented at the American Society of Mechanical Engineers 1966 Winter Meeting, New York, NY, November 27-December 1, 1966. "This facility was [later known as the Visual-Optical Simulator.] It presents to the pilot an out-the-window view of his target in correct 6 degrees of freedom motion. The scene is obtained by a television camera pick-up viewing a small-scale gimbaled model of the target." "For docking studies, the docking target picture was projected onto the surface of a 20-foot-diameter sphere and the pilot could, effectively, maneuver into contract. this facility was used in a comparison study with the Rendezvous Docking Simulator - one of the few comparison experiments in which conditions were carefully controlled and a reasonable sample of pilots used. All pilots preferred the more realistic RDS visual scene. The pilots generally liked the RDS angular motion cues although some objected to the false gravity cues that these motions introduced. Training time was shorter on the RDS, but final performance on both simulators was essentially equal. " "For station-keeping studies, since close approach is not required, the target was presented to the pilot through a virtual-image system which projects his view to infinity, providing a more realistic effect. In addition to the target, the system also projects a star and horizon background. "

ASSESSMENT OF MAST IN EUROPEAN PATIENT-CENTERED TELEMEDICINE PILOTS.

PubMed

Ekeland, Anne Granstrøm; Grøttland, Astrid

2015-01-01

Model for ASsessment of Telemedicine Applications (MAST) is a health technology assessment (HTA) inspired framework for assessing the effectiveness and contribution to quality of telemedicine applications based on rigorous, scientific data. This study reports from a study of how it was used and perceived in twenty-one pilots of the European project RENEWING HEALTH (RH). The objectives of RH were to implement large-scale, real-life test beds for the validation and subsequent evaluation of innovative patient-centered telemedicine services. The study is a contribution to the appraisal of HTA methods. A questionnaire was administered for project leaders of the pilots. It included questions about use and usefulness of MAST for (i) preceding considerations, (ii) evaluation of outcomes within seven domains, and (iii) considerations of transferability. Free text spaces allowed for proposals of improvement. The responses covered all pilots. A quantitative summary of use and a qualitative analysis of usefulness were performed. MAST was used and considered useful for pilot evaluations. Challenges included problems to scientifically determine alternative service options and outcome within the seven domains. Proposals for improvement included process studies and adding domains of technological usability, responsible innovation, health literacy, behavior change, caregiver perspectives and motivational issues of professionals. MAST was used according to its structure. Its usefulness in patient centered pilots can be improved by adding new stakeholder groups. Interdependencies between scientific rigor, resources and timeliness should be addressed. Operational options for improvements include process studies, literature reviews and sequential mini-HTAs for identification of areas for more elaborate investigations.

White Matter Integrity in High-Altitude Pilots Exposed to Hypobaria

PubMed Central

McGuire, Stephen A.; Boone, Goldie R.E.; Sherman, Paul M.; Tate, David F.; Wood, Joe D.; Patel, Beenish; Eskandar, George; Wijtenburg, S. Andrea; Rowland, Laura M.; Clarke, Geoffrey D.; Grogan, Patrick M.; Sladky, John H.; Kochunov, Peter V.

2017-01-01

Introduction Nonhypoxic hypobaric (low atmospheric pressure) occupational exposure, such as experienced by U.S. Air Force U-2 pilots and safety personnel operating inside altitude chambers, is associated with increased subcortical white matter hyperintensity (WMH) burden. The pathophysiological mechanisms underlying this discrete WMH change remain unknown. The objectives of this study were to demonstrate that occupational exposure to nonhypoxic hypobaria is associated with altered white matter integrity as quantified by fractional anisotropy (FA) measured using diffusion tensor imaging and relate these findings to WMH burden and neurocognitive ability. Methods There were 102 U-2 pilots and 114 age- and gender-controlled, health-matched controls who underwent magnetic resonance imaging. All pilots performed neurocognitive assessment. Whole-brain and tract-wise average FA values were compared between pilots and controls, followed by comparison within pilots separated into high and low WMH burden groups. Neurocognitive measurements were used to help interpret group difference in FA values. Results Pilots had significantly lower average FA values than controls (0.489/0.500, respectively). Regionally, pilots had higher FA values in the fronto-occipital tract where FA values positively correlated with visual-spatial performance scores (0.603/0.586, respectively). There was a trend for high burden pilots to have lower FA values than low burden pilots. Discussion Nonhypoxic hypobaric exposure is associated with significantly lower average FA in young, healthy U-2 pilots. This suggests that recurrent hypobaric exposure causes diffuse axonal injury in addition to focal white matter changes. PMID:28323582

Intermittent Renewable Management Pilot Phase 2

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

Kiliccote, Sila; Homan, Gregory; Anderson, Robert

The Intermittent Renewable Management Pilot - Phase 2 (IRM2) was designed to study the feasibility of demand-side resources to participate into the California Independent System Operator (CAISO) wholesale market as proxy demand resources (PDR). The pilot study focused on understanding the issues related with direct participation of third-parties and customers including customer acceptance; market transformation challenges (wholesale market, technology); technical and operational feasibility; and value to the rate payers, DR resource owners and the utility on providing an enabling mechanism for DR resources into the wholesale markets. The customer had the option of committing to either three contiguous hour blocksmore » for 24 days or six contiguous hours for 12 days a month with day-ahead notification that aligned with the CAISO integrated forward market. As a result of their being available, the customer was paid $10/ kilowatt (kW)-month for capacity in addition to CAISO energy settlements. The participants were limited to no more than a 2 megawatt (MW) capacity with a six-month commitment. Four participants successfully engaged in the pilot. In this report, we provide the description of the pilot, participant performance results, costs and value to participants as well as outline some of the issues encountered through the pilot. Results show that participants chose to participate with storage and the value of CAISO settlements were significantly lower than the capacity payments provided by the utility as incentive payments. In addition, this pilot revealed issues both on the participant side and system operations side. These issues are summarized in the report.The Intermittent Renewable Management Pilot - Phase 2 (IRM2) was designed to study the feasibility of demand-side resources to participate into the California Independent System Operator (CAISO) wholesale market as proxy demand resources (PDR). The pilot study focused on understanding the issues related with direct participation of third-parties and customers including customer acceptance; market transformation challenges (wholesale market, technology); technical and operational feasibility; and value to the rate payers, DR resource owners and the utility on providing an enabling mechanism for DR resources into the wholesale markets.« less

Marijuana and actual driving performance

DOT National Transportation Integrated Search

1993-11-01

This report concerns the effects of marijuana smoking on actual driving performance. It presents the results of one pilot and three actual driving studies. The pilot study's major purpose was to establish the THC dose current marijuana users smoke to...

