Different colors of light lead to different adaptation and activation as determined by high-density EEG.

Light adaptation is crucial for coping with the varying levels of ambient light. Using high-density electroencephalography (EEG), we investigated how adaptation to light of different colors affects brain responsiveness. In a within-subject design, sixteen young participants were adapted first to dim white light and then to blue, green, red, or white bright light (one color per session in a randomized order). Immediately after both dim and bright light adaptation, we presented brief light pulses and recorded event-related potentials (ERPs). We analyzed ERP response strengths and brain topographies and determined the underlying sources using electrical source imaging. Between 150 and 261ms after stimulus onset, the global field power (GFP) was higher after dim than bright light adaptation. This effect was most pronounced with red light and localized in the frontal lobe, the fusiform gyrus, the occipital lobe and the cerebellum. After bright light adaptation, within the first 100ms after light onset, stronger responses were found than after dim light adaptation for all colors except for red light. Differences between conditions were localized in the frontal lobe, the cingulate gyrus, and the cerebellum. These results indicate that very short-term EEG brain responses are influenced by prior light adaptation and the spectral quality of the light stimulus. We show that the early EEG responses are differently affected by adaptation to different colors of light which may contribute to known differences in performance and reaction times in cognitive tests.

Field Data Collection and Reporting Study, HR-377, 1997

A review of the Iowa Department of Transportation's field data collection and reporting system has been performed. Included were several systems used by the Office of Construction and Local Jurisdictions. The entire field data collection and reporting systems for asphalt cement concrete (ACC) paving, portland cement concrete (PCC) paving, and PCC structures were streamlined and computerized. The field procedures for materials acceptance were also reviewed. Best practices were identified and a method was developed to prioritize materials so transportation agencies could focus their efforts on high priority materials. Iowa State University researchers facilitated a discussion about Equal Employment Opportunity (EEO) and Affirmative Action (AA) procedures between the Office of Construction field staff and the Office of Contracts. A set of alternative procedures was developed. Later the Office of Contracts considered these alternatives as they developed new procedures that are currently being implemented. The job close-out package was reviewed and two unnecessary procedures were eliminated. Numerous other procedures were reviewed and flowcharted. Several changes have been recommended that will increase efficiency and allow staff time to be devoted to higher priority activities. It is estimated the improvements in ACC paving, PCC paving and structural concrete will by similar to three full time equivalent (FTE) positions to field construction, field materials and Office of Materials. Elimination of EEO interviews will be equivalent to one FTE position. It is estimated that other miscellaneous changes will be equivalent to at least one other FTE person. This is a total five FTEs. These are conservative estimates based on savings that are easily quantified. It is likely that total positive effect is greater when items that are difficult to quantify are considered.

Field Testing of Asphaltic Concrete Mixes, HR-101 and R-183, 1968

The amount of asphalt cement in asphaltic concrete has a definite effect on its durability under adverse conditions. The expansion of the transportation system to more and heavier loads has also made the percentage of asphalt cement in a mix more critical. The laboratory mixer does not duplicate the mixing effect of the large pugmills; therefore, it is impossible to be completely sure of the asphalt cement needed for each mix. This percentage quite often must be varied in the field. With a central testing laboratory and the high production of mixing plants today, a large amount of asphaltic concrete is produced before a sample can be tested to determine if the asphalt content is correct. If the asphalt content lowers the durability or stability of a mix, more maintenance will be required in the future. The purpose of this project is to determine the value of a mobile laboratory in the field, the feasibility of providing adequate, early testing in the field, and correlation with the central laboratory. The major purpose was to determine as soon as possible the best percentage of asphalt.

High-magnification vascular imaging to reject false-positive sites in situ during Hexvix® fluorescence cystoscopy

Fluorescence imaging for detection of non-muscle-invasive bladder cancer is based on the selective production and accumulation of fluorescing porphyrins-mainly, protoporphyrin IX-in cancerous tissues after the instillation of Hexvix®. Although the sensitivity of this procedure is very good, its specificity is somewhat limited due to fluorescence false-positive sites. Consequently, magnification cystoscopy has been investigated in order to discriminate false from true fluorescence positive findings. Both white-light and fluorescence modes are possible with the magnification cystoscope, allowing observation of the bladder wall with magnification ranging between 30× for standard observation and 650×. The optical zooming setup allows adjusting the magnification continuously in situ. In the high-magnification (HM) regime, the smallest diameter of the field of view is 600 microns and the resolution is 2.5 microns when in contact with the bladder wall. With this cystoscope, we characterized the superficial vascularization of the fluorescing sites in order to discriminate cancerous from noncancerous tissues. This procedure allowed us to establish a classification based on observed vascular patterns. Seventy-two patients subject to Hexvix® fluorescence cystoscopy were included in the study. Comparison of HM cystoscopy classification with histopathology results confirmed 32/33 (97%) cancerous biopsies and rejected 17/20 (85%) noncancerous lesions.

