Review of 2,4-dichlorophenoxyacetic acid (2,4-D) biomonitoring and epidemiology

PubMed Central

Burns, Carol J.; Swaen, Gerard M. H.

2012-01-01

A qualitative review of the epidemiological literature on the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and health after 2001 is presented. In order to compare the exposure of the general population, bystanders and occupational groups, their urinary levels were also reviewed. In the general population, 2,4-D exposure is at or near the level of detection (LOD). Among individuals with indirect exposure, i.e. bystanders, the urinary 2,4-D levels were also very low except in individuals with opportunity for direct contact with the herbicide. Occupational exposure, where exposure was highest, was positively correlated with behaviors related to the mixing, loading and applying process and use of personal protection. Information from biomonitoring studies increases our understanding of the validity of the exposure estimates used in epidemiology studies. The 2,4-D epidemiology literature after 2001 is broad and includes studies of cancer, reproductive toxicity, genotoxicity, and neurotoxicity. In general, a few publications have reported statistically significant associations. However, most lack precision and the results are not replicated in other independent studies. In the context of biomonitoring, the epidemiology data give no convincing or consistent evidence for any chronic adverse effect of 2,4-D in humans. PMID:22876750

General Rule of Negative Effective Ueff System & Materials Design of High-Tc Superconductors by ab initio Calculations

NASA Astrophysics Data System (ADS)

Katayama-Yoshida, Hiroshi; Nakanishi, Akitaka; Uede, Hiroki; Takawashi, Yuki; Fukushima, Tetsuya; Sato, Kazunori

2014-03-01

Based upon ab initio electronic structure calculation, I will discuss the general rule of negative effective U system by (1) exchange-correlation-induced negative effective U caused by the stability of the exchange-correlation energy in Hund's rule with high-spin ground states of d5 configuration, and (2) charge-excitation-induced negative effective U caused by the stability of chemical bond in the closed-shell of s2, p6, and d10 configurations. I will show the calculated results of negative effective U systems such as hole-doped CuAlO2 and CuFeS2. Based on the total energy calculations of antiferromagnetic and ferromagnetic states, I will discuss the magnetic phase diagram and superconductivity upon hole doping. I also discuss the computational materials design method of high-Tc superconductors by ab initio calculation to go beyond LDA and multi-scale simulations.

Good validity of the international spinal cord injury quality of life basic data set.

PubMed

Post, M W M; Adriaansen, J J E; Charlifue, S; Biering-Sørensen, F; van Asbeck, F W A

2016-04-01

Cross-sectional validation study. To examine the construct and concurrent validity of the International Spinal Cord Injury (SCI) Quality of Life (QoL) Basic Data Set. Dutch community. People 28-65 years of age, who obtained their SCI between 18 and 35 years of age, were at least 10 years post SCI and were wheelchair users in daily life. MEASURE(S): The International SCI QoL Basic Data Set consists of three single items on satisfaction with life as a whole, physical health and psychological health (0=complete dissatisfaction; 10=complete satisfaction). Reference measures were the Mental Health Inventory-5 and three items of the World Health Organization Quality of Life measure. Data of 261 participants were available. Mean time after SCI was 24.1 years (s.d. 9.1); 90.4% had a traumatic SCI, 81.5% a motor complete SCI and 40% had tetraplegia. Mean age was 47.9 years (s.d. 8.8) and 73.2% were male. Mean scores were 6.9 (s.d. 1.9) for general QoL, 5.8 (s.d. 2.2) for physical health and 7.1 (s.d. 1.9) for psychological health. No floor or ceiling effects were found. Strong inter-correlations (0.48-0.71) were found between the items, and Cronbach's alpha of the scale was good (0.81). Correlations with the reference measures showed the strongest correlations between the WHOQOL general satisfaction item and general QoL (0.64), the WHOQOL health and daily activities items and physical health (0.69 and 0.60) and the Mental Health Inventory-5 and psychological health (0.70). This first validity study of the International SCI QoL Basic Data Set shows that it appears valid for persons with SCI.

Lifestyle and Dietary Factors Associated with Serum 25-Hydroxyvitamin D Levels in Korean Young Adults.

PubMed

Joh, Hee-Kyung; Lim, Chun Soo; Cho, BeLong

2015-08-01

Inadequate vitamin D status is highly prevalent in the Korean population, especially among young adults. Nonetheless, correlates of suboptimal vitamin D levels in young adults are not well defined. This study aimed to investigate potentially modifiable determinants of vitamin D levels in young adults in Korea. This cross-sectional study was based on health check-up data from 3,450 healthy male and female university students aged 18-29 yr in Seoul between April and May 2013. Serum 25-hydroxyvitamin D [25(OH)D] levels were determined using chemiluminescent immunoassay. Anthropometric data were measured, and lifestyle, dietary, and sociodemographic factors were obtained through self-administered questionnaires. General linear regression was used to assess correlates of serum 25(OH)D levels. The mean serum 25(OH)D level was 11.1 ng/mL, and the prevalence of 25(OH)D levels less than 10 ng/mL was 44.7% (39.5% in men, 50.2% in women). In a final multivariable model, significant positive correlates of serum 25(OH)D were older age, male sex, increased physical activity, sunlight exposure ≥ 30 min/day, eating breakfast regularly, consumption of dairy and fatty fish, and use of vitamin D-containing supplements. In contrast, significant inverse correlates were obesity (body mass index, BMI ≥ 25 kg/m(2)) or underweight (BMI < 18.5 kg/m(2)), abdominal obesity, increased sedentary time, and frequent consumption of instant noodles and sugar-sweetened beverages. In conclusion, many modifiable lifestyle and dietary factors were associated with low serum 25(OH)D levels in Korean young adults. Further studies on potential mechanisms of the correlates and optimal strategies to improve vitamin D status in this vulnerable subpopulation are warranted.

Hospital Anxiety and Depression Scale Score Is an Independent Factor Associated With the EuroQoL 5-Dimensional Descriptive System in Patients With Rheumatoid Arthritis.

PubMed

Hattori, Yosuke; Katayama, Masao; Kida, Daihei; Kaneko, Atsushi

2018-05-01

This study aimed to examine anxiety and depression experienced by patients with rheumatoid arthritis (RA) using EuroQoL 5-Dimensional Descriptive System (EQ-5D) and Hospital Anxiety and Depression Scale (HADS) scores. We analyzed 1005 Japanese patients with RA. Stepwise multiple linear regression analysis was performed to evaluate the independent influence of variables on EQ-5D and HADS scores. Pearson correlation coefficients were also calculated to explore relationships between variables. The mean EQ-5D score was 0.74 for all patients (mean age, 63.2 years; mean disease duration, 13.6 years; mean Health Assessment Questionnaire Disability Index [HAQ-DI], 0.78; mean HADS total [HADS-T] score, 10.3; mean disease activity score assessed by 28 joints based on CRP [DAS28-CRP], 2.8). The EQ-5D score was strongly correlated with HAQ-DI and was moderately correlated with age, Steinbrocker functional class, HADS-T score, tender joint count assessed by 28 joints, pain on a visual analog scale (pain-VAS), patient's global assessment of disease activity (general-VAS), and DAS28-CRP. The HADS-T score was moderately correlated with HAQ-DI, pain-VAS, general-VAS, and DAS28-CRP. Factors that influenced the EQ-5D score included HAQ-DI (β = -0.533), pain-VAS (β = -0.128), HADS-T score (β = -0.142), DAS28-CRP (β = -0.187), and prednisolone use (β = -0.056). Factors that influenced the HADS score included HAQ-DI (β = 0.348), general-VAS (β = 0.145), disease duration (β = 0.094), and worklessness (β = 0.083). The HADS score is an independent factor associated with EQ-5D in patients with RA. Our findings suggest that the assessment of anxiety and depression is essential in achieving better quality of life for patients with RA.

New Quasi Low-Dimensional 4d and 5d Transition Metal Oxides with Correlated Electronic Properties - Synthesis and Characterizations

DTIC Science & Technology

2016-02-17

high pressure (HP) and high temperature ( HT ) synthesis to find new interesting and potentially useful polar materials. As will be shown here, we have...of general formula A2BB’O6. In addition, HP and HT were also used to prepare new metastable double perovskites and quadruple perovskites with unusual...transition metals and exotic correlated electronic properties was used in parallel with the HP/ HT projects. As the results enumerated below show, a

Correlation Decay in Fermionic Lattice Systems with Power-Law Interactions at Nonzero Temperature

NASA Astrophysics Data System (ADS)

Hernández-Santana, Senaida; Gogolin, Christian; Cirac, J. Ignacio; Acín, Antonio

2017-09-01

We study correlations in fermionic lattice systems with long-range interactions in thermal equilibrium. We prove a bound on the correlation decay between anticommuting operators and generalize a long-range Lieb-Robinson-type bound. Our results show that in these systems of spatial dimension D with, not necessarily translation invariant, two-site interactions decaying algebraically with the distance with an exponent α ≥2 D , correlations between such operators decay at least algebraically to 0 with an exponent arbitrarily close to α at any nonzero temperature. Our bound is asymptotically tight, which we demonstrate by a high temperature expansion and by numerically analyzing density-density correlations in the one-dimensional quadratic (free, exactly solvable) Kitaev chain with long-range pairing.

The Schwarzian theory — origins

NASA Astrophysics Data System (ADS)

Mertens, Thomas G.

2018-05-01

In this paper we further study the 1d Schwarzian theory, the universal low-energy limit of Sachdev-Ye-Kitaev models, using the link with 2d Liouville theory. We provide a path-integral derivation of the structural link between both theories, and study the relation between 3d gravity, 2d Jackiw-Teitelboim gravity, 2d Liouville and the 1d Schwarzian. We then generalize the Schwarzian double-scaling limit to rational models, relevant for SYK-type models with internal symmetries. We identify the holographic gauge theory as a 2d BF theory and compute correlators of the holographically dual 1d particle-on-a-group action, decomposing these into diagrammatic building blocks, in a manner very similar to the Schwarzian theory.

Fatigue crack growth under general-yielding cyclic-loading

NASA Technical Reports Server (NTRS)

Minzhong, Z.; Liu, H. W.

1986-01-01

In low cycle fatigue, cracks are initiated and propagated under general yielding cyclic loading. For general yielding cyclic loading, Dowling and Begley have shown that fatigue crack growth rate correlates well with the measured delta J. The correlation of da/dN with delta J was also studied by a number of other investigators. However, none of thse studies have correlated da/dN with delta J calculated specifically for the test specimens. Solomon measured fatigue crack growth in specimens in general yielding cyclic loading. The crack tips fields for Solomon's specimens are calculated using the finite element method and the J values of Solomon's tests are evaluated. The measured crack growth rate in Solomon's specimens correlates very well with the calculated delta J.

Ethnic differences in association of high body mass index with early onset of Type 1 diabetes - Arab ethnicity as case study.

PubMed

Channanath, Arshad M; Elkum, Naser; Al-Abdulrazzaq, Dalia; Tuomilehto, Jaakko; Shaltout, Azza; Thanaraj, Thangavel Alphonse

2017-01-01

The "accelerator hypothesis" predicts early onset of Type 1 diabetes (T1D) in heavier children. Studies testing direction of correlation between body mass index (BMI) and age at onset of T1D in different continental populations have reported differing results-inverse, direct, and neutral. Evaluating the correlation in diverse ethnic populations is required to generalize the accelerator hypothesis. The study cohort comprised 474 Kuwaiti children of Arab ethnicity diagnosed with T1D at age 6 to 18 years during 2011-2013. Age- and sex-adjusted BMI z-scores were calculated by comparing the BMI measured at diagnosis with Kuwaiti pediatric population reference data recorded during comparable time-period. Multiple linear regression and Pearson correlation analyses were performed. BMI z-score was seen inversely associated with onset age (r,-0.28; p-value<0.001). Children with BMI z-score>0 (i.e. BMI >national average) showed a stronger correlation (r,-0.38; p-value<0.001) than those with BMI z-score<0 (r,-0.19; p-value<0.001); the former group showed significantly lower mean onset age than the latter group (9.6±2.4 versus 10.5±2.7; p-value<0.001). Observed inverse correlation was consistent with that seen in Anglo-saxon, central european, caucasian, and white children while inconsistent with that seen in Indian, New Zealander, and Australian children. The accelerator hypothesis generalizes in Arab pediatric population from Kuwait.

The roles of carbohydrates, proteins and lipids in the process of aggregation of natural marine organic matter investigated by means of 2D correlation spectroscopy applied to infrared spectra.

PubMed

Mecozzi, Mauro; Pietrantonio, Eva; Pietroletti, Marco

2009-01-01

In this paper the marine organic matter soluble in an alkaline medium called extractable humic substance (EHS), was extracted from three sediment samples of Tyrrhenian Sea and separated by precipitation at pH 2 in the two fractions of fulvic acids (FAs) and humic acids (HAs). FAs were further fractionated in seven sub-samples of different molecular weight (mw) by means of seven different ultrafiltration membranes operating in the range between mw<1 kDa and mw>100 kDa. Then the qualitative composition of each sample of fractionated FAs and HAs was studied by means of one-dimensional Fourier transform infrared spectroscopy in reflectance mode (FTIR-DRIFT) and by two-dimensional (2D) correlation spectroscopy both in wavelength-wavelength (WW) and in sample-sample (SS) mode. The application of 2D correlation WW spectroscopy allows to elucidate the different roles played by carbohydrates and proteins with respect to some lipid compounds such as fatty acids and ester fatty acids during the process of aggregate formations from mw approximately 1 kDa to higher size aggregates. In addition, 2D correlation WW spectroscopy allows to observe some peculiar interactions between carbohydrates and proteins in the formation of EHS aggregates, interactions which vary from a sample to another sample. The results of 2D correlation SS spectroscopy confirm the general evidences obtained by 2D WW spectroscopy and moreover, they also describe the formation of EHS aggregates as a complex process where evolutionary links and connectivity between aggregates of neighbour molecular size ranges are not evident. Two-dimensional correlation spectroscopy applied to FTIR spectroscopy shows to be a powerful tool for the investigation of the mechanisms involved in EHS aggregation because it supports the acquisition of structural information which sometimes can be hardly obtained by one-dimensional FTIR spectroscopy.

Entanglement properties of boundary state and thermalization

NASA Astrophysics Data System (ADS)

Guo, Wu-zhong

2018-06-01

We discuss the regularized boundary state {e}^{-{τ}_0H}\\Big|{.B>}_a on two aspects in both 2D CFT and higher dimensional free field theory. One is its entanglement and correlation properties, which exhibit exponential decay in 2D CFT, the parameter 1 /τ 0 works as a mass scale. The other concerns with its time evolution, i.e., {e}^{-itH}{e}^{-{τ}_0H}\\Big|{.B>}_a . We investigate the Kubo-Martin-Schwinger (KMS) condition on correlation function of local operators to detect the thermal properties. Interestingly we find the correlation functions in the initial state {e}^{-{τ}_0H}\\Big|{.B>}_a also partially satisfy the KMS condition. In the limit t → ∞, the correlators will exactly satisfy the KMS condition. We generally analyse quantum quench by a pure state and obtain some constraints on the possible form of 2-point correlation function in the initial state if assuming they satisfies KMS condition in the final state. As a byproduct we find in an large τ 0 limit the thermal property of 2-point function in {e}^{-{τ}_0H}\\Big|{.B>}_a also appears.

Susceptibilities of Candidatus Liberibacter asiaticus-infected and noninfected Diaphorina citri to entomopathogenic fungi and their detoxification enzyme activities under different temperatures.

PubMed

Hussain, Mubasher; Akutse, Komivi Senyo; Lin, Yongwen; Chen, Shiman; Huang, Wei; Zhang, Jinguan; Idrees, Atif; Qiu, Dongliang; Wang, Liande

2018-03-25

Some entomopathogenic fungi species, Isaria fumosorosea, and Hirsutella citriformis were found to be efficient against the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). However, the susceptibility to these fungi increases when the psyllid infected with Candidatus Liberibacter asiaticus (Las), which is transmitted by D. citri and causes citrus greening disease. In this study, we examined the Las-infected and Las-uninfected D. citri susceptibility to entomopathogenic fungi at different temperature regimes (5-40°C). When D. citri adults exposed to cold temperature (5°C), they showed less susceptibility to entomopathogenic fungi as compared with control (27°C). Irrespective of infection with Las, a significantly positive correlation was observed between temperature and percentage mortality caused by different isolates of I. fumosorosea, 3A Ifr, 5F Ifr, PS Ifr, and H. citriformis isolates, HC3D and 2H. In contrast, a significantly negative correlation was found between temperature and percentage mortality for 3A Ifr for both Las-infected and Las-uninfected psyllids. Detoxification enzymes, Glutathione S-transferase levels in D. citri showed a negative correlation, whereas cytochrome P450 and general esterase levels were not correlated with changes in temperature. These findings revealed that detoxification enzymes and general esterase levels are not correlated with altered susceptibility to entomopathogenic fungi at the different temperature regimes. Conclusively, temperature fluctuations tested appear to be a significant factor impacting the management strategies of D. citri using entomopathogenic fungi. © 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Comparative Variable Temperature Studies of Polyamide II with a Benchtop Fourier Transform and a Miniature Handheld Near-Infrared Spectrometer Using 2D-COS and PCMW-2D Analysis.

PubMed

Unger, Miriam; Pfeifer, Frank; Siesler, Heinz W

2016-07-01

The main objective of this communication is to compare the performance of a miniaturized handheld near-infrared (NIR) spectrometer with a benchtop Fourier transform near-infrared (FT-NIR) spectrometer. Generally, NIR spectroscopy is an extremely powerful analytical tool to study hydrogen-bonding changes of amide functionalities in solid and liquid materials and therefore variable temperature NIR measurements of polyamide II (PAII) have been selected as a case study. The information content of the measurement data has been further enhanced by exploiting the potential of two-dimensional correlation spectroscopy (2D-COS) and the perturbation correlation moving window two-dimensional (PCMW2D) evaluation technique. The data provide valuable insights not only into the changes of the hydrogen-bonding structure and the recrystallization of the hydrocarbon segments of the investigated PAII but also in their sequential order. Furthermore, it has been demonstrated that the 2D-COS and PCMW2D results derived from the spectra measured with the miniaturized NIR instrument are equivalent to the information extracted from the data obtained with the high-performance FT-NIR instrument. © The Author(s) 2016.

[4D-CT-based plan target volume (PTV) definition compared with conventional PTV definition using general margin in radiotherapy for lung cancer].

PubMed

Ju, Xiao; Li, Minghui; Zhou, Zongmei; Zhang, Ke; Han, Wei; Fu, Guishan; Cao, Ying; Wang, Lyuhua

2014-01-01

To investigate the dosimetric benefit of 4D-CT in the planning target volume (PTV) definition process compared with conventional PTV definition using general margin in radiotherapy of lung cancer. A set of 4D-CT images and multiphase helical CT scans were obtained in 10 patients with lung cancer. The radiotherapeutic plans based on PTV determined by 4D-CT and in addition of general margin were performed, respectively. The 3D motion of the centroid of GTV and the 3D spatial motion vectors were calculated. The differences of the two kinds of PTVs, mean lung dose (MLD), V5,V10,V15,V20 of total lung, mean heart dose (MHD), V30 and V40 of heart, D99 and D95 were compared, and the correlation between them and the 3D spatial motion vector was analyzed. The PTV4D in eight patients were smaller than PTVconv, with a mean reduction of (13.0 ± 8.0)% (P = 0.018). In other two patients, whose respiration motion was great, PTV4D was larger than PTVconv. The mean 3D spatial motion vector of GTV centroid was (0.78 ± 0.72)cm. By using 4D-CT, the mean reduction of MLD was (8.6 ± 9.9)% (P = 0.037). V5, V10, V15, V20 of total lung were decreased averagely by (7.2 ± 10.5)%, (5.5 ± 8.9)%, (6.5 ± 8.4)% and (5.7 ± 7.4)%, respectively (P < 0.05 for all). There was a significant positive correlation between PTV4D/PTVconv and the 3D spatial motion vector of the GTV centroid (P = 0.008). A significant inverse correlation was found between D994D/D99conv and the 3D spatial motion vector of the GTV centroid (P = 0.002). D994D/D99conv, (MLDconv-MLD4D) /MLDconv, total lung (V5conv-V54D)/V5conv, total lung (V10conv-V104D)/V10conv, (MHDconv-MHD4D)/MHDconv, heart (V30conv-V304D)/V30conv were inversely correlated with PTV4D/PTVconv (P < 0.05 for all). 4D-CT can be used to evaluate the respiration motion of lung tumor accurately. The 4D-CT-based PTV definition and radiotherapeutic planing can reduce the volume of PTV in patients with small respiration motion, increase the intra-target dose, and decrease the dose of normal tissue sequentially. For patients with large respiration motion, especially those more than 1.5-2 cm, this method can avoid target miss, meanwhile, not increase the dose of normal tissue significantly.

The X40×10 Halogen Bonding Benchmark Revisited: Surprising Importance of (n-1)d Subvalence Correlation.

PubMed

Kesharwani, Manoj K; Manna, Debashree; Sylvetsky, Nitai; Martin, Jan M L

2018-03-01

We have re-evaluated the X40×10 benchmark for halogen bonding using conventional and explicitly correlated coupled cluster methods. For the aromatic dimers at small separation, improved CCSD(T)-MP2 "high-level corrections" (HLCs) cause substantial reductions in the dissociation energy. For the bromine and iodine species, (n-1)d subvalence correlation increases dissociation energies and turns out to be more important for noncovalent interactions than is generally realized; (n-1)sp subvalence correlation is much less important. The (n-1)d subvalence term is dominated by core-valence correlation; with the smaller cc-pVDZ-F12-PP and cc-pVTZ-F12-PP basis sets, basis set convergence for the core-core contribution becomes sufficiently erratic that it may compromise results overall. The two factors conspire to generate discrepancies of up to 0.9 kcal/mol (0.16 kcal/mol RMS) between the original X40×10 data and the present revision.

The Interaction between Leadership, Climate, and Satisfaction in a Professional Organization

DTIC Science & Technology

1974-12-01

DESCRIPTIVE STATISTICS 3^ B. IDENTIFICATION OF LEADERSHIP STYLES 35 C. FACTOR ANALYSIS ^0 D. CORRELATION ANALYSIS k2 E. PARTIAL CORRELATION...different definitions of supervisor behaviors of leadership styles in the comparisons with satis- faction, these studies have generally concluded that...Several norms, or recognized leadership styles , have been described in management; theory literature. It would not be beneficial to discuss or even

Aspects of the RVB Luttinger Liquid Theory of the High Temperature Superconductivity

NASA Astrophysics Data System (ADS)

Ren, Yong

1992-01-01

This thesis describes work on a large-U Hubbard model theory for high temperature superconductors. After an introduction to the Hubbard model and the normal state properties of the high T_{rm c} superconductors, we briefly examine the definition of the Fermi liquid and its breakdown. Then we explain why the 1D Hubbard model is the best starting point to approach our problem. In one dimension, the exact Lieb-Wu solution is available. We discuss the Lieb-Wu solution, and calculate various asymptotic correlation functions in the ground state. This clarifies the nature of the ground state which has not been known before. Instead of simply getting the exponents of the correlation functions from the Bethe Ansatz integral equations, we establish the connection between phase shifts at different Fermi points and the asymptotic correlation functions. We believe that this connection contains the most important physics and it can be readily generalized into higher dimensions. We then discuss bosonization in two dimensions and define the 2D RVB-Luttinger liquid theory, proposing that the ground state of the 2D Hubbard model belongs to a different fixed point than the Landau Fermi liquid-Luttinger liquid. Finally we apply the understanding of the 1D result to explain the normal state properties of the high T_ {c} superconductors, putting emphasis on how the non-Fermi liquid correlation functions explain the "anomalous" experimental results. In the Appendix, several issues related to the 1D and 2D Hubbard model are discussed.

Remarks on thermalization in 2D CFT

NASA Astrophysics Data System (ADS)

de Boer, Jan; Engelhardt, Dalit

2016-12-01

We revisit certain aspects of thermalization in 2D conformal field theory (CFT). In particular, we consider similarities and differences between the time dependence of correlation functions in various states in rational and non-rational CFTs. We also consider the distinction between global and local thermalization and explain how states obtained by acting with a diffeomorphism on the ground state can appear locally thermal, and we review why the time-dependent expectation value of the energy-momentum tensor is generally a poor diagnostic of global thermalization. Since all 2D CFTs have an infinite set of commuting conserved charges, generic initial states might be expected to give rise to a generalized Gibbs ensemble rather than a pure thermal ensemble at late times. We construct the holographic dual of the generalized Gibbs ensemble and show that, to leading order, it is still described by a Banados-Teitelboim-Zanelli black hole. The extra conserved charges, while rendering c <1 theories essentially integrable, therefore seem to have little effect on large-c conformal field theories.

Digit Ratio (2D:4D) Predicts Self-Reported Measures of General Competitiveness, but Not Behavior in Economic Experiments

PubMed Central

Bönte, Werner; Procher, Vivien D.; Urbig, Diemo; Voracek, Martin

2017-01-01

The ratio of index finger length to ring finger length (2D:4D) is considered to be a putative biomarker of prenatal androgen exposure (PAE), with previous research suggesting that 2D:4D is associated with human behaviors, especially sex-typical behaviors. This study empirically examines the relationship between 2D:4D and individual competitiveness, a behavioral trait that is found to be sexually dimorphic. We employ two related, but distinct, measures of competitiveness, namely behavioral measures obtained from economic experiments and psychometric self-reported measures. Our analyses are based on two independent data sets obtained from surveys and economic experiments with 461 visitors of a shopping mall (Study I) and 617 university students (Study II). The correlation between behavior in the economic experiment and digit ratios of both hands is not statistically significant in either study. In contrast, we find a negative and statistically significant relationship between psychometric self-reported measures of competitiveness and right hand digit ratios (R2D:4D) in both studies. This relationship is especially strong for younger people. Hence, this study provides some robust empirical evidence for a negative association between R2D:4D and self-reported competitiveness. We discuss potential reasons why digit ratio may relate differently to behaviors in specific economics experiments and to self-reported general competitiveness. PMID:29276479

Digit Ratio (2D:4D) Predicts Self-Reported Measures of General Competitiveness, but Not Behavior in Economic Experiments.

PubMed

Bönte, Werner; Procher, Vivien D; Urbig, Diemo; Voracek, Martin

2017-01-01

The ratio of index finger length to ring finger length (2D:4D) is considered to be a putative biomarker of prenatal androgen exposure (PAE), with previous research suggesting that 2D:4D is associated with human behaviors, especially sex-typical behaviors. This study empirically examines the relationship between 2D:4D and individual competitiveness, a behavioral trait that is found to be sexually dimorphic. We employ two related, but distinct, measures of competitiveness, namely behavioral measures obtained from economic experiments and psychometric self-reported measures. Our analyses are based on two independent data sets obtained from surveys and economic experiments with 461 visitors of a shopping mall (Study I) and 617 university students (Study II). The correlation between behavior in the economic experiment and digit ratios of both hands is not statistically significant in either study. In contrast, we find a negative and statistically significant relationship between psychometric self-reported measures of competitiveness and right hand digit ratios (R2D:4D) in both studies. This relationship is especially strong for younger people. Hence, this study provides some robust empirical evidence for a negative association between R2D:4D and self-reported competitiveness. We discuss potential reasons why digit ratio may relate differently to behaviors in specific economics experiments and to self-reported general competitiveness.

Algorithms for calculating mass-velocity and Darwin relativistic corrections with n-electron explicitly correlated Gaussians with shifted centers

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

Stanke, Monika, E-mail: monika@fizyka.umk.pl; Palikot, Ewa, E-mail: epalikot@doktorant.umk.pl; Adamowicz, Ludwik, E-mail: ludwik@email.arizona.edu

2016-05-07

Algorithms for calculating the leading mass-velocity (MV) and Darwin (D) relativistic corrections are derived for electronic wave functions expanded in terms of n-electron explicitly correlated Gaussian functions with shifted centers and without pre-exponential angular factors. The algorithms are implemented and tested in calculations of MV and D corrections for several points on the ground-state potential energy curves of the H{sub 2} and LiH molecules. The algorithms are general and can be applied in calculations of systems with an arbitrary number of electrons.

Pairing phase diagram of three holes in the generalized Hubbard model

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

Navarro, O.; Espinosa, J.E.

Investigations of high-{Tc} superconductors suggest that the electronic correlation may play a significant role in the formation of pairs. Although the main interest is on the physic of two-dimensional highly correlated electron systems, the one-dimensional models related to high temperature superconductivity are very popular due to the conjecture that properties of the 1D and 2D variants of certain models have common aspects. Within the models for correlated electron systems, that attempt to capture the essential physics of high-temperature superconductors and parent compounds, the Hubbard model is one of the simplest. Here, the pairing problem of a three electrons system hasmore » been studied by using a real-space method and the generalized Hubbard Hamiltonian. This method includes the correlated hopping interactions as an extension of the previously proposed mapping method, and is based on mapping the correlated many body problem onto an equivalent site- and bond-impurity tight-binding one in a higher dimensional space, where the problem was solved in a non-perturbative way. In a linear chain, the authors analyzed the pairing phase diagram of three correlated holes for different values of the Hamiltonian parameters. For some value of the hopping parameters they obtain an analytical solution for all kind of interactions.« less

Impact of IQ, computer-gaming skills, general dexterity, and laparoscopic experience on performance with the da Vinci surgical system.

PubMed

Hagen, Monika E; Wagner, Oliver J; Inan, Ihsan; Morel, Philippe

2009-09-01

Due to improved ergonomics and dexterity, robotic surgery is promoted as being easily performed by surgeons with no special skills necessary. We tested this hypothesis by measuring IQ elements, computer gaming skills, general dexterity with chopsticks, and evaluating laparoscopic experience in correlation to performance ability with the da Vinci robot. Thirty-four individuals were tested for robotic dexterity, IQ elements, computer-gaming skills and general dexterity. Eighteen surgically inexperienced and 16 laparoscopically trained surgeons were included. Each individual performed three different tasks with the da Vinci surgical system and their times were recorded. An IQ test (elements: logical thinking, 3D imagination and technical understanding) was completed by each participant. Computer skills were tested with a simple computer game (hand-eye coordination) and general dexterity was evaluated by the ability to use chopsticks. We found no correlation between logical thinking, 3D imagination and robotic skills. Both computer gaming and general dexterity showed a slight but non-significant improvement in performance with the da Vinci robot (p > 0.05). A significant correlation between robotic skills, technical understanding and laparoscopic experience was observed (p < 0.05). The data support the conclusion that there are no significant correlations between robotic performance and logical thinking, 3D understanding, computer gaming skills and general dexterity. A correlation between robotic skills and technical understanding may exist. Laparoscopic experience seems to be the strongest predictor of performance with the da Vinci surgical system. Generally, it appears difficult to determine non-surgical predictors for robotic surgery.

Eye laterality: a comprehensive analysis in refractive surgery candidates.

PubMed

Linke, Stephan J; Druchkiv, Vasyl; Steinberg, Johannes; Richard, Gisbert; Katz, Toam

2013-08-01

To explore eye laterality (higher refractive error in one eye) and its association with refractive state, spherical/astigmatic anisometropia, age and sex in refractive surgery candidates. Medical records of 12 493 consecutive refractive surgery candidates were filtered. Refractive error (subjective and cycloplegic) was measured in each subject and correlated with eye laterality. Only subjects with corrected distance visual acuity (CDVA) of >20/22 in each eye were enrolled to exclude amblyopia. Associations between eye laterality and refractive state were analysed by means of t-test, chi-squared test, Spearman's correlation and multivariate logistic regression analysis, respectively. There was no statistically significant difference in spherical equivalent between right (-3.47 ± 2.76 D) and left eyes (-3.47 ± 2.76 D, p = 0.510; Pearson's r = 0.948, p < 0.001). Subgroup analysis revealed (I) right eye laterality for anisometropia >2.5 D in myopic (-5.64 ± 2.5 D versus -4.92 ± 2.6 D; p = 0.001) and in hyperopic (4.44 ± 1.69 D versus 3.04 ± 1.79 D; p = 0.025) subjects, (II) a tendency for left eye cylindrical laterality in myopic subjects, and (III) myopic male subjects had a higher prevalence of left eye laterality. (IV) Age did not show any significant impact on laterality. Over the full refractive spectrum, this study confirmed previously described strong interocular refractive correlation but revealed a statistically significant higher rate of right eye laterality for anisometropia >2.5 D. In general, our results support the use of data from one eye only in studies of ocular refraction. © 2013 The Authors. Acta Ophthalmologica © 2013 Acta Ophthalmologica Scandinavica Foundation.

Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography.

PubMed

Shahgaldi, Kambiz; Gudmundsson, Petri; Manouras, Aristomenis; Brodin, Lars-Ake; Winter, Reidar

2009-08-25

Visual assessment of left ventricular ejection fraction (LVEF) is often used in clinical routine despite general recommendations to use quantitative biplane Simpsons (BPS) measurements. Even thou quantitative methods are well validated and from many reasons preferable, the feasibility of visual assessment (eyeballing) is superior. There is to date only sparse data comparing visual EF assessment in comparison to quantitative methods available. The aim of this study was to compare visual EF assessment by two-dimensional echocardiography (2DE) and triplane echocardiography (TPE) using quantitative real-time three-dimensional echocardiography (RT3DE) as the reference method. Thirty patients were enrolled in the study. Eyeballing EF was assessed using apical 4-and 2 chamber views and TP mode by two experienced readers blinded to all clinical data. The measurements were compared to quantitative RT3DE. There were an excellent correlation between eyeballing EF by 2D and TP vs 3DE (r = 0.91 and 0.95 respectively) without any significant bias (-0.5 +/- 3.7% and -0.2 +/- 2.9% respectively). Intraobserver variability was 3.8% for eyeballing 2DE, 3.2% for eyeballing TP and 2.3% for quantitative 3D-EF. Interobserver variability was 7.5% for eyeballing 2D and 8.4% for eyeballing TP. Visual estimation of LVEF both using 2D and TP by an experienced reader correlates well with quantitative EF determined by RT3DE. There is an apparent trend towards a smaller variability using TP in comparison to 2D, this was however not statistically significant.

Covariance NMR Processing and Analysis for Protein Assignment.

PubMed

Harden, Bradley J; Frueh, Dominique P

2018-01-01

During NMR resonance assignment it is often necessary to relate nuclei to one another indirectly, through their common correlations to other nuclei. Covariance NMR has emerged as a powerful technique to correlate such nuclei without relying on error-prone peak peaking. However, false-positive artifacts in covariance spectra have impeded a general application to proteins. We recently introduced pre- and postprocessing steps to reduce the prevalence of artifacts in covariance spectra, allowing for the calculation of a variety of 4D covariance maps obtained from diverse combinations of pairs of 3D spectra, and we have employed them to assign backbone and sidechain resonances in two large and challenging proteins. In this chapter, we present a detailed protocol describing how to (1) properly prepare existing 3D spectra for covariance, (2) understand and apply our processing script, and (3) navigate and interpret the resulting 4D spectra. We also provide solutions to a number of errors that may occur when using our script, and we offer practical advice when assigning difficult signals. We believe such 4D spectra, and covariance NMR in general, can play an integral role in the assignment of NMR signals.

Phase-aberration correction with a 3-D ultrasound scanner: feasibility study.