A pilot study to test multiple medication usage and driving functioning

DOT National Transportation Integrated Search

2008-06-01

The use of medications and multiple medications becomes more prevalent with increasing age. This pilot study explored the relationship between polypharmacy and driving functioning through separate but related research activities. A patient-level admi...

Analysis of empty ATLAS pilot jobs

NASA Astrophysics Data System (ADS)

Love, P. A.; Alef, M.; Dal Pra, S.; Di Girolamo, A.; Forti, A.; Templon, J.; Vamvakopoulos, E.; ATLAS Collaboration

2017-10-01

In this analysis we quantify the wallclock time used by short empty pilot jobs on a number of WLCG compute resources. Pilot factory logs and site batch logs are used to provide independent accounts of the usage. Results show a wide variation of wallclock time used by short jobs depending on the site and queue, and changing with time. For a reference dataset of all jobs in August 2016, the fraction of wallclock time used by empty jobs per studied site ranged from 0.1% to 0.8%. Aside from the wall time used by empty pilots, we also looked at how many pilots were empty as a fraction of all pilots sent. Binning the August dataset into days, empty fractions between 2% and 90% were observed. The higher fractions correlate well with periods of few actual payloads being sent to the site.

Synthesized speech rate and pitch effects on intelligibility of warning messages for pilots

NASA Technical Reports Server (NTRS)

Simpson, C. A.; Marchionda-Frost, K.

1984-01-01

In civilian and military operations, a future threat-warning system with a voice display could warn pilots of other traffic, obstacles in the flight path, and/or terrain during low-altitude helicopter flights. The present study was conducted to learn whether speech rate and voice pitch of phoneme-synthesized speech affects pilot accuracy and response time to typical threat-warning messages. Helicopter pilots engaged in an attention-demanding flying task and listened for voice threat warnings presented in a background of simulated helicopter cockpit noise. Performance was measured by flying-task performance, threat-warning intelligibility, and response time. Pilot ratings were elicited for the different voice pitches and speech rates. Significant effects were obtained only for response time and for pilot ratings, both as a function of speech rate. For the few cases when pilots forgot to respond to a voice message, they remembered 90 percent of the messages accurately when queried for their response 8 to 10 sec later.

Pilot-Induced Oscillations and Human Dynamic Behavior

NASA Technical Reports Server (NTRS)

McRuer, Duane T.

1995-01-01

This is an in-depth survey and study of pilot-induced oscillations (PIO's) as interactions between human pilot and vehicle dynamics; it includes a broad and comprehensive theory of PIO's. A historical perspective provides examples of the diversity of PIO's in terms of control axes and oscillation frequencies. The constituents involved in PIO phenomena, including effective aircraft dynamics, human pilot dynamic behavior patterns, and triggering precursor events, are examined in detail as the structural elements interacting to produce severe pilot-induced oscillations. The great diversity of human pilot response patterns, excessive lags and/or inappropriate gain in effective aircraft dynamics, and transitions in either the human or effective aircraft dynamics are among the key sources implicated as factors in severe PIO's. The great variety of interactions which may result in severe PIO's is illustrated by examples drawn from famous PIO's. These are generalized under a pilot-behavior-theory-based set of categories proposed as a classification scheme pertinent to a theory of PIO's. Finally, a series of interim prescriptions to avoid PIO is provided.

Developing a fatigue questionnaire for Chinese civil aviation pilots.

PubMed

Dai, Jing; Luo, Min; Hu, Wendong; Ma, Jin; Wen, Zhihong

2018-03-23

To assess the fatigue risk is an important challenge in improving flight safety in aviation industry. The aim of this study was to develop a comprehensive fatigue risk management indicators system and a fatigue questionnaire for Chinese civil aviation pilots. Participants included 74 (all males) civil aviation pilots. They finished the questionnaire in 20 minutes before a flight mission. The estimation of internal consistency with Cronbach's α and Student's t test as well as Pearson's correlation analysis were the main statistical methods. The results revealed that the fatigue questionnaire had acceptable internal consistency reliability and construct validity; there were significant differences on fatigue scores between international and domestic flight pilots. And some international flight pilots, who had taken medications as a sleep aid, had worse sleep quality than those had not. The long-endurance flight across time zones caused significant differences in circadian rhythm. The fatigue questionnaire can be used to measure Chinese civil aviation pilots' fatigue, which provided a reference for fatigue risk management system to civil aviation pilots.

The retention of manual flying skills in the automated cockpit.

PubMed

Casner, Stephen M; Geven, Richard W; Recker, Matthias P; Schooler, Jonathan W

2014-12-01

The aim of this study was to understand how the prolonged use of cockpit automation is affecting pilots' manual flying skills. There is an ongoing concern about a potential deterioration of manual flying skills among pilots who assume a supervisory role while cockpit automation systems carry out tasks that were once performed by human pilots. We asked 16 airline pilots to fly routine and nonroutine flight scenarios in a Boeing 747-400 simulator while we systematically varied the level of automation that they used, graded their performance, and probed them about what they were thinking about as they flew. We found pilots' instrument scanning and manual control skills to be mostly intact, even when pilots reported that they were infrequently practiced. However, when pilots were asked to manually perform the cognitive tasks needed for manual flight (e.g., tracking the aircraft's position without the use of a map display, deciding which navigational steps come next, recognizing instrument system failures), we observed more frequent and significant problems. Furthermore, performance on these cognitive tasks was associated with measures of how often pilots engaged in task-unrelated thought when cockpit automation was used. We found that while pilots' instrument scanning and aircraft control skills are reasonably well retained when automation is used, the retention of cognitive skills needed for manual flying may depend on the degree to which pilots remain actively engaged in supervising the automation.

Synthetic Vision Systems in GA Cockpit-Evaluation of Basic Maneuvers Performed by Low Time GA Pilots During Transition from VMC to IMC

NASA Technical Reports Server (NTRS)

Takallu, M. A.; Wong, D. T.; Uenking, M. D.