Thermal and magnetic field-induced martensite-austenite transition in Ni50.3Mn35.3Sn14.4 ribbons

Thermal and field-induced martensite-austenite transition was studied in melt spun Ni50.3Mn35.3Sn14.4 ribbons. Its distinct highly ordered columnarlike microstructure normal to ribbon plane allows the direct observation of critical fields at which field-induced and highly hysteretic reverse transformation starts (H=17kOe at 240K), and easy magnetization direction for austenite and martensite phases with respect to the rolling direction. Single phase L21 bcc austenite with TC of 313K transforms into a 7M orthorhombic martensite with thermal hysteresis of 21K and transformation temperatures of MS=226K, Mf=218K, AS=237K, and Af=244K

Genetic diversity and virulence pattern in field populations of Pyricularia grisea from rice cultivar Metica-1

Rice blast is a major yield constraint of the irrigated rice in the State of Tocantins, Brazil. The objective of this investigation was to study the phenotypic and genetic diversity within the pathogen population of Pyricularia grisea in samples collected from four individual farms of rice cultivar Metica-1, under epidemic conditions of leaf blast. A set of 87 isolates was tested on 32 rice genotypes including eight international differentials. Considering 80% similarity in virulence, two groups comprising a total of 81 isolates were recognized, independently of the farms from which they were collected. Eighty percent of the isolates pertained to pathotype ID-14, indicating high cultivar specificity and narrow diversity of virulence in the sample population. The virulence in pathogen population on rice cultivars BR-IRGA 409 and Rio Formoso was low. Analysis of P. grisea isolates using rep-PCR with two primer sequences from Pot2 generated fingerprint profiles of one to nine bands. Cluster analysis revealed the occurrence of six fingerprint groups with similarities ranging from 0.09 to 1. There was no straight relationship between virulence of the isolates based on reaction pattern on 32 genotypes and grouping based on Pot2 rep-PCR analysis of P. grisea isolates collected from 'Metica-1'.

Plasma PCSK9 concentrations during an oral fat load and after short term high-fat, high-fat high-protein and high-fructose diets.

BACKGROUND: PCSK9 (Proprotein Convertase Subtilisin Kexin type 9) is a circulating protein that promotes hypercholesterolemia by decreasing hepatic LDL receptor protein. Under non interventional conditions, its expression is driven by sterol response element binding protein 2 (SREBP2) and follows a diurnal rhythm synchronous with cholesterol synthesis. Plasma PCSK9 is associated to LDL-C and to a lesser extent plasma triglycerides and insulin resistance. We aimed to verify the effect on plasma PCSK9 concentrations of dietary interventions that affect these parameters. METHODS: We performed nutritional interventions in young healthy male volunteers and offspring of type 2 diabetic (OffT2D) patients that are more prone to develop insulin resistance, including: i) acute post-prandial hyperlipidemic challenge (n=10), ii) 4 days of high-fat (HF) or high-fat/high-protein (HFHP) (n=10), iii) 7 (HFruc1, n=16) or 6 (HFruc2, n=9) days of hypercaloric high-fructose diets. An acute oral fat load was also performed in two patients bearing the R104C-V114A loss-of-function (LOF) PCSK9 mutation. Plasma PCSK9 concentrations were measured by ELISA. For the HFruc1 study, intrahepatocellular (IHCL) and intramyocellular lipids were measured by 1H magnetic resonance spectroscopy. Hepatic and whole-body insulin sensitivity was assessed with a two-step hyperinsulinemic-euglycemic clamp (0.3 and 1.0 mU.kg-1.min-1). FINDINGS: HF and HFHP short-term diets, as well as an acute hyperlipidemic oral load, did not significantly change PCSK9 concentrations. In addition, post-prandial plasma triglyceride excursion was not altered in two carriers of PCSK9 LOF mutation compared with non carriers. In contrast, hypercaloric 7-day HFruc1 diet increased plasma PCSK9 concentrations by 28% (p=0.05) in healthy volunteers and by 34% (p=0.001) in OffT2D patients. In another independent study, 6-day HFruc2 diet increased plasma PCSK9 levels by 93% (p<0.0001) in young healthy male volunteers. Spearman's correlations revealed that plasma PCSK9 concentrations upon 7-day HFruc1 diet were positively associated with plasma triglycerides (r=0.54, p=0.01) and IHCL (r=0.56, p=0.001), and inversely correlated with hepatic (r=0.54, p=0.014) and whole-body (r=-0.59, p=0.0065) insulin sensitivity. CONCLUSIONS: Plasma PCSK9 concentrations vary minimally in response to a short term high-fat diet and they are not accompanied with changes in cholesterolemia upon high-fructose diet. Short-term high-fructose intake increased plasma PCSK9 levels, independent on cholesterol synthesis, suggesting a regulation independent of SREBP-2. Upon this diet, PCSK9 is associated with insulin resistance, hepatic steatosis and plasma triglycerides.