PubMed

Ivancevich, Nikolas M; Dahl, Jeremy J; Trahey, Gregg E; Smith, Stephen W

2006-08-01

We tested the feasibility of using adaptive imaging, namely phase-aberration correction, with two-dimensional (2-D) arrays and real-time, 3-D ultrasound. Because of the high spatial frequency content of aberrators, 2-D arrays, which generally have smaller pitch and thus higher spatial sampling frequency, and 3-D imaging show potential to improve the performance of adaptive imaging. Phase-correction algorithms improve image quality by compensating for tissue-induced errors in beamforming. Using the illustrative example of transcranial ultrasound, we have evaluated our ability to perform adaptive imaging with a real-time, 3-D scanner. We have used a polymer casting of a human temporal bone, root-mean-square (RMS) phase variation of 45.0 ns, full-width-half-maximum (FWHM) correlation length of 3.35 mm, and an electronic aberrator, 100 ns RMS, 3.76 mm correlation, with tissue phantoms as illustrative examples of near-field, phase-screen aberrators. Using the multilag, least-squares, cross-correlation method, we have shown the ability of 3-D adaptive imaging to increase anechoic cyst identification, image brightness, contrast-to-speckle ratio (CSR), and, in 3-D color Doppler experiments, the ability to visualize flow. For a physical aberrator skull casting we saw CSR increase by 13% from 1.01 to 1.14, while the number of detectable cysts increased from 4.3 to 7.7.

Correlation of Resistivity Value with Geotechnical N-Value of Sedimentary Area in Nusajaya, Johor, Malaysia

NASA Astrophysics Data System (ADS)

Akip Tan, S. N. Mohd; Edy Tonnizam, M.; Saad, R.; Dan, M. F. Md; Nordiana, M. M.; Hazreek, Z. A. M.; Madun, A.

2018-04-01

Electrical resistivity survey and the geotechnical SPT blow counts (N-value) were carried out simultaneously on the tropically weathered sedimentary rock mass for an excavation project at Nusajaya, Johor, Malaysia. This study aims to determine subsurface profile by using 2D-resistivity methods and correlate with N-value derived from boring works. Four boreholes were investigated in five survey lines that revealed the site is underlain by moderately to completely weathered sandstone, clay, silt and shale. Data analysis from 2D-resistivity image shows that zones with high resistivity value generally have high N-value, and vice versa. Five zones have inversed the proportional relation between N-value and resistivity Ωm value due to different types of soil lithology. It indicates that 2D-resistivity is significance to detect bodies of anomalous materials or estimating the depth of bedrock. As a conclusion, the integration of geophysical and geotechnical analysis provides a promise approach to understand some relationship concerning the subsurface subsurface ground through the combination of 2D-resistivity and N-value.

Determination of drug toxicity using 3D spheroids constructed from an immortal human hepatocyte cell line.

PubMed

Fey, Stephen J; Wrzesinski, Krzysztof

2012-06-01

Numerous publications have documented that the immortal cells grown in three-dimensional (3D) cultures possess physiological behavior, which is more reminiscent of their parental organ than when the same cells are cultivated using classical two-dimensional (2D) culture techniques. The goal of this study was to investigate whether this observation could be extended to the determination of LD(50) values and whether 3D data could be correlated to in vivo observations. We developed a noninvasive means to estimate the amount of protein present in a 3D spheroid from it is planar area (± 21%) so that a precise dose can be provided in a manner similar to in vivo studies. This avoided correction of the actual dose given based on a protein determination after treatment (when some cells may have lysed). Conversion of published in vitro LC(50) data (mM) for six common drugs (acetaminophen, amiodarone, diclofenac, metformin, phenformin, and valproic acid) to LD(50) data (mg compound/mg cellular protein) showed that the variation in LD(50) values was generally less than that suggested by the original LC(50) data. Toxicological analysis of these six compounds in 3D spheroid culture (either published or presented here) demonstrated similar LD(50) values. Although in vitro 2D HepG2 data showed a poor correlation, the primary hepatocyte and 3D spheroid data resulted in a much higher degree of correlation with in vivo lethal blood plasma levels. These results corroborate that 3D hepatocyte cultures are significantly different from 2D cultures and are more representative of the liver in vivo.

Determination of Drug Toxicity Using 3D Spheroids Constructed From an Immortal Human Hepatocyte Cell Line

PubMed Central

Fey, Stephen J.; Wrzesinski, Krzysztof

2012-01-01

Numerous publications have documented that the immortal cells grown in three-dimensional (3D) cultures possess physiological behavior, which is more reminiscent of their parental organ than when the same cells are cultivated using classical two-dimensional (2D) culture techniques. The goal of this study was to investigate whether this observation could be extended to the determination of LD50 values and whether 3D data could be correlated to in vivo observations. We developed a noninvasive means to estimate the amount of protein present in a 3D spheroid from it is planar area (± 21%) so that a precise dose can be provided in a manner similar to in vivo studies. This avoided correction of the actual dose given based on a protein determination after treatment (when some cells may have lysed). Conversion of published in vitro LC50 data (mM) for six common drugs (acetaminophen, amiodarone, diclofenac, metformin, phenformin, and valproic acid) to LD50 data (mg compound/mg cellular protein) showed that the variation in LD50 values was generally less than that suggested by the original LC50 data. Toxicological analysis of these six compounds in 3D spheroid culture (either published or presented here) demonstrated similar LD50 values. Although in vitro 2D HepG2 data showed a poor correlation, the primary hepatocyte and 3D spheroid data resulted in a much higher degree of correlation with in vivo lethal blood plasma levels. These results corroborate that 3D hepatocyte cultures are significantly different from 2D cultures and are more representative of the liver in vivo. PMID:22454432

Polarization effects in the reactions p + 3 He → π+ + 4 He, π+ + 4 He → p + 3 He and quantum character of spin correlations in the final (p, 3 He) system

NASA Astrophysics Data System (ADS)

Lyuboshitz, Valery V.; Lyuboshitz, Vladimir L.

2017-12-01

The general consequences of T invariance for the direct and inverse binary reactions a + b → c + d, c + d → a + b with spin-1/2 particles a, b and unpolarized particles c, d are considered. Using the formalism of helicity amplitudes, the polarization effects are studied in the reaction p + 3 He → π+ + 4 He and in the inverse process π+ + 4 He → p + 3 He. It is shown that in the reaction π + + 4 He → p + 3 He the spins of the final proton and 3 He nucleus are strongly correlated. A structural expression through helicity amplitudes, corresponding to arbitrary emission angles, is obtained for the correlation tensor. It is established that in the reaction π + + 4 He → p + 3 He one of the “classical” incoherence inequalities of the Bell type for diagonal components of the correlation tensor is necessarily violated and, thus, the spin correlations of the final particles have the strongly pronounced quantum character.

Application of LaserBreath-001 for breath acetone measurement in subjects with diabetes mellitus

NASA Astrophysics Data System (ADS)

Wang, Zhennan; Sun, Meixiu; Chen, Zhuying; Zhao, Xiaomeng; Li, Yingxin; Wang, Chuji

2016-11-01

Breath acetone is a promising biomarker of diabetes mellitus. With an integrated standalone, on-site cavity ringdown breath acetone analyzer, LaserBreath-001, we tested breath samples from 23 type 1 diabetic (T1D) patients, 312 type 2 diabetic (T2D) patients, 52 healthy subjects. In the cross-sectional studies, the obtained breath acetone concentrations were higher in the diabetic subjects compared with those in the control group. No correlation between breath acetone and simultaneous BG was observed in the T1D, T2D, and healthy subjects. A moderate positive correlation between the mean individual breath acetone concentrations and the mean individual BG levels was observed in the 20 T1D patients without ketoacidosis. In a longitudinal study, the breath acetone concentrations in a T1D patient with ketoacidosis decreased significantly and remained stable during the 5-day hospitalization. The results from a relatively large number of subjects tested indicate that an elevated mean breath acetone concentration exists in diabetic patients in general. Although many physiological parameters affect breath acetone concentrations, fast (<1 min) and on site breath acetone measurement can be used for diabetic screening and management under a specifically controlled condition.

Numerical simulation of velocity and temperature fields in natural circulation loop

NASA Astrophysics Data System (ADS)

Sukomel, L. A.; Kaban'kov, O. N.

2017-11-01

Low flow natural circulation regimes are realized in many practical applications and the existence of the reliable engineering and design calculation methods of flows driven exclusively by buoyancy forces is an actual problem. In particular it is important for the analysis of start up regimes of passive safety systems of nuclear power plants. In spite of a long year investigations of natural circulation loops no suitable predicting recommendations for heat transfer and friction for the above regimes have been proposed for engineering practice and correlations for forced flow are commonly used which considerably overpredicts the real flow velocities. The 2D numerical simulation of velocity and temperature fields in circular tubes for laminar flow natural circulation with reference to the laboratory experimental loop has been carried out. The results were compared with the 1D modified model and experimental data obtained on the above loop. The 1D modified model was still based on forced flow correlations, but in these correlations the physical properties variability and the existence of thermal and hydrodynamic entrance regions are taken into account. The comparison of 2D simulation, 1D model calculations and the experimental data showed that even subject to influence of liquid properties variability and entrance regions on heat transfer and friction the use of 1D model with forced flow correlations do not improve the accuracy of calculations. In general, according to 2D numerical simulation the wall shear stresses are mainly affected by the change of wall velocity gradient due to practically continuous velocity profiles deformation along the whole heated zone. The form of velocity profiles and the extent of their deformation in its turn depend upon the wall heat flux density and the hydraulic diameter.

Change in oral health status associated with menopause in Japanese dental hygienists.

PubMed

Yoshida, N; Sugimoto, K; Suzuki, S; Kudo, H

2018-02-01

Oral symptoms such as xerostomia and burning mouth syndrome have been recognized to increase associated with menopause. The purpose of this study was to clarify the changes in oral health as well as systemic health due to menopause and their relations with hormonal change and mental status. Ninety-seven female dental hygienists aged 40-59 years were assigned to premenopausal, menopausal and post-menopausal groups based on self-reported menstrual condition. Subjective health statuses were evaluated by questionnaire, and objective holistic and oral statuses were evaluated by measuring serum 17β-estradiol (E2), salivary flow rate, α-amylase and secretory IgA (SIgA) and taste sensitivity. A significant difference among the three groups was observed in the self-rating questionnaire of depression (SRQ-D) score and serum E2 level as well as unstimulated salivary flow rate, whereas no significant difference was observed in Simplified menopausal index, Short-Form 36-Item Health Survey, General Oral Health Assessment Index, salivary α-amylase activity, salivary SIgA concentration and taste threshold. Serum E2 levels positively correlated with unstimulated salivary flow rates and negatively correlated with SRQ-D scores and α-amylase activities. The results demonstrated a negative correlation between E2 levels and SRQ-D scores as well as salivary α-amylase activities, suggesting an influence of E2 on mental condition. Furthermore, E2 decrease may result in reduction of salivary flow which in turn causes various problems of oral health. Since the participants were graduates from several dental hygienist schools and working at various places, these results can be generalized to Japanese dental hygienists to some extent. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Novel density functional methodology for the computation of accurate electronic and thermodynamic properties of molecular systems and improved long-range behavior

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

Kafafi, S.A.

1998-12-10

A novel general purpose density functional methodology for the computation of accurate electronic and thermodynamic properties of molecules and improved long-range behavior is reported. Assuming the separability of the exchange (E{sub x}) and correlation (E{sub c}) contributions to the total exchange-correlation energy functional (E{sub xc}), the E{sub x} term consists of a hybrid mixture of 37.5% Hartree-Fock exchange and the appropriate local spin density exchange using the adiabatic connection formula. He demonstrated that E{sub x} and its corresponding potential V{sub x} [=dE{sub x}/d{rho}(r)] have the proper asymptotic limits at r = 0 and r {r_arrow} {infinity}, E{sub c} consists ofmore » the Vosko, Wilk, and Nusair formula for the free-electron gas correlation energy and a generalized gradient approximation term with one adjustable parameter. V{sub c} [=dE{sub c}/d{rho}(r)] was shown to obey the r {r_arrow} {infinity} limit of the corresponding potential derived from exact atomic exchange-correlation computations; namely, V{sub c} is proportional to r{sup {minus}4}. Most importantly, he demonstrated that, at r values where dispersion forces are operating, V{sub c} is proportional to 1/r{sup n} (n = 4, 6, 8, {hor_ellipsis}). The reported method was denoted by K2-BVWN because it used two adjustable parameters in its formulation. The K2-BVWN scheme scales as N{sup 3}, where N is the number of basis functions, compared to {approximately}N{sup 7} for Gaussian-2 (G2) ab initio theory and related methods, {approximately}N{sup 5} for Barone`s mPW1,3PW, and {approximately}N{sup 4} for Becke`s three-parameter density functional approaches. The G2 data set complemented by the reported molecular systems investigated in this work was recommended as a critical test for evaluating novel ab initio and density functional methodologies. The K2-BVWN method has been implemented in the Gaussian series of programs.« less

A non-Hermitian analysis of strongly correlated quantum systems

NASA Astrophysics Data System (ADS)

Nakamura, Yuichi; Hatano, Naomichi

2006-03-01

We study a non-Hermitian generalization of strongly correlated quantum systems in which the transfer energy of electrons is asymmetric. Hatano and Nelson[1] applied this technique to non-interacting random electron systems. They related a non-Hermitian critical point to the inverse localization length of the Hermitian systems. We here conjecture that we can obtain in the same way the correlation length of Hermitian interacting non-random systems[2]. We show for the Hubbard model and the antiferromagnetic XXZ model in one dimension that the non-Hermitian critical point of the ground state, where the energy gap vanishes, is equal to the inverse correlation length. We also show that the conjecture is consistent with numerical results for S=1/2 frustrated quantum spin chains with the nearest- and next-nearest-neighbor interactions including the Majumdar-Ghosh model[3]. [1] N. Hatano and D. R. Nelson, PRL 77 (1996) 570; PRB 56 (1997) 8651. [2] Y. Nakamura and N. Hatano, Physica B, accepted. [3] C. K. Majumdar and D. K. Ghosh, J. Phys. C3 (1970) 911; J. Math. Phys. 10 (1969) 1388, 1399.

Correlated natural transition orbital framework for low-scaling excitation energy calculations (CorNFLEx).

PubMed

Baudin, Pablo; Kristensen, Kasper

2017-06-07

We present a new framework for calculating coupled cluster (CC) excitation energies at a reduced computational cost. It relies on correlated natural transition orbitals (NTOs), denoted CIS(D')-NTOs, which are obtained by diagonalizing generalized hole and particle density matrices determined from configuration interaction singles (CIS) information and additional terms that represent correlation effects. A transition-specific reduced orbital space is determined based on the eigenvalues of the CIS(D')-NTOs, and a standard CC excitation energy calculation is then performed in that reduced orbital space. The new method is denoted CorNFLEx (Correlated Natural transition orbital Framework for Low-scaling Excitation energy calculations). We calculate second-order approximate CC singles and doubles (CC2) excitation energies for a test set of organic molecules and demonstrate that CorNFLEx yields excitation energies of CC2 quality at a significantly reduced computational cost, even for relatively small systems and delocalized electronic transitions. In order to illustrate the potential of the method for large molecules, we also apply CorNFLEx to calculate CC2 excitation energies for a series of solvated formamide clusters (up to 4836 basis functions).

Non-isotropic noise correlation in PET data reconstructed by FBP but not by OSEM demonstrated using auto-correlation function.

PubMed

Razifar, Pasha; Lubberink, Mark; Schneider, Harald; Långström, Bengt; Bengtsson, Ewert; Bergström, Mats

2005-05-13

BACKGROUND: Positron emission tomography (PET) is a powerful imaging technique with the potential of obtaining functional or biochemical information by measuring distribution and kinetics of radiolabelled molecules in a biological system, both in vitro and in vivo. PET images can be used directly or after kinetic modelling to extract quantitative values of a desired physiological, biochemical or pharmacological entity. Because such images are generally noisy, it is essential to understand how noise affects the derived quantitative values. A pre-requisite for this understanding is that the properties of noise such as variance (magnitude) and texture (correlation) are known. METHODS: In this paper we explored the pattern of noise correlation in experimentally generated PET images, with emphasis on the angular dependence of correlation, using the autocorrelation function (ACF). Experimental PET data were acquired in 2D and 3D acquisition mode and reconstructed by analytical filtered back projection (FBP) and iterative ordered subsets expectation maximisation (OSEM) methods. The 3D data was rebinned to a 2D dataset using FOurier REbinning (FORE) followed by 2D reconstruction using either FBP or OSEM. In synthetic images we compared the ACF results with those from covariance matrix. The results were illustrated as 1D profiles and also visualized as 2D ACF images. RESULTS: We found that the autocorrelation images from PET data obtained after FBP were not fully rotationally symmetric or isotropic if the object deviated from a uniform cylindrical radioactivity distribution. In contrast, similar autocorrelation images obtained after OSEM reconstruction were isotropic even when the phantom was not circular. Simulations indicated that the noise autocorrelation is non-isotropic in images created by FBP when the level of noise in projections is angularly variable. Comparison between 1D cross profiles on autocorrelation images obtained by FBP reconstruction and covariance matrices produced almost identical results in a simulation study. CONCLUSION: With asymmetric radioactivity distribution in PET, reconstruction using FBP, in contrast to OSEM, generates images in which the noise correlation is non-isotropic when the noise magnitude is angular dependent, such as in objects with asymmetric radioactivity distribution. In this respect, iterative reconstruction is superior since it creates isotropic noise correlations in the images.

A discrete Fourier-encoded, diagonal-free experiment to simplify homonuclear 2D NMR correlations.

PubMed

Huang, Zebin; Guan, Quanshuai; Chen, Zhong; Frydman, Lucio; Lin, Yulan

2017-07-21

Nuclear magnetic resonance (NMR) spectroscopy has long served as an irreplaceable, versatile tool in physics, chemistry, biology, and materials sciences, owing to its ability to study molecular structure and dynamics in detail. In particular, the connectivity of chemical sites within molecules, and thereby molecular structure, becomes visible by multi-dimensional NMR. Homonuclear correlation experiments are a powerful tool for identifying coupled spins. Generally, diagonal peaks in these correlation spectra display the strongest intensities and do not offer any new information beyond the standard one-dimensional spectrum, whereas weaker, symmetrically placed cross peaks contain most of the coupling information. The cross peaks near the diagonal are often affected by the tails of strong diagonal peaks or even obscured entirely by the diagonal. In this paper, we demonstrate a homonuclear encoding approach based on imparting a discrete phase modulation of the targeted cross peaks and combine it with a site-selective sculpting scheme, capable of simplifying the patterns arising in these 2D correlation spectra. The theoretical principles of the new methods are laid out, and experimental observations are rationalized on the basis of theoretical analyses. The ensuing techniques provide a new way to retrieve 2D coupling information within homonuclear spin systems, with enhanced sensitivity, speed, and clarity.

A discrete Fourier-encoded, diagonal-free experiment to simplify homonuclear 2D NMR correlations

NASA Astrophysics Data System (ADS)

Huang, Zebin; Guan, Quanshuai; Chen, Zhong; Frydman, Lucio; Lin, Yulan

2017-07-01

Nuclear magnetic resonance (NMR) spectroscopy has long served as an irreplaceable, versatile tool in physics, chemistry, biology, and materials sciences, owing to its ability to study molecular structure and dynamics in detail. In particular, the connectivity of chemical sites within molecules, and thereby molecular structure, becomes visible by multi-dimensional NMR. Homonuclear correlation experiments are a powerful tool for identifying coupled spins. Generally, diagonal peaks in these correlation spectra display the strongest intensities and do not offer any new information beyond the standard one-dimensional spectrum, whereas weaker, symmetrically placed cross peaks contain most of the coupling information. The cross peaks near the diagonal are often affected by the tails of strong diagonal peaks or even obscured entirely by the diagonal. In this paper, we demonstrate a homonuclear encoding approach based on imparting a discrete phase modulation of the targeted cross peaks and combine it with a site-selective sculpting scheme, capable of simplifying the patterns arising in these 2D correlation spectra. The theoretical principles of the new methods are laid out, and experimental observations are rationalized on the basis of theoretical analyses. The ensuing techniques provide a new way to retrieve 2D coupling information within homonuclear spin systems, with enhanced sensitivity, speed, and clarity.

Effects of cross-correlated noises on the relaxation time of the bistable system

NASA Astrophysics Data System (ADS)

Xie, Chong-Wei; Mei, Dong-Cheng

2003-11-01

The stationary correlation function and the associated relaxation time for a general system driven by cross-correlated white noises are derived, by virtue of a Stratonovich-like ansatz. The effects of correlated noises on the relaxation time of a bistable kinetic model coupled to an additive and a multiplicative white noises are studied. It is proved that for small fluctuations the relaxation time Tc as a function of lambda (the correlated intensity between noises) exhibits very different behaviours for alphaD (alpha and D, respectively, stand for the intensities of additive and multiplicative noises). When alpha>D, Tc increases with increasing lambda. But when alpha

Determinants of ocular deviation in esotropic subjects under general anesthesia.

PubMed

Daien, Vincent; Turpin, Chloé; Lignereux, François; Belghobsi, Riadh; Le Meur, Guylene; Lebranchu, Pierre; Pechereau, Alain

2013-01-01

The authors attempted to identify the determinants of ocular deviation in a population of patients with esotropia under general anesthesia. Forty-one patients with esotropia were included. Horizontal ocular deviation was evaluated by the photographic Hirschberg test both in the awakened state and under general anesthesia before surgery. Changes in ocular deviation were measured and a multivariate analysis was used to assess its clinical determinants. The mean age (± standard deviation [SD]) of study subjects was 13 ± 11 years and 51% were females. The mean spherical equivalent refraction of the right eye was 2.44 ± 2.50 diopters (D), with no significant difference between eyes (P = .26). The mean ocular deviation changed significantly, from 33.5 ± 12.5 prism diopters (PD) at preoperative examination to 8.8 ± 11.4 PD under general anesthesia (P = .0001). The changes in ocular deviation positively correlated with the pre-operative ocular deviation (correlation coefficient r = 0.59, P = .0001) and negatively correlated with patient age (correlation coefficient r = -0.53, P = .0001). These two determinants remained significant after multivariate adjustment of the following variables: preoperative ocular deviation; age; gender; spherical equivalent refraction; and number of previous strabismus surgeries (model r(2) = 0.49, P = .0001). The ocular position under general anesthesia was reported as a key factor in the surgical treatment of subjects with esotropia; therefore, its clinical determinants were assessed. The authors observed that preoperative ocular deviation and patient age were the main factors that influenced the ocular position under general anesthesia. Copyright 2013, SLACK Incorporated.

Characterizing spatial heterogeneity based on the b-value and fractal analyses of the 2015 Nepal earthquake sequence

NASA Astrophysics Data System (ADS)

Nampally, Subhadra; Padhy, Simanchal; Dimri, Vijay P.

2018-01-01

The nature of spatial distribution of heterogeneities in the source area of the 2015 Nepal earthquake is characterized based on the seismic b-value and fractal analysis of its aftershocks. The earthquake size distribution of aftershocks gives a b-value of 1.11 ± 0.08, possibly representing the highly heterogeneous and low stress state of the region. The aftershocks exhibit a fractal structure characterized by a spectrum of generalized dimensions, Dq varying from D2 = 1.66 to D22 = 0.11. The existence of a fractal structure suggests that the spatial distribution of aftershocks is not a random phenomenon, but it self-organizes into a critical state, exhibiting a scale-independent structure governed by a power-law scaling, where a small perturbation in stress is sufficient enough to trigger aftershocks. In order to obtain the bias in fractal dimensions resulting from finite data size, we compared the multifractal spectrum for the real data and random simulations. On comparison, we found that the lower limit of bias in D2 is 0.44. The similarity in their multifractal spectra suggests the lack of long-range correlation in the data, with an only weakly multifractal or a monofractal with a single correlation dimension D2 characterizing the data. The minimum number of events required for a multifractal process with an acceptable error is discussed. We also tested for a possible correlation between changes in D2 and energy released during the earthquakes. The values of D2 rise during the two largest earthquakes (M > 7.0) in the sequence. The b- and D2 values are related by D2 = 1.45 b that corresponds to the intermediate to large earthquakes. Our results provide useful constraints on the spatial distribution of b- and D2-values, which are useful for seismic hazard assessment in the aftershock area of a large earthquake.

SU-E-T-20: A Correlation Study of 2D and 3D Gamma Passing Rates for Prostate IMRT Plans

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

Zhang, D; Sun Yat-sen University Cancer Center, Guangzhou, Guangdong; Wang, B

2015-06-15

Purpose: To investigate the correlation between the two-dimensional gamma passing rate (2D %GP) and three-dimensional gamma passing rate (3D %GP) in prostate IMRT quality assurance. Methods: Eleven prostate IMRT plans were randomly selected from the clinical database and were used to obtain dose distributions in the phantom and patient. Three types of delivery errors (MLC bank sag errors, central MLC errors and monitor unit errors) were intentionally introduced to modify the clinical plans through an in-house Matlab program. This resulted in 187 modified plans. The 2D %GP and 3D %GP were analyzed using different dose-difference and distance-toagreement (1%-1mm, 2%-2mm andmore » 3%-3mm) and 20% dose threshold. The 2D %GP and 3D %GP were then compared not only for the whole region, but also for the PTVs and critical structures using the statistical Pearson’s correlation coefficient (γ). Results: For different delivery errors, the average comparison of 2D %GP and 3D %GP showed different conclusions. The statistical correlation coefficients between 2D %GP and 3D %GP for the whole dose distribution showed that except for 3%/3mm criterion, 2D %GP and 3D %GP of 1%/1mm criterion and 2%/2mm criterion had strong correlations (Pearson’s γ value >0.8). Compared with the whole region, the correlations of 2D %GP and 3D %GP for PTV were better (the γ value for 1%/1mm, 2%/2mm and 3%/3mm criterion was 0.959, 0.931 and 0.855, respectively). However for the rectum, there was no correlation between 2D %GP and 3D %GP. Conclusion: For prostate IMRT, the correlation between 2D %GP and 3D %GP for the PTV is better than that for normal structures. The lower dose-difference and DTA criterion shows less difference between 2D %GP and 3D %GP. Other factors such as the dosimeter characteristics and TPS algorithm bias may also influence the correlation between 2D %GP and 3D %GP.« less

First two-reagent vitamin D assay for general clinical chemistry.

PubMed

Saida, Fakhri B; Padilla-Chee, Mario; Dou, Chao; Yuan, Chong

2018-05-01

Vitamin D is a lipid-soluble molecule that plays key physiological roles in the metabolism of calcium, phosphate and magnesium. Recent studies show that deficiency in vitamin D is linked to cardiovascular diseases, autoimmune diseases and cancer. As a result, regular monitoring of 25-OH vitamin D (the main circulating form of vitamin D) is becoming essential. Current 25-OH vitamin D testing methodologies are cumbersome (too many reagents, long incubation times, phase separation) and are not compatible with general clinical chemistry platforms. Here, we report on a novel method to detect 25-OH vitamin D that is fast (results in 10 min or less), simple (two reagents) and compatible with virtually all general clinical chemistry analyzers. An immunoturbidimetric assay for 25-OH vitamin D (the Diazyme EZ Vitamin D Assay) has been developed using nanoparticles and vitamin D-specific antibodies. The performance of the assay kit, which consists of two reagents and five calibrators, was tested on the Beckman AU680 analyzer (AU680). The new assay was precise, sensitive (LOD = 7.2 nmol/L), linear (up to 390.1 nmol/L) and correlated strongly (R 2  > 0.95) with major commercial 25-OH vitamin D assays. Additionally, the assay was found to be the fastest to date, with the first results obtained within 10 min. Throughput on the AU680 was estimated at over 300 tests per hour. The newly developed 25-OH vitamin D assay is fast, precise and accurate. It can be run on most general chemistry analyzers. This assay aims at providing vitamin D-testing capabilities to all clinical chemistry laboratories. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Correlates of vitamin D in psychotic disorders: A comprehensive systematic review.

PubMed

Adamson, James; Lally, John; Gaughran, Fiona; Krivoy, Amir; Allen, Lauren; Stubbs, Brendon

2017-03-01

People with psychosis have high prevalence of low vitamin D levels but the correlates and relevance of this deficiency are unclear. A systematic search of major databases from inception to 03/2016 was undertaken investigating correlates of vitamin D in people with psychosis. Data was summarised with a best evidence synthesis. Across 23 included studies (n=1770 psychosis, n=8171 controls) a mean difference in vitamin D levels between both groups of -11.14ng/ml±0.59 was found. 53 unique correlations between vitamin D and outcomes in people with psychosis were identified. The evidence base was broadly equivocal although season of blood sampling (67% of studies found a positive correlation with warmer seasons) and parathyroid hormone (100% of studies found a negative correlation) were associated with vitamin D levels. The most commonly non-correlated variables were: BMI (83% found no correlation), age (73%), gender (86%), smoking (100%), duration of illness (100%) and general assessment of functioning score (100%). In conclusion, whilst many unique correlates have been investigated, there is weak and inconclusive evidence regarding the consistency and meaning of the correlates of vitamin D levels in people with psychosis. Future longitudinal studies should consider the correlates of vitamin D in people with psychosis. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography

PubMed Central

Shahgaldi, Kambiz; Gudmundsson, Petri; Manouras, Aristomenis; Brodin, Lars-Åke; Winter, Reidar

2009-01-01

Background Visual assessment of left ventricular ejection fraction (LVEF) is often used in clinical routine despite general recommendations to use quantitative biplane Simpsons (BPS) measurements. Even thou quantitative methods are well validated and from many reasons preferable, the feasibility of visual assessment (eyeballing) is superior. There is to date only sparse data comparing visual EF assessment in comparison to quantitative methods available. The aim of this study was to compare visual EF assessment by two-dimensional echocardiography (2DE) and triplane echocardiography (TPE) using quantitative real-time three-dimensional echocardiography (RT3DE) as the reference method. Methods Thirty patients were enrolled in the study. Eyeballing EF was assessed using apical 4-and 2 chamber views and TP mode by two experienced readers blinded to all clinical data. The measurements were compared to quantitative RT3DE. Results There were an excellent correlation between eyeballing EF by 2D and TP vs 3DE (r = 0.91 and 0.95 respectively) without any significant bias (-0.5 ± 3.7% and -0.2 ± 2.9% respectively). Intraobserver variability was 3.8% for eyeballing 2DE, 3.2% for eyeballing TP and 2.3% for quantitative 3D-EF. Interobserver variability was 7.5% for eyeballing 2D and 8.4% for eyeballing TP. Conclusion Visual estimation of LVEF both using 2D and TP by an experienced reader correlates well with quantitative EF determined by RT3DE. There is an apparent trend towards a smaller variability using TP in comparison to 2D, this was however not statistically significant. PMID:19706183

A Transition from Localized to Strongly Correlated Electron Behavior and Mixed Valence Driven by Physical or Chemical Pressure in ACo 2As 2 (A = Eu and Ca)

DOE PAGES

Tan, Xiaoyan; Fabbris, Gilberto; Haskel, Daniel; ...

2016-02-03

In this paper, we demonstrate that the action of physical pressure, chemical compression, or aliovalent substitution in ACo 2As 2 (A = Eu and Ca) has a general consequence of causing these antiferromagnetic materials to become ferromagnets. In all cases, the mixed valence triggered at the electropositive A site results in the increase of the Co 3d density of states at the Fermi level. Remarkably, the dramatic alteration of magnetic behavior results from the very minor (<0.15 electron) change in the population of the 3d orbitals. The mixed valence state of Eu observed in the high-pressure (HP) form of EuComore » 2As 2 exhibits a remarkable stability, achieving the average oxidation state of +2.25 at 12.6 GPa. In the case of CaCo 2As 2, substituting even 10% of Eu or La into the Ca site causes ferromagnetic ordering of Co moments. Similar to HP-EuCo 2As 2, the itinerant 3d ferromagnetism emerges from electronic doping into the Co layer because of chemical compression of Eu sites in Ca 0.9Eu 0.1Co 1.91As 2 or direct electron doping in Ca 0.85La 0.15Co 1.89As 2. Finally, the results reported herein demonstrate the general possibility of amplifying minor localized electronic effects to achieve major changes in material’s properties via involvement of strongly correlated electrons.« less

Frontiers of Two-Dimensional Correlation Spectroscopy. Part 1. New concepts and noteworthy developments

NASA Astrophysics Data System (ADS)

Noda, Isao

2014-07-01

A comprehensive survey review of new and noteworthy developments, which are advancing forward the frontiers in the field of 2D correlation spectroscopy during the last four years, is compiled. This review covers books, proceedings, and review articles published on 2D correlation spectroscopy, a number of significant conceptual developments in the field, data pretreatment methods and other pertinent topics, as well as patent and publication trends and citation activities. Developments discussed include projection 2D correlation analysis, concatenated 2D correlation, and correlation under multiple perturbation effects, as well as orthogonal sample design, predicting 2D correlation spectra, manipulating and comparing 2D spectra, correlation strategy based on segmented data blocks, such as moving-window analysis, features like determination of sequential order and enhanced spectral resolution, statistical 2D spectroscopy using covariance and other statistical metrics, hetero-correlation analysis, and sample-sample correlation technique. Data pretreatment operations prior to 2D correlation analysis are discussed, including the correction for physical effects, background and baseline subtraction, selection of reference spectrum, normalization and scaling of data, derivatives spectra and deconvolution technique, and smoothing and noise reduction. Other pertinent topics include chemometrics and statistical considerations, peak position shift phenomena, variable sampling increments, computation and software, display schemes, such as color coded format, slice and power spectra, tabulation, and other schemes.

Positive semidefinite tensor factorizations of the two-electron integral matrix for low-scaling ab initio electronic structure.

PubMed

Hoy, Erik P; Mazziotti, David A

2015-08-14

Tensor factorization of the 2-electron integral matrix is a well-known technique for reducing the computational scaling of ab initio electronic structure methods toward that of Hartree-Fock and density functional theories. The simplest factorization that maintains the positive semidefinite character of the 2-electron integral matrix is the Cholesky factorization. In this paper, we introduce a family of positive semidefinite factorizations that generalize the Cholesky factorization. Using an implementation of the factorization within the parametric 2-RDM method [D. A. Mazziotti, Phys. Rev. Lett. 101, 253002 (2008)], we study several inorganic molecules, alkane chains, and potential energy curves and find that this generalized factorization retains the accuracy and size extensivity of the Cholesky factorization, even in the presence of multi-reference correlation. The generalized family of positive semidefinite factorizations has potential applications to low-scaling ab initio electronic structure methods that treat electron correlation with a computational cost approaching that of the Hartree-Fock method or density functional theory.

Correlation between friction and thickness of vanadium-pentoxide nanowires

NASA Astrophysics Data System (ADS)

Kim, Taekyeong

2015-11-01

We investigated the correlation between friction and thickness of vanadium-pentoxide nanowires (V2O5 NWs) by using friction/atomic force microscopy (FFM/AFM). We observed that the friction signal generally increased with thickness in the FFM/AFM image of the V2O5 NWs. We constructed a two-dimensional (2D) correlation distribution of the frictional force and the thickness of the V2O5 NWs and found that they are strongly correlated; i.e., thicker NWs had higher friction. We also generated a histogram for the correlation factors obtained from each distribution and found that the most probable factor is ~0.45. Furthermore, we found that the adhesion force between the tip and the V2O5 NWs was about -3 nN, and that the friction increased with increasing applied load for different thicknesses of V2O5 NWs. Our results provide an understanding of tribological and nanomechanical studies of various one-dimensional NWs for future fundamental research.

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

Hill, J. Grant, E-mail: grant.hill@sheffield.ac.uk, E-mail: kipeters@wsu.edu; Peterson, Kirk A., E-mail: grant.hill@sheffield.ac.uk, E-mail: kipeters@wsu.edu

New correlation consistent basis sets, cc-pVnZ-PP-F12 (n = D, T, Q), for all the post-d main group elements Ga–Rn have been optimized for use in explicitly correlated F12 calculations. The new sets, which include not only orbital basis sets but also the matching auxiliary sets required for density fitting both conventional and F12 integrals, are designed for correlation of valence sp, as well as the outer-core d electrons. The basis sets are constructed for use with the previously published small-core relativistic pseudopotentials of the Stuttgart-Cologne variety. Benchmark explicitly correlated coupled-cluster singles and doubles with perturbative triples [CCSD(T)-F12b] calculations of themore » spectroscopic properties of numerous diatomic molecules involving 4p, 5p, and 6p elements have been carried out and compared to the analogous conventional CCSD(T) results. In general the F12 results obtained with a n-zeta F12 basis set were comparable to conventional aug-cc-pVxZ-PP or aug-cc-pwCVxZ-PP basis set calculations obtained with x = n + 1 or even x = n + 2. The new sets used in CCSD(T)-F12b calculations are particularly efficient at accurately recovering the large correlation effects of the outer-core d electrons.« less

Novel three-dimensional imaging volumetry in autosomal dominant polycystic kidney disease: comparison with 2D volumetry.