2002-01-01

An experimental investigation was conducted to study the effectiveness of modern flight displays in general aviation cockpits for mitigating Low Visibility Loss of Control and the Controlled Flight Into Terrain accidents. A total of 18 General Aviation (GA) pilots with private pilot, single engine land rating, with no additional instrument training beyond private pilot license requirements, were recruited to evaluate three different display concepts in a fixed-based flight simulator at the NASA Langley Research Center's General Aviation Work Station. Evaluation pilots were asked to continue flight from Visual Meteorological Conditions (VMC) into Instrument Meteorological Conditions (IMC) while performing a series of 4 basic precision maneuvers. During the experiment, relevant pilot/vehicle performance variables, pilot control inputs and physiological data were recorded. Human factors questionnaires and interviews were administered after each scenario. Qualitative and quantitative data have been analyzed and the results are presented here. Pilot performance deviations from the established target values (errors) were computed and compared with the FAA Practical Test Standards. Results of the quantitative data indicate that evaluation pilots committed substantially fewer errors when using the Synthetic Vision Systems (SVS) displays than when they were using conventional instruments. Results of the qualitative data indicate that evaluation pilots perceived themselves to have a much higher level of situation awareness while using the SVS display concept.

Social Interactions Sparked by Pictorial Warnings on Cigarette Packs

PubMed Central

Hall, Marissa G.; Peebles, Kathryn; Bach, Laura E.; Noar, Seth M.; Ribisl, Kurt M.; Brewer, Noel T.

2015-01-01

The Message Impact Framework suggests that social interactions may offer smokers the opportunity to process pictorial warnings on cigarette packs more deeply. We aimed to describe adult smokers’ social interactions about pictorial cigarette pack warnings in two longitudinal pilot studies. In Pilot Study 1, 30 smokers used cigarette packs with one of nine pictorial warnings for two weeks. In Pilot Study 2, 46 smokers used cigarette packs with one of five pictorial warnings for four weeks. Nearly all smokers (97%/96% in Pilot Study 1/2) talked about the warnings with other people, with the most common people being friends (67%/87%) and spouses/significant others (34%/42%). Pilot Study 2 found that 26% of smokers talked about the warnings with strangers. Discussions about the health effects of smoking and quitting smoking were more frequent during the first week of exposure to pictorial warnings than in the week prior to beginning the study (both p < 0.05). Pictorial warnings sparked social interactions about the warnings, the health effects of smoking, and quitting smoking, indicating that pictorial warnings may act as a social intervention reaching beyond the individual. Future research should examine social interactions as a potential mediator of the impact of pictorial warnings on smoking behavior. PMID:26506363

Meal-induced platelet activation in diabetes mellitus type 1 or type 2 is related to postprandial insulin rather than glucose levels.

PubMed

Spectre, Galia; Stålesen, Ragnhild; Östenson, Claes-Göran; Hjemdahl, Paul

2016-05-01

Postprandial platelet activation was related to postprandial insulin rather than glucose levels in a previous meal insulin study in type 2 diabetes mellitus (T2DM). We therefore compared postprandial platelet activation in type 1 (T1DM) patients without insulin secretion and T2DM patients with high postprandial insulin levels. Patients with T1DM (n=11) and T2DM (n=12) were studied before and 90min after a standardized meal without premeal insulin. Five T1DM patients volunteered for a restudy with their regular premeal insulin. Platelet activation was assessed by flow cytometry, with and without the thromboxane analogue U46619 or ADP, and by whole blood aggregometry (Multiplate®). Effects of insulin (100μU/mL) in vitro were also studied. Before the meal, glucose, insulin and platelet activation markers other than platelet-leukocyte aggregates (PLAs) were similar in T1DM and T2DM; PLAs were higher in T1DM. Postprandial glucose levels increased more markedly in T1DM (to 22.1±1.4 vs. 11.2±0.6mmol/L) while insulin levels increased only in T2DM (from 24.4±4.4 to 68.8±12.3μU/mL). Platelet P-selectin expression, fibrinogen binding and PLA formation stimulated by U46619 were markedly enhanced (approximately doubled) and whole blood aggregation stimulated by U46619 was increased (p<0.05 for all) after the meal in T2DM patients but not in T1DM patients. The pilot study with premeal insulin in T1DM patients showed postprandial platelet activation when postprandial insulin levels increased. In vitro insulin mildly activated platelets in both groups. Postprandial platelet activation via the thromboxane pathway is related to postprandial hyperinsulinemia and not to postprandial hyperglycaemia in patients with diabetes. Copyright © 2016 Elsevier Ltd. All rights reserved.

EMAP WESTERN UNITED STATES LANDSCAPE CHARACTERIZATION SOUTHERN ROCKIES PILOT STUDY AREA DATA AND PRODUCT BROWSER

EPA Science Inventory

The United States Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP) is conducting a pilot study in the western United States. This study will advance the science of ecological monitoring and demonstrate techniques for regional-scale assessme...

EMAP WESTERN UNITED STATES LANDSCAPE CHARACTERIZATION NORTHWEST OREGON PILOT STUDY AREA DATA AND PRODUCT BROWSER

EPA Science Inventory

The United States Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP) is conducting a pilot study in the western United States. This study will advance the science of ecological monitoring and demonstrate techniques for regional-scale assessme...

A preliminary study of maximal control force capability of female pilots.

DOT National Transportation Integrated Search

1972-07-01

The growing number of female pilots entering the field of civil aviation has suggested the need for a study of the maximum allowable forces which should be specified for operating aircraft controls. : Therefore, a study was made of the maximal volunt...

U.S. Army Primary Helicopter School Training Program Performance Norms.

ERIC Educational Resources Information Center

Barnes, John A.; Statham, Flavous D.

The Helicopter Pilot Training Program of the Army differs from those of the other services in concept. It takes nonpilot servicemen and trains them to fly helicopters. The study provides normative performance data for a pilot trainee in an army light-observation helicopter as a first step toward establishing normative data for pilot performance in…

"Tower, Am I Cleared to Land?": Problematic Communication in Aviation Discourse

ERIC Educational Resources Information Center

Howard, John W., III

2008-01-01

This study examined problematic communication in pilot-air traffic controller (ATC) interaction. More than 15 hours of pilot-ATC dialogue were collected by monitoring control tower frequencies at 15 U.S. airports. The transcribed data yielded a total of 34 ATCs, 270 pilots, and 1,799 turns of talk. Analyses revealed that (a) communication…

Automated Pilot Performance Assessment in the T-37: A Feasibility Study. Final Report (May 1968-April 1971).

ERIC Educational Resources Information Center

Knoop, Patricia A.; Welde, William L.

Air Force investigators conducted a three year program to develop a capability for automated quantification and assessment of in-flight pilot performance. Such a capability enhances pilot training by making ratings more objective, valid, reliable and sensitive, and by freeing instructors from rating responsibilities, allowing them to concentrate…

Flight Instructor-Student Pilot Perceptive Similarity and Its Effect on Flight Training Time.

ERIC Educational Resources Information Center

Kreienkamp, Ronald A.