Proton NMR of (15)N-choline metabolites enhanced by dynamic nuclear polarization.

Chemical shifts of protons can report on metabolic transformations such as the conversion of choline to phosphocholine. To follow such processes in vivo, magnetization can be enhanced by dynamic nuclear polarization (DNP). We have hyperpolarized in this manner nitrogen-15 spins in (15)N-labeled choline up to 3.3% by irradiating the 94 GHz electron spin resonance of admixed TEMPO nitroxide radicals in a magnetic field of 3.35 T during ca. 3 h at 1.2 K. The sample was subsequently transferred to a high-resolution magnet, and the enhanced polarization was converted from (15)N to methyl- and methylene protons, using the small (2,3)J((1)H,(15)N) couplings in choline. The room-temperature lifetime of nitrogen polarization in choline, T(1)((15)N) approximately 200 s, could be considerably increased by partial deuteration of the molecule. This procedure enables studies of choline metabolites in vitro and in vivo using DNP-enhanced proton NMR.

A 4-wk high-fructose diet alters lipid metabolism without affecting insulin sensitivity or ectopic lipids in healthy humans.

BACKGROUND: High fructose consumption is suspected to be causally linked to the epidemics of obesity and metabolic disorders. In rodents, fructose leads to insulin resistance and ectopic lipid deposition. In humans, the effects of fructose on insulin sensitivity remain debated, whereas its effect on ectopic lipids has never been investigated. OBJECTIVE: We assessed the effect of moderate fructose supplementation on insulin sensitivity (IS) and ectopic lipids in healthy male volunteers (n = 7). DESIGN: IS, intrahepatocellular lipids (IHCL), and intramyocellular lipids (IMCL) were measured before and after 1 and 4 wk of a high-fructose diet containing 1.5 g fructose . kg body wt(-1) . d(-1). Adipose tissue IS was evaluated from nonesterified fatty acid suppression, hepatic IS from suppression of hepatic glucose output (6,6-2H2-glucose), and muscle IS from the whole-body glucose disposal rate during a 2-step hyperinsulinemic euglycemic clamp. IHCL and IMCL were measured by 1H magnetic resonance spectroscopy. RESULTS: Fructose caused significant (P < 0.05) increases in fasting plasma concentrations of triacylglycerol (36%), VLDL-triacylglycerol (72%), lactate (49%), glucose (5.5%), and leptin (48%) without any significant changes in body weight, IHCL, IMCL, or IS. IHCL were negatively correlated with triacylglycerol after 4 wk of the high-fructose diet (r = -0.78, P < 0.05). CONCLUSION: Moderate fructose supplementation over 4 wk increases plasma triacylglycerol and glucose concentrations without causing ectopic lipid deposition or insulin resistance in healthy humans.