PubMed

Shin, Dongsuk; Lee, Kyu-Beck; Hyun, Young Youl; Lee, Young Rae; Hwang, Young-Hwan; Park, Hayne Cho; Ahn, Curie

2014-08-01

Autosomal dominant polycystic kidney disease (ADPKD) volumetry is an important marker for evaluating the progression of disease. Three-dimensional (3D) volumetry is generally more timesaving than 2D volumetry, but its reliability and accuracy are uncertain. Small and large phantoms simulating polycystic kidneys and 20 patients with ADPKD underwent magnetic resonance imaging (MRI) volumetry. We evaluated the total kidney volume (TKV) and total cyst volume (TCV) using a novel 3D volumetry program (XelisTM) and compared 3D volumetry data with the conventional 2D method (the reference volume values). After upload and threshold setting, the other organs surrounding the kidney were removed by picking and sculpting. The novel method involves drawing of the kidney or cyst and automatic measurement of kidney volume and cyst volume in 3D images. The 3D volume estimation of the small and large phantoms differed from the actual values by 6.9% and -8.2%, respectively, for TKV and by 2.1% and 1.4% for TCV. In ADPKD patients, the intra-reader reliability of 3D volumetry was 30 ± 180 mL (1.3 ± 10.3%) and 25 ± 113 mL (1.2 ± 9.4%), respectively, for TKV and TCV. Correlation between 3D volumetry and 2D volumetry of TKV and TCV resulted in a high correlation coefficient and a regression slope approaching 1.00 (r = 0.97 - 0.98). The mean of the volume percentage differences for 3D vs. 2D for TKV : TCV were -6.0 ± 8.9% : 2.0 ± 11.8% in large ADPKD and -16.1 ± 10.4% : 13.2 ± 21.9% in small ADPKD. Our study showed that 3D volumetry has reliability and accuracy compared with 2D volumetry in ADPKD. 3D volumetry is more accurate for TCV and large ADPKD.

Interpreting digit ratio (2D:4D)-behavior correlations: 2D:4D sex difference, stability, and behavioral correlates and their replicability in young children.

PubMed

Wong, Wang I; Hines, Melissa

2016-02-01

The popularity of using the ratio of the second to the fourth digit (2D:4D) to study influences of early androgen exposure on human behavior relies, in part, on a report that the ratio is sex-dimorphic and stable from age 2 years (Manning etal., 1998). However, subsequent research has rarely replicated this finding. Moreover, although 2D:4D has been correlated with many behaviors, these correlations are often inconsistent. Young children's 2D:4D-behavior correlations may be more consistent than those of older individuals, because young children have experienced fewer postnatal influences. To evaluate the usefulness of 2D:4D as a biomarker of prenatal androgen exposure in studies of 2D:4D-behavior correlations, we assessed its sex difference, temporal stability, and behavioral correlates over a 6- to 8-month period in 126, 2- to 3-year-old children, providing a rare same-sample replicability test. We found a moderate sex difference on both hands and high temporal stability. However, between-sex overlap and within-sex variability were also large. Only 3 of 24 correlations with sex-typed behaviors-scores on the Preschool Activities Inventory (PSAI), preference for a boy-typical toy, preference for a girl-typical toy, were significant and in the predicted direction, all of which involved the PSAI, partially confirming findings from another study. Correlation coefficients were larger for behaviors that showed larger sex differences. But, as in older samples, the overall pattern showed inconsistency across time, sex, and hand. Therefore, although sex-dimorphic and stable, 2D:4D-behavior correlations are no more consistent for young children than for older samples. Theoretical and methodological implications are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

The Psychometric Properties of the Center for Epidemiologic Studies Depression Scale in Chinese Primary Care Patients: Factor Structure, Construct Validity, Reliability, Sensitivity and Responsiveness.

PubMed

Chin, Weng Yee; Choi, Edmond P H; Chan, Kit T Y; Wong, Carlos K H

2015-01-01

The Center for Epidemiologic Studies Depression Scale (CES-D) is a commonly used instrument to measure depressive symptomatology. Despite this, the evidence for its psychometric properties remains poorly established in Chinese populations. The aim of this study was to validate the use of the CES-D in Chinese primary care patients by examining factor structure, construct validity, reliability, sensitivity and responsiveness. The psychometric properties were assessed amongst a sample of 3686 Chinese adult primary care patients in Hong Kong. Three competing factor structure models were examined using confirmatory factor analysis. The original CES-D four-structure model had adequate fit, however the data was better fit into a bi-factor model. For the internal construct validity, corrected item-total correlations were 0.4 for most items. The convergent validity was assessed by examining the correlations between the CES-D, the Patient Health Questionnaire 9 (PHQ-9) and the Short Form-12 Health Survey (version 2) Mental Component Summary (SF-12 v2 MCS). The CES-D had a strong correlation with the PHQ-9 (coefficient: 0.78) and SF-12 v2 MCS (coefficient: -0.75). Internal consistency was assessed by McDonald's omega hierarchical (ωH). The ωH value for the general depression factor was 0.855. The ωH values for "somatic", "depressed affect", "positive affect" and "interpersonal problems" were 0.434, 0.038, 0.738 and 0.730, respectively. For the two-week test-retest reliability, the intraclass correlation coefficient was 0.91. The CES-D was sensitive in detecting differences between known groups, with the AUC >0.7. Internal responsiveness of the CES-D to detect positive and negative changes was satisfactory (with p value <0.01 and all effect size statistics >0.2). The CES-D was externally responsive, with the AUC>0.7. The CES-D appears to be a valid, reliable, sensitive and responsive instrument for screening and monitoring depressive symptoms in adult Chinese primary care patients. In its original four-factor and bi-factor structure, the CES-D is supported for cross-cultural comparisons of depression in multi-center studies.

Recent advancement in the field of two-dimensional correlation spectroscopy

NASA Astrophysics Data System (ADS)

Noda, Isao

2008-07-01

The recent advancement in the field of 2D correlation spectroscopy is reviewed with the emphasis on a number of papers published during the last two years. Topics covered by this comprehensive review include books, review articles, and noteworthy developments in the theory and applications of 2D correlation spectroscopy. New 2D correlation techniques are discussed, such as kernel analysis and augmented 2D correlation, model-based correlation, moving window analysis, global phase angle, covariance and correlation coefficient mapping, sample-sample correlation, hybrid and hetero correlation, pretreatment and transformation of data, and 2D correlation combined with other chemometrics techniques. Perturbation methods of both static (e.g., temperature, composition, pressure and stress, spatial distribution and orientation) and dynamic types (e.g., rheo-optical and acoustic, chemical reactions and kinetics, H/D exchange, sorption and diffusion) currently in use are examined. Analytical techniques most commonly employed in 2D correlation spectroscopy are IR, Raman, and NIR, but the growing use of other probes is also noted, including fluorescence, emission, Raman optical activity and vibrational circular dichroism, X-ray absorption and scattering, NMR, mass spectrometry, and even chromatography. The field of applications for 2D correlation spectroscopy is very diverse, encompassing synthetic polymers, liquid crystals, Langmuir-Blodgett films, proteins and peptides, natural polymers and biomaterials, pharmaceuticals, food and agricultural products, water, solutions, inorganic, organic, hybrid or composite materials, and many more.

Feminist activist women are masculinized in terms of digit-ratio and social dominance: a possible explanation for the feminist paradox.

PubMed

Madison, Guy; Aasa, Ulrika; Wallert, John; Woodley, Michael A

2014-01-01

The feminist movement purports to improve conditions for women, and yet only a minority of women in modern societies self-identify as feminists. This is known as the feminist paradox. It has been suggested that feminists exhibit both physiological and psychological characteristics associated with heightened masculinization, which may predispose women for heightened competitiveness, sex-atypical behaviors, and belief in the interchangeability of sex roles. If feminist activists, i.e., those that manufacture the public image of feminism, are indeed masculinized relative to women in general, this might explain why the views and preferences of these two groups are at variance with each other. We measured the 2D:4D digit ratios (collected from both hands) and a personality trait known as dominance (measured with the Directiveness scale) in a sample of women attending a feminist conference. The sample exhibited significantly more masculine 2D:4D and higher dominance ratings than comparison samples representative of women in general, and these variables were furthermore positively correlated for both hands. The feminist paradox might thus to some extent be explained by biological differences between women in general and the activist women who formulate the feminist agenda.

Recent mathematical developments in 2D correlation spectroscopy

NASA Astrophysics Data System (ADS)

Noda, I.

2000-03-01

Recent mathematical developments in the field of 2D correlation spectroscopy, especially those related to the statistical theory, are reported. The notion of correlation phase angle is introduced. The significance of correlation phase angle between dynamic fluctuations of signals measured at two different spectral variables may be linked to more commonly known statistical concepts, such as coherence and correlation coefficient. This treatment provides the direct mathematical connection between the synchronous 2D correlation spectrum with a continuous form of the variance-covariance matrix. Moreover, it gives the background for the formal definition of the disrelation spectrum, which may be used as a heuristic substitution for the asynchronous 2D spectrum. The 2D correlation intensity may be separated into two independent factors representing the normalized extent of signal fluctuation coherence (i.e., correlation coefficient) and the magnitude of spectral intensity changes (i.e., variance). Such separation offers a convenient way to artificially enhance the discriminating power of 2D correlation spectra.

Correlation dimensions of climate subsystems and their geographic variability

NASA Astrophysics Data System (ADS)

Gan, Thian Yew; Wang, Qiang; Seneka, Michael

2002-12-01

The correlation dimension D2 of precipitation (Canada and Africa), air temperature (Canada, New Zealand, and Southern Hemisphere), geo-potential height (Canada), and unregulated streamflow (Canada, USA, and Africa) were estimated using the Hill procedure of Mikosch and Wang [1995] and the bias correction of Wang and Gan [1998]. After bias correction, it seems that D2 is distinct between climate subsystems, such that for precipitation, it is between 8 and 9, for streamflow, it is between 7 and 9, for temperature, it is between 10 and 11, and for geo-potential heights, it is between 12 and 14. The results seem to suggest that climate might be viewed as a loosely coupled set of fairly high-dimensional subsystems and that different climate variables can yield different D2 values. Further, results also suggest that the D2 values of the climate subsystems studied, generally, have low geographic variability, as found between the precipitation data of Western Canada and Uganda, between the streamflow data of basins representing wide range climate and scales from Canada, USA, and Africa, and among the temperature data of Western Canada, New Zealand, and the southern hemisphere, and that the original D2 values analyzed from Canadian geo-potential heights are similar to that of Western Europe, eastern North America, and Germany. There is at most a weak relationship among basin physical characteristics, location, basin scale, and streamflow D2, while climatic influence is more obvious, as shown by drier basins having slightly higher D2 values than basins of wetter climate, basins from temperate climate having higher D2 values than those from cold or hot climates, and comparable D2 values between precipitation and streamflow data.

Analysis of woven and braided fabric reinforced composites

NASA Technical Reports Server (NTRS)

Naik, Rajiv A.

1994-01-01

A general purpose micromechanics analysis that discretely models the yarn architecture within the textile repeating unit cell, was developed to predict overall, three dimensional, thermal and mechanical properties. This analytical technique was implemented in a user-friendly, personal computer-based, windows compatible code called Textile Composite Analysis for Design (TEXCAD). TEXCAD was used to analyze plain, 5-harness satin, and 8-harness satin weave composites along with 2-D braided and 2x2, 2-D triaxial braided composites. The calculated overall stiffnesses correlated well with available 3-D finite element results and test data for both the woven and the braided composites. Parametric studies were performed to investigate the effects of yarn size on the yarn crimp and the overall thermal and mechanical constants for plain weave composites. The effects of braid angle were investigated for the 2-D braided composites. Finally, the effects of fiber volume fraction on the yarn undulations and the thermal and mechanical properties of 2x2, 2-D triaxial braided composites were also investigated.

Conformationally averaged vertical detachment energy of finite size NO3(-)·nH2O clusters: a route connecting few to many.

PubMed

Pathak, Arup Kumar; Samanta, Alok Kumar; Maity, Dilip Kumar

2011-04-07

We report conformationally averaged VDEs (VDE(w)(n)) for different sizes of NO(3)(-)·nH(2)O clusters calculated by using uncorrelated HF, correlated hybrid density functional (B3LYP, BHHLYP) and correlated ab intio (MP2 and CCSD(T)) theory. It is observed that the VDE(w)(n) at the B3LYP/6-311++G(d,p), B3LYP/Aug-cc-Pvtz and CCSD(T)/6-311++G(d,p) levels is very close to the experimentally measured VDE. It is shown that the use of calculated results of the conformationally averaged VDE for small-sized solvated negatively-charged clusters and a microscopic theory-based general expression for the same provides a route to obtain the VDE for a wide range of cluster sizes, including bulk.

Two-dimensional correlation spectroscopy — Biannual survey 2007-2009

NASA Astrophysics Data System (ADS)

Noda, Isao

2010-06-01

The publication activities in the field of 2D correlation spectroscopy are surveyed with the emphasis on papers published during the last two years. Pertinent review articles and conference proceedings are discussed first, followed by the examination of noteworthy developments in the theory and applications of 2D correlation spectroscopy. Specific topics of interest include Pareto scaling, analysis of randomly sampled spectra, 2D analysis of data obtained under multiple perturbations, evolution of 2D spectra along additional variables, comparison and quantitative analysis of multiple 2D spectra, orthogonal sample design to eliminate interfering cross peaks, quadrature orthogonal signal correction and other data transformation techniques, data pretreatment methods, moving window analysis, extension of kernel and global phase angle analysis, covariance and correlation coefficient mapping, variant forms of sample-sample correlation, and different display methods. Various static and dynamic perturbation methods used in 2D correlation spectroscopy, e.g., temperature, composition, chemical reactions, H/D exchange, physical phenomena like sorption, diffusion and phase transitions, optical and biological processes, are reviewed. Analytical probes used in 2D correlation spectroscopy include IR, Raman, NIR, NMR, X-ray, mass spectrometry, chromatography, and others. Application areas of 2D correlation spectroscopy are diverse, encompassing synthetic and natural polymers, liquid crystals, proteins and peptides, biomaterials, pharmaceuticals, food and agricultural products, solutions, colloids, surfaces, and the like.

AdS/CFT, Black Holes, And Fuzzballs

NASA Astrophysics Data System (ADS)

Zadeh, Ida G.

In this thesis we investigate two different aspects of the AdS/CFT correspondence. We first investigate the holographic AdS/CMT correspondence. Gravitational backgrounds in d + 2 dimensions have been proposed as holographic duals to Lifshitz-like theories describing critical phenomena in d + 1 dimensions with critical exponent z ≥ 1. We numerically explore a dilaton-Einstein-Maxwell model admitting such backgrounds as solutions. We show how to embed these solutions into AdS space for a range of values of z and d. We next investigate the AdS3/CFT2 correspondence and focus on the microscopic CFT description of the D1--D5 system on T4 x S1. In the context of the fuzzball programme, we investigate deforming the CFT away from the orbifold point and study lifting of the low-lying string states. We start by considering general 2D orbifold CFTs of the form M N/SN, with M a target space manifold and SN the symmetric group. The Lunin-Mathur covering space technique provides a way to compute correlators in these orbifold theories, and we generalize this technique in two ways. First, we consider excitations of twist operators by modes of fields that are not twisted by that operator, and show how to account for these excitations when computing correlation functions in the covering space. Second, we consider non-twist sector operators and show how to include the effects of these insertions in the covering space. Using the generalization of the Lunin-Mathur symmetric orbifold technology and conformal perturbation theory, we initiate a program to compute the anomalous dimensions of low-lying string states in the D1--D5 superconformal field theory. Our method entails finding four-point functions involving a string operator O of interest and the deformation operator, taking coincidence limits to identify which other operators mix with O, subtracting conformal families of these operators, and computing their mixing coefficients. We find evidence of operator mixing at first order in the deformation parameter, which means that the string state acquires an anomalous dimension. After diagonalization this will mean that anomalous dimensions of some string states in the D1--D5 SCFT must decrease away from the orbifold point while others increase. Finally, we summarize our results and discuss some future directions of research.

Liver-related factors associated with low vitamin D levels in HIV and HIV/HCV coinfected patients and comparison to general population.

PubMed

Milazzo, Laura; Mazzali, Cristina; Bestetti, Giovanna; Longhi, Erika; Foschi, Antonella; Viola, Anita; Vago, Tarcisio; Galli, Massimo; Parravicini, Carlo; Antinori, Spinello

2011-04-01

Low 25-Hydroxyvitamin D (25[OH]D) was associated with severe fibrosis and low sustained virological response (SVR) after interferon (IFN)-based therapy in chronic hepatitis C. Furthermore, hypovitaminosis D was reported in HIV-infected individuals, but its role in liver disease progression in HIV/HCV coinfection is unknown. 25(OH)D was retrospectively measured in 237 HIV-infected patients (93 with HCV coinfection) and 76 healthy controls. Multivariate analysis included season, immuno-virological data, combined antiretroviral therapy (cART) and, in a subgroup of 51 HIV/HCV-genotype 1 coinfected patients, factors influencing SVR to pegylated-IFN and ribavirin. In a group of 20 patients, liver expression of cytochrome (CY)-P27A1 and CYP2R1, 25-hydroxylating enzymes, was assessed by immunohistochemistry. Median 25(OH)D levels were 23.4 (interquartile range 16.7-33.7) ng/mL in the HIV-infected population and 24 ng/mL (18.3-29.5) in healthy controls (p=0.9). At multiple regression analysis, only winter/spring measurements correlated with lower 25(OH)D levels. No correlation with HCV coinfection, nor with cART regimens was found. Low 25(OH)D was independently associated with advanced fibrosis in HIV/HCV coinfected patients (p=0.023), whereas no association emerged with SVR to IFN-based therapy. CYP27A1 and CYP2R1 expression was associated neither with 25(OH)D serum levels nor with HCV-infection, liver histology, or cART. In our experience, despite the high prevalence of 25(OH)D insufficiency, HIV and HCV-infection did not seem to influence vitamin D status. The role of HIV, HCV and cART on hypovitaminosis D needs further validation in larger cohorts that account for the vitamin levels in general populations and for seasonal and regional variability.

Equilibration and GGE in interacting-to-free quantum quenches in dimensions d\\gt 1

NASA Astrophysics Data System (ADS)

Sotiriadis, Spyros; Martelloni, Gabriele

2016-03-01

Ground states ofinteracting QFTs are non-Gaussian states, i.e. their connected n-point correlation functions do not vanish for n\\gt 2, in contrast to the free QFT case. We show that, when the ground state of an interacting QFT evolves under a free massive QFT for a long time (a scenario that can be realised by a quantum quench), the connected correlation functions decay and all local physical observables equilibrate to values that are given by a Gaussian density matrix that retains memory only of the two-point initial correlation function. The argument hinges upon the fundamental physical principle of cluster decomposition, which is valid for the ground state of a general QFT. An analogous result was already known to be valid in the case of d = 1 spatial dimensions, where it is a special case of the so-called generalised Gibbs ensemble (GGE) hypothesis, and we now generalise it to higher dimensions. Moreover, in the case of massless free evolution, despite the fact that the evolution may lead not to equilibration but instead to unbounded increase of correlations with time, the GGE gives correctly the leading-order asymptotic behaviour of correlation functions in the thermodynamic and large time limit. The demonstration is performed in the context of a bosonic relativistic QFT, but the arguments apply more generally.

Self-consistent expansion for the molecular beam epitaxy equation.

PubMed

Katzav, Eytan

2002-03-01

Motivated by a controversy over the correct results derived from the dynamic renormalization group (DRG) analysis of the nonlinear molecular beam epitaxy (MBE) equation, a self-consistent expansion for the nonlinear MBE theory is considered. The scaling exponents are obtained for spatially correlated noise of the general form D(r-r('),t-t('))=2D(0)[r-->-r(')](2rho-d)delta(t-t(')). I find a lower critical dimension d(c)(rho)=4+2rho, above which the linear MBE solution appears. Below the lower critical dimension a rho-dependent strong-coupling solution is found. These results help to resolve the controversy over the correct exponents that describe nonlinear MBE, using a reliable method that proved itself in the past by giving reasonable results for the strong-coupling regime of the Kardar-Parisi-Zhang system (for d>1), where DRG failed to do so.

Responsiveness Comparison of the EQ-5D, PROMIS Global Health, and VR-12 Questionnaires in Knee Arthroscopy.

PubMed

Oak, Sameer R; Strnad, Gregory J; Bena, James; Farrow, Lutul D; Parker, Richard D; Jones, Morgan H; Spindler, Kurt P

2016-12-01

The EuroQol 5 dimensions questionnaire (EQ-5D), Patient-Reported Outcomes Measurement Information System (PROMIS) 10 Global Health, and Veterans RAND 12-Item Health Survey (VR-12) are generic patient-reported outcome (PRO) questionnaires that assess a patient's general health. In choosing a PRO to track general health status, it is necessary to consider which measure will be the most responsive to change after treatment. To date, no studies exist comparing responsiveness among the EQ-5D, PROMIS 10 Global Health, and the Veterans Rand 12-Item Health Survey (VR-12). To determine which of the generic PROs are most responsive internally and externally in the setting of knee arthroscopy. Cohort study (diagnosis); Level of evidence, 3. Fifty patients who underwent knee arthroscopy were surveyed preoperatively and a mean 3.6 months postoperatively, with 90% follow-up. PROs included the EQ-5D, EQ-5D visual analog scale, PROMIS 10 Global Health (PROMIS 10) physical and mental components, VR-12 physical and mental components, and the Knee injury and Osteoarthritis Outcome Score (KOOS)-pain subscale. Internal responsiveness was evaluated by performing paired t tests on the changes in measures and calculating 2 measures of effect size: Cohen d and standardized response mean (SRM). External responsiveness was evaluated by comparing Pearson correlation measures between the disease-specific reference KOOS-pain and generic PROs. For internal responsiveness, 3 PROs showed a statistically significant improvement in score after treatment (EQ-5D: +0.10 [95% CI, 0.06-0.15], VR-12 physical: +7.2 [95% CI, 4.0-10.4]), and PROMIS 10 physical: +4.4 [95% CI, 2.6-6.3]) and effect size statistics with moderate change (Cohen d and SRM, 0.5-0.8). Assessing external responsiveness, a high correlation with the disease-specific reference (KOOS-pain score) was found for EQ-5D (0.65), VR-12 physical (0.57), and PROMIS 10 physical (0.77). For both internal and external responsiveness, the EQ-5D, VR-12 physical, and PROMIS 10 physical showed significantly greater responsiveness compared with the other general PRO measures but no statistical differences among themselves. There is no statistical difference in internal or external responsiveness to change among the EQ-5D, VR-12 physical, and PROMIS 10 physical instruments. In tracking longitudinal patient health, researchers and administrators have the flexibility to choose any of the general PROs among the EQ-5D, VR-12 physical, and PROMIS 10 physical. We recommend that any study tracking PROs in knee arthroscopy include 1 of these generic instruments.

Monitoring tumor motion by real time 2D/3D registration during radiotherapy.

PubMed

Gendrin, Christelle; Furtado, Hugo; Weber, Christoph; Bloch, Christoph; Figl, Michael; Pawiro, Supriyanto Ardjo; Bergmann, Helmar; Stock, Markus; Fichtinger, Gabor; Georg, Dietmar; Birkfellner, Wolfgang

2012-02-01

In this paper, we investigate the possibility to use X-ray based real time 2D/3D registration for non-invasive tumor motion monitoring during radiotherapy. The 2D/3D registration scheme is implemented using general purpose computation on graphics hardware (GPGPU) programming techniques and several algorithmic refinements in the registration process. Validation is conducted off-line using a phantom and five clinical patient data sets. The registration is performed on a region of interest (ROI) centered around the planned target volume (PTV). The phantom motion is measured with an rms error of 2.56 mm. For the patient data sets, a sinusoidal movement that clearly correlates to the breathing cycle is shown. Videos show a good match between X-ray and digitally reconstructed radiographs (DRR) displacement. Mean registration time is 0.5 s. We have demonstrated that real-time organ motion monitoring using image based markerless registration is feasible. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

One Dimensional(1D)-to-2D Crossover of Spin Correlations in the 3D Magnet ZnMn 2O 4

DOE PAGES

Disseler, S. M.; Chen, Y.; Yeo, S.; ...

2015-12-08

In this paper we report on the intriguing evolution of the dynamical spin correlations of the frustrated spinel ZnMn 2O 4. Inelastic neutron scattering and magnetization studies reveal that the dynamical correlations at high temperatures are 1D. At lower temperature, these dynamical correlations become 2D. Surprisingly, the dynamical correlations condense into a quasi 2D Ising-like ordered state, making this a rare observation of two dimensional order on the spinel lattice. Remarkably, 3D ordering is not observed down to temperatures as low as 300 mK. This unprecedented dimensional crossover stems from frustrated exchange couplings due to the huge Jahn-Teller distortions aroundmore » Mn 3+ ions on the spinel lattice.« less

Longitudinal analysis of direct and indirect effects on average daily gain in rabbits using a structured antedependence model.

PubMed

David, Ingrid; Sánchez, Juan-Pablo; Piles, Miriam

2018-05-10

Indirect genetic effects (IGE) are important components of various traits in several species. Although the intensity of social interactions between partners likely vary over time, very few genetic studies have investigated how IGE vary over time for traits under selection in livestock species. To overcome this issue, our aim was: (1) to analyze longitudinal records of average daily gain (ADG) in rabbits subjected to a 5-week period of feed restriction using a structured antedependence (SAD) model that includes IGE and (2) to evaluate, by simulation, the response to selection when IGE are present and genetic evaluation is based on a SAD model that includes IGE or not. The direct genetic variance for ADG (g/d) increased from week 1 to 3 [from 8.03 to 13.47 (g/d) 2 ] and then decreased [6.20 (g/d) 2 at week 5], while the indirect genetic variance decreased from week 1 to 4 [from 0.43 to 0.22 (g/d) 2 ]. The correlation between the direct genetic effects of different weeks was moderate to high (ranging from 0.46 to 0.86) and tended to decrease with time interval between measurements. The same trend was observed for IGE for weeks 2 to 5 (correlations ranging from 0.62 to 0.91). Estimates of the correlation between IGE of week 1 and IGE of the other weeks did not follow the same pattern and correlations were lower. Estimates of correlations between direct and indirect effects were negative at all times. After seven generations of simulated selection, the increase in ADG from selection on EBV from a SAD model that included IGE was higher (~ 30%) than when those effects were omitted. Indirect genetic effects are larger just after mixing animals at weaning than later in the fattening period, probably because of the establishment of social hierarchy that is generally observed at that time. Accounting for IGE in the selection criterion maximizes genetic progress.

Observation and modelling of main-sequence stellar chromospheres - VII. Rotation and metallicity of dM1 stars

NASA Astrophysics Data System (ADS)

Houdebine, E. R.

2008-11-01

We have measured v sini and metallicity from high-resolution spectroscopic observations of a selected sample of dM1-type stars. To measure v sini, we first selected three template stars known for their slow rotation or their very low activity levels and then cross-correlated their spectra with those of our target stars. The excess broadening of the cross-correlation peaks gives v sini. For metallicity, we compiled all available measurements from the literature and correlated them with the stellar radius. Provided the parallax is known, this new method allows us to derive metallicities for all our target stars. We measured v sini to an accuracy of 2 kms-1. These values were combined with other measurements taken from the literature. We have detected rotation in seven dM1e stars and 11 dM1 stars and upper limits for 20 other dM1 stars. Our results show that the distribution of the rotation period may be bimodal for dM1 stars, i.e. there are two groups of stars: the fast rotators with Prot ~ 6 d and the slow rotators with Prot ~ 24 d. There is a gap between these two groups. We obtained a correlation between metallicity and stellar radius which allows us to derive metallicities for all stars in our sample and more generally for all dM1 stars with [M/H] in the range -1.5 to 0.5 dex, with a reasonable accuracy. We compare this correlation to models and find a significant disagreement in radii. However, the observed shape of the correlation is globally reproduced by the models. We derive the metallicity for 87 M1 dwarfs and subdwarfs. Based on observations collected at Observatoire de Haute Provence and the European Southern Observatory and on Hipparcos parallax measurements. E-mail: eric_houdebine@yahoo.fr

Prevalence of clinically relevant muscle weakness and its association with vitamin D status among older adults in Ecuador.

PubMed

Orces, Carlos H

2017-10-01

Muscle weakness and 25-hydroxyvitamin D (25(OH)D) deficiency have been associated with adverse outcomes among older adults. However, little is known about the relationship between clinically relevant muscle weakness and 25(OH)D levels in Ecuador. To examine the prevalence of muscle weakness and its association with 25(OH)D status among subjects aged 60 years and older in Ecuador. The present study was based on data from 2205 participants in the first National Survey of Health, Wellbeing, and Aging. The Foundation for the National Institute of Health Sarcopenia Project criteria was used to examine muscle weakness prevalence rates. Gender-specific general linear and logistic regression models adjusted for potential confounders were created to compare mean 25(OH)D concentrations and 25(OH)D deficiency across muscle strength categories, respectively. An estimated 32.2% of women and 33.4% of men had evidence of clinically relevant muscle weakness in Ecuador. In general, increased muscle weakness prevalence rates were present among Indigenous, residents in the rural Andes Mountains, underweight subjects, and those with a sedentary lifestyle. Muscle strength was significantly and directly correlated with mean 25(OH)D levels. After controlling for potential confounders, 25(OH)D deficiency prevalence rates were 31 and 43% higher among men and women with muscle weakness than those with normal strength, respectively. One-third of older adults nationwide had evidence of muscle weakness. While the present study found a significant correlation between muscle strength and 25(OH)D concentrations, further research is needed to examine whether optimizing 25(OH)D levels may improve muscle weakness among older adults.

Topological model of composite fermions in the cyclotron band generator picture: New insights

NASA Astrophysics Data System (ADS)

Staśkiewicz, Beata

2018-03-01

A combinatorial group theory in the braid groups is correlated with the unusual "anyon" statistic of particles in 2D Hall system in the fractional quantum regime well. On this background has been derived cyclotron band generator as a modification and generalization band generator, first established to solve the word and conjugacy problems in the braid group terms. Topological commensurability condition has been embraced by canonical factors - like, based on the concept of parallel descending cycles. Owing to this we can mathematically capture the general hierarchy of correlated states in the lowest Landau level, describing the fractional quantum Hall effect hierarchy, in terms of cyclotron band generators, especially for those being beyond conventional composite fermions model. It has been also shown that cyclotron braid subgroups, developed for interpretation of Laughlin correlations, are a special case of the right-angled Artin groups.

Large-scale 3D galaxy correlation function and non-Gaussianity

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

Raccanelli, Alvise; Doré, Olivier; Bertacca, Daniele

We investigate the properties of the 2-point galaxy correlation function at very large scales, including all geometric and local relativistic effects --- wide-angle effects, redshift space distortions, Doppler terms and Sachs-Wolfe type terms in the gravitational potentials. The general three-dimensional correlation function has a nonzero dipole and octupole, in addition to the even multipoles of the flat-sky limit. We study how corrections due to primordial non-Gaussianity and General Relativity affect the multipolar expansion, and we show that they are of similar magnitude (when f{sub NL} is small), so that a relativistic approach is needed. Furthermore, we look at how large-scalemore » corrections depend on the model for the growth rate in the context of modified gravity, and we discuss how a modified growth can affect the non-Gaussian signal in the multipoles.« less

Correlation factors for atomic diffusion in nondilute multicomponent alloys with arbitrary vacancy concentration

NASA Astrophysics Data System (ADS)

Tahir-Kheli, R. A.

1983-09-01

Vacancy-assisted tracer diffusion in a multicomponent kinetic alloy consisting of xλ N atoms with hopping rate Jλ (where λ≡A, B, C, etc.) and υN vacancies (where υ=1-λxλ) distributed randomly over a regular d-dimensional (where d>=2) hypercubic, or close-packed, lattice of N sites is analyzed through a self-consistent renormalization of a recent theory of Tahir-Kheli and Elliott combined with a generalization of concepts introduced by Manning. The result for the tracer-diffusion correlation factor is the following: ftr=H''(tr)[H''(tr)+2J0], where J0 is the tracer-hopping rate, H''(tr) is a generalized effective vacancy escape frequency, H''(tr)=[M(1-υ)[J0υftr+Jeff], where Jeff is an effective hopping rate of the background atoms averaged with a weighting factor proportional to xλ and fλ, i.e., Jeff=λ(Jλxλfλ)λ(xλfλ) and M=-(1+<θ>)<θ>. For a single-component alloy, with particle concentration x, Jλ=J, and vacancy concentration υ=1-x our theory provides an excellent overall description of the correlation factor as long as JJ0>~z-2. Indeed, even for J-->0, the calculated results agree with the Monte Carlo estimates, except in the immediate vicinity of the percolation threshold, υp, which is located self-consistently to an accuracy of the order 1z.

Integrated Sachs-Wolfe effect from the cross correlation of WMAP 3year and the NRAO VLA sky survey data: New results and constraints on dark energy

NASA Astrophysics Data System (ADS)

Pietrobon, Davide; Balbi, Amedeo; Marinucci, Domenico

2006-08-01

We cross correlate the new 3 year Wilkinson Microwave Anistropy Probe (WMAP) cosmic microwave background data with the NRAO VLA Sky Survey radio galaxy data and find further evidence of late integrated Sachs-Wolfe (ISW) effect taking place at late times in cosmic history. Our detection makes use of a novel statistical method (P. Baldi, G. Kerkyacharian, D. Marinucci, and D. Picard, math.ST/0606154 and P. Baldi, G. Kerkyacharian, D. Marinucci, D. Picard, math.ST/0606599) based on a new construction of spherical wavelets, called needlets. The null hypothesis (no ISW) is excluded at more than 99.7% confidence. When we compare the measured cross correlation with the theoretical predictions of standard, flat cosmological models with a generalized dark energy component parameterized by its density, ΩDE, equation of state w and speed of sound cs2, we find 0.3≤ΩDE≤0.8 at 95% C.L., independently of cs2 and w. If dark energy is assumed to be a cosmological constant (w=-1), the bound on density shrinks to 0.41≤ΩDE≤0.79. Models without dark energy are excluded at more than 4σ. The bounds on w depend rather strongly on the assumed value of cs2. We find that models with more negative equation of state (such as phantom models) are a worse fit to the data in the case cs2=1 than in the case cs2=0.

3d-4f magnetic interaction with density functional theory plus u approach: local Coulomb correlation and exchange pathways.