This study attempts to identify factors that may contribute to the learning process of the student pilot in order to lower flight costs while maintaining or increasing safety factors. Specifically, it tests the hypothesis that a significant relationship exists between the similarity of flight instructor and student pilot perceptive styles and the…

Physiological effects of night vision goggle counterweights on neck musculature of military helicopter pilots.

PubMed

Harrison, Michael F; Neary, J Patrick; Albert, Wayne J; Veillette, Major Dan W; Forcest, Canadian; McKenzie, Neil P; Croll, James C

2007-08-01

Increased helmet-mounted mass and specific neck postures have been found to be a cause of increased muscular activity and stress. However, pilots who use night vision goggles (NVG) frequently use counterweight (CW) equipment such as a lead mass that is attached to the back of the flight helmet to provide balance to counter the weight of the NVG equipment mounted to the front of the flight helmet. It is proposed that this alleviates this stress. However, no study has yet investigated the physiological effects of CW during an extended period of time during which the pilots performed normal operational tasks. Thirty-one Canadian Forces pilots were monitored on consecutive days during a day and a NVG mission in a CH-146 flight simulator. Near infrared spectroscopy probes were attached bilaterally to the trapezius muscles and hemodynamics, i.e., total oxygenation index, total hemoglobin, oxyhemoglobin, and deoxyhemoglobin, were monitored for the duration of the mission. Pilots either wore CW (n = 25) or did not wear counterweights (nCW, n = 6) as per their usual operational practice. Levene's statistical tests were conducted to test for homogeneity and only total oxygenation index returned a significant result (p < or = 0.05). For the near infrared spectroscopy variables, significant differences were found to exist between CW and nCW pilots for total hemoglobin, deoxyhemoglobin, and oxyhemoglobin during NVG flights. The CW pilots displayed less metabolic and hemodynamic stress during simulated missions as compared to the nCW pilots. The results of this study would suggest that the use of CW equipment during NVG missions in military helicopter pilots does minimize the metabolic and hemodynamic responses of the trapezius muscles.

Flight Deck Data Link Displays: An Evaluation of Textual and Graphical Implementations

NASA Technical Reports Server (NTRS)

McGann, Alison; Lozito, Sandy; Corker, Kevin; Ashford, Rose (Technical Monitor)

2001-01-01

In Experiment 1, 16 pilots participated in a part-task simulation study that evaluated pilot data link communication for short and long message types and for two textual formats. No differences were found between the two textual formats when evaluating data link transaction times and pilot performance on a secondary task. Pilots initiated flight changes more quickly with the T-Scan format, where location of clearance information roughly corresponded to the cockpit instrument layout. Longer messages were less problematic than two short messages sent in close succession as pilots required more verbal clarification for closely spaced messages. 24 pilots participated in a second experiment that evaluated pilot communication performance for textual data link, two implementations of graphical data link, and a combined graphical and textual information modality. The two modalities incorporating text resulted in significantly faster transaction times and better performance on the secondary task than the two graphical-only implementations. The interval between messages was also more systematically varied in Experiment 2, and a short interval between messages significantly increased the access time for the second message. This delay in access was long enough to increase significantly the total transaction time of the second message, and this effect was exaggerated for the graphical-only implementations. Time to view the message before acknowledgement and time to initiate flight changes were not affected by the interval manipulation, This suggests that pilots adopt a sequential message handling strategy, and presenting messages closely in succession may present operational problems in a data link Air Traffic Control (ATC) environment. The results of this study also indicate that the perceived importance of message content is currently a crucial element in pilot data link communication.

Brief report: Bereaved parents informing research design: The place of a pilot study.

PubMed

Donovan, L A; Wakefield, C E; Russell, V; Hetherington, Kate; Cohn, R J

2018-02-23

Risk minimization in research with bereaved parents is important. However, little is known about which research methods balance the sensitivity required for bereaved research participants and the need for generalizable results. To explore parental experiences of participating in mixed method bereavement research via a pilot study. A convergent parallel mixed method design assessing bereaved parents' experience of research participation. Eleven parents whose child was treated for cancer at The Royal Children's Hospital, Brisbane completed the questionnaire/interview being piloted (n = 8 mothers; n = 3 fathers; >6 months and <6 years bereaved). Of these, eight parents completed the pilot study evaluation questionnaire, providing feedback on their experience of participation. Participants acknowledged the importance of bereaved parents being central to research design and the development of bereavement programs. Sixty-three per cent (n = 5/8) of parents described completion of the questionnaire as 'not at all/a little bit' of a burden. Seventy-five per cent (n = 6/8) of parents opting into the telephone interview described participation as 'not at all/a little bit' of a burden. When considering the latest timeframes for participation in bereavement research 63% (n = 5/8) of parents indicated 'no endpoint.' Findings from the pilot study enabled important adjustments to be made to a large-scale future study. As a research method, pilot studies may be utilized to minimize harm and maximize the potential benefits for vulnerable research participants. A mixed method approach allows researchers to generalize findings to a broader population while also drawing on the depth of the lived experience.

Information for patients with cancer. Does personalization make a difference? Pilot study results and randomised trial in progress.

PubMed Central

Jones, R.; Pearson, J.; Cawsey, A.; Barrett, A.

1996-01-01

Although there are a number of groups working on the provision of personalized patient information there has been little evaluation. We have developed and piloted a method of giving patients on-line access to their own medical records with associated explanations. We are comparing, in a randomised trial, personalized with general computer based information for patients undergoing radiotherapy for cancer. We present results from the pilot study and the evaluation methods to be employed. PMID:8947701

Effect of lift-to-drag ratio in pilot rating of the HL-20 landing task

NASA Technical Reports Server (NTRS)

Jackson, E. B.; Rivers, Robert A.; Bailey, Melvin L.

1993-01-01

A man-in-the-loop simulation study of the handling qualities of the HL-20 lifting-body vehicle was made in a fixed-base simulation cockpit at NASA Langley Research Center. The purpose of the study was to identify and substantiate opportunities for improving the original design of the vehicle from a handling qualities and landing performance perspective. Using preliminary wind-tunnel data, a subsonic aerodynamic model of the HL-20 was developed. This model was adequate to simulate the last 75-90 s of the approach and landing. A simple flight-control system was designed and implemented. Using this aerodynamic model as a baseline, visual approaches and landings were made at several vehicle lift-to-drag ratios. Pilots rated the handling characteristics of each configuration using a conventional numerical pilot-rating scale. Results from the study showed a high degree of correlation between the lift-to-drag ratio and pilot rating. Level 1 pilot ratings were obtained when the L/D ratio was approximately 3.8 or higher.