Quantitative integration of high-resolution hydrogeophysical data through Monte-Carlo-type conditional simulations

Geophysical techniques can help to bridge the inherent gap with regard to spatial resolution and the range of coverage that plagues classical hydrological methods. This has lead to the emergence of the new and rapidly growing field of hydrogeophysics. Given the differing sensitivities of various geophysical techniques to hydrologically relevant parameters and their inherent trade-off between resolution and range the fundamental usefulness of multi-method hydrogeophysical surveys for reducing uncertainties in data analysis and interpretation is widely accepted. A major challenge arising from such endeavors is the quantitative integration of the resulting vast and diverse database in order to obtain a unified model of the probed subsurface region that is internally consistent with all available data. To address this problem, we have developed a strategy towards hydrogeophysical data integration based on Monte-Carlo-type conditional stochastic simulation that we consider to be particularly suitable for local-scale studies characterized by high-resolution and high-quality datasets. Monte-Carlo-based optimization techniques are flexible and versatile, allow for accounting for a wide variety of data and constraints of differing resolution and hardness and thus have the potential of providing, in a geostatistical sense, highly detailed and realistic models of the pertinent target parameter distributions. Compared to more conventional approaches of this kind, our approach provides significant advancements in the way that the larger-scale deterministic information resolved by the hydrogeophysical data can be accounted for, which represents an inherently problematic, and as of yet unresolved, aspect of Monte-Carlo-type conditional simulation techniques. We present the results of applying our algorithm to the integration of porosity log and tomographic crosshole georadar data to generate stochastic realizations of the local-scale porosity structure. Our procedure is first tested on pertinent synthetic data and then applied to corresponding field data collected at the Boise Hydrogeophysical Research Site near Boise, Idaho, USA.

Can 3T multiparametric magnetic resonance imaging accurately detect prostate cancer extracapsular extension?

BACKGROUND: Accurate staging is essential to determine the correct management of patients diagnosed with prostate cancer. We assess the accuracy of 3T multiparametric magnetic resonance imaging (MRI) with endorectal coil (3TemMRI) in detecting prostate cancer local extension. METHODS: We retrospectively reviewed charts from January 2008 to July 2012 from all patients undergoing radical prostatectomy. Patients were only included if 3TemMRI and radical prostatectomy were performed at our institution. Based on the presence of extracapsular extension (ECE) at 3TemMRI, prostate cancer was dichotomized into locally advanced or organ-confined disease. The accuracy of 3TemMRI local staging was then evaluated using definitive pathology as a reference. RESULTS: Overall, 177 radical prostatectomies were performed within the timeframe. After applying exclusion criteria, 60 patients were included in the final analysis. The mean patient age was 67 ± 7 (standard deviation) years. Mean prostate-specific antigen value was 12.7 ± 12.7 ng/L. Based on preoperative characteristics, we considered 38 of the 60 patients (63%) patients high risk. 3TemMRI identified an organ-confined tumour in 46 patients and locally advanced disease in 14 patients. When correlated to final pathology, 3TemMRI specificity, sensitivity, negative and positive predictive values, and accuracy in detecting locally advanced prostate cancer were 90%, 35%, 57%, 79% and 62%, respectively. INTERPRETATION: This study shows that the use of preoperative 3TemMRI can be used to identify organ-confined prostate cancer when locally advanced disease is suspected.

Development of Quality Standards for Inclusion of High Recycled Asphalt Pavement Content in Asphalt Mixtures – Phase II, TR-658, 2015

To conserve natural resources and energy, the amount of recycled asphalt pavement has been steadily increasing in the construction of asphalt pavements. The objective of this study is to develop quality standards for inclusion of high RAP content. To determine if the higher percentage of RAP materials can be used on Iowa’s state highways, three test sections with target amounts of RAP materials of 30%, 35% and 40% by weight were constructed on Highway 6 in Iowa City. To meet Superpave mix design requirements for mixtures with high RAP contents, it was necessary to fractionate the RAP materials. Three test sections with actual RAP materials of 30.0%, 35.5% and 39.2% by weight were constructed and the average field densities from the cores were measured as 95.3%, 94.0%, and 94.3%, respectively. Field mixtures were compacted in the laboratory to evaluate moisture sensitivity using a Hamburg Wheel Tracking Device. After 20,000 passes, rut depths were less than 3mm for mixtures obtained from three test sections. The binder was extracted from the field mixtures from each test section and tested to identify the effects of RAP materials on the performance grade of the virgin binder. Based on Dynamic Shear Rheometer and Bending Beam Rheometer tests, the virgin binders (PG 64-28) from test sections with 30.0%, 35.5% and 39.2% RAP materials were stiffened to PG 76-22, PG 76-16, and PG 82-16, respectively. The Semi-Circular Bending (SCB) test was performed on laboratory compacted field mixtures with RAP amounts of 30.0%, 35.5% and 39.2% at two different temperatures of -18 and -30 °C. As the test temperature decreased, the fracture energy decreased and the stiffness increased. As the RAP amount increased, the stiffness increased and the fracture energy decreased. Finally, a condition survey of the test sections was conducted to evaluate their short-term pavement performance and the reflective transverse cracking did not increase as RAP amount was increased from 30.0% to 39.2%.