PubMed

Zhang, Yachao; Yang, Yang; Jiang, Hong

2013-12-12

The 3d-4f exchange interaction plays an important role in many lanthanide based molecular magnetic materials such as single-molecule magnets and magnetic refrigerants. In this work, we study the 3d-4f magnetic exchange interactions in a series of Cu(II)-Gd(III) (3d(9)-4f(7)) dinuclear complexes based on the numerical atomic basis-norm-conserving pseudopotential method and density functional theory plus the Hubbard U correction approach (DFT+U). We obtain improved description of the 4f electrons by including the semicore 5s5p states in the valence part of the Gd-pseudopotential. The Hubbard U correction is employed to treat the strongly correlated Cu-3d and Gd-4f electrons, which significantly improve the agreement of the predicted exchange constants, J, with experiment, indicating the importance of accurate description of the local Coulomb correlation. The high efficiency of the DFT+U approach enables us to perform calculations with molecular crystals, which in general improve the agreement between theory and experiment, achieving a mean absolute error smaller than 2 cm(-1). In addition, through analyzing the physical effects of U, we identify two magnetic exchange pathways. One is ferromagnetic and involves an interaction between the Cu-3d, O-2p (bridge ligand), and the majority-spin Gd-5d orbitals. The other one is antiferromagnetic and involves Cu-3d, O-2p, and the empty minority-spin Gd-4f orbitals, which is suppressed by the planar Cu-O-O-Gd structure. This study demonstrates the accuracy of the DFT+U method for evaluating the 3d-4f exchange interactions, provides a better understanding of the exchange mechanism in the Cu(II)-Gd(III) complexes, and paves the way for exploiting the magnetic properties of the 3d-4f compounds containing lanthanides other than Gd.

Cross-correlation patterns in social opinion formation with sequential data

NASA Astrophysics Data System (ADS)

Chakrabarti, Anindya S.

2016-11-01

Recent research on large-scale internet data suggests existence of patterns in the collective behavior of billions of people even though each of them may pursue own activities. In this paper, we interpret online rating activity as a process of forming social opinion about individual items, where people sequentially choose a rating based on the current information set comprising all previous ratings and own preferences. We construct an opinion index from the sequence of ratings and we show that (1) movie-specific opinion converges much slower than an independent and identically distributed (i.i.d.) sequence of ratings, (2) rating sequence for individual movies shows lesser variation compared to an i.i.d. sequence of ratings, (3) the probability density function of the asymptotic opinions has more spread than that defined over opinion arising from i.i.d. sequence of ratings, (4) opinion sequences across movies are correlated with significantly higher and lower correlation compared to opinion constructed from i.i.d. sequence of ratings, creating a bimodal cross-correlation structure. By decomposing the temporal correlation structures from panel data of movie ratings, we show that the social effects are very prominent whereas group effects cannot be differentiated from those of surrogate data and individual effects are quite small. The former explains a large part of extreme positive or negative correlations between sequences of opinions. In general, this method can be applied to any rating data to extract social or group-specific effects in correlation structures. We conclude that in this particular case, social effects are important in opinion formation process.

Detection and characterization of murine colitis and carcinogenesis by molecularly targeted contrast-enhanced ultrasound

PubMed Central

Brückner, Markus; Heidemann, Jan; Nowacki, Tobias M; Cordes, Friederike; Stypmann, Jörg; Lenz, Philipp; Gohar, Faekah; Lügering, Andreas; Bettenworth, Dominik

2017-01-01

AIM To study mucosal addressin cellular adhesion molecule-1 (MAdCAM-1) and vascular endothelial growth factor (VEGF)-targeted contrast enhanced ultrasound (CEUS) for the assessment of murine colitis and carcinogenesis. METHODS C57BL/6 mice were challenged with 3% dextran sodium-sulfate (DSS) for three, six or nine days to study the development of acute colitis. Ultrasound was performed with and without the addition of unspecific contrast agents. MAdCAM-1-targeted contrast agent was used to detect and quantify MAdCAM-1 expression. Inflammatory driven colorectal azoxymethane (AOM)/DSS-induced carcinogenesis was examined on day 42 and 84 using VEGF-targeted contrast agent. Highly specific tissue echogenicity was quantified using specialized software. Sonographic findings were correlated to tissue staining, western blot analysis and immunohistochemistry to quantify the degree of inflammation and stage of carcinogenesis. RESULTS Native ultrasound detected increased general bowel wall thickening that correlated with more progressed and more severe DSS-colitis (healthy mice: 0.3 mm ± 0.03 vs six days DSS: 0.5 mm ± 0.2 vs nine days DSS: 0.6 mm ± 0.2, P < 0.05). Moreover, these sonographic findings correlated well with clinical parameters such as weight loss (r2 = 0.74) and histological damage (r2 = 0.86) (P < 0.01). In acute DSS-induced murine colitis, CEUS targeted against MAdCAM-1 detected and differentiated stages of mild, moderate and severe colitis via calculation of mean pixel contrast intensity in decibel (9.6 dB ± 1.6 vs 12.9 dB ± 1.4 vs 18 dB ± 3.33, P < 0.05). Employing the AOM/DSS-induced carcinogenesis model, tumor development was monitored by CEUS targeted against VEGF and detected a significantly increased echogenicity in tumors as compared to adjacent healthy mucosa (healthy mucosa, 1.6 dB ± 1.4 vs 42 d, 18.2 dB ± 3.3 vs 84 d, 18.6 dB ± 4.9, P < 0.01). Tissue echogenicity strongly correlated with histological analysis and immunohistochemistry findings (VEGF-positive cells in 10 high power fields of healthy mucosa: 1 ± 1.2 vs 42 d after DSS start: 2.4 ± 1.6 vs 84 d after DSS start: 3.5 ± 1.3, P < 0.01). CONCLUSION Molecularly targeted CEUS is a highly specific and non-invasive imaging modality, which characterizes murine intestinal inflammation and carcinogenesis in vivo. PMID:28522908

Detection and characterization of murine colitis and carcinogenesis by molecularly targeted contrast-enhanced ultrasound.

PubMed

Brückner, Markus; Heidemann, Jan; Nowacki, Tobias M; Cordes, Friederike; Stypmann, Jörg; Lenz, Philipp; Gohar, Faekah; Lügering, Andreas; Bettenworth, Dominik

2017-04-28

To study mucosal addressin cellular adhesion molecule-1 (MAdCAM-1) and vascular endothelial growth factor (VEGF)-targeted contrast enhanced ultrasound (CEUS) for the assessment of murine colitis and carcinogenesis. C57BL/6 mice were challenged with 3% dextran sodium-sulfate (DSS) for three, six or nine days to study the development of acute colitis. Ultrasound was performed with and without the addition of unspecific contrast agents. MAdCAM-1-targeted contrast agent was used to detect and quantify MAdCAM-1 expression. Inflammatory driven colorectal azoxymethane (AOM)/DSS-induced carcinogenesis was examined on day 42 and 84 using VEGF-targeted contrast agent. Highly specific tissue echogenicity was quantified using specialized software. Sonographic findings were correlated to tissue staining, western blot analysis and immunohistochemistry to quantify the degree of inflammation and stage of carcinogenesis. Native ultrasound detected increased general bowel wall thickening that correlated with more progressed and more severe DSS-colitis (healthy mice: 0.3 mm ± 0.03 vs six days DSS: 0.5 mm ± 0.2 vs nine days DSS: 0.6 mm ± 0.2, P < 0.05). Moreover, these sonographic findings correlated well with clinical parameters such as weight loss ( r 2 = 0.74) and histological damage ( r 2 = 0.86) ( P < 0.01). In acute DSS-induced murine colitis, CEUS targeted against MAdCAM-1 detected and differentiated stages of mild, moderate and severe colitis via calculation of mean pixel contrast intensity in decibel (9.6 dB ± 1.6 vs 12.9 dB ± 1.4 vs 18 dB ± 3.33, P < 0.05). Employing the AOM/DSS-induced carcinogenesis model, tumor development was monitored by CEUS targeted against VEGF and detected a significantly increased echogenicity in tumors as compared to adjacent healthy mucosa (healthy mucosa, 1.6 dB ± 1.4 vs 42 d, 18.2 dB ± 3.3 vs 84 d, 18.6 dB ± 4.9, P < 0.01). Tissue echogenicity strongly correlated with histological analysis and immunohistochemistry findings (VEGF-positive cells in 10 high power fields of healthy mucosa: 1 ± 1.2 vs 42 d after DSS start: 2.4 ± 1.6 vs 84 d after DSS start: 3.5 ± 1.3, P < 0.01). Molecularly targeted CEUS is a highly specific and non-invasive imaging modality, which characterizes murine intestinal inflammation and carcinogenesis in vivo .

Index to ring digit ratio in Saudi Arabia at Almadinah Almonawarah province: a direct and indirect measurement study

PubMed Central

Almasry, Shaima M; El Domiaty, Magda A; Algaidi, Sami A; Elbastawisy, Yasser M; Safwat, Maha D

2011-01-01

The digit ratio, or the relative lengths, of the 2nd and 4th digits (2D : 4D) shows a sex difference, with males tending to have lower values in comparison with females. This sex differences arises early in the fetus and may result from the effects of prenatal testosterone and estrogen on the relative growth rate of the 2nd and 4th digits. This study aimed to estimate finger lengths and the 2D : 4D ratios for the first time in Saudi Arabian subjects using direct and indirect measurements, and to evaluate the correlations between both indirect and direct 2D : 4D with adult testosterone and various sexually dimorphic physical traits. The results revealed the following: (i) mean 2D : 4D in Saudi Arabian samples varied from 0.96 to 0.99; (ii) mean 2D : 4D was lower for indirect compared to direct 2D : 4D; (iii) sex differences in indirect 2D : 4D were higher than in direct 2D : 4D measurements; (iv) there were no significant correlations between indirect or direct 2D : 4D and testosterone level; (v) there were four significant correlations between direct 2D : 4D and body size traits but no significant correlations between indirect 2D : 4D and body size. PMID:21044064

Feminist activist women are masculinized in terms of digit-ratio and social dominance: a possible explanation for the feminist paradox

PubMed Central

Madison, Guy; Aasa, Ulrika; Wallert, John; Woodley, Michael A.

2014-01-01

The feminist movement purports to improve conditions for women, and yet only a minority of women in modern societies self-identify as feminists. This is known as the feminist paradox. It has been suggested that feminists exhibit both physiological and psychological characteristics associated with heightened masculinization, which may predispose women for heightened competitiveness, sex-atypical behaviors, and belief in the interchangeability of sex roles. If feminist activists, i.e., those that manufacture the public image of feminism, are indeed masculinized relative to women in general, this might explain why the views and preferences of these two groups are at variance with each other. We measured the 2D:4D digit ratios (collected from both hands) and a personality trait known as dominance (measured with the Directiveness scale) in a sample of women attending a feminist conference. The sample exhibited significantly more masculine 2D:4D and higher dominance ratings than comparison samples representative of women in general, and these variables were furthermore positively correlated for both hands. The feminist paradox might thus to some extent be explained by biological differences between women in general and the activist women who formulate the feminist agenda. PMID:25250010

3d expansions of 5d instanton partition functions

NASA Astrophysics Data System (ADS)

Nieri, Fabrizio; Pan, Yiwen; Zabzine, Maxim

2018-04-01

We propose a set of novel expansions of Nekrasov's instanton partition functions. Focusing on 5d supersymmetric pure Yang-Mills theory with unitary gauge group on C_{q,{t}^{-1}}^2× S^1 , we show that the instanton partition function admits expansions in terms of partition functions of unitary gauge theories living on the 3d subspaces C_q× S^1 , C_{t^{-1}}× S^1 and their intersection along S^1 . These new expansions are natural from the BPS/CFT viewpoint, as they can be matched with W q,t correlators involving an arbitrary number of screening charges of two kinds. Our constructions generalize and interpolate existing results in the literature.

Differentiation of Asian ginseng, American ginseng and Notoginseng by Fourier transform infrared spectroscopy combined with two-dimensional correlation infrared spectroscopy

NASA Astrophysics Data System (ADS)

Lu, Guang-hua; Zhou, Qun; Sun, Su-qin; Leung, Kelvin Sze-yin; Zhang, Hao; Zhao, Zhong-zhen

2008-07-01

The herbal materials of Asian ginseng (the root of Panax ginseng), American ginseng (the root of Panax quinquefolius) and Notoginseng (the root of Panax notoginseng) were differentiated by conventional Fourier transform infrared spectroscopy (1D-FTIR) and two-dimensional (2D) correlation FTIR applying a thermal perturbation. Altogether 30 samples were collected and analyzed. Their entire 1D-FTIR spectra in the range of 4000-400 cm -1 and 2D-FTIR spectra in the region of 850-1530 cm -1 were generally similar based on the peaks position and intensities. This indicated the chemical constituents in these species of herbs were not distinctively different. However, variation in peak intensity were observed at about 1640 cm -1, 1416 cm -1, 1372 cm -1 and 1048 cm -1 in the 1D-FTIR spectra among these species for their ease differentiation. Clustering analysis of 1D-FTIR showed that these species located in different clusters. Much difference in their second derivative FTIR pattern among the three species also provided information for easy differentiation. These species of herbs were further identified based on the positions and intensities of relatively strong auto-peaks, positive or negative cross-peaks in their 2D-FTIR spectra. The findings provide a rapid and new operational procedure for the differentiation of these notable herbs. The visual and colorful 2D-FTIR spectra can provide dynamic structural information of chemical components in analyte and demonstrated as a powerful and useful approach for herbs identification.

The Psychometric Properties of the Center for Epidemiologic Studies Depression Scale in Chinese Primary Care Patients: Factor Structure, Construct Validity, Reliability, Sensitivity and Responsiveness

PubMed Central

2015-01-01

Background The Center for Epidemiologic Studies Depression Scale (CES-D) is a commonly used instrument to measure depressive symptomatology. Despite this, the evidence for its psychometric properties remains poorly established in Chinese populations. The aim of this study was to validate the use of the CES-D in Chinese primary care patients by examining factor structure, construct validity, reliability, sensitivity and responsiveness. Methods and Results The psychometric properties were assessed amongst a sample of 3686 Chinese adult primary care patients in Hong Kong. Three competing factor structure models were examined using confirmatory factor analysis. The original CES-D four-structure model had adequate fit, however the data was better fit into a bi-factor model. For the internal construct validity, corrected item-total correlations were 0.4 for most items. The convergent validity was assessed by examining the correlations between the CES-D, the Patient Health Questionnaire 9 (PHQ-9) and the Short Form-12 Health Survey (version 2) Mental Component Summary (SF-12 v2 MCS). The CES-D had a strong correlation with the PHQ-9 (coefficient: 0.78) and SF-12 v2 MCS (coefficient: -0.75). Internal consistency was assessed by McDonald’s omega hierarchical (ωH). The ωH value for the general depression factor was 0.855. The ωH values for “somatic”, “depressed affect”, “positive affect” and “interpersonal problems” were 0.434, 0.038, 0.738 and 0.730, respectively. For the two-week test-retest reliability, the intraclass correlation coefficient was 0.91. The CES-D was sensitive in detecting differences between known groups, with the AUC >0.7. Internal responsiveness of the CES-D to detect positive and negative changes was satisfactory (with p value <0.01 and all effect size statistics >0.2). The CES-D was externally responsive, with the AUC>0.7. Conclusions The CES-D appears to be a valid, reliable, sensitive and responsive instrument for screening and monitoring depressive symptoms in adult Chinese primary care patients. In its original four-factor and bi-factor structure, the CES-D is supported for cross-cultural comparisons of depression in multi-center studies. PMID:26252739

Chern-Simons gauge theory on orbifolds: Open strings from three dimensions

NASA Astrophysics Data System (ADS)

Hořava, Petr

1996-12-01

Chern-Simons gauge theory is formulated on three-dimensional Z2 orbifolds. The locus of singular points on a given orbifold is equivalent to a link of Wilson lines. This allows one to reduce any correlation function on orbifolds to a sum of more complicated correlation functions in the simpler theory on manifolds. Chern-Simons theory on manifolds is known to be related to two-dimensional (2D) conformal field theory (CFT) on closed-string surfaces; here it is shown that the theory on orbifolds is related to 2D CFT of unoriented closed- and open-string models, i.e. to worldsheet orbifold models. In particular, the boundary components of the worldsheet correspond to the components of the singular locus in the 3D orbifold. This correspondence leads to a simple identification of the open-string spectra, including their Chan-Paton degeneration, in terms of fusing Wilson lines in the corresponding Chern-Simons theory. The correspondence is studied in detail, and some exactly solvable examples are presented. Some of these examples indicate that it is natural to think of the orbifold group Z2 as a part of the gauge group of the Chern-Simons theory, thus generalizing the standard definition of gauge theories.

Anisotropic stress correlations in two-dimensional liquids

DOE PAGES

Wu, Bin; Iwashita, Takuya; Egami, Takeshi

2015-03-01

In this paper we demonstrate the presence of anisotropic stress correlations in the simulated 2D liquids. Whereas the temporal correlation of macroscopic shear stress is known to contribute to viscosity via the Green-Kubo formula, the general question regarding angular dependence of the spatial correlation among atomic level stresses in liquids without external shear has not been explored. Besides the apparent anisotropicity with well-defined symmetry, we found that the characteristic length of shear stress correlation depends on temperature and follows the power law, suggesting divergence around the glass transition temperature. The anisotropy of the stress correlations can be explained in termsmore » of the inclusion model by Eshelby, based upon which we suggest that the mismatch between the atom and its nearest neighbor cage produces the atomic level stress as well as the long-range stress fields.« less

Self-consistent expansion for the molecular beam epitaxy equation

NASA Astrophysics Data System (ADS)

Katzav, Eytan

2002-03-01

Motivated by a controversy over the correct results derived from the dynamic renormalization group (DRG) analysis of the nonlinear molecular beam epitaxy (MBE) equation, a self-consistent expansion for the nonlinear MBE theory is considered. The scaling exponents are obtained for spatially correlated noise of the general form D(r-->-r',t-t')=2D0\\|r-->- r'\\|2ρ-dδ(t-t'). I find a lower critical dimension dc(ρ)=4+2ρ, above which the linear MBE solution appears. Below the lower critical dimension a ρ-dependent strong-coupling solution is found. These results help to resolve the controversy over the correct exponents that describe nonlinear MBE, using a reliable method that proved itself in the past by giving reasonable results for the strong-coupling regime of the Kardar-Parisi-Zhang system (for d>1), where DRG failed to do so.

3D General Circulation Model of the Middle Atmosphere of Jupiter

NASA Astrophysics Data System (ADS)

Zube, Nicholas Gerard; Zhang, Xi; Li, Cheng; Le, Tianhao

2017-10-01

The characteristics of Jupiter’s large-scale stratospheric circulation remain largely unknown. Detailed distributions of temperature and photochemical species have been provided by recent observations [1], but have not yet been accurately reproduced by middle atmosphere general circulation models (GCM). Jupiter’s stratosphere and upper troposphere are influenced by radiative forcing from solar insolation and infrared cooling from hydrogen and hydrocarbons, as well as waves propagating from the underlying troposphere [2]. The relative significance of radiative and mechanical forcing on stratospheric circulation is still being debated [3]. Here we present a 3D GCM of Jupiter’s atmosphere with a correlated-k radiative transfer scheme. The simulation results are compared with observations. We analyze the impact of model parameters on the stratospheric temperature distribution and dynamical features. Finally, we discuss future tracer transport and gravity wave parameterization schemes that may be able to accurately simulate the middle atmosphere dynamics of Jupiter and other giant planets.[1] Kunde et al. 2004, Science 305, 1582.[2] Zhang et al. 2013a, EGU General Assembly, EGU2013-5797-2.[3] Conrath 1990, Icarus, 83, 255-281.

Statistical image reconstruction from correlated data with applications to PET

PubMed Central

Alessio, Adam; Sauer, Ken; Kinahan, Paul

2008-01-01

Most statistical reconstruction methods for emission tomography are designed for data modeled as conditionally independent Poisson variates. In reality, due to scanner detectors, electronics and data processing, correlations are introduced into the data resulting in dependent variates. In general, these correlations are ignored because they are difficult to measure and lead to computationally challenging statistical reconstruction algorithms. This work addresses the second concern, seeking to simplify the reconstruction of correlated data and provide a more precise image estimate than the conventional independent methods. In general, correlated variates have a large non-diagonal covariance matrix that is computationally challenging to use as a weighting term in a reconstruction algorithm. This work proposes two methods to simplify the use of a non-diagonal covariance matrix as the weighting term by (a) limiting the number of dimensions in which the correlations are modeled and (b) adopting flexible, yet computationally tractable, models for correlation structure. We apply and test these methods with simple simulated PET data and data processed with the Fourier rebinning algorithm which include the one-dimensional correlations in the axial direction and the two-dimensional correlations in the transaxial directions. The methods are incorporated into a penalized weighted least-squares 2D reconstruction and compared with a conventional maximum a posteriori approach. PMID:17921576

ACIRF User’s Guide for the General Model (Version 3.5)

DTIC Science & Technology

1992-06-01

61 3c Example ACIRF formatted output for the frozen-in model (summary of measured realization statistics for antenr.. 2...must be delta correlated in angle, delay, and Doppler frequency: < z(KL,O)o) *(Kijj",o) = S(K±,T, O)D) 5(KL-K’) 8(T-r’) 8(0D-Oab) .( 61 ) The first-order... 61 , and the central limit theorem could be invoked to argue that h(p,r,t) and hA(p,rt) are zero- mean, normally-distributed complex quantities. Indeed

Structure-Function Correlations using Scanning Laser Polarimetry in Primary Angle-Closure Glaucoma and Primary Open Angle Glaucoma

PubMed Central

Lee, Pei-Jung; Liu, Catherine Jui-Ling.; Wojciechowski, Robert; Bailey-Wilson, Joan E.; Cheng, Ching-Yu

2010-01-01

Purpose To assess the correlations between retinal nerve fiber layer (RNFL) thickness measured with scanning laser polarimetry (SLP) and visual field (VF) sensitivity in primary open angle glaucoma (POAG) and primary angle-closure glaucoma (PACG). Design Prospective, comparative, observational cases series Methods Fifty patients with POAG and 56 with PACG were examined using SLP with variable corneal compensation (GDx VCC) and Humphrey VF analyzer between August 2005 and July 2006 at Taipei Veterans General Hospital. Correlations between RNFL thickness and VF sensitivity, expressed as mean sensitivity (MS) in both decibel (dB) and 1/Lambert (L) scales, were estimated by Spearman's rank correlation coefficient (rs) and multivariate median regression models (pseudo R2). The correlations were determined globally and for six RNFL sectors and their corresponding VF regions. Results The correlation between RNFL thickness and MS (in dB) was weaker in the PACG group (rs = 0.38, P = 0.004, pseudo R2 = 0.17) than in the POAG group (rs = 0.51, P <0.001, pseudo R2 = 0.31), but the difference in the magnitude of correlation was not significant (P = 0.42).With Bonferroni correction, the structure-function correlation was significant in the superotemporal (rs = 0.62), superonasal (rs = 0.56), inferonasal (rs = 0.53), and inferotemporal (rs = 0.50) sectors in the POAG group (all P <0.001), while it was significant only in the superotemporal (rs = 0.53) and inferotemporal (rs = 0.48) sectors in the PACG group (both P <0.001). The results were similar when MS was expressed as 1/L scale. Conclusions Both POAG and PACG eyes had moderate structure-function correlations using SLP. Compared to eyes with POAG, fewer RNFL sectors have significant structure-function correlations in eyes with PACG. PMID:20202618

Low expression of D2R and Wntless correlates with high motivation for heroin.

PubMed

Tacelosky, Diana M; Alexander, Danielle N; Morse, Megan; Hajnal, Andras; Berg, Arthur; Levenson, Robert; Grigson, Patricia S

2015-12-01

Drug overdose now exceeds car accidents as the leading cause of accidental death in the United States. Of those drug overdoses, a large percentage of the deaths are due to heroin and/or pharmaceutical overdose, specifically misuse of prescription opioid analgesics. It is imperative, then, that we understand the mechanisms that lead to opioid abuse and addiction. The rewarding actions of opioids are mediated largely by the mu-opioid receptor (MOR), and signaling by this receptor is modulated by various interacting proteins. The neurotransmitter dopamine also contributes to opioid reward, and opioid addiction has been linked to reduced expression of dopamine D2 receptors (D2R) in the brain. That said, it is not known if alterations in the expression of these proteins relate to drug exposure and/or to the "addiction-like" behavior exhibited for the drug. Here, we held total drug self-administration constant across acquisition and showed that reduced expression of the D2R and the MOR interacting protein, Wntless, in the medial prefrontal cortex was associated with greater addiction-like behavior for heroin in general and with a greater willingness to work for the drug in particular. In contrast, reduced expression of the D2R in the nucleus accumbens and hippocampus was correlated with greater seeking during signaled nonavailability of the drug. Taken together, these data link reduced expression of both the D2R and Wntless to the explicit motivation for the drug rather than to differences in total drug intake per se. (c) 2015 APA, all rights reserved).

Correlation analysis between 2D and quasi-3D gamma evaluations for both intensity-modulated radiation therapy and volumetric modulated arc therapy

PubMed Central

Kim, Jung-in; Choi, Chang Heon; Wu, Hong-Gyun; Kim, Jin Ho; Kim, Kyubo; Park, Jong Min

2017-01-01

The aim of this work was to investigate correlations between 2D and quasi-3D gamma passing rates. A total of 20 patients (10 prostate cases and 10 head and neck cases, H&N) were retrospectively selected. For each patient, both intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans were generated. For each plan, 2D gamma evaluation with radiochromic films and quasi-3D gamma evaluation with fluence measurements were performed with both 2%/2 mm and 3%/3 mm criteria. Gamma passing rates were grouped together according to delivery techniques and treatment sites. Statistical analyses were performed to examine the correlation between 2D and quasi-3D gamma evaluations. Statistically significant difference was observed between delivery techniques only in the quasi-3D gamma passing rates with 2%/2 mm. Statistically significant differences were observed between treatment sites in the 2D gamma passing rates (differences of less than 8%). No statistically significant correlations were observed between 2D and quasi-3D gamma passing rates except the VMAT group and the group including both IMRT and VMAT with 3%/3 mm (r = 0.564 with p = 0.012 for theVMAT group and r = 0.372 with p = 0.020 for the group including both IMRT and VMAT), however, those were not strong. No strong correlations were observed between 2D and quasi-3D gamma evaluations. PMID:27690300

Analytical and clinical evaluation of the new Fujirebio Lumipulse®G non-competitive assay for 25(OH)-vitamin D and three immunoassays for 25(OH)D in healthy subjects, osteoporotic patients, third trimester pregnant women, healthy African subjects, hemodialyzed and intensive care patients.

PubMed

Cavalier, Etienne; Lukas, Pierre; Bekaert, Anne-Catherine; Peeters, Stéphanie; Le Goff, Caroline; Yayo, Eric; Delanaye, Pierre; Souberbielle, Jean-Claude

2016-08-01

In this study, we provide a short analytical evaluation of the new Fujirebio Lumipulse®G non-competitive immunoassay for 25(OH)D. Clinical performance was compared with three commercial competitive automated immunoassays against a Vitamin D Standardization Program (VDSP)-traceable liquid chromatography-tandem mass spectrometry (LC-MS/MS) in six different clinically relevant populations. Lumipulse®G 25(OH)D precision, measurement uncertainty, recovery, limit of quantification were assessed, as well as 25(OH)D2 and C3-epimer recovery. For method comparison, 250 serum samples obtained in healthy Caucasians and Africans, osteoporotic, hemodialyzed and intensive care patients and 3rd trimester pregnant women were analyzed by all methods. Correlation was studied using Passing-Bablok and Bland-Altman analysis. Concordance correlation coefficient (CCC) was calculated to evaluate agreement between immunoassays and the LC-MS/MS. The Lumipulse®G 25(OH)D assay presented interesting analytical features and showed excellent correlation to the LC-MS/MS results (y=1.00×-1.35 ng/mL), as obtained in healthy Caucasian individuals. In the other special populations, Lumipulse®G presented a concordance with LC-MS/MS which was generally higher than competitors, even if all methods significantly under-recovered 25(OH)D in hemodialyzed patients. Intra-assay CV ranged from 12.1% at 9.6 ng/mL to 2.1% at 103.7 ng/mL and inter-assay CV ranged from 16.2 to 3.7% at the same concentrations, respectively. Measurement uncertainty, with a probability of 95%, were respectively 33.1 and 7.6% at these concentrations. LOQ was found to be at 4.6 ng/mL. Mean (95% CI) 25(OH)D2 revovery was 77% (74-81) and no cross-reactivity was observed with C3-epimer. Fujirebio Lumipulse®G 25-OH Vitamin D Total assay is therefore considered suitable for assessment of vitamin D status in clinical routine.

Estimate of the Coulomb correlation energy in CeAg2Ge2 from inverse photoemission and high resolution photoemission spectroscopy

NASA Astrophysics Data System (ADS)

Banik, Soma; Arya, A.; Bendounan, Azzedine; Maniraj, M.; Thamizhavel, A.; Vobornik, I.; Dhar, S. K.; Deb, S. K.

2014-08-01

The occupied and the unoccupied electronic structure of CeAg2Ge2 single crystal has been studied using high resolution photoemission and inverse photoemission spectroscopy, respectively. High resolution photoemission reveals the clear signature of Ce 4f states in the occupied electronic structure which was not observed clearly in our earlier studies. The Coulomb correlation energy in this system has been determined experimentally from the position of the 4f states above and below the Fermi level. Theoretically, the correlation energy has been determined by using the first principles density functional calculations within the generalized gradient approximations taking into account the strong intra-atomic (on-site) interaction Hubbard Ueff term. The calculated valence band shows minor changes in the spectral shape with increasing Ueff due to the fact that the density of Ce 4f state is narrow in the occupied part and is hybridized with the Ce 5d, Ag 4d and Ge 4p states. On the other hand, substantial changes are observed in the spectral shape of the calculated conduction band with increasing Ueff since the density of Ce 4f state is very large in the unoccupied part, compared to other states. The estimated value of correlation energy for CeAg2Ge2 from the experiment and the theory is ≈ 4.2 eV. The resonant photoemission data are analyzed in the framework of the single-impurity Anderson model which further confirms the presence of the Coulomb correlation energy and small hybridization in this system.

Digit ratio (2D:4D), aggression, and testosterone in men exposed to an aggressive video stimulus.

PubMed

Kilduff, Liam P; Hopp, Renato N; Cook, Christian J; Crewther, Blair T; Manning, John T

2013-10-10

The relative lengths of the 2(nd) and 4(th) digits (2D:4D) is a negative biomarker for prenatal testosterone, and low 2D:4D may be associated with aggression. However, the evidence for a 2D:4D-aggression association is mixed. Here we test the hypothesis that 2D:4D is robustly linked to aggression in "challenge" situations in which testosterone is increased. Participants were exposed to an aggressive video and a control video. Aggression was measured after each video and salivary free testosterone levels before and after each video. Compared to the control video, the aggressive video was associated with raised aggression responses and a marginally significant increase in testosterone. Left 2D:4D was negatively correlated with aggression after the aggressive video and the strength of the correlation was higher in those participants who showed the greatest increases in testosterone. Left 2D:4D was also negatively correlated to the difference between aggression scores in the aggressive and control conditions. The control video did not influence testosterone concentrations and there were no associations between 2D:4D and aggression. We conclude that 2D:4D moderates the impact of an aggressive stimulus on aggression, such that an increase in testosterone resulting from a "challenge" is associated with a negative correlation between 2D:4D and aggression.

The agreement between 3D, standard 2D and triplane 2D speckle tracking: effects of image quality and 3D volume rate.

PubMed

Trache, Tudor; Stöbe, Stephan; Tarr, Adrienn; Pfeiffer, Dietrich; Hagendorff, Andreas

2014-12-01

Comparison of 3D and 2D speckle tracking performed on standard 2D and triplane 2D datasets of normal and pathological left ventricular (LV) wall-motion patterns with a focus on the effect that 3D volume rate (3DVR), image quality and tracking artifacts have on the agreement between 2D and 3D speckle tracking. 37 patients with normal LV function and 18 patients with ischaemic wall-motion abnormalities underwent 2D and 3D echocardiography, followed by offline speckle tracking measurements. The values of 3D global, regional and segmental strain were compared with the standard 2D and triplane 2D strain values. Correlation analysis with the LV ejection fraction (LVEF) was also performed. The 3D and 2D global strain values correlated good in both normally and abnormally contracting hearts, though systematic differences between the two methods were observed. Of the 3D strain parameters, the area strain showed the best correlation with the LVEF. The numerical agreement of 3D and 2D analyses varied significantly with the volume rate and image quality of the 3D datasets. The highest correlation between 2D and 3D peak systolic strain values was found between 3D area and standard 2D longitudinal strain. Regional wall-motion abnormalities were similarly detected by 2D and 3D speckle tracking. 2DST of triplane datasets showed similar results to those of conventional 2D datasets. 2D and 3D speckle tracking similarly detect normal and pathological wall-motion patterns. Limited image quality has a significant impact on the agreement between 3D and 2D numerical strain values.

Time dependence of correlation functions following a quantum quench.

PubMed

Calabrese, Pasquale; Cardy, John

2006-04-07

We show that the time dependence of correlation functions in an extended quantum system in d dimensions, which is prepared in the ground state of some Hamiltonian and then evolves without dissipation according to some other Hamiltonian, may be extracted using methods of boundary critical phenomena in d + 1 dimensions. For d = 1 particularly powerful results are available using conformal field theory. These are checked against those available from solvable models. They may be explained in terms of a picture, valid more generally, whereby quasiparticles, entangled over regions of the order of the correlation length in the initial state, then propagate classically through the system.

Association of vitamin D status with semen quality and reproductive hormones in Iranian subfertile men.

PubMed

Abbasihormozi, Sh; Kouhkan, A; Alizadeh, A R; Shahverdi, A H; Nasr-Esfahani, M H; Sadighi Gilani, M A; Salman Yazdi, R; Matinibehzad, A; Zolfaghari, Z

2017-01-01

Although vitamin D deficiency is one of the most common health problems throughout the world, including Iran, conflicting information exists on the potential association between serum vitamin D levels and semen quality. This study intended to evaluate the association between serum vitamin D [25(OH) D3] with semen quality and hormones in Iranian subfertile men. We also compared mean vitamin D and hormone levels in normospermic men with oligoasthenoteratozoospermia (OAT) men. This cross-sectional study was conducted on 278 men who were referred to Royan Infertility Clinic (Tehran, Iran) from March to September 2014. The participants were categorized into two groups; of 186 normospermic and 92 OAT patients according to World Health Organization 2010 criteria. Each participant provided informed consent prior to launching research. Participants completed two general questionnaires of nutritional status. Blood and semen samples were obtained for assessment, and all data were adjusted for age, body mass index (BMI), and season. Vitamin D levels were classified according to Institute of Medicine guidelines. Vitamin D deficiency, insufficiency, and normal levels were observed in 8.6%, 43.6%, 47.8% of participants, respectively. No association was found between daily dietary intake of vitamin D and calcium with sperm parameters. Serum vitamin D was inversely correlated with PTH (p < 0.045). In normospermic men, serum vitamin D levels categorized were not correlated with semen parameters and reproductive hormones (FSH, LH, testosterone(T), and FT), whereas sperm motility showed a positive correlation with vitamin D categorized in OAT men (rs = 0.131, p = 0.028). In conclusion, there was a high incidence of deficiency and insufficiency 25(OH) D Levels (<20ng/ml) observed in Iranian men (52.2%). Moreover, our findings showed a correlation between vitamin D levels and sperm motility in OAT men, which requires further studies. © 2016 American Society of Andrology and European Academy of Andrology.

Sequential /sup 1/H NMR assignments and secondary structure of hen egg white lysozyme in solution

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

Redfield, C.; Dobson, C.M.