Effect of lift-to-drag ratio in pilot rating of the HL-20 landing task

NASA Astrophysics Data System (ADS)

Jackson, E. B.; Rivers, Robert A.; Bailey, Melvin L.

1993-10-01

A man-in-the-loop simulation study of the handling qualities of the HL-20 lifting-body vehicle was made in a fixed-base simulation cockpit at NASA Langley Research Center. The purpose of the study was to identify and substantiate opportunities for improving the original design of the vehicle from a handling qualities and landing performance perspective. Using preliminary wind-tunnel data, a subsonic aerodynamic model of the HL-20 was developed. This model was adequate to simulate the last 75-90 s of the approach and landing. A simple flight-control system was designed and implemented. Using this aerodynamic model as a baseline, visual approaches and landings were made at several vehicle lift-to-drag ratios. Pilots rated the handling characteristics of each configuration using a conventional numerical pilot-rating scale. Results from the study showed a high degree of correlation between the lift-to-drag ratio and pilot rating. Level 1 pilot ratings were obtained when the L/D ratio was approximately 3.8 or higher.

Experimental and Numerical Study on Effect of Sample Orientation on Auto-Ignition and Piloted Ignition of Poly(methyl methacrylate)

PubMed Central

Peng, Fei; Zhou, Xiao-Dong; Zhao, Kun; Wu, Zhi-Bo; Yang, Li-Zhong

2015-01-01

In this work, the effect of seven different sample orientations from 0° to 90° on pilot and non-pilot ignition of PMMA (poly(methyl methacrylate)) exposed to radiation has been studied with experimental and numerical methods. Some new and significant conclusions are drawn from the study, including a U-shape curve of ignition time and critical mass flux as sample angle increases for pilot ignition conditions. However, in auto-ignition, the ignition time and critical mass flux increases with sample angle α. Furthermore, a computational fluid dynamic model have been built based on the Fire Dynamics Simulator (FDS6) code to investigate the mechanisms controlling the dependence on sample orientation of the ignition of PMMA under external radiant heating. The results of theoretical analysis and modeling results indicate the decrease of total incident heat flux at sample surface plays the dominant role during the ignition processes of auto-ignition, but the volatiles gas flow has greater influence for piloted ignition conditions. PMID:28793421

The Introduction of New Cockpit Technology: A Human Factors Study

NASA Technical Reports Server (NTRS)

Curry, R. E.

1985-01-01

A joint Airline/NASA field study of B-767 training and operations was conducted during the period this aircraft was being introduced into line service. The objectives of the study were: (1) to identify any adverse reactions to the new technology; (2) to provide a clearing house of information for the airlines and pilots during the introductory period; (3) to provide feedback on airline training programs for the new aircraft; and (4) to provide field data to NASA and other researchers to help them develop principles of human interaction with automated systems. It is concluded that: (1) a large majority of pilots enjoy flying the B-767 more than the older aircraft; (2) pilots accept new cockpit technology and find it useful; (3) pilots are aware of the potential loss of flying skills because of automation, and take steps to prevent this from happening; (4) autopilot/autothrottle interactions and FMS operations were sometimes confusing or surprising to pilots, and they desired more training in this area; and (5) highly automated cockpits can result in a loss of effective monitoring performance.

Learning About Cockpit Automation: From Piston Trainer to Jet Transport

NASA Technical Reports Server (NTRS)

Casner, Stephen M.

2003-01-01

Two experiments explored the idea of providing cockpit automation training to airline-bound student pilots using cockpit automation equipment commonly found in small training airplanes. In a first experiment, pilots mastered a set of tasks and maneuvers using a GPS navigation computer, autopilot, and flight director system installed in a small training airplane Students were then tested on their ability to complete a similar set of tasks using the cockpit automation system found in a popular jet transport aircraft. Pilot were able to successfully complete 77% of all tasks in the jet transport on their first attempt. An analysis of a control group suggests that the pilot's success was attributable to the application of automation principles they had learned in the small airplane. A second experiment looked at two different ways of delivering small-aeroplane cockpit automation training: a self-study method, and a dual instruction method. The results showed a slight advantage for the self-study method. Overall, the results of the two studies cast a strong vote for the incorporation of cockpit automation training in curricula designed for pilot who will later transition to the jet fleet.

APMP Pilot Study on Transmittance Haze

NASA Astrophysics Data System (ADS)

Liu, Wen-Chun; Hwang, Jisoo; Koo, Annette; Wu, Houping; Leecharoen, Rojana; Yu, Hsueh-Ling

2018-02-01

Five NMIs within APMP, including CMS/ITRI, MSL, NIM, NIMT and KRISS from TCPR applied to the APMP technical committee initiative project for funding to carry out a pilot comparison of transmittance haze in 2012. The project started in 2014 and the final report was completed at the end of 2016. In this pilot comparison, three different haze standards were adopted, and transmittance haze for each standard was measured according to ASTM D1003 or ISO 14782. This paper presents the first results of an APMP pilot study of transmittance haze and the analysis of the variation among different haze measurement systems which are commonly used. The study shows that the variables such as sphere multiplier, transmittance distribution, fluorescence of samples and optical path of the incident beam cause discrepancies among NMIs and highlight deficiencies in current documentary standards.

Human factors in cockpit automation: A field study of flight crew transition

NASA Technical Reports Server (NTRS)

Wiener, E. L.

1985-01-01

The factors which affected two groups of airline pilots in the transition from traditional airline cockpits to a highly automated version were studied. All pilots were highly experienced in traditional models of the McDonnell-Douglas DC-9 prior to their transition to the more automated DC-9-80. Specific features of the new aircraft, particularly the digital flight guidance system (DFGS) and other automatic features such as the autothrottle system (ATS), autobrake, and digital display were studied. Particular attention was paid to the first 200 hours of line flying experience in the new aircraft, and the difficulties that some pilots found in adapting to the new systems during this initial operating period. Efforts to prevent skill loss from automation, training methods, traditional human factors issues, and general views of the pilots toward cockpit automation are discussed.

Monitoring of tissue optical properties using OCT: application for blood glucose analysis

NASA Astrophysics Data System (ADS)

Larin, Kirill V.; Eledrisi, Mohsen S.; Ashitkov, Taras V.; Motamedi, Massoud; Esenaliev, Rinat O.