[(18)F]Fluoroethyltyrosine- positron emission tomography-guided radiotherapy for high-grade glioma.

BACKGROUND: To compare morphological gross tumor volumes (GTVs), defined as pre- and postoperative gadolinium enhancement on T1-weighted magnetic resonance imaging to biological tumor volumes (BTVs), defined by the uptake of (18)F fluoroethyltyrosine (FET) for the radiotherapy planning of high-grade glioma, using a dedicated positron emission tomography (PET)-CT scanner equipped with three triangulation lasers for patient positioning. METHODS: Nineteen patients with malignant glioma were included into a prospective protocol using FET PET-CT for radiotherapy planning. To be eligible, patients had to present with residual disease after surgery. Planning was performed using the clinical target volume (CTV = GTV union or logical sum BTV) and planning target volume (PTV = CTV + 20 mm). First, the interrater reliability for BTV delineation was assessed among three observers. Second, the BTV and GTV were quantified and compared. Finally, the geometrical relationships between GTV and BTV were assessed. RESULTS: Interrater agreement for BTV delineation was excellent (intraclass correlation coefficient 0.9). Although, BTVs and GTVs were not significantly different (p = 0.9), CTVs (mean 57.8 +/- 30.4 cm(3)) were significantly larger than BTVs (mean 42.1 +/- 24.4 cm(3); p < 0.01) or GTVs (mean 38.7 +/- 25.7 cm(3); p < 0.01). In 13 (68%) and 6 (32%) of 19 patients, FET uptake extended >or= 10 and 20 mm from the margin of the gadolinium enhancement. CONCLUSION: Using FET, the interrater reliability had excellent agreement for BTV delineation. With FET PET-CT planning, the size and geometrical location of GTVs and BTVs differed in a majority of patients.

Pattern dystrophy with high intrafamilial variability associated with Y141C mutation in the peripherin/RDS gene and successful treatment of subfoveal CNV related to multifocal pattern type with anti-VEGF (ranibizumab) intravitreal injections.

OBJECTIVE: To identify disease causing mutation in three generations of a Swiss family with pattern dystrophy and high intrafamilial variability of phenotype. To assess the effect of intravitreal ranibizumab injections in the treatment of subfoveal choroidal neovascularization associated with pattern dystrophy in one patient. METHODS: Affected family members were ascertained for phenotypic and genotypic characterization. Ophthalmic evaluations included fundus photography, autofluorescence imaging, optical coherence tomography, and International Society for Clinical Electrophysiology of Vision standard full-field electroretinography. When possible family members had genetic testing. The proband presented with choroidal neovascularization and had intravitreal injections as needed according to visual acuity and optical coherence tomography. RESULTS: Proband had a multifocal type pattern dystrophy, and his choroidal neovascularization regressed after four intravitreal injections. The vision improved from 0.8 to 1.0, and optical coherence tomography showed complete anatomical restoration. A butterfly-shaped pattern was observed in her cousin, whereas a fundus pulverulentus pattern was seen in a second cousin. Aunt had a multifocal atrophic appearance, simulating geographic atrophy in age-related macular degeneration. The Y141C mutation was identified in the peripherin/RDS gene and segregated with disease in the family. CONCLUSION: This is the first report of marked intrafamilial variation of pattern dystrophy because of peripherin/RDS Y141C mutation. Intravitreal ranibizumab injections might be a valuable treatment for associated subfoveal choroidal neovascularization.

Stochastic resonance in a dipole

We show that the dipole, a system usually proposed to model relaxation phenomena, exhibits a maximum in the signal-to-noise ratio at a nonzero noise level, thus indicating the appearance of stochastic resonance. The phenomenon occurs in two different situations, i.e., when the minimum of the potential of the dipole remains fixed in time and when it switches periodically between two equilibrium points. We have also found that the signal-to-noise ratio has a maximum for a certain value of the amplitude of the oscillating field.