Assignments of /sup 1/H NMR resonances of 121 of the 129 residues of hen egg white lysozyme have been obtained by sequence-specific methods. Spin systems were identified with phase-sensitive two-dimensional (2-D) correlated spectroscopy and single and double relayed coherence transfer spectroscopy. For key types of amino acid residues, particularly alanine, threonine, valine, and glycine, complete spin systems were identified. For other residues a less complete definition of the spin system was found to be adequate for the purpose of sequential assignment. Sequence-specific assignments were achieved by phase-sensitive 2-D nuclear Overhauser enhancement spectroscopy (NOESY). Exploitation of the wide range of hydrogenmore » exchange rates found in lysozyme was a useful approach to overcoming the problem of spectral overlap. The sequential assignment was built up from 21 peptide segments ranging in length from 2 to 13 residues. The NOESY spectra were also used to provide information about the secondary structure of the protein in solution. Three helical regions and two regions of ..beta..-sheet were identified from the NOESY data; these regions are identical with those found in the X-ray structure of hen lysozyme. Slowly exchanging amides are generally correlated with hydrogen bonding identified in the X-ray structure; a number of exceptions to this general trend were, however, found. The results presented in this paper indicate that highly detailed information can be obtained from 2-D NMR spectra of a protein that is significantly larger than those studies previously.« less

C-reactive protein and fibrinogen of bedridden older patients in a six-month vitamin D supplementation trial.

PubMed

Bjorkman, M P; Sorva, A J; Tilvis, R S

2009-05-01

To elucidate the association between vitamin D status, C-reactive protein (CRP) and fibrinogen. Secondary analysis of a randomised double-blind placebo controlled trial. Four longterm care hospitals (1215 beds) in Helsinki, Finland. 218 long-term inpatients aged over 65 years. Eligible patients (n = 218) were randomized to receive 0 IU/d, 400 IU/d, or 1200 IU/d cholecalciferol for six months. Plasma 25-hydroxyvitamin D (25-OHD), parathyroid hormone (PTH), high sensitive CRP, fibrinogen, amino-terminal propeptide of type I procollagen (PINP), and carboxy-terminal telopeptide of type I collagen (ICTP) were measured. The patients were aged (84.5 +/- 7.5 years), vitamin D deficient (25-OHD = 23 +/- 10 nmol/l), chronically bedridden and in stable general condition. The mean baseline CRP and fibrinogen were 10.86 mg/l (0.12 mg/l - 125.00 mg/l) and 4,7 g/l (2.3 g/l - 8.6 g/l), respectively. CRP correlated with ICTP (r = 0.217, p = 0.001), but not with vitamin D status. Supplementation significantly increased 25-OHD concentrations, but the changes in CRP and fibrinogen were insignificant and inconsistent. The post-trial CRP concentrations (0.23 mg/l -138.00 mg/l) correlated with ICTP (r = 0.156, p < 0.001), but no association was found with vitamin D status. The baseline and post-trial fibrinogen correlated with CRP, only. CRP concentrations are associated with bone turnover, but not with vitamin D status, and vitamin D supplementation has no major effect on CRP or fibrinogen concentrations in bedridden older patients.

Short-Term Adaptive Modification of Dynamic Ocular Accommodation

PubMed Central

Bharadwaj, Shrikant R.; Vedamurthy, Indu; Schor, Clifton M.

2009-01-01

Purpose Indirect observations suggest that the neural control of accommodation may undergo adaptive recalibration in response to age-related biomechanical changes in the accommodative system. However, there has been no direct demonstration of such an adaptive capability. This investigation was conducted to demonstrate short-term adaptation of accommodative step response dynamics to optically induced changes in neuromuscular demands. Methods Repetitive changes in accommodative effort were induced in 15 subjects (18–34 years) with a double-step adaptation paradigm wherein an initial 2-D step change in blur was followed 350 ms later by either a 2-D step increase in blur (increasing-step paradigm) or a 1.75-D step decrease in blur (decreasing-step paradigm). Peak velocity, peak acceleration, and latency of 2-D single-step test responses were assessed before and after 1.5 hours of training with these paradigms. Results Peak velocity and peak acceleration of 2-D step responses increased after adaptation to the increasing-step paradigm (9/12 subjects), and they decreased after adaptation to the decreasing-step paradigm (4/9 subjects). Adaptive changes in peak velocity and peak acceleration generalized to responses that were smaller (1 D) and larger (3 D) than the 2-D adaptation stimulus. The magnitude of adaptation correlated poorly with the subject's age, but it was significantly negatively correlated with the preadaptation dynamics. Response latency decreased after adaptation, irrespective of the direction of adaptation. Conclusions Short-term adaptive changes in accommodative step response dynamics could be induced, at least in some of our subjects between 18 and 34 years, with a directional bias toward increasing rather than decreasing the dynamics. PMID:19255153

Thyroid hormones and deiodinase activity in plasma and tissues in relation to high levels of organohalogen contaminants in East Greenland polar bears (Ursus maritimus).

PubMed

Gabrielsen, Kristin Møller; Krokstad, Julie Stene; Villanger, Gro Dehli; Blair, David A D; Obregon, Maria-Jesus; Sonne, Christian; Dietz, Rune; Letcher, Robert J; Jenssen, Bjørn Munro

2015-01-01

Previous studies have shown relationships between organohalogen contaminants (OHCs) and circulating levels of thyroid hormones (THs) in arctic wildlife. However, there is a lack of knowledge concerning the possible functional effects of OHCs on TH status in target tissues for TH-dependent activity. The relationships between circulating (plasma) levels of OHCs and various TH variables in plasma as well as in liver, muscle and kidney tissues from East Greenland sub-adult polar bears (Ursus maritimus) sampled in 2011 (n=7) were therefore investigated. The TH variables included 3.3',5.5'-tetraiodothyronine or thyroxine (T4), 3.3',5-triiodothyronine (T3) and type 1 (D1) and type 2 (D2) deiodinase activities. Principal component analysis (PCA) combined with correlation analyses demonstrated negative relationships between individual polychlorinated biphenyls (PCBs) and their hydroxylated (OH-) metabolites and T4 in both plasma and muscle. There were both positive and negative relationships between individual OHCs and D1 and D2 activities in muscle, liver and kidney tissues. In general, PCBs, OH-PCBs and polybrominated dipehenyl ethers (PBDEs) were positively correlated to D1 and D2 activities, whereas organochlorine pesticides and byproducts (OCPs) were negatively associated with D1 and D2 activities. These results support the hypothesis that OHCs can affect TH status and action in the target tissues of polar bears. TH levels and deiodinase activities in target tissues can be sensitive endpoints for exposure of TH-disrupting compounds in arctic wildlife, and thus, tissue-specific responses in target organs should be further considered when assessing TH disruption in wildlife studies. Copyright © 2014 Elsevier Inc. All rights reserved.

Health-related utility values of patients with primary Sjögren's syndrome and its predictors.

PubMed

Lendrem, Dennis; Mitchell, Sheryl; McMeekin, Peter; Bowman, Simon; Price, Elizabeth; Pease, Colin T; Emery, Paul; Andrews, Jacqueline; Lanyon, Peter; Hunter, John; Gupta, Monica; Bombardieri, Michele; Sutcliffe, Nurhan; Pitzalis, Costantino; McLaren, John; Cooper, Annie; Regan, Marian; Giles, Ian; Isenberg, David; Vadivelu, Saravanan; Coady, David; Dasgupta, Bhaskar; McHugh, Neil; Young-Min, Steven; Moots, Robert; Gendi, Nagui; Akil, Mohammed; Griffiths, Bridget; Ng, Wan-Fai

2014-07-01

EuroQoL-5 dimension (EQ-5D) is a standardised preference-based tool for measurement of health-related quality of life and EQ-5D utility values can be converted to quality-adjusted life years (QALYs) to aid cost-utility analysis. This study aimed to evaluate the EQ-5D utility values of 639 patients with primary Sjögren's syndrome (PSS) in the UK. Prospective data collected using a standardised pro forma were compared with UK normative data. Relationships between utility values and the clinical and laboratory features of PSS were explored. The proportion of patients with PSS reporting any problem in mobility, self-care, usual activities, pain/discomfort and anxiety/depression were 42.2%, 16.7%, 56.6%, 80.6% and 49.4%, respectively, compared with 5.4%, 1.6%, 7.9%, 30.2% and 15.7% for the UK general population. The median EQ-5D utility value was 0.691 (IQR 0.587-0.796, range -0.239 to 1.000) with a bimodal distribution. Bivariate correlation analysis revealed significant correlations between EQ-5D utility values and many clinical features of PSS, but most strongly with pain, depression and fatigue (R values>0.5). After adjusting for age and sex differences, multiple regression analysis identified pain and depression as the two most important predictors of EQ-5D utility values, accounting for 48% of the variability. Anxiety, fatigue and body mass index were other statistically significant predictors, but they accounted for <5% in variability. This is the first report on the EQ-5D utility values of patients with PSS. These patients have significantly impaired utility values compared with the UK general population. EQ-5D utility values are significantly related to pain and depression scores in PSS. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Timely Reperfusion in Stroke and Myocardial Infarction Is Not Correlated: An Opportunity for Better Coordination of Acute Care.

PubMed

Sauser Zachrison, Kori; Levine, Deborah A; Fonarow, Gregg C; Bhatt, Deepak L; Cox, Margueritte; Schulte, Phillip; Smith, Eric E; Suter, Robert E; Xian, Ying; Schwamm, Lee H

2017-03-01

Timely reperfusion is critical in acute ischemic stroke (AIS) and ST-segment-elevation myocardial infarction (STEMI). The degree to which hospital performance is correlated on emergent STEMI and AIS care is unknown. Primary objective of this study was to determine whether there was a positive correlation between hospital performance on door-to-balloon (D2B) time for STEMI and door-to-needle (DTN) time for AIS, with and without controlling for patient and hospital differences. Prospective study of all hospitals in both Get With The Guidelines-Stroke and Get With The Guidelines-Coronary Artery Disease from 2006 to 2009 and treating ≥10 patients. We compared hospital-level DTN time and D2B time using Spearman rank correlation coefficients and hierarchical linear regression modeling. There were 43 hospitals with 1976 AIS and 59 823 STEMI patients. Hospitals' DTN times for AIS did not correlate with D2B times for STEMI (ρ=-0.09; P =0.55). There was no correlation between hospitals' proportion of eligible patients treated within target time windows for AIS and STEMI (median DTN time <60 minutes: 21% [interquartile range, 11-30]; median D2B time <90 minutes: 68% [interquartile range, 62-79]; ρ=-0.14; P =0.36). The lack of correlation between hospitals' DTN and D2B times persisted after risk adjustment. We also correlated hospitals' DTN time and D2B time data from 2013 to 2014 using Get With The Guidelines (DTN time) and Hospital Compare (D2B time). From 2013 to 2014, hospitals' DTN time performance in Get With The Guidelines was not correlated with D2B time performance in Hospital Compare (n=546 hospitals). We found no correlation between hospitals' observed or risk-adjusted DTN and D2B times. Opportunities exist to improve hospitals' performance of time-critical care processes for AIS and STEMI in a coordinated approach. © 2017 American Heart Association, Inc.

Timely Reperfusion in Stroke and Myocardial Infarction is Not Correlated: An Opportunity for Better Coordination of Acute Care

PubMed Central

Zachrison, Kori Sauser; Levine, Deborah A.; Fonarow, Gregg C.; Bhatt, Deepak L.; Cox, Margueritte; Schulte, Phillip; Smith, Eric E.; Suter, Robert E.; Xian, Ying; Schwamm, Lee H.

2017-01-01

Background Timely reperfusion is critical in acute ischemic stroke (AIS) and ST Segment Elevation acute myocardial infarction (STEMI). The degree to which hospital performance is correlated on emergent STEMI and AIS care is unknown. Primary objective: to determine whether there was a positive correlation between hospital performance on door-to-balloon time (D2B) for STEMI and door-to-needle time (DTN) for AIS, with and without controlling for patient and hospital differences. Methods and Results Prospective study of all hospitals in both Get With The Guidelines (GWTG)-Stroke and GWTG–Coronary Artery Disease from 2006–2009 and treating ≥10 patients. We compared hospital-level DTN and D2B using Spearman’s rank correlation coefficients and hierarchical linear regression modeling. There were 43 hospitals with 1976 AIS and 59,823 STEMI patients. Hospitals’ DTN times for AIS did not correlate with D2B times for STEMI (ρ=−0.09; p=0.55). There was no correlation between hospitals’ proportion of eligible patients treated within target time windows for AIS and STEMI (median DTN<60 minutes: 21% [IQR, 11–30]; median D2B<90 minutes: 68% [IQR, 62–79]; ρ= −0.14; p=0.36). The lack of correlation between hospitals’ DTN and D2B times persisted after risk adjustment. We also correlated hospitals’ DTN and D2B data from 2013–14 using GWTG (DTN) and Hospital Compare (D2B). From 2013–14, hospitals’ DTN performance in GWTG was not correlated with D2B performance in Hospital Compare (N=546 hospitals). Conclusions We found no correlation between hospitals’ observed or risk-adjusted DTN and D2B times. Opportunities exist to improve hospitals’ performance of time-critical care processes for AIS and STEMI in a coordinated approach. PMID:28283469

Martingales, detrending data, and the efficient market hypothesis

NASA Astrophysics Data System (ADS)

McCauley, Joseph L.; Bassler, Kevin E.; Gunaratne, Gemunu H.

2008-01-01

We discuss martingales, detrending data, and the efficient market hypothesis (EMH) for stochastic processes x( t) with arbitrary diffusion coefficients D( x, t). Beginning with x-independent drift coefficients R( t) we show that martingale stochastic processes generate uncorrelated, generally non-stationary increments. Generally, a test for a martingale is therefore a test for uncorrelated increments. A detrended process with an x-dependent drift coefficient is generally not a martingale, and so we extend our analysis to include the class of ( x, t)-dependent drift coefficients of interest in finance. We explain why martingales look Markovian at the level of both simple averages and 2-point correlations. And while a Markovian market has no memory to exploit and presumably cannot be beaten systematically, it has never been shown that martingale memory cannot be exploited in 3-point or higher correlations to beat the market. We generalize our Markov scaling solutions presented earlier, and also generalize the martingale formulation of the EMH to include ( x, t)-dependent drift in log returns. We also use the analysis of this paper to correct a misstatement of the ‘fair game’ condition in terms of serial correlations in Fama's paper on the EMH. We end with a discussion of Levy's characterization of Brownian motion and prove that an arbitrary martingale is topologically inequivalent to a Wiener process.

Molecular Packing of Amphiphilic Nanosheets Resolved by X-ray Scattering

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

Harutyunyan, Boris; Dannenhoffer, Adam; Kewalramani, Sumit

2016-12-29

Molecular packing in light harvesting 2D assemblies of photocatalytic materials is a critical factor for solar-to-fuel conversion efficiency. However, structure–function correlations have yet to be fully established. This is partly due to the difficulties in extracting the molecular arrangements from the complex 3D powder averaged diffraction patterns of 2D lattices, obtained via in situ wide-angle X-ray scattering. Here, we develop a scattering theory formalism and couple it with a simple geometrical model for the molecular shape of chromophore 9-methoxy-N-(sodium hexanoate)perylene-3,4-dicarboximide (MeO-PMI) used in our study. This generally applicable method fully reproduces the measured diffraction pattern including the asymmetric line shapesmore » for the Bragg reflections and yields the molecular packing arrangement within a 2D crystal structure with a remarkable degree of detail. We find an approximate edge-centered herringbone structure for the PMI fused aromatic rings and ordering of the carboxypentyl chains above and below the nanosheets. Such a packing arrangement differs from the more symmetric face-to-face orientation of the unsubstituted PMI rings. This structural difference is correlated to our measurement of the reduced catalytic performance of MeO-PMI nanosheets as compared to the mesoscopically similar unsubstituted PMI assemblies.« less

The associations between internet use time and school performance among Korean adolescents differ according to the purpose of internet use.

PubMed

Kim, So Young; Kim, Min-Su; Park, Bumjung; Kim, Jin-Hwan; Choi, Hyo Geun

2017-01-01

Although overuse of the internet has been suggested to be related to poor academic performance, the effects of internet use for education on academic performance showed conflict results in previous studies. Accordingly, the associations of school performance with internet use for study and for general purpose were explored in a large population of Korean adolescents. Cross-sectional data from the 2013 Korean Youth Risk Behaviour Web-based Survey (KYRBWS) were retrieved for 59,105 12- to 18-year-old adolescents. The associations between school performance and internet use were analysed using multinomial logistic regression with complex sampling. Days of physical activity, sex, obesity, region of residence, income level, parental education level, stress, sleep time, smoking, alcohol consumption, drug use, and total study time were recorded and adjusted for as confounders. Higher school performance was positively associated with longer internet use for study (adjusted odds ratio, AOR, of 2+ h [95% confidence interval] = 2.43 [2.10-2.82], 2.02 [1.78-2.30], 1.66 [1.46-1.89], and 1.30 [1.15-1.47] for performance groups A, B, C, and D, respectively, P < 0.001) but negatively associated with longer internet use for general purpose (AOR of 3+ h [95% confidence interval] = 0.68 [0.60-0.78], 0.85 [0.76-0.94], 0.83 [0.75-0.92], and 0.98 [0.89-1.08] for performance groups A, B, C, and D, respectively, P < 0.001). Higher school performance significantly positively correlated with internet use for study but negatively correlated with internet use for general purpose. Academic use of the internet could be a means of achieving good school performance.

The associations between internet use time and school performance among Korean adolescents differ according to the purpose of internet use

PubMed Central

Kim, So Young; Kim, Min-Su; Park, Bumjung; Kim, Jin-Hwan

2017-01-01

Although overuse of the internet has been suggested to be related to poor academic performance, the effects of internet use for education on academic performance showed conflict results in previous studies. Accordingly, the associations of school performance with internet use for study and for general purpose were explored in a large population of Korean adolescents. Cross-sectional data from the 2013 Korean Youth Risk Behaviour Web-based Survey (KYRBWS) were retrieved for 59,105 12- to 18-year-old adolescents. The associations between school performance and internet use were analysed using multinomial logistic regression with complex sampling. Days of physical activity, sex, obesity, region of residence, income level, parental education level, stress, sleep time, smoking, alcohol consumption, drug use, and total study time were recorded and adjusted for as confounders. Higher school performance was positively associated with longer internet use for study (adjusted odds ratio, AOR, of 2+ h [95% confidence interval] = 2.43 [2.10–2.82], 2.02 [1.78–2.30], 1.66 [1.46–1.89], and 1.30 [1.15–1.47] for performance groups A, B, C, and D, respectively, P < 0.001) but negatively associated with longer internet use for general purpose (AOR of 3+ h [95% confidence interval] = 0.68 [0.60–0.78], 0.85 [0.76–0.94], 0.83 [0.75–0.92], and 0.98 [0.89–1.08] for performance groups A, B, C, and D, respectively, P < 0.001). Higher school performance significantly positively correlated with internet use for study but negatively correlated with internet use for general purpose. Academic use of the internet could be a means of achieving good school performance. PMID:28369147

Nanoporous active carbons at ambient conditions: a comparative study using X-ray scattering and diffraction, Raman spectroscopy and N2 adsorption

NASA Astrophysics Data System (ADS)

Shiryaev, A. A.; Voloshchuk, A. M.; Volkov, V. V.; Averin, A. A.; Artamonova, S. D.

2017-05-01

Furfural-derived sorbents and activated carbonaceous fibers were studied using Small- and Wide-angle X-ray scattering (SWAXS), X-ray diffraction and multiwavelength Raman spectroscopy after storage at ambient conditions. Correlations between structural features with degree of activation and with sorption parameters are observed for samples obtained from a common precursor and differing in duration of activation. However, the correlations are not necessarily applicable to the carbons obtained from different precursors. Using two independent approaches we show that treatment of SWAXS results should be performed with careful analysis of applicability of the Porod law to the sample under study. In general case of a pore with rough/corrugated surface deviations from the Porod law may became significant and reflect structure of the pore-carbon interface. Ignorance of these features may invalidate extraction of closed porosity values. In most cases the pore-matrix interface in the studied samples is not atomically sharp, but is characterized by 1D or 2D fluctuations of electronic density responsible for deviations from the Porod law. Intensity of the pores-related small-angle scattering correlates positively with SBET values obtained from N2 adsorption.

Selective One-Dimensional Total Correlation Spectroscopy Nuclear Magnetic Resonance Experiments for a Rapid Identification of Minor Components in the Lipid Fraction of Milk and Dairy Products: Toward Spin Chromatography?

PubMed

Papaemmanouil, Christina; Tsiafoulis, Constantinos G; Alivertis, Dimitrios; Tzamaloukas, Ouranios; Miltiadou, Despoina; Tzakos, Andreas G; Gerothanassis, Ioannis P

2015-06-10

We report a rapid, direct, and unequivocal spin-chromatographic separation and identification of minor components in the lipid fraction of milk and common dairy products with the use of selective one-dimensional (1D) total correlation spectroscopy (TOCSY) nuclear magnetic resonance (NMR) experiments. The method allows for the complete backbone spin-coupling network to be elucidated even in strongly overlapped regions and in the presence of major components from 4 × 10(2) to 3 × 10(3) stronger NMR signal intensities. The proposed spin-chromatography method does not require any derivatization steps for the lipid fraction, is selective with excellent resolution, is sensitive with quantitation capability, and compares favorably to two-dimensional (2D) TOCSY and gas chromatography-mass spectrometry (GC-MS) methods of analysis. The results of the present study demonstrated that the 1D TOCSY NMR spin-chromatography method can become a procedure of primary interest in food analysis and generally in complex mixture analysis.

Correlation between ECM guidance and actin polymerization on osteogenic differentiation of human adipose-derived stem cells

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

Keller, Vivian; Deiwick, Andrea; Pflaum, Michael

The correlation between extracellular matrix (ECM) components, cell shape, and stem cell guidance can shed light in understanding and mimicking the functionality of stem cell niches for various applications. This interplay on osteogenic guidance of human adipose-derived stem cells (hASCs) was focus of this study. Proliferation and osteogenic markers like alkaline phosphatase activity and calcium mineralization were slightly increased by the ECM components laminin (LA), collagen I (COL), and fibronectin (FIB); with control medium no differentiation occurred. ECM guided differentiation was rather dependent on osterix than on Runx2 pathway. FIB significantly enhanced cell elongation even in presence of actin polymerizationmore » blockers cytochalasin D (CytoD) and ROCK inhibitor Y-27632, which generally caused more rounded cells. Except for the COL surface, both inhibitors increased the extent of osterix, while the Runx2 pathway was more sensitive to the culture condition. Both inhibitors did not affect hASC proliferation. CytoD enabled osteogenic differentiation independently from the ECM, while it was rather blocked via Y-27632 treatment; on FIB the general highest extent of differentiation occurred. Taken together, the ECM effect on hASCs occurs indirectly and selectively via a dominant role of FIB: it sustains osteogenic differentiation in case of a tension-dependent control of actin polymerization. - Highlights: • Interplay of ECM and cell shape guides osteogenic differentiation of hASCs. • ECM components only present a promotive but not stimulative effect. • No direct correlation between ECM-enhanced cell elongation and differentiation. • Suppression of differentiation depends on a specific actin polymerization blocking. • Fibronectin sustains cell elongation and differentiation in case of blocking actin.« less

Counting conformal correlators

NASA Astrophysics Data System (ADS)

Kravchuk, Petr; Simmons-Duffin, David

2018-02-01

We introduce simple group-theoretic techniques for classifying conformallyinvariant tensor structures. With them, we classify tensor structures of general n-point functions of non-conserved operators, and n ≥ 4-point functions of general conserved currents, with or without permutation symmetries, and in any spacetime dimension d. Our techniques are useful for bootstrap applications. The rules we derive simultaneously count tensor structures for flat-space scattering amplitudes in d + 1 dimensions.

Digit ratio (2D:4D), testosterone, cortisol, aggression, personality and hand-grip strength: Evidence for prenatal effects on strength.

PubMed

Ribeiro, Evaldo; Neave, Nick; Morais, Rosana Nogueiro; Kilduff, Liam; Taylor, Suzan R; Butovskaya, Marina; Fink, Bernhard; Manning, John T

2016-09-01

Digit ratio (2D:4D) is a putative marker for prenatal testosterone and is correlated with performance in many sports. Low 2D:4D has been linked to strength but the evidence is mixed and strength is also influenced by mass, testosterone, and behavioural factors. It has been hypothesised that the 2D:4D-strength correlation may be strongest in challenge conditions when short-term changes occur in steroid hormones. We tested this suggestion in men. We used a cross-over study design with a challenge (an aggressive video of rugby tackles) and control (a blank screen) condition. 89 healthy men. Finger lengths (2nd and 4th for both hands), hand-grip strength (HGS), testosterone (T), cortisol (C), aggression (Buss-Perry Aggression Questionnaire) and personality type (Ten Item Personality Measure). In both conditions participants provided saliva samples (for hormone assays). In the challenge condition there was a highly significant increase in HGS, and modest changes in T, physical aggression and emotional stability. HGS correlated negatively with left hand 2D:4D. In a multiple regression, left hand 2D:4D was negatively related to HGS and emotional stability was positively related to HGS. In the control condition HGS was not correlated with 2D:4D. In a multiple regression, BMI, physical aggression, and emotional stability were significantly related to HGS. 2D:4D is a negative correlate of strength in challenge situations. This finding may in part explain associations between 2D:4D and sports performance. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Correlation of 3D Shift and 3D Tilt of the Patella in Patients With Recurrent Dislocation of the Patella and Healthy Volunteers: An In Vivo Analysis Based on 3-Dimensional Computer Models.

PubMed

Yamada, Yuzo; Toritsuka, Yukiyoshi; Nakamura, Norimasa; Horibe, Shuji; Sugamoto, Kazuomi; Yoshikawa, Hideki; Shino, Konsei

2017-11-01

The concepts of lateral deviation and lateral inclination of the patella, characterized as shift and tilt, have been applied in combination to evaluate patellar malalignment in patients with patellar dislocation. It is not reasonable, however, to describe the 3-dimensional (3D) positional relation between the patella and the femur according to measurements made on 2-dimensional (2D) images. The current study sought to clarify the relation between lateral deviation and inclination of the patella in patients with recurrent dislocation of the patella (RDP) by redefining them via 3D computer models as 3D shift and 3D tilt. Descriptive laboratory study. Altogether, 60 knees from 56 patients with RDP and 15 knees from 10 healthy volunteers were evaluated. 3D shift and tilt of the patella were analyzed with 3D computer models created by magnetic resonance imaging scans obtained at 10° intervals of knee flexion (0°-50°). 3D shift was defined as the spatial distance between the patellar reference point and the midsagittal plane of the femur; it is expressed as a percentage of the interepicondylar width. 3D tilt was defined as the spatial angle between the patellar reference plane and the transepicondylar axis. Correlations between the 2 parameters were assessed with the Pearson correlation coefficient. The patients' mean Pearson correlation coefficient was 0.895 ± 0.186 (range, -0.073 to 0.997; median, 0.965). In all, 56 knees (93%) had coefficients >0.7 (strong correlation); 1 knee (2%), >0.4 (moderate correlation); 2 knees (3%), >0.2 (weak correlation); and 1 knee (2%), <0.2 (no correlation). The mean correlation coefficient of the healthy volunteers was 0.645 ± 0.448 (range, -0.445 to 0.982; median, 0.834). A statistically significant difference was found in the distribution of the correlation coefficients between the patients and the healthy volunteers ( P = .0034). When distribution of the correlation coefficients obtained by the 3D analyses was compared with that by the 2D (conventional) analyses, based on the bisect offset index and patellar tilt angle, the 3D analyses showed statistically higher correlations between the lateral deviation and inclination of the patella ( P < .01). 3D shift and 3D tilt of the patella were moderately or strongly correlated in 95% of patients with RDP at 0° to 50° of knee flexion. It is not always necessary to use both parameters when evaluating patellar alignment, at least for knees with RDP at 0° to 50° of flexion. Such a description may enable surgeons to describe patellar alignment more simply, leading to a better, easier understanding of the characteristics of each patient with RDP.

Stable isotope systematics in mesozoic granites of Central and Northern California and Southwestern Oregon

USGS Publications Warehouse

Masi, U.; O'Neil, J.R.; Kistler, R.W.

1981-01-01

18O, D, and H2O+ contents were measured for whole-rock specimens of granitoid rocks from 131 localitics in California and southwestern Oregon. With 41 new determinations in the Klamath Mountains and Sierra Nevada, initial strontium isotope ratios are known for 104 of these samples. Large variations in ??18O (5.5 to 12.4), ??D (-130 to -31), water contents (0.14 to 2.23 weight percent) and initial strontium isotope ratios (0.7028 to 0.7095) suggest a variety of source materials and identify rocks modified by secondary processes. Regular patterns of variation in each isotopic ratio exist over large geographical regions, but correlations between the ratios are generally absent except in restricted areas. For example, the regular decrease in ??D values from west to east in the Sierra Nevada batholith is not correlative with a quite complex pattern of ??18O values, implying that different processes were responsible for the isotopic variations in these two elements. In marked contrast to a good correlation between (87Sr/86Sr)o and ??18O observed in the Peninsular Ranges batholith to the south, such correlations are lacking except in a few areas. ??D values, on the other hand, correlate well with rock types, chemistry, and (87Sr/86Sr)o except in the Coast Ranges where few of the isotopic signatures are primary. The uniformly low ??D values of samples from the Mojave Desert indicate that meteoric water contributed much of the hydrogen to the rocks in that area. Even so, the ??18O values and 18O fractionations between quartz and feldspar are normal in these same rocks. This reconnaissance study has identified regularities in geochemical parameters over enormous geographical regions. These patterns are not well understood but merit more detailed examination because they contain information critical to our understanding of the development of granitoid batholiths. ?? 1981 Springer-Verlag.

Seawater-groundwater exchange and nutrients carried by submarine groundwater discharge in different types of wetlands at Jiaozhou Bay, China

NASA Astrophysics Data System (ADS)

Qu, Wenjing; Li, Hailong; Huang, Hao; Zheng, Chunmiao; Wang, Chaoyue; Wang, Xuejing; Zhang, Yan

2017-12-01

In Jiaozhou Bay, there are four wetland types, including sandy beaches, mud flats, tidal marshes, and estuarine intertidal zones. Four typical transects representing each of the wetland types were selected to investigate the flow dynamics, seawater-groundwater exchange and nutrients carried by submarine groundwater discharge (SGD). Based on field measurements of groundwater heads and salinity along each transect, the SGD averaged over the observation period was estimated using generalized Darcy's law. The SGD along the four transects ranges from 3.6 × 10-3 to 7.6 cm/d with the maximum occurring at the sandy beach. The SGD rate has a good correlation with the hydraulic conductivities of the wetland sediments. There is a positive correlation between the ratio of NO3-N/DIN and SGD rates. The SGD-associated nutrient output rate ranges from 3.3 × 10-2 to 9.5 mmol/m2/d for DIN (dissolved inorganic nitrogen), and from 6.2 × 10-5 to 1.8 × 10-2 mmol/m2/d for DIP (dissolved inorganic phosphorus). Compared to the nutrients delivered by the river, nutrients carried by SGD provide a more important source for the phosphate-limited environment to plankton in Jiaozhou Bay.

Plasma homovanillic acid, plasma anti-D1 and -D2 dopamine-receptor activity, and negative symptoms in chronically mediated schizophrenia.

PubMed

Suzuki, E; Kanba, S; Nibuya, M; Koshikawa, H; Nakaki, T; Yagi, G

1992-02-15

We have investigated the relationship between the concentration of homovanillic acid in human plasma (pHVA) and plasma anti-D1 and anti-D2 dopamine receptor activity in chronic schizophrenic patients whose neuroleptic dosage was changed. The change in pHVA level correlated with that in anti-D1, not anti-D2 activity, thus suggesting that the neuroleptic-induced changes in pHVA concentration may be associated with the blocking of D1- as well as D2- receptors. The change of scores on the Scale for the Assessment of Negative Symptoms did not significantly correlate with changes in anti-D1 or anti-D2 activity, but did so correlated with the change in pHVA level.

Generalized recursion relations for correlators in the gauge-gravity correspondence.

PubMed

Raju, Suvrat

2011-03-04

We show that a generalization of the Britto-Cachazo-Feng-Witten recursion relations gives a new and efficient method of computing correlation functions of the stress tensor or conserved currents in conformal field theories with an (d+1)-dimensional anti-de Sitter space dual, for d≥4, in the limit where the bulk theory is approximated by tree-level Yang-Mills theory or gravity. In supersymmetric theories, additional correlators of operators that live in the same multiplet as a conserved current or stress tensor can be computed by these means.

Localized 2D COSY sequences: Method and experimental evaluation for a whole metabolite quantification approach

NASA Astrophysics Data System (ADS)

Martel, Dimitri; Tse Ve Koon, K.; Le Fur, Yann; Ratiney, Hélène

2015-11-01

Two-dimensional spectroscopy offers the possibility to unambiguously distinguish metabolites by spreading out the multiplet structure of J-coupled spin systems into a second dimension. Quantification methods that perform parametric fitting of the 2D MRS signal have recently been proposed for resolved PRESS (JPRESS) but not explicitly for Localized Correlation Spectroscopy (LCOSY). Here, through a whole metabolite quantification approach, correlation spectroscopy quantification performances are studied. The ability to quantify metabolite relaxation constant times is studied for three localized 2D MRS sequences (LCOSY, LCTCOSY and the JPRESS) in vitro on preclinical MR systems. The issues encountered during implementation and quantification strategies are discussed with the help of the Fisher matrix formalism. The described parameterized models enable the computation of the lower bound for error variance - generally known as the Cramér Rao bounds (CRBs), a standard of precision - on the parameters estimated from these 2D MRS signal fittings. LCOSY has a theoretical net signal loss of two per unit of acquisition time compared to JPRESS. A rapid analysis could point that the relative CRBs of LCOSY compared to JPRESS (expressed as a percentage of the concentration values) should be doubled but we show that this is not necessarily true. Finally, the LCOSY quantification procedure has been applied on data acquired in vivo on a mouse brain.

The proportion of dyslipidemia in systemic lupus erythematosus patient and distribution of correlated factors.

PubMed

Wijaya, Linda K; Kasjmir, Yoga Iwanoff; Sukmana, Nanang; Subekti, Imam; Prihartono, Joedo

2005-01-01

To understand the proportion of dyslipidemia in systemic lupus erythematosus (SLE) patients and the influencing factors of dyslipidemia. AN observational, cross-sectional study was conducted on new and longstanding SLE patients who had been diagnosed based on ARA criteria 1982 with 1997 revision. They had been hospitalized and treated at Department of Internal Medicine, Cipto Mangunkusumo National Central General Hospital and the other private Hospitals in Jakarta, i.e. Kramat Hospital in July - November 2003. The sample was selected by non probability sampling method with consecutive sampling technique. Every participant underwent history taking, physical and laboratory examination. There were 77 patients satisfying the inclusion criteria. The proportion of dyslipidemia in this study was 75.3%. By confidence interval of 95%, the dyslipidemia in SLE patient was 65.3% - 84.6%. The distribution of lipid profile in sample population were 43% with total cholesterol > or = 200 mg/dL, 26% with HDL cholesterol level < 40 mg/dL, 26.4% with LDL cholesterol level > or = 130 mg/dl and 44.2% with triglycerides serum level > or = 150 mg/dL. The characteristics of influencing factors in dyslipidemia prevalence for sample population consisted of 24.7% with renal involvement, 53.2% with > or = 3 years illness periods, 26% had received > or = 30 mg/day prednisone, 94.8% had not received chloroquines, and 58.4% had illness activity of Mex-SLEDAI > or = 2. By bivariate analysis, we found that illness period < 3 years tends to affect dyslipidemia with OR value of 12.04 (CI 95%, 2.54-57.05, p = 0.001). After conducting multivariate analysis by backward methods, it appears that only one significant influencing factor of dyslipidemia prevalence in SLE patient i.e. Illness period od < 3 years with OR value 12.04 (CI 95% 2.54 - 57.05, p = 0.001). Illness period of 3 years is represent a significant correlative factor for dyslipedemia prevalence. Prednisone > or = 30 mg/dL is the correlative factor for total cholesterol > or = 200 mg.dL and triglycerides > or = 150 mg/dL. Mex-SLEDAI > or = 2 is the corrective factor for HDL cholesterol < 40 mg/dL.