2002-07-01

Noninvasive monitoring of tissue optical properties in real time could significantly improve diagnostics and management of various diseases. Recently we proposed to use high- resolution Optical Coherence Tomography (OCT) technique for measurement of tissue scattering coefficient at the depth of up to 1mm. Our pilot studies performed in vitro and in vivo demonstrated that measurement of tissue scattering with this technique can potentially be applied for noninvasive monitoring of blood glucose concentration. High resolution and coherent photon detection of the OCT technique allowed detection of glucose-induced changes in the scattering coefficient. In this paper we report results of in vivo studies performed in dog, New Zealand rabbits, and first human subjects. OCT system with the wavelength of 1300 nm was used in our experiments. OCT signal slope was measured and compared with actual blood glucose concentration. Bolus glucose injections and glucose clamping administrations were used in animal studies. OCT signals were recorded form human subjects during oral glucose tolerance test. Results obtained form both animal and human studies show good correlation between slope of the OCT signals and actual blood glucose concentration measured using standard glucometesr. Sensitivity and accuracy of blood glucose concentrations monitoring with the OCT is discussed. Obtained result suggest that OCT is a promising technique for noninvasive monitoring of tissue analytes including glucose.

Benefits of controller-pilot data link ATC communications in terminal airspace : final report

DOT National Transportation Integrated Search

1996-09-30

This report documents a Federal Aviation Administration (FAA) study that was : conducted to demonstrate and quantify benefits associated with the implementation of controller-pilot Data Link communications in terminal : airspace. The study was suppor...

Pilot study of proposed revisions to specifications for hydraulic cement concrete.

DOT National Transportation Integrated Search

1985-01-01

This report summarizes the results of a pilot study of the statistical acceptance procedures proposed for adoption by the Virginia Department of Highways and Transportation. The proposed procedures were recommended in the report titled "Improved Spec...

Use of Highways in the Sky and a virtual pad for landing Head Up Display symbology to enable improved helicopter pilots situation awareness and workload in degraded visual conditions.

PubMed

Stanton, Neville A; Plant, Katherine L; Roberts, Aaron P; Allison, Craig K

2017-12-15

Flight within degraded visual conditions is a great challenge to pilots of rotary-wing craft. Environmental cues typically used to guide interpretation of speed, location and approach can become obscured, forcing the pilots to rely on data available from in-cockpit instrumentation. To ease the task of flight during degraded visual conditions, pilots require easy access to flight critical information. The current study examined the effect of 'Highways in the Sky' symbology and a conformal virtual pad for landing presented using a Head Up Display (HUD) on pilots' workload and situation awareness for both clear and degraded conditions across a series of simulated rotary-wing approach and landings. Results suggest that access to the HUD lead to significant improvements to pilots' situation awareness, especially within degraded visual conditions. Importantly, access to the HUD facilitated pilot awareness in all conditions. Results are discussed in terms of future HUD development. Practitioner Summary: This paper explores the use of a novel Heads Up Display, to facilitate rotary-wing pilots' situation awareness and workload for simulated flights in both clear and degraded visual conditions. Results suggest that access to HUD facilitated pilots' situation awareness, especially when flying in degraded conditions.

Pilot Human Factors in Stall/Spin Accidents of Supersonic Fighter Aircraft

NASA Technical Reports Server (NTRS)

Anderson, S. B.; Enevoldson, E. K.; Nguyen, L. T.

1983-01-01

A study has been made of pilot human factors related to stall/spin accidents of supersonic fighter aircraft. The military specifications for flight at high angles of attack are examined. Several pilot human factors problems related to stall/spin are discussed. These problems include (1) unsatisfactory nonvisual warning cues; (2) the inability of the pilot to quickly determine if the aircraft is spinning out of control, or to recognize the type of spin; (3) the inability of the pilot to decide on and implement the correct spin recovery technique; (4) the inability of the pilot to move, caused by high angular rotation; and (5) the tendency of pilots to wait too long in deciding to abandon the irrecoverable aircraft. Psycho-physiological phenomena influencing pilot's behavior in stall/spin situations include (1) channelization of sensory inputs, (2) limitations in precisely controlling several muscular inputs, (3) inaccurate judgment of elapsed time, and (4) disorientation of vestibulo-ocular inputs. Results are given of pilot responses to all these problems in the F14A, F16/AB, and F/A-18A aircraft. The use of departure spin resistance and automatic spin prevention systems incorporated on recent supersonic fighters are discussed. These systems should help to improve the stall/spin accident record with some compromise in maneuverability.

Long-term effects of exercise programs among helicopter pilots with flying related LBP

PubMed Central

Andersen, Knut; Baardsen, Roald; Dalen, Ingvild; Larsen, Jan Petter

2017-01-01

BACKGROUND: Flying related transient Low Back Pain (LBP) among helicopter pilots is considered an occupational distress. OBJECTIVE: To examine if exercise programs can alleviate transient LBP. METHODS: Sixty-five helicopter pilots (92% males), all reporting flying related LBP, responded to an epidemiological survey and a long-term follow-up, 44.8 months later, comprising questions regarding transient LBP and number of sick leaves. Data from 37 pilots participating in two exercise programs, A; general for LBP, B; focused for lumbar trunk (LT), included information from clinical examinations and muscular endurance tests of the LT before and after intervention. Twenty-eight pilots did not participate in any intervention. RESULTS: At long-term follow-up 42% of the pilots still reported flying related transient LBP. Among participants in program B 26% had persistent pain, 70% in program A and 46% among pilots without intervention. Sick-leave reduction was only observed among participants in program B (30% to 4%). Upon re-occurrence of LBP symptoms, half of the pilots in program B again performed exercises to improve their pain. CONCLUSION: This study indicates that exercise programs focused towards lumbar trunk muscular endurance reduces flying related transient LBP and sick-leave among helicopter pilots. These findings may have implications for the pilots’ working conditions. PMID:29278872

Consumer Perceptions About Pilot Training: An Emotional Response

NASA Astrophysics Data System (ADS)

Rosser, Timothy G.

Civilian pilot training has followed a traditional path for several decades. With a potential pilot shortage approaching, ICAO proposed a new paradigm in pilot training methodology called the Multi-Crew Pilot License. This new methodology puts a pilot in the cockpit of an airliner with significantly less flight time experience than the traditional methodology. The purpose of this study was to determine to what extent gender, country of origin and pilot training methodology effect an aviation consumer's willingness to fly. Additionally, this study attempted to determine what emotions mediate a consumer's decision. This study surveyed participants from India and the United States to measure their willingness to fly using the Willingness to Fly Scale shown to be valid and reliable by Rice et al. (2015). The scale uses a five point Likert-type scale. In order to determine the mediating emotions, Ekman and Friesen's (1979) universal emotions, which are happiness, surprise, fear, disgust, anger, and sadness were used. Data were analyzed using SPSS. Descriptive statistics are provided for respondent's age and willingness to fly values. An ANOVA was conducted to test the first four hypotheses and Hayes (2004, 2008) bootstrapping process was used for the mediation analysis. Results indicated a significant main effect for training, F(1,972) = 227.76, p . .001, etap 2 = 0.190, country of origin, F(1, 972) = 28.86, p < .001, .p 2 = 0.029, and a two-way interaction was indicated between training and country of origin, F(7, 972) = 46.71, p < .001, etap 2 = 0.252. Mediation analysis indicated the emotions anger, fear, happiness, and surprise mediated the relationship between training and country of origin, and training. The findings of this study are important to designers of MPL training programs and airline marketers.

Assessment of Muscular Fitness as a Predictor of Flight Duty Limitation.

PubMed

Honkanen, Tuomas; Mäntysaari, Matti; Avela, Janne; Kyröläinen, Heikki; Leino, Tuomo

2018-05-08

The high acceleration (Gz) exposure among military pilots flying fighter aircraft has been associated with an increased risk for cervical and lumbar disorders. It has been suggested that an adequate level of physical performance could reduce the risk of experiencing these disorders. The Finnish Air Force has for several years used aerobic (bicycle ergometer) and muscular fitness tests (battery of five tests) in the selection process of military pilot candidates in order to evaluate their physical fitness level. The aim of the study was to determine if these selection phase tests and anthropometry measures can predispose those individuals who might be at risk of developing severe spinal disorders leading to permanent flight duty limitations later during their military pilots' career. The study population consisted of 23 pilots flying with Gz limitation (+2 Gz, +4 Gz or +5 Gz) due to spinal disorders and 50 experienced (+1,000 flight hours) symptomless controls flying actively in operative missions. Data obtained retrospectively for all subjects included anthropometry, physical (aerobic and muscular fitness) test results and self-reported physical activity levels at a pilot selection phase. Aerobic fitness was measured with a maximal ergometer test and muscular endurance was evaluated with a test battery (standing long jump, pull-ups, sit-ups, back extensions, and push-up tests). Fighter pilots flying without Gz limitation had significantly better mean (±SE) results in pull-up (14.4 ± 4.2 vs. 11.5 ± 2.0, p < 0.05) and back extension (71.1 ± 14.1 vs. 60.0 ± 12.2, p < 0.05) tests during the pilot selection when compared with the limited pilots. Similarly, the non-limited pilots had a better total muscular fitness test score (13.7 ± 1.7 vs. 12.4 ± 1.6, p < 0.05) during the pilot selection. They had also participated in significantly more competitive sports (54% vs. 22%, p < 0.05) at the time of selection when compared with pilots flying with Gz limitation due to spinal disorders. The aerobic fitness test results and anthropometric measures were not statistically different among the groups. Higher levels of muscular fitness, particularly axial strength in military pilot selection may have a protective role for reducing spinal disorders which if developed, can often lead to limiting the availability of pilots for flight duty. The present findings also do not support the assumption that aerobic fitness above the required minimum level would protect pilots from developing spinal disorders and, therefore, from limiting flight duty.

The role of culture and language in avoiding misinformation: pilot findings.

PubMed

Aydin, Cagla; Ceci, Stephen J

2013-01-01

In two pilot studies, we investigate the possibility that patterns in our linguistic environment affect the likelihood of accepting misinformation. Turkish, which marks its verbs for the source of a speaker's evidence (first-hand perception vs. hearsay), was contrasted with English which does not mark its verbs but which, to signal strength of evidence, must employ optional lexical marking. In the first pilot study, Turkish adults were shown to be affected by that language's obligatory evidential markings: their free recall for details of the events changed as a function of the type of the tense-aspect marker in use, and strong evidential markers led to increased levels of suggestibility when employed with misleading questions. In the second pilot study, Turkish- and English-speaking children were shown to be differentially suggestible depending on combinations of evidential markers in the story presented and the evidential marker employed in the misinformation subsequently provided. Together, these two pilot studies show promise in this area of research, which has been ignored by the forensic community and yet would seem to be relevant when interviewing, taking statements, and giving testimony in cross-linguistic settings. Copyright © 2013 John Wiley & Sons, Ltd.

Airborne Conflict Management within Confined Airspace in a Piloted Simulation of DAG-TM Autonomous Aircraft Operations

NASA Technical Reports Server (NTRS)

Barmore, Bryan; Johnson, Edward; Wing, David J.; Barhydt, Richard

2003-01-01

A human-in-the-loop experiment was performed at the NASA Langley Research Center to study the feasibility of Distributed Air/Ground Traffic Management (DAG-TM) autonomous aircraft operations in highly constrained airspace. The airspace was constrained by a pair of special use airspace (SUA) regions on either side of the pilot s planned route. The available airspace was further varied by changing the separation standard for lateral separation between 3 nm and 5 nm. The pilot had to maneuver through the corridor between the SUA s, avoid other traffic and meet flow management constraints. Traffic flow management (TFM) constraints were imposed as a required time of arrival and crossing altitude at an en route fix. This is a follow-up study to work presented at the 4th USA/Europe Air Traffic Management R&D Seminar in December 2001. Nearly all of the pilots were able to meet their TFM constraints while maintaining adequate separation from other traffic. In only 3 out of 59 runs were the pilots unable to meet their required time of arrival. Two loss of separation cases are studied and it is found that the pilots need conflict prevention information presented in a clearer manner. No degradation of performance or safety was seen between the wide and narrow corridors. Although this was not a thorough study of the consequences of reducing the en route lateral separation, nothing was found that would refute the feasibility of reducing the separation requirement from 5 nm to 3 nm. The creation of additional, second-generation conflicts is also investigated. Two resolution methods were offered to the pilots: strategic and tactical. The strategic method is a closed-loop alteration to the Flight Management System (FMS) active route that considers other traffic as well as TFM constraints. The tactical resolutions are short-term resolutions that leave avoiding other traffic conflicts and meeting the TFM constraints to the pilot. Those that made use of the strategic tools avoided additional conflicts, whereas, those making tactical maneuvers often caused additional conflicts. Many of these second-generation conflicts could be avoided by improved conflict prevention tools that clearly present to the pilot which maneuver choices will result in a conflict-free path. These results, together with previously reported studies, continue to support the feasibility of autonomous aircraft operations.