Density functional studies on the exchange interaction of a dinuclear Gd(iii)-Cu(ii) complex: method assessment, magnetic coupling mechanism and magneto-structural correlations.

PubMed

Rajaraman, Gopalan; Totti, Federico; Bencini, Alessandro; Caneschi, Andrea; Sessoli, Roberta; Gatteschi, Dante

2009-05-07

Density functional calculations have been performed on a [Gd(iii)Cu(ii)] complex [L(1)CuGd(O(2)CCF(3))(3)(C(2)H(5)OH)(2)] () (where L(1) is N,N'-bis(3-ethoxy-salicylidene)-1,2-diamino-2-methylpropanato) with an aim of assessing a suitable functional within the DFT formalism to understand the mechanism of magnetic coupling and also to develop magneto-structural correlations. Encouraging results have been obtained in our studies where the application of B3LYP on the crystal structure of yields a ferromagnetic J value of -5.8 cm(-1) which is in excellent agreement with the experimental value of -4.42 cm(-1) (H = JS(Gd).S(Cu)). After testing varieties of functional for the method assessment we recommend the use of B3LYP with a combination of an effective core potential basis set. For all electron basis sets the relativistic effects should be incorporated either via the Douglas-Kroll-Hess (DKH) or zeroth-order regular approximation (ZORA) methods. A breakdown approach has been adopted where the calculations on several model complexes of have been performed. Their wave functions have been analysed thereafter (MO and NBO analysis) in order to gain some insight into the coupling mechanism. The results suggest, unambiguously, that the empty Gd(iii) 5d orbitals have a prominent role on the magnetic coupling. These 5d orbitals gain partial occupancy via Cu(ii) charge transfer as well as from the Gd(iii) 4f orbitals. A competing 4f-3d interaction associated with the symmetry of the complex has also been observed. The general mechanism hence incorporates both contributions and sets forth rather a prevailing mechanism for the 3d-4f coupling. The magneto-structural correlations reveal that there is no unique parameter which the J values are strongly correlated with, but an exponential relation to the J value found for the O-Cu-O-Gd dihedral angle parameter is the most credible correlation.

The half-metallicity of Co2FeGe full Heusler alloy in (001) thin film: First principles study

NASA Astrophysics Data System (ADS)

Hyun, Jung-Min; Kim, Miyoung

2018-01-01

The electronic and magnetic properties of the Co2FeGe full Heusler alloy in (001) thin film are investigated using the first-principles electronic structure calculations within the density functional theory. We employ various exchange correlation functionals including the local density approximation (LDA), the generalized gradient approximation (GGA), and the additional + U corrections for strong on-site Coulomb interaction of transition metal 3d states, aiming to examine the correlation effect on the electronic structures which determine the spin gap and thus the half-metallicity. Our results reveal that the Co2FeGe thin film is metallic in both LDA and GGA, while the + U correction opens up the spin gap for spin minority channel in GGA+ U but not in LDA+U in contrast to its bulk alloy which is predicted to be half-metallic in both LDA+ U and GGA+ U approaches with total spin magnetic moment of 6 μ B . It is found that the surface states developed around the Fermi level and the enhanced 3d e g - t 2 g band splitting for the spin minority channel due to the correlation effect play critical roles to determine the emergence of the half-metallicity.

3D displacement field measurement with correlation based on the micro-geometrical surface texture

NASA Astrophysics Data System (ADS)

Bubaker-Isheil, Halima; Serri, Jérôme; Fontaine, Jean-François

2011-07-01

Image correlation methods are widely used in experimental mechanics to obtain displacement field measurements. Currently, these methods are applied using digital images of the initial and deformed surfaces sprayed with black or white paint. Speckle patterns are then captured and the correlation is performed with a high degree of accuracy to an order of 0.01 pixels. In 3D, however, stereo-correlation leads to a lower degree of accuracy. Correlation techniques are based on the search for a sub-image (or pattern) displacement field. The work presented in this paper introduces a new correlation-based approach for 3D displacement field measurement that uses an additional 3D laser scanner and a CMM (Coordinate Measurement Machine). Unlike most existing methods that require the presence of markers on the observed object (such as black speckle, grids or random patterns), this approach relies solely on micro-geometrical surface textures such as waviness, roughness and aperiodic random defects. The latter are assumed to remain sufficiently small thus providing an adequate estimate of the particle displacement. The proposed approach can be used in a wide range of applications such as sheet metal forming with large strains. The method proceeds by first obtaining cloud points using the 3D laser scanner mounted on a CMM. These points are used to create 2D maps that are then correlated. In this respect, various criteria have been investigated for creating maps consisting of patterns, which facilitate the correlation procedure. Once the maps are created, the correlation between both configurations (initial and moved) is carried out using traditional methods developed for field measurements. Measurement validation was conducted using experiments in 2D and 3D with good results for rigid displacements in 2D, 3D and 2D rotations.

Correlated Signatures of Gravitational-wave and Neutrino Emission in Three-dimensional General-relativistic Core-collapse Supernova Simulations

NASA Astrophysics Data System (ADS)

Kuroda, Takami; Kotake, Kei; Hayama, Kazuhiro; Takiwaki, Tomoya

2017-12-01

We present results from general-relativistic (GR) three-dimensional (3D) core-collapse simulations with approximate neutrino transport for three nonrotating progenitors (11.2, 15, and 40 M ⊙) using different nuclear equations of state (EOSs). We find that the combination of progenitor’s higher compactness at bounce and the use of softer EOS leads to stronger activity of the standing accretion shock instability (SASI). We confirm previous predications that the SASI produces characteristic time modulations both in neutrino and gravitational-wave (GW) signals. By performing a correlation analysis of the SASI-modulated neutrino and GW signals, we find that the correlation becomes highest when we take into account the time-delay effect due to the advection of material from the neutrino sphere to the proto-neutron star core surface. Our results suggest that the correlation of the neutrino and GW signals, if detected, would provide a new signature of the vigorous SASI activity in the supernova core, which can be hardly seen if neutrino-convection dominates over the SASI.

Two-dimensional fluorescence lifetime correlation spectroscopy. 2. Application.

PubMed

Ishii, Kunihiko; Tahara, Tahei

2013-10-03

In the preceding article, we introduced the theoretical framework of two-dimensional fluorescence lifetime correlation spectroscopy (2D FLCS). In this article, we report the experimental implementation of 2D FLCS. In this method, two-dimensional emission-delay correlation maps are constructed from the photon data obtained with the time-correlated single photon counting (TCSPC), and then they are converted to 2D lifetime correlation maps by the inverse Laplace transform. We develop a numerical method to realize reliable transformation, employing the maximum entropy method (MEM). We apply the developed actual 2D FLCS to two real systems, a dye mixture and a DNA hairpin. For the dye mixture, we show that 2D FLCS is experimentally feasible and that it can identify different species in an inhomogeneous sample without any prior knowledge. The application to the DNA hairpin demonstrates that 2D FLCS can disclose microsecond spontaneous dynamics of biological molecules in a visually comprehensible manner, through identifying species as unique lifetime distributions. A FRET pair is attached to the both ends of the DNA hairpin, and the different structures of the DNA hairpin are distinguished as different fluorescence lifetimes in 2D FLCS. By constructing the 2D correlation maps of the fluorescence lifetime of the FRET donor, the equilibrium dynamics between the open and the closed forms of the DNA hairpin is clearly observed as the appearance of the cross peaks between the corresponding fluorescence lifetimes. This equilibrium dynamics of the DNA hairpin is clearly separated from the acceptor-missing DNA that appears as an isolated diagonal peak in the 2D maps. The present study clearly shows that newly developed 2D FLCS can disclose spontaneous structural dynamics of biological molecules with microsecond time resolution.

Generalized -deformed correlation functions as spectral functions of hyperbolic geometry

NASA Astrophysics Data System (ADS)

Bonora, L.; Bytsenko, A. A.; Guimarães, M. E. X.

2014-08-01

We analyze the role of vertex operator algebra and 2d amplitudes from the point of view of the representation theory of infinite-dimensional Lie algebras, MacMahon and Ruelle functions. By definition p-dimensional MacMahon function, with , is the generating function of p-dimensional partitions of integers. These functions can be represented as amplitudes of a two-dimensional c = 1 CFT, and, as such, they can be generalized to . With some abuse of language we call the latter amplitudes generalized MacMahon functions. In this paper we show that generalized p-dimensional MacMahon functions can be rewritten in terms of Ruelle spectral functions, whose spectrum is encoded in the Patterson-Selberg function of three-dimensional hyperbolic geometry.

Partial differential equations of 3D boundary layer and their numerical solutions in turbomachinery

NASA Astrophysics Data System (ADS)

Zhang, Guoqing; Hua, Yaonan; Wu, Chung-Hua

1991-08-01

This paper studies the 3D boundary layer equations (3DBLE) and their numerical solutions in turbomachinery: (1) the general form of 3DBLE in turbomachines with rotational and curvature effects are derived under the semiorthogonal coordinate system, in which the normal pressure gradient is not equal to zero; (2) the method of solution of the 3DBLE is discussed; (3) the 3D boundary layers on the rotating blade surface, IGV endwall, rotor endwall (with a relatively moving boundary) are numerically solved, and the predicted data correlates well with the measured data; and (4) the comparison is made between the numerical results of 3DBLE with and without normal pressure gradient.

Unraveling the Nature of Magnetism of the 5 d4 Double Perovskite Ba2 YIrO6

NASA Astrophysics Data System (ADS)

Fuchs, S.; Dey, T.; Aslan-Cansever, G.; Maljuk, A.; Wurmehl, S.; Büchner, B.; Kataev, V.

2018-06-01

We report electron spin resonance (ESR) spectroscopy results on the double perovskite Ba2 YIrO6 . On general grounds, this material is expected to be nonmagnetic due to the strong coupling of the spin and orbital momenta of Ir5 + (5 d4 ) ions. However, controversial experimental reports on either strong antiferromagnetism with static order at low temperatures or just a weakly paramagnetic behavior have triggered a discussion on the breakdown of the generally accepted scenario of the strongly spin-orbit coupled ground states in the 5 d4 iridates and the emergence of a novel exotic magnetic state. Our data evidence that the magnetism of the studied material is solely due to a few percent of Ir4 + and Ir6 + magnetic defects while the regular Ir5 + sites remain nonmagnetic. Remarkably, the defect Ir6 + species manifest magnetic correlations in the ESR spectra at T ≲20 K , suggesting a long-range character of superexchange in the double perovskites as proposed by recent theories.

Monte Carlo sampling in diffusive dynamical systems

NASA Astrophysics Data System (ADS)

Tapias, Diego; Sanders, David P.; Altmann, Eduardo G.

2018-05-01

We introduce a Monte Carlo algorithm to efficiently compute transport properties of chaotic dynamical systems. Our method exploits the importance sampling technique that favors trajectories in the tail of the distribution of displacements, where deviations from a diffusive process are most prominent. We search for initial conditions using a proposal that correlates states in the Markov chain constructed via a Metropolis-Hastings algorithm. We show that our method outperforms the direct sampling method and also Metropolis-Hastings methods with alternative proposals. We test our general method through numerical simulations in 1D (box-map) and 2D (Lorentz gas) systems.

Digit ratio (2D:4D) and hand preference for writing in the BBC Internet Study.

PubMed

Manning, J T; Peters, M

2009-09-01

The ratio of the length of the second to the fourth digit (2D:4D) may be negatively correlated with prenatal testosterone. Hand preference has been linked with prenatal testosterone and 2D:4D. Here we show that 2D:4D is associated with hand preference for writing in a large internet sample (n>170,000) in which participants self-reported their finger lengths. We replicated a significant association between right 2D:4D and writing hand preference (low right 2D:4D associated with left hand preference) as well as a significant correlation between writing hand preference and the difference between left and right 2D:4D or Dr-l (low Dr-l associated with left hand preference). A new significant correlation between left 2D:4D and writing hand preference was also shown (high left 2D:4D associated with left hand preference). There was a clear interaction between writing hand preference and 2D:4D: The left 2D:4D was significantly larger than the right 2D:4D in male and female left-handed writers, and the right hand 2D:4D was significantly larger than the left hand 2D:4D in male and female right-handed writers.

Genetic correlations between body weight change and reproduction traits in Merino ewes depend on age.

PubMed

Rose, G; Mulder, H A; van der Werf, J H J; Thompson, A N; van Arendonk, J A M

2014-08-01

Merino sheep in Australia experience periods of variable feed supply. Merino sheep can be bred to be more resilient to this variation by losing less BW when grazing poor quality pasture and gaining more BW when grazing good quality pasture. Therefore, selection on BW change might be economically attractive but correlations with other traits in the breeding objective need to be known. The genetic correlations (rg) between BW, BW change, and reproduction were estimated using records from approximately 7,350 fully pedigreed Merino ewes managed at Katanning in Western Australia. Number of lambs and total weight of lambs born and weaned were measured on approximately 5,300 2-yr-old ewes, approximately 4,900 3-yr-old ewes, and approximately 3,600 4-yr-old ewes. On a proportion of these ewes BW change was measured: approximately 1,950 2-yr-old ewes, approximately 1,500 3-yr-old ewes, and approximately 1,100 4-yr-old ewes. The BW measurements were for 3 periods. The first period was during mating period over 42 d on poor pasture. The second period was during pregnancy over 90 d for ewes that got pregnant on poor and medium quality pasture. The third period was during lactation over 130 d for ewes that weaned a lamb on good quality pasture. Genetic correlations between weight change and reproduction were estimated within age classes. Genetic correlations were tested to be significantly greater magnitude than 0 using likelihood ratio tests. Nearly all BW had significant positive genetic correlations with all reproduction traits. In 2-yr-old ewes, BW change during the mating period had a positive genetic correlation with number of lambs weaned (rg = 0.58); BW change during pregnancy had a positive genetic correlation with total weight of lambs born (rg = 0.33) and a negative genetic correlation with number of lambs weaned (rg = -0.49). All other genetic correlations were not significantly greater magnitude than 0 but estimates of genetic correlations for 3-yr-old ewes were generally consistent with these findings. The direction of the genetic correlations mostly coincided with the energy requirements of the ewes and the stage of maturity of the ewes. In conclusion, optimized selection strategies on BW changes to increase resilience will depend on the genetic correlations with reproduction and are dependent on age.

[2D correlation spectral study of a coordination polymer [Eu(PCPOA)3 (H2O)]n].

PubMed

Sun, Rui-qing; Zhang, Han-hui; Cao, Yan-ning; Chen, Yi-ping; Yang, Qi-yu; Wang, Zhi-yang

2007-05-01

A novel two dimensional coordination polymer [Eu(PCPOA)3 (H2O)], was synthesized under hydrothermal condition. Based on the determination of the structure, the 2D correlation FTIR spectra with the perturbation of magnetism and the 2D correlation fluorescence spectra with the perturbation of temperature were investigated. The energy bonds were calculated using CASTEP Program of Material studio. The Europium ions are nine-coordinated and the ligands adopted two different modes to connect the Eu3+ ions to 2D layer structure. The study of the 2D-FTIR reveals that the carboxylates coordinate with the center ions not only as monodentate, but also as bidentate chelate. The 2D fluorescence spectra indicates that the transition of (5)D0-->(7)F2 is influenced intensively by the perturbation of temperature.

Heritabilities of measured and mid-infrared predicted milk fat globule size, milk fat and protein percentages, and their genetic correlations.

PubMed

Fleming, A; Schenkel, F S; Koeck, A; Malchiodi, F; Ali, R A; Corredig, M; Mallard, B; Sargolzaei, M; Miglior, F

2017-05-01

The objective of this study was to estimate the heritability of milk fat globule (MFG) size and mid-infrared (MIR) predicted MFG size in Holstein cattle. The genetic correlations between measured and predicted MFG size with milk fat and protein percentage were also investigated. Average MFG size was measured in 1,583 milk samples taken from 254 Holstein cows from 29 herds across Canada. Size was expressed as volume moment mean (D[4,3]) and surface moment mean (D[3,2]). Analyzed milk samples also had average MFG size predicted from their MIR spectral records. Fat and protein percentages were obtained for all test-day milk samples in the cow's lactation. Univariate and bivariate repeatability animal models were used to estimate heritability and genetic correlations. Moderate heritabilities of 0.364 and 0.466 were found for D[4,3] and D[3,2], respectively, and a strong genetic correlation was found between the 2 traits (0.98). The heritabilities for the MIR-predicted MFG size were lower than those estimated for the measured MFG size at 0.300 for predicted D[4,3] and 0.239 for predicted D[3,2]. The genetic correlation between measured and predicted D[4,3] was 0.685; the correlation was slightly higher between measured and predicted D[3,2] at 0.764, likely due to the better prediction accuracy of D[3,2]. Milk fat percentage had moderate genetic correlations with both D[4,3] and D[3,2] (0.538 and 0.681, respectively). The genetic correlation between predicted MFG size and fat percentage was much stronger (greater than 0.97 for both predicted D[4,3] and D[3,2]). The stronger correlation suggests a limitation for the use of the predicted values of MFG size as indicator traits for true average MFG size in milk in selection programs. Larger samples sizes are required to provide better evidence of the estimated genetic parameters. A genetic component appears to exist for the average MFG size in bovine milk, and the variation could be exploited in selection programs. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Density-functional theory applied to d- and f-electron systems

NASA Astrophysics Data System (ADS)

Wu, Xueyuan

Density functional theory (DFT) has been applied to study the electronic and geometric structures of prototype d- and f-electron systems. For the d-electron system, all electron DFT with gradient corrections to the exchange and correlation functionals has been used to investigate the properties of small neutral and cationic vanadium clusters. Results are in good agreement with available experimental and other theoretical data. For the f-electron system, a hybrid DFT, namely, B3LYP (Becke's 3-parameter hybrid functional using the correlation functional of Lee, Yang and Parr) with relativistic effective core potentials and cluster models has been applied to investigate the nature of chemical bonding of both the bulk and the surfaces of plutonium monoxide and dioxide. Using periodic models, the electronic and geometric structures of PuO2 and its (110) surface, as well as water adsorption on this surface have also been investigated using DFT in both local density approximation (LDA) and generalized gradient approximation (GGA) formalisms.

Disease-specific self-efficacy in spasmodic dysphonia patients.

PubMed

Hu, Amanda; Isetti, Derek; Hillel, Allen D; Waugh, Patricia; Comstock, Bryan; Meyer, Tanya K

2013-03-01

Self-efficacy (SE) is an optimistic self-belief that one can perform a novel task. This concept involves empowerment, self-esteem, and adaptation to a stressful situation. SE is a strong predictor of health behaviors. Our objectives were to study SE in spasmodic dysphonia (SD) and to develop a disease-specific SE-SD scale. Prospective study. Academic hospital. Disease-specific SE-SD items were developed with laryngologists, speech pathologists, and SD patients. These items, General SE Scale, Voice Handicap Index-10 (VHI-10), Consensus Auditory Perceptual Evaluation of Voice (CAPE-V), and Hospital Anxiety and Depression Scale (HADS), were administered to SD patients who presented for botulinum toxin injections. One hundred forty-five SD patients (mean age 59.5 ± 13.6 years) had a general SE score (Cronbach's α = 0.894) of 33.4 ± 5.2 out of 40. This was negatively correlated with HADS-A (r = -0.42, P < 0.001) and HADS-D (r = -0.42, P < .001), but not correlated with VHI-10 (r = -0.098, P = .243) and CAPE-V (r = -0.047, P = .57). Factor analysis selected 8 items from the general SE scale and 5 disease-specific SE-SD items to generate a 13-item disease-specific SE-SD scale (Cronbach's α = 0.907). Disease-specific SE-SD score was 42.1 ± 6.9 out of 52 and was negatively correlated with VHI-10 (r = -0.19, P = .005), HADS-A (r = -0.43, P < .001), and HADS-D (r = -0.57, P < .001), but not correlated with CAPE-V (r = -0.024, P = .60). SD patients established on botulinum toxin injections have high degrees of general and disease-specific SE. Patients with higher SE-SD demonstrate lower vocal handicap and lower levels of anxiety and depression. A 13-item disease-specific SE-SD scale has been developed.

Evaluation of methods to produce an image library for automatic patient model localization for dose mapping during fluoroscopically guided procedures

NASA Astrophysics Data System (ADS)

Kilian-Meneghin, Josh; Xiong, Z.; Rudin, S.; Oines, A.; Bednarek, D. R.

2017-03-01

The purpose of this work is to evaluate methods for producing a library of 2D-radiographic images to be correlated to clinical images obtained during a fluoroscopically-guided procedure for automated patient-model localization. The localization algorithm will be used to improve the accuracy of the skin-dose map superimposed on the 3D patient- model of the real-time Dose-Tracking-System (DTS). For the library, 2D images were generated from CT datasets of the SK-150 anthropomorphic phantom using two methods: Schmid's 3D-visualization tool and Plastimatch's digitally-reconstructed-radiograph (DRR) code. Those images, as well as a standard 2D-radiographic image, were correlated to a 2D-fluoroscopic image of a phantom, which represented the clinical-fluoroscopic image, using the Corr2 function in Matlab. The Corr2 function takes two images and outputs the relative correlation between them, which is fed into the localization algorithm. Higher correlation means better alignment of the 3D patient-model with the patient image. In this instance, it was determined that the localization algorithm will succeed when Corr2 returns a correlation of at least 50%. The 3D-visualization tool images returned 55-80% correlation relative to the fluoroscopic-image, which was comparable to the correlation for the radiograph. The DRR images returned 61-90% correlation, again comparable to the radiograph. Both methods prove to be sufficient for the localization algorithm and can be produced quickly; however, the DRR method produces more accurate grey-levels. Using the DRR code, a library at varying angles can be produced for the localization algorithm.

Sunspot Pattern Classification using PCA and Neural Networks (Poster)

NASA Technical Reports Server (NTRS)

Rajkumar, T.; Thompson, D. E.; Slater, G. L.

2005-01-01

The sunspot classification scheme presented in this paper is considered as a 2-D classification problem on archived datasets, and is not a real-time system. As a first step, it mirrors the Zuerich/McIntosh historical classification system and reproduces classification of sunspot patterns based on preprocessing and neural net training datasets. Ultimately, the project intends to move from more rudimentary schemes, to develop spatial-temporal-spectral classes derived by correlating spatial and temporal variations in various wavelengths to the brightness fluctuation spectrum of the sun in those wavelengths. Once the approach is generalized, then the focus will naturally move from a 2-D to an n-D classification, where "n" includes time and frequency. Here, the 2-D perspective refers both to the actual SOH0 Michelson Doppler Imager (MDI) images that are processed, but also refers to the fact that a 2-D matrix is created from each image during preprocessing. The 2-D matrix is the result of running Principal Component Analysis (PCA) over the selected dataset images, and the resulting matrices and their eigenvalues are the objects that are stored in a database, classified, and compared. These matrices are indexed according to the standard McIntosh classification scheme.

Phenotypic relationships between docility and reproduction in Angus heifers.

PubMed

White, K L; Bormann, J M; Olson, K C; Jaeger, J R; Johnson, S; Downey, B; Grieger, D M; Waggoner, J W; Moser, D W; Weaber, R L

2016-02-01

The objective of this study was to elucidate the phenotypic relationships between docility and first-service AI conception rate in heifers. Data ( = 337) collected from 3 cooperator herds in Kansas at the start of synchronization protocol included exit velocity (EV), chute score (CS), fecal cortisol (FC), and blood serum cortisol (BC). Data were analyzed using logistic regression with 30-d pregnancy rate as the dependent variable. The model included the fixed effect of contemporary group and the covariates FC, BC, EV, CS, BW, and age. Correlation coefficients were calculated between all continuous traits. Pregnancy rate ranged from 34% to 60% between herds. Blood cortisol positively correlated with EV ( = 0.22, < 0.01), negatively correlated with age ( = -0.12, < 0.03), and tended to be negatively correlated with BW ( = -0.10, = 0.09). Exit velocity was positively correlated with CS ( = 0.24, < 0.01) and negatively correlated with BW ( = -0.15, < 0.01) and age ( = -0.12, < 0.03). Chute score negatively correlated with age ( = -0.14, < 0.01), and age and BW were moderately positively correlated ( = 0.42, < 0.01), as expected. Older, heavier animals generally had better temperament, as indicated by lower BC, EV, and CS. The power of our test could detect no significant predictors of 30-d pregnancy for the combined data from all ranches. When the data were divided by ranch, CS ( < 0.03) and BW ( < 0.01) were both significant predictors for 30-d pregnancy for ranch 1. The odds ratio estimate for CS has an inverse relationship with pregnancy, meaning that a 1-unit increase in average CS will reduce the probability of pregnancy at ranch 1 by 48.1%. Weight also has a negative impact on pregnancy because a 1-kg increase in BW will decrease the probability of pregnancy by 2.2%. Fertility is a complex trait that depends on many factors; our data suggest that docility is 1 factor that warrants further investigation.

The effects of correlated noise in intra-complex DSN arrays for S-band Galileo telemetry reception

NASA Technical Reports Server (NTRS)

Dewey, R. J.

1992-01-01

A number of the proposals for supporting a Galileo S-band (2.3-GHz) mission involve arraying several antennas to maximize the signal-to-noise ratio (and bit rate) obtainable from a given set of antennas. Arraying is no longer a new idea, having been used successfully during the Voyager encounters with Uranus and Neptune. However, arraying for Galileo's tour of Jupiter is complicated by Jupiter's strong radio emission, which produces correlated noise effects. This article discusses the general problem of correlated noise due to a planet, or other radio source, and applies the results to the specific case of an array of antennas at the DSN's Tidbinbilla, Australia, complex (DSS 42, DSS 43, DSS 45, and the yet-to-be-built DSS 34). The effects of correlated noise are highly dependent on the specific geometry of the array and on the spacecraft-planet configuration; in some cases, correlated noise effects produce an enhancement, rather than a degradation, of the signal-to-noise ratio. For the case considered here--an array of the DSN's Australian antennas observing Galileo and Jupiter--there are three regimes of interest. If the spacecraft-planet separation is approximately less than 75 arcsec, the average effect of correlated noise is a loss of signal to noise (approximately 0.2 dB as the spacecraft-planet separation approaches zero). For spacecraft-planet separations approximately greater than 75 arcsec, but approximately less than 400 arcsec, the effects of correlated noise cause signal-to-noise variations as large as several tenths of a decibel over time scales of hours or changes in spacecraft-planet separation of tens of arcseconds; however, on average its effects are small (less than 0.01 dB). When the spacecraft is more than 400 arcsec from Jupiter (as is the case for about half of Galileo's tour), correlated noise is a less than 0.05-dB effect.

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

Harmon, S; Jeraj, R; Galavis, P

Purpose: Sensitivity of PET-derived texture features to reconstruction methods has been reported for features extracted from axial planes; however, studies often utilize three dimensional techniques. This work aims to quantify the impact of multi-plane (3D) vs. single-plane (2D) feature extraction on radiomics-based analysis, including sensitivity to reconstruction parameters and potential loss of spatial information. Methods: Twenty-three patients with solid tumors underwent [{sup 18}F]FDG PET/CT scans under identical protocols. PET data were reconstructed using five sets of reconstruction parameters. Tumors were segmented using an automatic, in-house algorithm robust to reconstruction variations. 50 texture features were extracted using two Methods: 2D patchesmore » along axial planes and 3D patches. For each method, sensitivity of features to reconstruction parameters was calculated as percent difference relative to the average value across reconstructions. Correlations between feature values were compared when using 2D and 3D extraction. Results: 21/50 features showed significantly different sensitivity to reconstruction parameters when extracted in 2D vs 3D (wilcoxon α<0.05), assessed by overall range of variation, Rangevar(%). Eleven showed greater sensitivity to reconstruction in 2D extraction, primarily first-order and co-occurrence features (average Rangevar increase 83%). The remaining ten showed higher variation in 3D extraction (average Range{sub var}increase 27%), mainly co-occurence and greylevel run-length features. Correlation of feature value extracted in 2D and feature value extracted in 3D was poor (R<0.5) in 12/50 features, including eight co-occurrence features. Feature-to-feature correlations in 2D were marginally higher than 3D, ∣R∣>0.8 in 16% and 13% of all feature combinations, respectively. Larger sensitivity to reconstruction parameters were seen for inter-feature correlation in 2D(σ=6%) than 3D (σ<1%) extraction. Conclusion: Sensitivity and correlation of various texture features were shown to significantly differ between 2D and 3D extraction. Additionally, inter-feature correlations were more sensitive to reconstruction variation using single-plane extraction. This work highlights a need for standardized feature extraction/selection techniques in radiomics.« less

Cognitive fatigue in patients with myasthenia gravis.

PubMed

Jordan, Berit; Schweden, Tabea L K; Mehl, Theresa; Menge, Uwe; Zierz, Stephan

2017-09-01

Cognitive fatigue has frequently been reported in myasthenia gravis (MG). However, objective assessment of cognitive fatigability has never been evaluated. Thirty-three MG patients with stable generalized disease and 17 healthy controls underwent a test battery including repeated testing of attention and concentration (d2-R) and Paced Auditory Serial Addition Test. Fatigability was based on calculation of linear trend (LT) reflecting dynamic performance within subsequent constant time intervals. Additionally, fatigue questionnaires were used. MG patients showed a negative LT in second d2-R testing, indicating cognitive fatigability. This finding significantly differed from stable cognitive performance in controls (P < 0.05). Results of Paced Auditory Serial Addition Test testing did not differ between groups. Self-assessed fatigue was significantly higher in MG patients compared with controls (P < 0.001), but did not correlate with LT. LT quantifies cognitive fatigability as an objective measurement of performance decline in MG patients. Self-assessed cognitive fatigue is not correlated with objective findings. Muscle Nerve 56: 449-457, 2017. © 2016 Wiley Periodicals, Inc.

Fibrillation mechanism of a model intrinsically disordered protein revealed by 2D correlation deep UV resonance Raman spectroscopy.

PubMed

Sikirzhytski, Vitali; Topilina, Natalya I; Takor, Gaius A; Higashiya, Seiichiro; Welch, John T; Uversky, Vladimir N; Lednev, Igor K

2012-05-14

Understanding of numerous biological functions of intrinsically disordered proteins (IDPs) is of significant interest to modern life science research. A large variety of serious debilitating diseases are associated with the malfunction of IDPs including neurodegenerative disorders and systemic amyloidosis. Here we report on the molecular mechanism of amyloid fibrillation of a model IDP (YE8) using 2D correlation deep UV resonance Raman spectroscopy. YE8 is a genetically engineered polypeptide, which is completely unordered at neutral pH yet exhibits all properties of a fibrillogenic protein at low pH. The very first step of the fibrillation process involves structural rearrangements of YE8 at the global structure level without the detectable appearance of secondary structural elements. The formation of β-sheet species follows the global structural changes and proceeds via the simultaneous formation of turns and β-strands. The kinetic mechanism revealed is an important new contribution to understanding of the general fibrillation mechanism proposed for IDP.

Prevalence and correlates of depressive symptoms in korean adults: results of a 2009 korean community health survey.

PubMed

Oh, Dong Hoon; Kim, Shin Ah; Lee, Hye Young; Seo, Joo Youn; Choi, Bo-Youl; Nam, Jung Hyun

2013-01-01

The aim of this study was to investigate the prevalence and correlates of depressive symptoms in the largest number of Korean individuals examined to date. We analyzed cross-sectional data collected from 229,595 Korean adults aged 19 yr and above who participated in a Korean Community Health Survey conducted in 2009. The Center for Epidemiologic Studies Depression Scale (CES-D) was used as the measurement tool for depressive symptoms (CES-D score over 16) and definite depression (CES-D score over 25). Multivariate logistic regression analysis was performed to identify associations between sociodemographic factors and depressive symptoms. The percentages of depressive symptoms and definite depression in the total study population were 11% (7.8% for men, 14.0% for women) and 3.7%, (2.4% for men, 5.0% for women), respectively. Female gender, older age, disrupted marital status, low education and income level, multigenerational household composition and metropolitan residence were associated with greater risk of depressive symptoms. The present study provides a valid prevalence and correlates of depressive symptoms, using the largest representative sample of the Korean general population to date. Various sociodemographic factors contribute to the prevalence and effects of depressive symptoms in Korea.

Analysis of Carina Position as Surrogate Marker for Delivering Phase-Gated Radiotherapy

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

Weide, Lineke van der; Soernsen de Koste, John R. van; Lagerwaard, Frank J.

2008-07-15

Purpose: Respiratory gating can mitigate the effect of tumor mobility in radiotherapy (RT) for lung cancer. Because the tumor is generally not visualized, external surrogates of tumor position are used to trigger respiration-gated RT. We evaluated the suitability of the carina position as a surrogate in respiration-gated RT. Methods and Materials: A total of 30 four-dimensional (4D) computed tomography (CT) scans from 14 patients with lung cancer were retrospectively analyzed. Both uncoached (free breathing) and audio-coached 4D-CT scans were acquired from 9 patients, and 12 uncoached 4D-CT scans were acquired from 5 other patients during a 2-4-week period of stereotacticmore » RT. The repeat scans were co-registered. The carina position was identified on the coronal cut planes in all 4D-CT phases. The correlation between the carina position and the total lung volume for each phase was determined, and the reproducibility of the carina position was studied in the 5 patients with repeat uncoached 4D-CT scans. Results: The mean extent of carina motion in 21 uncoached scans was 5.3 {+-} 1.6 mm in the craniocaudal (CC), 2.3 {+-} 1.4 mm in the anteroposterior, and 1.5 {+-} 0.7 mm in the mediolateral direction. Audio coaching resulted in a twofold increase in carina mobility in all directions. The CC carina position correlated with changes in the total lung volume (R = 0.89 {+-} 0.14), but the correlation was better for the audio-coached than for the uncoached 4D-CT scans (R = 0.93 {+-} 0.08 vs. R = 0.85 {+-} 0.17; paired t test, p = 0.034). Preliminary data from the 5 patients indicated that the CC carina motion correlated better with tumor motion than did the motion of the diaphragm. Conclusions: The CC position of the carina correlated well with the total lung volume, indicating that the carina is a good surrogate for verifying the total lung volume during respiration-gated RT.« less

Density functional plus dynamical mean-field theory of the metal-insulator transition in early transition-metal oxides

NASA Astrophysics Data System (ADS)

Dang, Hung T.; Ai, Xinyuan; Millis, Andrew J.; Marianetti, Chris A.

2014-09-01

The combination of density functional theory and single-site dynamical mean-field theory, using both Hartree and full continuous-time quantum Monte Carlo impurity solvers, is used to study the metal-insulator phase diagram of perovskite transition-metal oxides of the form ABO3 with a rare-earth ion A =Sr, La, Y and transition metal B =Ti, V, Cr. The correlated subspace is constructed from atomiclike d orbitals defined using maximally localized Wannier functions derived from the full p-d manifold; for comparison, results obtained using a projector method are also given. Paramagnetic DFT + DMFT computations using full charge self-consistency along with the standard "fully localized limit" (FLL) double counting are shown to incorrectly predict that LaTiO3, YTiO3, LaVO3, and SrMnO3 are metals. A more general examination of the dependence of physical properties on the mean p-d energy splitting, the occupancy of the correlated d states, the double-counting correction, and the lattice structure demonstrates the importance of charge-transfer physics even in the early transition-metal oxides and elucidates the factors underlying the failure of the standard approximations. If the double counting is chosen to produce a p-d splitting consistent with experimental spectra, single-site dynamical mean-field theory provides a reasonable account of the materials properties. The relation of the results to those obtained from "d-only" models in which the correlation problem is based on the frontier orbital p-d antibonding bands is determined. It is found that if an effective interaction U is properly chosen the d-only model provides a good account of the physics of the d1 and d2 materials.

Are there intracellular Ca2+ oscillations correlated with flagellar beating in human sperm? A three vs. two-dimensional analysis.