In silico simulation and in vitro evaluation of an elastomeric scaffold using ultrasonic shear wave imaging

NASA Astrophysics Data System (ADS)

Yu, Jiao; Nie, Erwei; Zhu, Yanying; Hong, Yi

2018-03-01

Biodegradable elastomeric scaffolds for soft tissue repair represent a growing area of biomaterials research. Mechanical strength is one of the key factors to consider in the evaluation of candidate materials and the designs for tissue scaffolds. It is desirable to develop non-invasive evaluation methods of the mechanical property of scaffolds which would provide options for monitoring temporal mechanical property changes in situ. In this paper, we conduct in silico simulation and in vitro evaluation of an elastomeric scaffold using a novel ultrasonic shear wave imaging (USWI). The scaffold is fabricated from a biodegradable elastomer, poly(carbonate urethane) urea using salt leaching method. A numerical simulation is performed to test the robustness of the developed inversion algorithm for the elasticity map reconstruction which will be implemented in the phantom experiment. The generation and propagation of shear waves in a homogeneous tissue-mimicking medium with a circular scaffold inclusion is simulated and the elasticity map is well reconstructed. A PVA phantom experiment is performed to test the ability of USWI combined with the inversion algorithm to non-invasively characterize the mechanical property of a porous, biodegradable elastomeric scaffold. The elastic properties of the tested scaffold can be easily differentiated from the surrounding medium in the reconstructed image. The ability of the developed method to identify the edge of the scaffold and characterize the elasticity distribution is demonstrated. Preliminary results in this pilot study support the idea of applying the USWI based method for non-invasive elasticity characterization of tissue scaffolds.

Gene-activated fat grafts for the repair of spinal cord injury: a pilot study.

PubMed

Betz, Volker M; Sitoci-Ficici, K Hakan; Uckermann, Ortrud; Leipnitz, Elke; Iltzsche, Anne; Thirion, Christian; Salomon, Michael; Zwipp, Hans; Schackert, Gabriele; Betz, Oliver B; Kirsch, Matthias

2016-02-01

Spinal cord injury (SCI) is a complex disease requiring a concerted multi-target approach. The most appropriate combination of therapeutic gene, cellular vehicle, and space filling scaffold still has to be determined. We present an approach that employs syngeneic adipose tissue serving as a three-dimensional biological implant, source of progenitor cells, and delivery system for therapeutic genes. In this pilot experiment, we evaluated the feasibility and short-term effects using gene-activated autologous fat grafts after SCI. An experimental SCI model was established in syngeneic Fischer 344 rats by a T9-T10 hemimyelonectomy. Fat tissue was harvested from two donor rats. Animals were divided into four groups and treated with either (i) fat grafts activated by an adenoviral vector carrying the human NT-3 cDNA, (ii) or BDNF, (iii) or with untreated fat grafts or (iv) remained untreated. Animals were euthanized either 7 or 21 days after surgery, and spinal cord tissue was investigated by histological and immunohistochemical methods. NT-3 and BDNF were produced by gene-activated fat grafts for at least 21 days in vitro and in vivo. Fat tissue grafts remained stable at the site of implantation at 7 days and at 21 days. Neither BDNF-activated nor NT-3-activated fat graft had a detectable limiting effect on the neuronal degeneration. BDNF recruited microglia to perilesional site and attenuated their inflammatory response. Gene-activated syngeneic fat tissue serves as a three-dimensional biological material delivering therapeutic molecules to the site of SCI over an extended period of time. The BDNF-fat graft attenuated the inflammatory response. Whether these findings translate into functional recovery will require extended observation times.

Prediction and measurement of human pilot dynamic characteristics in a manned rotorcraft simulation

NASA Technical Reports Server (NTRS)

Hess, Ronald A.; Reedy, James T.

1988-01-01

An analytical and experimental study of the human pilot control strategies in a manned rotorcraft simulation is described. The task simulated involves a low-speed, constant-altitude maneuvering task in which a head-down display is utilized to allow the pilot to track a moving hover point. The efficacy of the display law driving an acceleration symbol is determined and the manner in which the prediction and measurement of pilot/vehicle dynamics can be made part of man/machine system evaluations is demonstrated.

78 FR 52548 - The National Children's Study, Vanguard (Pilot) Study Proposed Collection; 60-day Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-23

... the initiation of methodological substudies. The NCS Vanguard Study is a prospective, longitudinal pilot study of child health and development that will inform the design of the Main Study of the... variables and designed to collect core data at every study visit contact from the time that the enrolled...

Study Skills Analysis: A Pilot Study Linking a Success and Psychology Course

ERIC Educational Resources Information Center

Urciuoli, Jannette Alejandra; Bluestone, Cheryl

2013-01-01

This study explored a concept that learning study skills in the context of the content area under study may transfer across courses, multiplying the benefits towards academic success. Methods that have been reported to influence academic growth at the community college level include success courses and applied study skills. In this pilot project…

Quality of reporting of pilot and feasibility cluster randomised trials: a systematic review

PubMed Central

Chan, Claire L; Leyrat, Clémence; Eldridge, Sandra M

2017-01-01

Objectives To systematically review the quality of reporting of pilot and feasibility of cluster randomised trials (CRTs). In particular, to assess (1) the number of pilot CRTs conducted between 1 January 2011 and 31 December 2014, (2) whether objectives and methods are appropriate and (3) reporting quality. Methods We searched PubMed (2011–2014) for CRTs with ‘pilot’ or ‘feasibility’ in the title or abstract; that were assessing some element of feasibility and showing evidence the study was in preparation for a main effectiveness/efficacy trial. Quality assessment criteria were based on the Consolidated Standards of Reporting Trials (CONSORT) extensions for pilot trials and CRTs. Results Eighteen pilot CRTs were identified. Forty-four per cent did not have feasibility as their primary objective, and many (50%) performed formal hypothesis testing for effectiveness/efficacy despite being underpowered. Most (83%) included ‘pilot’ or ‘feasibility’ in the title, and discussed implications for progression from the pilot to the future definitive trial (89%), but fewer reported reasons for the randomised pilot trial (39%), sample size rationale (44%) or progression criteria (17%). Most defined the cluster (100%), and number of clusters randomised (94%), but few reported how the cluster design affected sample size (17%), whether consent was sought from clusters (11%), or who enrolled clusters (17%). Conclusions That only 18 pilot CRTs were identified necessitates increased awareness of the importance of conducting and publishing pilot CRTs and improved reporting. Pilot CRTs should primarily be assessing feasibility, avoiding formal hypothesis testing for effectiveness/efficacy and reporting reasons for the pilot, sample size rationale and progression criteria, as well as enrolment of clusters, and how the cluster design affects design aspects. We recommend adherence to the CONSORT extensions for pilot trials and CRTs. PMID:29122791