PubMed

Corkidi, G; Montoya, F; Hernández-Herrera, P; Ríos-Herrera, W A; Müller, M F; Treviño, C L; Darszon, A

2017-09-01

Are there intracellular Ca2+ ([Ca2+]i) oscillations correlated with flagellar beating in human sperm? The results reveal statistically significant [Ca2+]i oscillations that are correlated with the human sperm flagellar beating frequency, when measured in three-dimensions (3D). Fast [Ca2+]i oscillations that are correlated to the beating flagellar frequency of cells swimming in a restricted volume have been detected in hamster sperm. To date, such findings have not been confirmed in any other mammalian sperm species. An important question that has remained regarding these observations is whether the fast [Ca2+]i oscillations are real or might they be due to remaining defocusing effects of the Z component arising from the 3D beating of the flagella. Healthy donors whose semen samples fulfill the WHO criteria between the age of 18-28 were selected. Cells from at least six different donors were utilized for analysis. Approximately the same number of experimental and control cells were analyzed. Motile cells were obtained by the swim-up technique and were loaded with Fluo-4 (Ca2+ sensitive dye) or with Calcein (Ca2+ insensitive dye). Ni2+ was used as a non-specific plasma membrane Ca2+ channel blocker. Fluorescence data and flagella position were acquired in 3D. Each cell was recorded for up to 5.6 s within a depth of 16 microns with a high speed camera (coupled to an image intensifier) acquiring at a rate of 3000 frames per second, while an oscillating objective vibrated at 90 Hz via a piezoelectric device. From these samples, eight experimental and nine control sperm cells were analyzed in both 2D and 3D. We have implemented a new system that allows [Ca2+]i measurements of the human sperm flagellum beating in 3D. These measurements reveal statistically significant [Ca2+]i oscillations that correlate with the flagellar beating frequency. These oscillations may arise from intracellular sources and/or Ca2+ transporters, as they were insensitive to external Ni2+, a non-specific plasma membrane Ca2+ channel blocker. N/A. Analysis in 3D needs a very fast image acquisition rate to correctly sample a volume containing swimming sperm. This condition requires a very short exposure time per image making it necessary to use an image intensifier which also increases noise. The lengthy analysis time required to obtain reliable results limited the number of cells that could be analyzed. The possibility of recording flagellar [Ca2+]i oscillations described here may open a new avenue to better understand ciliary and flagellar beating that are fundamental for mucociliary clearance, oocyte transport, fertilization, cerebrospinal fluid pressure regulation and developmental left-right symmetry breaking in the embryonic node. This work was supported by Consejo Nacional de Ciencia y Tecnología (CONACyT) (grants 253952 to G.C.; 156667 to F.M.M. and Fronteras 71 39908-Q to A.D. and Post-doctoral scholarships 366844 to P.H.-H. and 291028 to F.M.) and the Dirección General de Asuntos del Personal Académico of the Universidad Nacional Autónoma de México (DGAPA-UNAM) (grants CJIC/CTIC/4898/2016 to F.M. and IN205516 to A.D.). There are no conflicts of interest to declare. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Reduced electronic correlation effects in half substituted Ba(Fe1-xCox)2As2

NASA Astrophysics Data System (ADS)

Liu, Z.-H.; Yaresko, A. N.; Li, Y.; Evtushinsky, D. V.; Dai, P.-C.; Borisenko, S. V.

2018-06-01

We report a comprehensive study of the tridimensional nature and orbital character of the low-energy electronic structure in 50% Cobalt doped Ba(Fe1-xCox)2As2 (d6.5), by using polarization- and photon energy-dependent angle-resolved photoemission spectroscopy. An extra electron-like Fermi surface is observed around the Brillouin zone boundary compared with isoelectronic KyFe2-xSe2 (d6.5). The bands near the Fermi level (EF) are mainly derived from Fe/Co 3d t2g orbitals, revealing visible dispersions along the kz direction. In combination with the local density approximation and the dynamical mean-field theory calculations, we find that the As 4p bands are non-renormalized and the whole 3d band needs to be renormalized by a "single" factor of ˜1.6, indicating moderate electronic correlation effects. The "single" factor description of the correlation strength among the different 3d orbitals is also in sharp contrast to orbital-dependent correlation effects in BaFe2As2. Our findings indicate a remarkable reduction of correlation effects with little difference among 3d orbitals in BaFeCoAs2, due to the increased filling of the electronic 3d shell in the presence of significant Hund's coupling. The results support that the electronic correlation effects and multiple orbital physics play an important role in the superconductivity of the 122 system and in other ferropnictides.

Two-dimensional auto-correlation analysis and Fourier-transform analysis of second-harmonic-generation image for quantitative analysis of collagen fiber in human facial skin

NASA Astrophysics Data System (ADS)

Ogura, Yuki; Tanaka, Yuji; Hase, Eiji; Yamashita, Toyonobu; Yasui, Takeshi

2018-02-01

We compare two-dimensional auto-correlation (2D-AC) analysis and two-dimensional Fourier transform (2D-FT) for evaluation of age-dependent structural change of facial dermal collagen fibers caused by intrinsic aging and extrinsic photo-aging. The age-dependent structural change of collagen fibers for female subjects' cheek skin in their 20s, 40s, and 60s were more noticeably reflected in 2D-AC analysis than in 2D-FT analysis. Furthermore, 2D-AC analysis indicated significantly higher correlation with the skin elasticity measured by Cutometer® than 2D-AC analysis. 2D-AC analysis of SHG image has a high potential for quantitative evaluation of not only age-dependent structural change of collagen fibers but also skin elasticity.

The reliability and criterion validity of 2D video assessment of single leg squat and hop landing.

PubMed

Herrington, Lee; Alenezi, Faisal; Alzhrani, Msaad; Alrayani, Hasan; Jones, Richard

2017-06-01

The objective was to assess the intra-tester, within and between day reliability of measurement of hip adduction (HADD) and frontal plane projection angles (FPPA) during single leg squat (SLS) and single leg landing (SLL) using 2D video and the validity of these measurements against those found during 3D motion capture. 15 healthy subjects had their SLS and SLL assessed using 3D motion capture and video analysis. Inter-tester reliability for both SLS and SLL when measuring FPPA and HADD show excellent correlations (ICC 2,1 0.97-0.99). Within and between day assessment of SLS and SLL showed good to excellent correlations for both variables (ICC 3,1 0.72-91). 2D FPPA measures were found to have good correlation with knee abduction angle in 3-D (r=0.79, p=0.008) during SLS, and also to knee abduction moment (r=0.65, p=0.009). 2D HADD showed very good correlation with 3D HADD during SLS (r=0.81, p=0.001), and a good correlation during SLL (r=0.62, p=0.013). All other associations were weak (r<0.4). This study suggests that 2D video kinematics have a reasonable association to what is being measured with 3D motion capture. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fragmentation modeling of a resin bonded sand

NASA Astrophysics Data System (ADS)

Hilth, William; Ryckelynck, David

2017-06-01

Cemented sands exhibit a complex mechanical behavior that can lead to sophisticated models, with numerous parameters without real physical meaning. However, using a rather simple generalized critical state bonded soil model has proven to be a relevant compromise between an easy calibration and good results. The constitutive model formulation considers a non-associated elasto-plastic formulation within the critical state framework. The calibration procedure, using standard laboratory tests, is complemented by the study of an uniaxial compression test observed by tomography. Using finite elements simulations, this test is simulated considering a non-homogeneous 3D media. The tomography of compression sample gives access to 3D displacement fields by using image correlation techniques. Unfortunately these fields have missing experimental data because of the low resolution of correlations for low displacement magnitudes. We propose a recovery method that reconstructs 3D full displacement fields and 2D boundary displacement fields. These fields are mandatory for the calibration of the constitutive parameters by using 3D finite element simulations. The proposed recovery technique is based on a singular value decomposition of available experimental data. This calibration protocol enables an accurate prediction of the fragmentation of the specimen.

Soft exfoliation of 2D SnO with size-dependent optical properties

NASA Astrophysics Data System (ADS)

Singh, Mandeep; Della Gaspera, Enrico; Ahmed, Taimur; Walia, Sumeet; Ramanathan, Rajesh; van Embden, Joel; Mayes, Edwin; Bansal, Vipul

2017-06-01

Two-dimensional (2D) materials have recently gained unprecedented attention as potential candidates for next-generation (opto)electronic devices due to their fascinating optical and electrical properties. Tin monoxide, SnO, is an important p-type semiconductor with applications across photocatalysis (water splitting) and electronics (transistors). However, despite its potential in several important technological applications, SnO remains underexplored in its 2D form. Here we present a soft exfoliation strategy to produce 2D SnO nanosheets with tunable optical and electrical properties. Our approach involves the initial synthesis of layered SnO microspheres, which are readily exfoliated through a low-power sonication step to form high quality SnO nanosheets. We demonstrate that the properties of 2D SnO are strongly dependent on its dimensions. As verified through optical absorption and photoluminescence studies, a strong size-dependent quantum confinement effect in 2D SnO leads to substantial variation in its optical and electrical properties. This results in a remarkable (>1 eV) band gap widening in atomically thin SnO. Through photoconductivity measurements, we further validate a strong correlation between the quantum-confined properties of 2D SnO and the selective photoresponse of atomically thin sheets in the high energy UV light. Such tunable semiconducting properties of 2D SnO could be exploited for a variety of applications including photocatalysis, photovoltaics and optoelectronics in general.

Minimum spanning tree filtering of correlations for varying time scales and size of fluctuations

NASA Astrophysics Data System (ADS)

Kwapień, Jarosław; Oświecimka, Paweł; Forczek, Marcin; DroŻdŻ, Stanisław

2017-05-01

Based on a recently proposed q -dependent detrended cross-correlation coefficient, ρq [J. Kwapień, P. Oświęcimka, and S. Drożdż, Phys. Rev. E 92, 052815 (2015), 10.1103/PhysRevE.92.052815], we generalize the concept of the minimum spanning tree (MST) by introducing a family of q -dependent minimum spanning trees (q MST s ) that are selective to cross-correlations between different fluctuation amplitudes and different time scales of multivariate data. They inherit this ability directly from the coefficients ρq, which are processed here to construct a distance matrix being the input to the MST-constructing Kruskal's algorithm. The conventional MST with detrending corresponds in this context to q =2 . In order to illustrate their performance, we apply the q MSTs to sample empirical data from the American stock market and discuss the results. We show that the q MST graphs can complement ρq in disentangling "hidden" correlations that cannot be observed in the MST graphs based on ρDCCA, and therefore, they can be useful in many areas where the multivariate cross-correlations are of interest. As an example, we apply this method to empirical data from the stock market and show that by constructing the q MSTs for a spectrum of q values we obtain more information about the correlation structure of the data than by using q =2 only. More specifically, we show that two sets of signals that differ from each other statistically can give comparable trees for q =2 , while only by using the trees for q ≠2 do we become able to distinguish between these sets. We also show that a family of q MSTs for a range of q expresses the diversity of correlations in a manner resembling the multifractal analysis, where one computes a spectrum of the generalized fractal dimensions, the generalized Hurst exponents, or the multifractal singularity spectra: the more diverse the correlations are, the more variable the tree topology is for different q 's. As regards the correlation structure of the stock market, our analysis exhibits that the stocks belonging to the same or similar industrial sectors are correlated via the fluctuations of moderate amplitudes, while the largest fluctuations often happen to synchronize in those stocks that do not necessarily belong to the same industry.

2D and 3D T2-weighted MR sequences for the assessment of neurovascular bundle changes after nerve-sparing radical retropubic prostatectomy with erectile function correlation.

PubMed

Panebianco, Valeria; Sciarra, Alessandro; Osimani, Marcello; Lisi, Danilo; Ciccariello, Mauro; Salciccia, Stefano; Gentile, Vincenzo; Di Silverio, Franco; Passariello, Roberto

2009-01-01

The aim of this study was to assess the capability of a 3D isotropic MRI T2-weighted sequence (3D T2 ISO) in the depiction of changes of neurovascular bundles (NVBs) after bilateral nerve-sparing radical retropubic prostatectomy (RRP). Furthermore, our aim was also to introduce a new MRI classification score of the NVB alteration patterns using the International Index Erectile Function Five-Item (IIEF-5) score as standard of reference. Fifty-three consecutive patients were postoperatively submitted to two MR examinations, including both 2D TSE T2-weighted (2D T2) and 3D T2 ISO sequences. Image findings were scored using a relative five-point classification and correlated with the postoperative IIEF-5 score. Radiologists attributed 13.2% of patients to class 0, 11.3% to class I, 34% to class II, 24.5% to class III, and 16.9% to class IV. With 3D T2 ISO images, the same radiologists determined 43.3% class 0, 32% class I, 11.4% class II, 7.5% class III, and 5.7% class IV. In all cases, the correlation and regression analysis between the 3D T2 ISO and IIEF-5 score resulted in higher coefficients values. The 3D sequence correlated most closely with patients' grading of erectile function.

Social withdrawal of persons with vascular dementia associated with disturbance of basic daily activities, apathy, and impaired social judgment.

PubMed

Honda, Yukiko; Meguro, Kenichi; Meguro, Mitsue; Akanuma, Kyoko

2013-01-01

Patients with vascular dementia (VaD) are often isolated, withdrawn from society because of negative symptoms and functional disabilities. The aim of this study was to detect factors associated with social withdrawal in patients with VaD. The participants were 36 institutionalized patients with VaD. Social withdrawal was assessed with the social withdrawal of the Multidimensional Observation Scale for Elderly Subjects (MOSES). Possible explanatory variables were the MOSES items depression and self-care, Cognitive Abilities Screening Instrument (CASI), apathy evaluation scale (AES), and Behavioral Pathology in Alzheimer's Disease Frequency-Weighted Severity Scale (BEHAVE-AD-FW). Multiple regression analyses were conducted for two groups: Analysis 1 was performed in all patients (N = 36) and Analysis 2 was performed in the patients with the ability to move by themselves (i.e., independent walking or independent movement with a cane or a wheelchair; n = 28). In Analysis 1, MOSES item social withdrawal was correlated with AES and MOSES item self-care. In Analysis 2, MOSES item social withdrawal was correlated with AES and CASI domain abstraction and judgment. Decreased social activities of VaD were not related to general cognitive function or depression. Disturbed activities of daily living (ADLs) for self-care may involve decreased frontal lobe function, indicating that comprehensive rehabilitation for both ADL and dementia are needed to improve the social activities of patients with VaD.

Anatomical relationships between serotonin 5-HT2A and dopamine D2 receptors in living human brain.

PubMed

Ishii, Tatsuya; Kimura, Yasuyuki; Ichise, Masanori; Takahata, Keisuke; Kitamura, Soichiro; Moriguchi, Sho; Kubota, Manabu; Zhang, Ming-Rong; Yamada, Makiko; Higuchi, Makoto; Okubo, Yoshinori; Suhara, Tetsuya

2017-01-01

Seven healthy volunteers underwent PET scans with [18F]altanserin and [11C]FLB 457 for 5-HT2A and D2 receptors, respectively. As a measure of receptor density, a binding potential (BP) was calculated from PET data for 76 cerebral cortical regions. A correlation matrix was calculated between the binding potentials of [18F]altanserin and [11C]FLB 457 for those regions. The regional relationships were investigated using a bicluster analysis of the correlation matrix with an iterative signature algorithm. We identified two clusters of regions. The first cluster identified a distinct profile of correlation coefficients between 5-HT2A and D2 receptors, with the former in regions related to sensorimotor integration (supplementary motor area, superior parietal gyrus, and paracentral lobule) and the latter in most cortical regions. The second cluster identified another distinct profile of correlation coefficients between 5-HT2A receptors in the bilateral hippocampi and D2 receptors in most cortical regions. The observation of two distinct clusters in the correlation matrix suggests regional interactions between 5-HT2A and D2 receptors in sensorimotor integration and hippocampal function. A bicluster analysis of the correlation matrix of these neuroreceptors may be beneficial in understanding molecular networks in the human brain.

Disparate Vitamin D Activity in the Prostate of Men with African Ancestry

DTIC Science & Technology

2017-12-01

Consequently, ~65% of AA men are vitamin D3 deficient compared to ~20% of EA men. The level of skin pigmentation is correlated with the extent of...of EA men. The level of skin pigmentation is correlated with the extent of African ancestry and serum vitamin D3 status. Besides vitamin D3 status...and not significantly different (Appendix A, Figure 2A). The 25D and 1,25D only correlated in the EA men, not the AA men (Appendix A, Figure 2B

Athermal Mechanisms of Size-Dependent Crystal Flow Gleaned from Three-Dimensional Discrete Dislocation Simulations

DTIC Science & Technology

2008-01-01

Sevillano, et. al . directly developed a definition of the single-slip glide-resistance correlation length, 10//5.8 o  , from 2d simulations of single...dislocation percolation through point-obstacle fields [35, 36]. Subsequently, predictions for the size- dependence of * from Gil Sevillano, et. al ...Sevillano, et. al ., and microcrystal deformation experiments was perhaps fortuitous, significant merit remains within their treatment. The more general

Baryon acoustic oscillations from the complete SDSS-III Lyα-quasar cross-correlation function at z = 2.4

DOE PAGES

du Mas des Bourboux, Helion; Le Goff, Jean-Marc; Blomqvist, Michael; ...

2017-08-08

We present a measurement of baryon acoustic oscillations (BAO) in the cross-correlation of quasars with the Lyα-forest flux-transmission at a mean redshift z = 2.40. The measurement uses the complete SDSS-III data sample: 168,889 forests and 234,367 quasars from the SDSS Data Release DR12. In addition to the statistical improvement on our previous study using DR11, we have implemented numerous improvements at the analysis level allowing a more accurate measurement of this cross-correlation. We also developed the first simulations of the cross-correlation allowing us to test different aspects of our data analysis and to search for potential systematic errors inmore » the determination of the BAO peak position. We measure the two ratios D H(z = 2.40)=r d = 9.01 ± 0.36 and D M(z = 2.40)=r d = 35.7 ±1.7, where the errors include marginalization over the non-linear velocity of quasars and the metal - quasar cross-correlation contribution, among other effects. These results are within 1.8σ of the prediction of the flat-ΛCDM model describing the observed CMB anisotropies.We combine this study with the Lyα-forest auto-correlation function (Bautista et al. 2017), yielding D H(z = 2.40)=r d = 8.94 ± 0.22 and D M(z = 2.40)=r d = 36.6 ± 1.2, within 2.3σ of the same flat-ΛCDM model.« less

Baryon acoustic oscillations from the complete SDSS-III Lyα-quasar cross-correlation function at z = 2.4

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

du Mas des Bourboux, Helion; Le Goff, Jean-Marc; Blomqvist, Michael

We present a measurement of baryon acoustic oscillations (BAO) in the cross-correlation of quasars with the Lyα-forest flux-transmission at a mean redshift z = 2.40. The measurement uses the complete SDSS-III data sample: 168,889 forests and 234,367 quasars from the SDSS Data Release DR12. In addition to the statistical improvement on our previous study using DR11, we have implemented numerous improvements at the analysis level allowing a more accurate measurement of this cross-correlation. We also developed the first simulations of the cross-correlation allowing us to test different aspects of our data analysis and to search for potential systematic errors inmore » the determination of the BAO peak position. We measure the two ratios D H(z = 2.40)=r d = 9.01 ± 0.36 and D M(z = 2.40)=r d = 35.7 ±1.7, where the errors include marginalization over the non-linear velocity of quasars and the metal - quasar cross-correlation contribution, among other effects. These results are within 1.8σ of the prediction of the flat-ΛCDM model describing the observed CMB anisotropies.We combine this study with the Lyα-forest auto-correlation function (Bautista et al. 2017), yielding D H(z = 2.40)=r d = 8.94 ± 0.22 and D M(z = 2.40)=r d = 36.6 ± 1.2, within 2.3σ of the same flat-ΛCDM model.« less

Labile rhizosphere soil solution fraction for prediction of bioavailability of heavy metals and rare earth elements to plants.

PubMed

Shan, Xiao-Quan; Wang, Zhongwen; Wang, Weisheng; Zhang, Shuzhen; Wen, Bei

2003-02-01

A labile rhizosphere soil solution fraction has been recommended to predict the bioavailability of heavy metals and rare earth elements to plants. This method used moist rhizosphere soil in combination with a mixture of 0.01 mol L(-1) of low-molecular-weight organic acids (LMWOAs) as extractant. The extracted soil solutions were fractionated into two colloidal fractions of <0.45 microm (F(3)) and <0.2 microm (F(2)), and one truly dissolved fraction including free metal ions and inorganic and organic complexes (fractionr(0.2 microm, LMWOAs) approximately r(0.45 microm, LMWOAs). In the case of rare earth elements the good correlation was obtained for both the wheat roots and shoots. Generally, the correlation coefficients obtained by LMWAOs were better than that obtained by the first step of BCR method. Therefore, LMWAOs and F(lrss) were strongly recommended to predict the bioavailability of metals in soil pools to plants.

Relationships between digit ratio (2D:4D) and basketball performance in Australian men.

PubMed

Frick, Nathan A; Hull, Melissa J; Manning, John T; Tomkinson, Grant R

2017-05-06

To investigate relationships between the digit ratio (2D:4D) and competitive basketball performance in Australian men. Using an observational cross-sectional design a total of 221 Australian basketball players who competed in the Olympic Games, International Basketball Federation World Championships/Cup, Australian National Basketball League, Central Australian Basketball League or socially had their 2D:4Ds measured. Analysis of variance was used to assess differences in mean 2D:4Ds between men playing at different competitive standards, with relationships between 2D:4Ds and basketball game-related statistics assessed using Pearson's product moment correlations in men playing at a single competitive standard. There were significant differences between competitive standards for the left 2D:4D following Bonferroni correction, but not for the right 2D:4D, with basketballers who achieved higher competitive standards tending to have lower left 2D:4Ds. No important correlations between 2D:4D and basketball game-related statistics were found, with correlations typically negligible. This study indicated that the 2D:4D can discriminate between basketballers competing at different standards, but not between basketballers within a single competitive standard using objective game-related statistics. © 2016 Wiley Periodicals, Inc.

Obtaining T1-T2 distribution functions from 1-dimensional T1 and T2 measurements: The pseudo 2-D relaxation model

NASA Astrophysics Data System (ADS)

Williamson, Nathan H.; Röding, Magnus; Galvosas, Petrik; Miklavcic, Stanley J.; Nydén, Magnus

2016-08-01

We present the pseudo 2-D relaxation model (P2DRM), a method to estimate multidimensional probability distributions of material parameters from independent 1-D measurements. We illustrate its use on 1-D T1 and T2 relaxation measurements of saturated rock and evaluate it on both simulated and experimental T1-T2 correlation measurement data sets. Results were in excellent agreement with the actual, known 2-D distribution in the case of the simulated data set. In both the simulated and experimental case, the functional relationships between T1 and T2 were in good agreement with the T1-T2 correlation maps from the 2-D inverse Laplace transform of the full 2-D data sets. When a 1-D CPMG experiment is combined with a rapid T1 measurement, the P2DRM provides a double-shot method for obtaining a T1-T2 relationship, with significantly decreased experimental time in comparison to the full T1-T2 correlation measurement.

2D Echocardiographic Evaluation of Right Ventricular Function Correlates With 3D Volumetric Models in Cardiac Surgery Patients.

PubMed

Magunia, Harry; Schmid, Eckhard; Hilberath, Jan N; Häberle, Leo; Grasshoff, Christian; Schlensak, Christian; Rosenberger, Peter; Nowak-Machen, Martina

2017-04-01

The early diagnosis and treatment of right ventricular (RV) dysfunction are of critical importance in cardiac surgery patients and impact clinical outcome. Two-dimensional (2D) transesophageal echocardiography (TEE) can be used to evaluate RV function using surrogate parameters due to complex RV geometry. The aim of this study was to evaluate whether the commonly used visual evaluation of RV function and size using 2D TEE correlated with the calculated three-dimensional (3D) volumetric models of RV function. Retrospective study, single center, University Hospital. Seventy complete datasets were studied consisting of 2D 4-chamber view loops (2-3 beats) and the corresponding 4-chamber view 3D full-volume loop of the right ventricle. RV function and RV size of the 2D loops then were assessed retrospectively purely qualitatively individually by 4 clinician echocardiographers certified in perioperative TEE. Corresponding 3D volumetric models calculating RV ejection fraction and RV end-diastolic volumes then were established and compared with the 2D assessments. 2D assessment of RV function correlated with 3D volumetric calculations (Spearman's rho -0.5; p<0.0001). No correlation could be established between 2D estimates of RV size and actual 3D volumetric end-diastolic volumes (Spearman's rho 0.15; p = 0.25). The 2D assessment of right ventricular function based on visual estimation as frequently used in clinical practice appeared to be a reliable method of RV functional evaluation. However, 2D assessment of RV size seemed unreliable and should be used with caution. Copyright © 2017 Elsevier Inc. All rights reserved.

Environmental correlates of upstream migration of yellow-phase American eels in the Potomac River drainage

USGS Publications Warehouse

Welsh, Stuart A.; Heather L. Liller,

2013-01-01

Assessing the relationships between upstream migration and environmental variables is important to understanding the ecology of yellow-phase American Eels Anguilla rostrata. During an American Eel migration study within the lower Shenandoah River (Potomac River drainage), we counted and measured American Eels at the Millville Dam eel ladder for three periods: 14 May–23 July 2004, 7–30 September 2004, and 1 June–31 July 2005. Using generalized estimating equations, we modeled each time series of daily American Eel counts by fitting time-varying environmental covariates of lunar illumination (LI), river discharge (RD), and water temperature (WT), including 1-d and 2-d lags of each covariate. Information-theoretic approaches were used for model selection and inference. A total of 4,847 American Eels (19–74 cm total length) used the ladder during the three periods, including 2,622 individuals during a 2-d span following a hurricane-induced peak in river discharge. Additive-effects models of RD + WT, a 2-d lag of LI + RD, and LI + RD were supported for the three periods, respectively. Parameter estimates were positive for river discharge for each time period, negative for lunar illumination for two periods and positive for water temperature during one period. Additive-effects models supported synergistic influences of environmental variables on the upstream migration of yellow-phase American Eels, although river discharge was consistently supported as an influential correlate of upstream migration.

Tracking Image Correlation: Combining Single-Particle Tracking and Image Correlation

PubMed Central

Dupont, A.; Stirnnagel, K.; Lindemann, D.; Lamb, D.C.

2013-01-01

The interactions and coordination of biomolecules are crucial for most cellular functions. The observation of protein interactions in live cells may provide a better understanding of the underlying mechanisms. After fluorescent labeling of the interacting partners and live-cell microscopy, the colocalization is generally analyzed by quantitative global methods. Recent studies have addressed questions regarding the individual colocalization of moving biomolecules, usually by using single-particle tracking (SPT) and comparing the fluorescent intensities in both color channels. Here, we introduce a new method that combines SPT and correlation methods to obtain a dynamical 3D colocalization analysis along single trajectories of dual-colored particles. After 3D tracking, the colocalization is computed at each particle’s position via the local 3D image cross correlation of the two detection channels. For every particle analyzed, the output consists of the 3D trajectory, the time-resolved 3D colocalization information, and the fluorescence intensity in both channels. In addition, the cross-correlation analysis shows the 3D relative movement of the two fluorescent labels with an accuracy of 30 nm. We apply this method to the tracking of viral fusion events in live cells and demonstrate its capacity to obtain the time-resolved colocalization status of single particles in dense and noisy environments. PMID:23746509

Anatomical background and generalized detectability in tomosynthesis and cone-beam CT.

PubMed

Gang, G J; Tward, D J; Lee, J; Siewerdsen, J H

2010-05-01

Anatomical background presents a major impediment to detectability in 2D radiography as well as 3D tomosynthesis and cone-beam CT (CBCT). This article incorporates theoretical and experimental analysis of anatomical background "noise" in cascaded systems analysis of 2D and 3D imaging performance to yield "generalized" metrics of noise-equivalent quanta (NEQ) and detectability index as a function of the orbital extent of the (circular arc) source-detector orbit. A physical phantom was designed based on principles of fractal self-similarity to exhibit power-law spectral density (kappa/Fbeta) comparable to various anatomical sites (e.g., breast and lung). Background power spectra [S(B)(F)] were computed as a function of source-detector orbital extent, including tomosynthesis (approximately 10 degrees -180 degrees) and CBCT (180 degrees + fan to 360 degrees) under two acquisition schemes: (1) Constant angular separation between projections (variable dose) and (2) constant total number of projections (constant dose). The resulting S(B) was incorporated in the generalized NEQ, and detectability index was computed from 3D cascaded systems analysis for a variety of imaging tasks. The phantom yielded power-law spectra within the expected spatial frequency range, quantifying the dependence of clutter magnitude (kappa) and correlation (beta) with increasing tomosynthesis angle. Incorporation of S(B) in the 3D NEQ provided a useful framework for analyzing the tradeoffs among anatomical, quantum, and electronic noise with dose and orbital extent. Distinct implications are posed for breast and chest tomosynthesis imaging system design-applications varying significantly in kappa and beta, and imaging task and, therefore, in optimal selection of orbital extent, number of projections, and dose. For example, low-frequency tasks (e.g., soft-tissue masses or nodules) tend to benefit from larger orbital extent and more fully 3D tomographic imaging, whereas high-frequency tasks (e.g., microcalcifications) require careful, application-specific selection of orbital extent and number of projections to minimize negative effects of quantum and electronic noise. The complex tradeoffs among anatomical background, quantum noise, and electronic noise in projection imaging, tomosynthesis, and CBCT can be described by generalized cascaded systems analysis, providing a useful framework for system design and optimization.

Bony defects in chronic anterior posttraumatic dislocation of the shoulder: Is there a correlation between humeral and glenoidal lesions?

PubMed

Ciais, Grégoire; Klouche, Shahnaz; Fournier, Alexandre; Rousseau, Benoit; Bauer, Thomas; Hardy, Philippe

2016-08-01

The prevalence of combined humeral and glenoid defects varies between 79 and 84 % in case of chronic posttraumatic anterior shoulder instability. The main goal of this study was to evaluate the relationship between humeral and glenoid defects based on quantitative radiological criteria. A retrospective study was performed between 2000 and 2011 including patients who underwent primary surgical shoulder stabilization for chronic posttraumatic anterior shoulder instability, with bone defects in both the glenoid and humerus and a healthy contralateral shoulder. The following measurements were taken: D/R ratio (Hill-Sachs lesion depth/humeral head radius) on an AP X-ray in internal rotation and the D1/D2 ratio [diameter of the involved glenoid articular surfaces (D1)/the healthy one (D2)] on a comparative Bernageau glenoid profile view. Measurements were taken by two observers. Correlations were determined by the Spearman correlation coefficients (r), Bland and Altman diagrams, and intra-class correlation coefficients (ICC). A sample size calculation was done. Thirty patients were included, 25 men/5 women, mean age 29.8 ± 11.2 years. The mean D/R was 23 ± 12 % for observer 1 and 23 ± 10 % for observer 2. The mean D1/D2 was 95 ± 4 % for observer 1 and 94 ± 6 % for observer 2. No significant correlation was found between humeral and glenoid bone defects by observer 1 (r = 0.23, p = 0.22) or observer 2 (r = 0.05, p = 0.78). Agreement of the observers for the D/R ratio was excellent (ICC = 0.89 ± 0.04, p < 0.00001) and good for the D1/D2 ratio (ICC = 0.54 ± 0.14, p = 0.006). Humeral and glenoid bone defects were not correlated. Inter-observer reliability was excellent for the D/R ratio and good for the D1/D2 ratio. Nonconsecutive Patients, Diagnostic Study, Level III.

Digit ratio (2D:4D) and physical fitness (Eurofit test battery) in school children.

PubMed

Ranson, R; Stratton, G; Taylor, S R

2015-05-01

The relative lengths of the index finger to the ring finger (2D:4D) is sexually dimorphic and is thought to be a correlate of prenatal sex steroids (low 2D:4D=high prenatal testosterone and low prenatal oestrogen). In adults there have been reports that low 2D:4D is consistently associated with high sports performance. To investigate correlations between 2D:4D and fitness levels in children. Right 2D:4D and body size were measured, in addition to flexibility, speed, endurance and strength (Eurofit tests). 922 boys and 835 girls (mean ages (years): 10.8 ± 1.01 and 10.07 ± 1.00 respectively). height, mass, BMI, triceps and subscapular skinfolds, 20 m shuttle run, sit and reach, standing broad jump, hand grip strength, 10 × 5m sprint, and the sit and reach test. Boys significantly outperformed the girls in the 10 × 5m sprints, the 20 m shuttle run, standing broad jump, and hand grip strength. In boys but not girls, 2D:4D was significantly negatively correlated with scores in all these tests except the standing broad jump. In girls but not boys, 2D:4D was significantly positively correlated to stature, mass, BMI and waist circumference. It is suggested that high prenatal testosterone and low prenatal oestrogen (low 2D:4D) is implicated in high sprinting speed, endurance and hand grip strength in boys. In girls low prenatal testosterone and high prenatal oestrogen is associated with large body size. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Influence of genetic background, salinity, and inoculum size on growth of the ichthyotoxic golden alga (Prymnesium parvum).

PubMed

Rashel, Rakib H; Patiño, Reynaldo

2017-06-01

Salinity (5-30) effects on golden alga growth were determined at a standard laboratory temperature (22°C) and one associated with natural blooms (13°C). Inoculum-size effects were determined over a wide size range (100-100,000cellsml -1 ). A strain widely distributed in the USA, UTEX-2797 was the primary study subject but another of limited distribution, UTEX-995 was used to evaluate growth responses in relation to genetic background. Variables examined were exponential growth rate (r), maximum cell density (max-D) and, when inoculum size was held constant (100cellsml -1 ), density at onset of exponential growth (early-D). In UTEX-2797, max-D increased as salinity increased from 5 to ∼10-15 and declined thereafter regardless of temperature but r remained generally stable and only declined at salinity of 25-30. In addition, max-D correlated positively with r and early-D, the latter also being numerically highest at salinity of 15. In UTEX-995, max-D and r responded similarly to changes in salinity - they remained stable at salinity of 5-10 and 5-15, respectively, and declined at higher salinity. Also, max-D correlated with r but not early-D. Inoculum size positively and negatively influenced max-D and r, respectively, in both strains and these effects were significant even when the absolute size difference was small (100 versus 1000 cells ml -1 ). When cultured under similar conditions, UTEX-2797 grew faster and to much higher density than UTEX-995. In conclusion, (1) UTEX-2797's superior growth performance may explain its relatively wide distribution in the USA, (2) the biphasic growth response of UTEX-2797 to salinity variation, with peak abundance at salinity of 10-15, generally mirrors golden alga abundance-salinity associations in US inland waters, and (3) early cell density - whether artificially manipulated or naturally attained - can influence UTEX-2797 bloom potential. Published by Elsevier B.V.

A new method for the calculation of the conductivity of inhomogeneous systems

NASA Astrophysics Data System (ADS)

Byshkin, M. S.; Turkin, A. A.

2005-06-01

A new method for computing the conductivity of random irregular resistor networks is developed. This method is a generalization of the transfer-matrix technique, proposed by Derrida and Vannimenus for regular 2D and 3D lattices. At the same time for large systems the method presented in this paper is more efficient than the transfer-matrix technique. To demonstrate the method it is applied to a cubic lattice at the percolation threshold and away from it. The conductivity has been found for lattices with size up to 3243. The ratio between the conductivity exponent t and the correlation length exponent η was estimated to be t/η = 2.315, in good agreement with the literature data.

Avoidant coping moderates the relationship between paternal involvement in the child's type 1 diabetes (T1D) care and parenting stress.

PubMed

Teasdale, Ashley; Limbers, Christine

2018-01-01

Fathers may experience greater parenting stress and anxiety when they are more involved in their child's type 1 diabetes (T1D) care. The present study evaluated whether seeking social support and avoidant coping strategies moderate the relationship between paternal involvement in the child's T1D care and parenting stress in an international sample. Two hundred forty-nine fathers of young children with T1D completed the Parenting Stress Index (PSI), Pediatric Inventory for Parents (PIP), Dads' Active Disease Support scale (DADS), COPE Inventory, Self-Care Inventory (SCI-R), and a demographic questionnaire online. Pearson's product moment correlations were computed, and multiple linear regression analysis was conducted with three separate models in which the PSI Child Domain, PIP Frequency, and PIP Difficulty scores represented different parenting stress outcomes. The interaction between use of denial coping and DADS Involvement was significantly correlated with general parenting stress ( p < .05). There were no significant interactions between instrumental social support and DADS Involvement; however, use of instrumental social support coping was significantly correlated with difficulty of pediatric parenting stress ( p < .05), DADS Involvement ( p < .001), and SCI-R better adherence to the child diabetes treatment regimen ( p < .001). Avoidant coping strategies are associated with more general parenting stress, especially when fathers are more involved in T1D management.

Seismic tomography of Basse-Terre volcanic island, Guadeloupe, Lesser Antilles, using earthquake travel times and noise correlations

NASA Astrophysics Data System (ADS)

Barnoud, Anne; Coutant, Olivier; Bouligand, Claire; Massin, Frédérick; Stehly, Laurent

2015-04-01

We image the volcanic island of Basse-Terre, Guadeloupe, Lesser Antilles, using both earthquake travel times and noise correlations. (1) A new earthquake catalog was recently compiled for the Lesser Antilles by the CDSA/OVSG/IPGP (Massin et al., EGU General Assembly 2014) and allows us to perform classical travel time tomography to obtain smooth 3D body wave velocity models. The geometrical configuration of the volcanic arc controls the resolution of the model in our zone of interest. (2) Surface wave tomography using noise correlations was successfully applied to volcanoes (Brenguier et al., Geophys. Res. Lett. 2007). We use seismic noise recorded at 16 broad-band stations and 9 short-period stations from Basse-Terre over a period of six years (2007-2012). For each station pair, we extract a dispersion curve from the noise correlation to get surface wave velocity models. The inversion of the dispersion curves produces a 3D S-wave velocity model of the island. The spatial distribution of seismic stations accross the island is highly heterogeneous, leading to higher resolution near the dome of the Soufrière of Guadeloupe volcano. Resulting velocity models are compared with densities obtained by 3D inversion of gravimetric data (Barnoud et al., AGU Fall Meeting 2013). Further work should include simultaneous inversion of seismic and gravimetric datasets to overcome resolution limitations.

White Blood Cells, Neutrophils, and Reactive Oxygen Metabolites among Asymptomatic Subjects.

PubMed

Kotani, Kazuhiko; Sakane, Naoki

2012-06-01

Chronic inflammation and oxidative stress are associated with health and the disease status. The objective of the present study was to investigate the association among white blood cell (WBC) counts, neutrophil counts as a WBC subpopulation, and diacron reactive oxygen metabolites (d-ROMs) levels in an asymptomatic population. The clinical data, including general cardiovascular risk variables and high-sensitivity C-reactive protein (hs-CRP), were collected from 100 female subjects (mean age, 62 years) in outpatient clinics. The correlation of the d-ROMs with hs-CRP, WBC, and neutrophil counts was examined. The mean/median levels were WBC counts 5.9 × 10(9)/L, neutrophil counts 3.6 × 10(9)/L, hs-CRP 0.06 mg/dL, and d-ROMs 359 CURR U. A simple correlation analysis showed a significant positive correlation of the d-ROMs with the WBC counts, neutrophil counts, or hs-CRP levels. The correlation between d-ROMs and neutrophil counts (β = 0.22, P < 0.05), as well as that between d-ROMs and hs-CRP (β = 0.28, P < 0.01), remained significant and independent in a multiple linear regression analysis adjusted for other variables. A multiple linear regression analysis showed that WBC counts had only a positive correlation tendency to the d-ROMs. Neutrophils may be slightly but more involved in the oxidative stress status, as assessed by d-ROMs, in comparison to the overall WBC. Further studies are needed to clarify the biologic mechanism(s) of the observed relationship.

The Sense of Incompleteness as a Motivator of Obsessive-Compulsive Symptoms: An Empirical Analysis of Concepts and Correlates

PubMed Central

Taylor, Steven; McKay, Dean; Crowe, Katherine B.; Abramowitz, Jonathan S.; Conelea, Christine A.; Calamari, John E.; Sica, Claudio

2014-01-01

Contemporary models of obsessive-compulsive disorder emphasize the importance of harm avoidance (HA) and related dysfunctional beliefs as motivators of obsessive-compulsive (OC) symptoms. Recently, there has been a resurgence of interest in Janet’s (1908) concept of incompleteness (INC) as another potentially important motivator. Contemporary investigators define INC as the sense that one’s actions, intentions, or experiences have not been properly achieved. Janet defined INC more broadly to include alexithymia, depersonalization, derealization, and impaired psychological mindedness. We conducted two studies to address four issues: (a) the clinical correlates of INC; (b) whether INC and HA are distinguishable constructs; (c) whether INC predicts OC symptoms after controlling for HA; and (d) the relative merits of broad versus narrow conceptualizations of INC. Study 1 was a meta-analysis of the clinical correlates of narrowly defined INC (16 studies, N=5,940). INC was correlated with all types of OC symptoms, and was more strongly correlated with OC symptoms than with general distress. Study 2 (N=534 nonclinical participants) showed that: (a) INC and HA were strongly correlated but factor analytically distinguishable; (b) INC statistically predicted all types of OC symptoms even after controlling for HA; and (c) narrow INC was most strongly correlated with OC symptoms whereas broad INC was most strongly correlated with general distress. Although the findings are limited by being correlational in nature, they support the hypothesis that INC, especially in its narrow form, is a motivator of OC symptoms. PMID:24491200

H I, CO, and Planck/IRAS dust properties in the high latitude cloud complex, MBM 53, 54, 55 and HLCG 92 – 35. Possible evidence for an optically thick H I envelope around the CO clouds

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

Fukui, Yasuo; Okamoto, Ryuji; Kaji, Ryohei

We present an analysis of the H I and CO gas in conjunction with the Planck/IRAS submillimeter/far-infrared dust properties toward the most outstanding high latitude clouds MBM 53, 54, 55 and HLCG 92 – 35 at b = –30° to – 45°. The CO emission, dust opacity at 353 GHz (τ{sub 353}), and dust temperature (T {sub d}) show generally good spatial correspondence. On the other hand, the correspondence between the H I emission and the dust properties is less clear than in CO. The integrated H I intensity W{sub H} {sub I} and τ{sub 353} show a large scattermore » with a correlation coefficient of ∼0.6 for a T {sub d} range from 16 K to 22 K. We find, however, that W{sub H} {sub I} and τ{sub 353} show better correlation for smaller ranges of T {sub d} every 0.5 K, generally with a correlation coefficient of 0.7-0.9. We set up a hypothesis that the H I gas associated with the highest T {sub d} ≥ 21.5 K is optically thin, whereas the H I emission is generally optically thick for T {sub d} lower than 21.5 K. We have determined a relationship for the optically thin H I gas between atomic hydrogen column density and τ{sub 353}, N{sub H} {sub I} (cm{sup −2})=(1.5×10{sup 26})⋅τ{sub 353}, under the assumption that the dust properties are uniform and we have applied this to estimate N{sub H} {sub I} from τ{sub 353} for the whole cloud. N{sub H} {sub I} was then used to solve for T {sub s} and τ{sub H} {sub I} over the region. The result shows that the H I is dominated by optically thick gas having a low spin temperature of 20-40 K and a density of 40-160 cm{sup –3}. The H I envelope has a total mass of ∼1.2 × 10{sup 4} M {sub ☉}, an order of magnitude larger than that of the CO clouds. The H I envelope properties derived by this method do not rule out a mixture of H I and H{sub 2} in the dark gas, but we present indirect evidence that most of the gas mass is in the atomic state.« less

Dynamics of an integral membrane peptide: a deuterium NMR relaxation study of gramicidin.

PubMed Central

Prosser, R S; Davis, J H

1994-01-01

Solid state deuterium (2H) NMR inversion-recovery and Jeener-Broekaert relaxation experiments were performed on oriented multilamellar dispersions consisting of 1,2-dilauroyl-sn-glycero-3-phosphatidylcholine and 2H exchange-labeled gramicidin D, at a lipid to protein molar ratio (L/P) of 15:1, in order to study the dynamics of the channel conformation of the peptide in a liquid crystalline phase. Our dynamic model for the whole body motions of the peptide includes diffusion of the peptide around its helix axis and a wobbling diffusion around a second axis perpendicular to the local bilayer normal in a simple Maier-Saupe mean field potential. This anisotropic diffusion is characterized by the correlation times, tau R parallel and tau R perpendicular. Aligning the bilayer normal perpendicular to the magnetic field and graphing the relaxation rate, 1/T1Z, as a function of (1-S2N-2H), where S2N-2H represents the orientational order parameter, wer were able to estimate the correlation time, tau R parallel, for rotational diffusion. Although in the quadrupolar splitting, which varies as (3 cos2 theta D-1), has in general two possible solutions to theta D in the range 0 < or = theta D < or = 90 degrees, the 1/T1Z vs. (1-S2N-2H) curve can be used to determine a single value of theta D in this range. Thus, the 1/T1Z vs. (1-S2N-2H) profile can be used both to define the axial diffusion rate and to remove potential structural ambiguities in the splittings. The T1Z anisotropy permits us to solve for the two correlation times (tau R parallel = 6.8 x 10(-9) s and tau R perpendicular = 6 x 10(-6) s). The simulated parameters were corroborated by a Jeener-Broekaert experiment where the bilayer normal was parallel to the principal magnetic field. At this orientation the ratio, J2(2 omega 0)/J1(omega 0) was obtained in order to estimate the strength of the restoring potential in a model-independent fashion. This measurement yields the rms angle, 1/2 (= 16 +/- 2 degrees at 34 degrees C), formed by the peptide helix axis and the average bilayer normal. PMID:7520294

Defining the cognitive enhancing properties of video games: Steps Towards Standardization and Translation.

PubMed

Goodwin, Shikha Jain; Dziobek, Derek

2016-09-01

Ever since video games were available to the general public, they have intrigued brain researchers for many reasons. There is an enormous amount of diversity in the video game research, ranging from types of video games used, the amount of time spent playing video games, the definition of video gamer versus non-gamer to the results obtained after playing video games. In this paper, our goal is to provide a critical discussion of these issues, along with some steps towards generalization using the discussion of an article published by Clemenson and Stark (2005) as the starting point. The authors used a distinction between 2D versus 3D video games to compare their effects on the learning and memory in humans. The primary hypothesis of the authors is that the exploration of virtual environments while playing video games is a human correlate of environment enrichment. Authors found that video gamers performed better than the non-video gamers, and if non-gamers are trained on playing video gamers, 3D games provide better environment enrichment compared to 2D video games, as indicated by better memory scores. The end goal of standardization in video games is to be able to translate the field so that the results can be used for greater good.

Defining the cognitive enhancing properties of video games: Steps Towards Standardization and Translation

PubMed Central

Goodwin, Shikha Jain; Dziobek, Derek

2016-01-01

Ever since video games were available to the general public, they have intrigued brain researchers for many reasons. There is an enormous amount of diversity in the video game research, ranging from types of video games used, the amount of time spent playing video games, the definition of video gamer versus non-gamer to the results obtained after playing video games. In this paper, our goal is to provide a critical discussion of these issues, along with some steps towards generalization using the discussion of an article published by Clemenson and Stark (2005) as the starting point. The authors used a distinction between 2D versus 3D video games to compare their effects on the learning and memory in humans. The primary hypothesis of the authors is that the exploration of virtual environments while playing video games is a human correlate of environment enrichment. Authors found that video gamers performed better than the non-video gamers, and if non-gamers are trained on playing video gamers, 3D games provide better environment enrichment compared to 2D video games, as indicated by better memory scores. The end goal of standardization in video games is to be able to translate the field so that the results can be used for greater good. PMID:27747256

Toward Obtaining Reliable Particulate Air Quality Information from Satellites

NASA Astrophysics Data System (ADS)

Strawa, A. W.; Chatfield, R. B.; Legg, M.; Esswein, R.; Justice, E.

2009-12-01

Air quality agencies use ground sites to monitor air quality, providing accurate information at particular points. Using measurements from satellite imagery has the potential to provide air quality information in a timely manner with better spatial resolution and at a lower cost that can also useful for model validation. While previous studies show acceptable correlations between Aerosol Optical Depth (AOD) derived from MODIS and surface Particulate Matter (PM) measurements on the eastern US, the data do not correlate well in the western US (Al-Saadi et al., 2005; Engle-Cox et al., 2004) . This paper seeks to improve the AOD-PM correlations by using advanced statistical analysis techniques. Our study area is the San Joaquin Valley in California because air quality in this region has failed to meet state and federal attainment standards for PM for the past several years. A previous investigation found good correlation of the AOD values between MODIS, MISR and AERONET, but poor correlations (R2 ~ 0.02) between satellite-based AOD and surface PM2.5 measurements. PM2.5 measurements correlated somewhat better (R2 ~ 0.18) with MODIS-derived AOD using the Deep Blue surface reflectance algorithm (Hsu et al., 2006) rather than the standard MODIS algorithm. This level of correlation is not adequate for reliable air quality measurements. Pelletier et al. (2007) used generalized additive models (GAMs) and meteorological data to improve the correlation between PM and AERONET AOD in western Europe. Additive models are more flexible than linear models and the functional relationships can be plotted to give a sense of the relationship between the predictor and the response. In this paper we use GAMs to improve surface PM2.5 to MODIS-AOD correlations. For example, we achieve an R2 ~ 0.44 using a GAM that includes the Deep Blue AOD, and day of year as parameters. Including NOx observations, improves the R2 ~ 0.64. Surprisingly Ångström exponent did not prove to be a significant factor. The relationships between the predictor and the response are discussed. Al-Saadi, J., J. Szykman, R.B. Pierce, C. Kittaka, D. Neil, D.A. Chu, L. Remer, L. Gumley, E. Prins, L. Weinstock, C. MacDonald, R. Wayland, F. Dimmick, and J. Fishman, Imporving national air quality forecasts with satellite aerosol observations, Bull. Amer, Met. Soc. (Sept), 1249-1261, 2005. Engle-Cox, J.A., C.H. Holloman, B.W. Coutant, and R.M. Hoff, Qualitative and quantitative evaluation of MODIS satellite sensor data for regional and urban scale air quality, Atmos. En., 38, 2495-2509, 2004. Hsu, N.C., S.-C. Tsay, M.D. King, and J.R. Herman, Deep blue retrievals of Asian Aerosol properties during ACE-Asia, IEEE Trans. on Geosci.a nd Remote Sensing, 44 (11), 3180, 2006. Pelletier, B., R. Santer, and J. Vidot, Retrieving of particulate matter from optical measurements: A semi-parametric approach, J. Geophys. Res., 112 (D06208), 2007.

Linear game non-contextuality and Bell inequalities—a graph-theoretic approach

NASA Astrophysics Data System (ADS)

Rosicka, M.; Ramanathan, R.; Gnaciński, P.; Horodecki, K.; Horodecki, M.; Horodecki, P.; Severini, S.

2016-04-01

We study the classical and quantum values of a class of one- and two-party unique games, that generalizes the well-known XOR games to the case of non-binary outcomes. In the bipartite case the generalized XOR (XOR-d) games we study are a subclass of the well-known linear games. We introduce a ‘constraint graph’ associated to such a game, with the constraints defining the game represented by an edge-coloring of the graph. We use the graph-theoretic characterization to relate the task of finding equivalent games to the notion of signed graphs and switching equivalence from graph theory. We relate the problem of computing the classical value of single-party anti-correlation XOR games to finding the edge bipartization number of a graph, which is known to be MaxSNP hard, and connect the computation of the classical value of XOR-d games to the identification of specific cycles in the graph. We construct an orthogonality graph of the game from the constraint graph and study its Lovász theta number as a general upper bound on the quantum value even in the case of single-party contextual XOR-d games. XOR-d games possess appealing properties for use in device-independent applications such as randomness of the local correlated outcomes in the optimal quantum strategy. We study the possibility of obtaining quantum algebraic violation of these games, and show that no finite XOR-d game possesses the property of pseudo-telepathy leaving the frequently used chained Bell inequalities as the natural candidates for such applications. We also show this lack of pseudo-telepathy for multi-party XOR-type inequalities involving two-body correlation functions.

A comparison of gantry-mounted x-ray-based real-time target tracking methods.

PubMed

Montanaro, Tim; Nguyen, Doan Trang; Keall, Paul J; Booth, Jeremy; Caillet, Vincent; Eade, Thomas; Haddad, Carol; Shieh, Chun-Chien

2018-03-01

Most modern radiotherapy machines are built with a 2D kV imaging system. Combining this imaging system with a 2D-3D inference method would allow for a ready-made option for real-time 3D tumor tracking. This work investigates and compares the accuracy of four existing 2D-3D inference methods using both motion traces inferred from external surrogates and measured internally from implanted beacons. Tumor motion data from 160 fractions (46 thoracic/abdominal patients) of Synchrony traces (inferred traces), and 28 fractions (7 lung patients) of Calypso traces (internal traces) from the LIGHT SABR trial (NCT02514512) were used in this study. The motion traces were used as the ground truth. The ground truth trajectories were used in silico to generate 2D positions projected on the kV detector. These 2D traces were then passed to the 2D-3D inference methods: interdimensional correlation, Gaussian probability density function (PDF), arbitrary-shape PDF, and the Kalman filter. The inferred 3D positions were compared with the ground truth to determine tracking errors. The relationships between tracking error and motion magnitude, interdimensional correlation, and breathing periodicity index (BPI) were also investigated. Larger tracking errors were observed from the Calypso traces, with RMS and 95th percentile 3D errors of 0.84-1.25 mm and 1.72-2.64 mm, compared to 0.45-0.68 mm and 0.74-1.13 mm from the Synchrony traces. The Gaussian PDF method was found to be the most accurate, followed by the Kalman filter, the interdimensional correlation method, and the arbitrary-shape PDF method. Tracking error was found to strongly and positively correlate with motion magnitude for both the Synchrony and Calypso traces and for all four methods. Interdimensional correlation and BPI were found to negatively correlate with tracking error only for the Synchrony traces. The Synchrony traces exhibited higher interdimensional correlation than the Calypso traces especially in the anterior-posterior direction. Inferred traces often exhibit higher interdimensional correlation, which are not true representation of thoracic/abdominal motion and may underestimate kV-based tracking errors. The use of internal traces acquired from systems such as Calypso is advised for future kV-based tracking studies. The Gaussian PDF method is the most accurate 2D-3D inference method for tracking thoracic/abdominal targets. Motion magnitude has significant impact on 2D-3D inference error, and should be considered when estimating kV-based tracking error. © 2018 American Association of Physicists in Medicine.

Effect of chemical kinetics uncertainties on calculated constituents in a tropospheric photochemical model

NASA Technical Reports Server (NTRS)

Thompson, Anne M.; Stewart, Richard W.

1991-01-01

Random photochemical reaction rates are employed in a 1D photochemical model to examine uncertainties in tropospheric concentrations and thereby determine critical kinetic processes and significant correlations. Monte Carlo computations are used to simulate different chemical environments and their related imprecisions. The most critical processes are the primary photodissociation of O3 (which initiates ozone destruction) and NO2 (which initiates ozone formation), and the OH/methane reaction is significant. Several correlations and anticorrelations between species are discussed, and the ozone/transient OH correlation is examined in detail. One important result of the modeling is that estimates of global OH are generally about 25 percent uncertain, limiting the precision of photochemical models. Techniques for reducing the imprecision are discussed which emphasize the use of species and radical species measurements.

Preliminary findings of an investigation into the relationship between national culture and EQ-5D value sets.

PubMed

Bailey, Henry; Kind, Paul

2010-10-01

Despite the growing importance of the EQ-5D descriptive system as a basis for the valuation of QALYs in cost-utility analysis, for most countries, there are no EQ-5D value sets. Researchers and policy makers wishing to use the EQ-5D descriptive system in a country for which there is no value set are advised to use one from a nearby or 'similar' population. Factors other than geographic proximity can affect the relative values of EQ-5D states. This study explores the links between national culture and EQ-5D value sets. Rank correlation analysis is used to explore relationships between the relative values of a set of EQ-5D states and dimensions of national culture. The latter are taken from Hofstede's framework which operationalizes national culture in five dimensions. For the data currently available (countries for which EQ-5D value sets and scores on dimensions of culture both exist), moderate and strong correlations were found between the culture dimension of power distance and individualism and the EQ-5D dimensions of pain/discomfort and anxiety/depression. Moderate correlations were also observed between the cultural dimension of masculinity and the EQ-5D dimensions of self care, usual activities and pain/discomfort. Uncertainty avoidance correlates with the EQ-5D dimension of anxiety/depression. The correlation patterns observed are generally consistent with a priori expectations based on the nature of the dimensions of culture and the EQ-5D model. This analysis demonstrates the potential of national culture in providing insight into the drivers of the relative values of EQ-5D dimensions for different countries and in informing decisions about which EQ-5D value sets to use in situations where one does not exist.

The correlation between NK cell and liver function in patients with primary hepatocellular carcinoma.

PubMed

Sha, Wei Hong; Zeng, Xiao Hui; Min, Lu

2014-05-01

This study aimed to detect the expression of natural killer (NK) cell receptor natural killer group 2D (NKG2D) in the peripheral blood of patients with primary hepatocellular carcinoma and to discuss the correlation between NK cell cytotoxicity and liver function. The number of NK cells and the expression of NK cell receptor NKG2D in peripheral blood were determined by flow cytometry in patients with primary hepatocellular carcinoma, hepatitis B cirrhosis, chronic hepatitis B, and healthy controls. When compared with patients in the healthy and the chronic hepatitis B groups, the primary hepatocellular carcinoma group showed significant decreases in all parameters, including the cytotoxicity of NK cells on K562 cells, expression rate of NKG2D in NK cells, number of NKG2D(+) NK cells, expression level of NKG2D, and number of NK cells (p<0.05). The activity of NK cells showed a positive correlation, whereas the Child-Pugh scores in the primary hepatocellular carcinoma and the hepatitis B cirrhosis groups showed a negative correlation with all parameters detected above. The decrease of NK cell activity in patients with primary hepatocellular carcinoma is closely related to their lower expression of NKG2D. Liver function affects the expression of NKG2D and the activity of NK cells.

Correlation between reactive oxygen metabolites & atherosclerotic risk factors in patients with type 2 diabetes mellitus.

PubMed

Kotani, Kazuhiko; Tsuzaki, Kokoro; Taniguchi, Nobuyuki; Sakane, Naoki

2013-04-01

Oxidative stress plays important roles in the pathophysiology of type 2 diabetes mellitus (T2DM). The diacron reactive oxygen metabolites (d-ROMs) test has been used in the clinics. The present study was aimed to investigate the correlation of the oxidative stress status, as evaluated by the d-ROMs, with atherosclerotic risk factors in T2DM patients, in comparison to controls. The study included 200 subjects (100 patients with T2DM and 100 controls; 86 males/114 females; mean age 59.0 yr). Clinical variables including the body mass index, blood pressure (BP), glucose and lipid panels, in addition to the d-ROMs, were measured. Patients with T2DM showed significantly higher d-ROMs levels than controls (322 ± 60 vs. 345 ± 64 U. Carr., P<0.05). A multiple linear regression analysis revealed that systolic BP (β=0.26, P<0.05) and high-density lipoprotein cholesterol (HDL-C: β= -0.30, P<0.05) were independently and significantly correlated with the d-ROMs levels in patients with T2DM, although these correlations were not significant in the controls. The gender-based analysis showed that systolic BP (β = 0.44, P<0.05) and HDL-C (β = -0.36, P<0.05) were independently and significantly correlated with the d-ROMs levels in females with T2DM, while there was a marginally significant correlation between HDL-C and the d-ROMs levels (β = -0.36, P=0.06) in males with T2DM. The present findings may reinforce the importance of BP control in female patients with T2DM, as well as the management of HDL-C in male and female patients with T2DM, under the linkage between oxidative stress and atherosclerosis.

Urdu translation of the Hamilton Rating Scale for Depression: Results of a validation study

PubMed Central

Hashmi, Ali M.; Naz, Shahana; Asif, Aftab; Khawaja, Imran S.

2016-01-01

Objective: To develop a standardized validated version of the Hamilton Rating Scale for Depression (HAM-D) in Urdu. Methods: After translation of the HAM-D into the Urdu language following standard guidelines, the final Urdu version (HAM-D-U) was administered to 160 depressed outpatients. Inter-item correlation was assessed by calculating Cronbach alpha. Correlation between HAM-D-U scores at baseline and after a 2-week interval was evaluated for test-retest reliability. Moreover, scores of two clinicians on HAM-D-U were compared for inter-rater reliability. For establishing concurrent validity, scores of HAM-D-U and BDI-U were compared by using Spearman correlation coefficient. The study was conducted at Mayo Hospital, Lahore, from May to December 2014. Results: The Cronbach alpha for HAM-D-U was 0.71. Composite scores for HAM-D-U at baseline and after a 2-week interval were also highly correlated with each other (Spearman correlation coefficient 0.83, p-value < 0.01) indicating good test-retest reliability. Composite scores for HAM-D-U and BDI-U were positively correlated with each other (Spearman correlation coefficient 0.85, p < 0.01) indicating good concurrent validity. Scores of two clinicians for HAM-D-U were also positively correlated (Spearman correlation coefficient 0.82, p-value < 0.01) indicated good inter-rater reliability. Conclusion: The HAM-D-U is a valid and reliable instrument for the assessment of Depression. It shows good inter-rater and test-retest reliability. The HAM-D-U can be a tool either for clinical management or research. PMID:28083049

Urdu translation of the Hamilton Rating Scale for Depression: Results of a validation study.

PubMed

Hashmi, Ali M; Naz, Shahana; Asif, Aftab; Khawaja, Imran S

2016-01-01

To develop a standardized validated version of the Hamilton Rating Scale for Depression (HAM-D) in Urdu. After translation of the HAM-D into the Urdu language following standard guidelines, the final Urdu version (HAM-D-U) was administered to 160 depressed outpatients. Inter-item correlation was assessed by calculating Cronbach alpha. Correlation between HAM-D-U scores at baseline and after a 2-week interval was evaluated for test-retest reliability. Moreover, scores of two clinicians on HAM-D-U were compared for inter-rater reliability. For establishing concurrent validity, scores of HAM-D-U and BDI-U were compared by using Spearman correlation coefficient. The study was conducted at Mayo Hospital, Lahore, from May to December 2014. The Cronbach alpha for HAM-D-U was 0.71. Composite scores for HAM-D-U at baseline and after a 2-week interval were also highly correlated with each other (Spearman correlation coefficient 0.83, p-value < 0.01) indicating good test-retest reliability. Composite scores for HAM-D-U and BDI-U were positively correlated with each other (Spearman correlation coefficient 0.85, p < 0.01) indicating good concurrent validity. Scores of two clinicians for HAM-D-U were also positively correlated (Spearman correlation coefficient 0.82, p-value < 0.01) indicated good inter-rater reliability. The HAM-D-U is a valid and reliable instrument for the assessment of Depression. It shows good inter-rater and test-retest reliability. The HAM-D-U can be a tool either for clinical management or research.

Syntheses of conformationally defined analogues of tyramine and phenylethanolamine and their biological evaluations at central dopamine receptors and the active site of phenylethanolamine N-methyltransferase

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

Ye, Q.

Tyramine analogues 31-33 and 37-39 were evaluated for dopaminergic activities on rat striatal tissues with radioligands ({sup 3}H)SCH23390 for D-1 receptor and ({sup 3}H)spiroperidol for D-2 receptor. The tertiary amines 37-39 were generally more potent than the primary amines 31-33. In the primary amines, 33 (2-OH) was more potent than 31 and 32, and in the tertiary amines, 37 (4-OH) was more potent than 38 and 39 at both D-1 and D-2 receptors. The reduced activity of 31-33 and 37-39 compared with corresponding hydroxyl-substituted 2ATs is consistent with a negative interaction from the extra ethano bridge in their binding tomore » the dopamine receptors. No selectivity was observed in both these conformationally defined tyramines (31-33 and 37-39) and conformationally restricted tyramines; a good correlation was observed between log IC{sub 5}O values at D-1 and D-2 receptors. The tyramines 31-33, the phenylethanolamines 45 and 46, and the phenylethylamine 44 (X, Y = H) were evaluated for activities as either substrates or inhibitors of phenylethanolamine N-methyltransferase (PNMT) by an in vitro radiochemical assay.« less

Does vitamin D have any role in the improvement of diabetic peripheral neuropathy in type 1 diabetic patients?

PubMed

Ozuguz, U; Oruc, S; Ulu, M S; Demirbas, H; Acay, A; Coker, B; Beyazıt, B; Yaman, M; Koken, T

2016-12-01

The aim of this study was to evaluate the relationship between diabetic peripheral neuropathy (DPN) and vitamin D, nerve growth factor (NGF) and oxidative stress markers in patients with type 1 diabetes. Ninety-six patients with type 1 diabetes were included in the study. All patients were evaluated for DPN with Michigan Neuropathy Screening Instrument. Fasting blood glucose, HbA1c, lipid parameters, 25 (OH) D3, NGF, total oxidant status, total antioxidant status and oxidative stress index were measured. Twenty-six patients (27 %) had DPN (group 1) and 70 patients did not have neuropathy (group 2). When the groups were evaluated with respect to general demographic characteristics, no differences were detected. Mean age, duration of diabetes and retinopathy were found significantly higher in patients who had neuropathy. Glomerular filtration rate levels were significantly lower in the neuropathy group. Between the groups, 25 (OH) vitamin D levels were significantly lower in the neuropathy group, while there were no differences in NGF levels or in oxidative stress markers. Michigan neuropathy examination score was positively correlated with age, and diabetes duration was negatively correlated with 25 (OH) vitamin D levels. In addition, 25 (OH) vitamin D was positively correlated with NGF. In the logistic regression analysis to determine the independent variables that will affect the development of neuropathy, duration of diabetes was detected as the only factor (p = 0.039, OR = 1.071). It seems that the most important risk factor for the development of neuropathy in type 1 diabetic patients is disease duration.

Microstructure representations for sound absorbing fibrous media: 3D and 2D multiscale modelling and experiments

NASA Astrophysics Data System (ADS)

Zieliński, Tomasz G.

2017-11-01

The paper proposes and investigates computationally-efficient microstructure representations for sound absorbing fibrous media. Three-dimensional volume elements involving non-trivial periodic arrangements of straight fibres are examined as well as simple two-dimensional cells. It has been found that a simple 2D quasi-representative cell can provide similar predictions as a volume element which is in general much more geometrically accurate for typical fibrous materials. The multiscale modelling allowed to determine the effective speeds and damping of acoustic waves propagating in such media, which brings up a discussion on the correlation between the speed, penetration range and attenuation of sound waves. Original experiments on manufactured copper-wire samples are presented and the microstructure-based calculations of acoustic absorption are compared with the corresponding experimental results. In fact, the comparison suggested the microstructure modifications leading to representations with non-uniformly distributed fibres.

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

NASA Astrophysics Data System (ADS)

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

2017-11-01

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

Cigarette Use and Striatal Dopamine D2/3 Receptors: Possible Role in the Link between Smoking and Nicotine Dependence.

PubMed

Okita, Kyoji; Mandelkern, Mark A; London, Edythe D

2016-11-01

Cigarette smoking induces dopamine release in the striatum, and smoking- or nicotine-induced ventral striatal dopamine release is correlated with nicotine dependence. Smokers also exhibit lower dopamine D2/3 receptor availability in the dorsal striatum than nonsmokers. Negative correlations of striatal dopamine D2/3 receptor availability with smoking exposure and nicotine dependence, therefore, might be expected but have not been tested. Twenty smokers had positron emission tomography scans with [ 18 F]fallypride to measure dopamine D2/3 receptor availability in ventral and dorsal regions of the striatum and provided self-report measures of recent and lifetime smoking and of nicotine dependence. As reported before, lifetime smoking was correlated with nicotine dependence. New findings were that ventral striatal dopamine D2/3 receptor availability was negatively correlated with recent and lifetime smoking and also with nicotine dependence. The results suggest an effect of smoking on ventral striatal D2/3 dopamine receptors that may contribute to nicotine dependence. © The Author 2016. Published by Oxford University Press on behalf of CINP.

Magnetic properties of tapiolite (FeTa2O6); a quasi two-dimensional (2D) antiferromagnet

NASA Astrophysics Data System (ADS)

Chung, E. M. L.; Lees, M. R.; McIntyre, G. J.; Wilkinson, C.; Balakrishnan, G.; Hague, J. P.; Visser, D.; McK Paul, D.

2004-11-01

The possibilities of two-dimensional (2D) short-range magnetic correlations and frustration effects in the mineral tapiolite are investigated using bulk-property measurements and neutron Laue diffraction. In this study of the magnetic properties of synthetic single-crystals of tapiolite, we find that single crystals of FeTa2O6 order antiferromagnetically at TN = 7.95 ± 0.05 K, with extensive two-dimensional correlations existing up to at least 40 K. Although we find no evidence that FeTa2O6 is magnetically frustrated, hallmarks of two-dimensional magnetism observed in our single-crystal data include: (i) broadening of the susceptibility maximum due to short-range correlations, (ii) a spin-flop transition and (iii) lambda anomalies in the heat capacity and d(χT)/dT. Complementary neutron Laue diffraction measurements reveal 1D magnetic diffuse scattering extending along the c* direction perpendicular to the magnetic planes. This magnetic diffuse scattering, observed for the first time using the neutron Laue technique by VIVALDI, arises directly as a result of 2D short-range spin correlations.

[Prevalence and symptoms of vitamin D deficiency in general practices].

PubMed

Merlo, C; Ross, C; Trummler, M; Zeller, A

2012-10-31

In 776 primary care patients serum vitamin D level was measured in month of september showing deficiency (<50 nmol/l) in 45,1%, severe deficiency (<30 nmol/l) in 9,8% and serum levels below the recommended target level of 75 nmol/l in 88,9% of cases. Three possible symptoms of vitamin D deficiency were assessed by a visual analogue scale (0-10): fatigue, muscle weakness, and muscle and joint pain. A significant correlation between muscle weakness and degree of vitamin D deficiency was shown (p=0,04), whereas there was no correlation in the two other symptoms. However, patients with vitamin D deficiency more frequently reported fatigue (p=0,02) and muscle weakness (p=0,009) than patients without deficiency did, and no difference was seen concerning muscle and joint pain.

Multiscale multifractal detrended-fluctuation analysis of two-dimensional surfaces

NASA Astrophysics Data System (ADS)

Wang, Fang; Fan, Qingju; Stanley, H. Eugene

2016-04-01

Two-dimensional (2D) multifractal detrended fluctuation analysis (MF-DFA) has been used to study monofractality and multifractality on 2D surfaces, but when it is used to calculate the generalized Hurst exponent in a fixed time scale, the presence of crossovers can bias the outcome. To solve this problem, multiscale multifractal analysis (MMA) was recent employed in a one-dimensional case. MMA produces a Hurst surface h (q ,s ) that provides a spectrum of local scaling exponents at different scale ranges such that the positions of the crossovers can be located. We apply this MMA method to a 2D surface and identify factors that influence the results. We generate several synthesized surfaces and find that crossovers are consistently present, which means that their fractal properties differ at different scales. We apply MMA to the surfaces, and the results allow us to observe these differences and accurately estimate the generalized Hurst exponents. We then study eight natural texture images and two real-world images and find (i) that the moving window length (WL) and the slide length (SL) are the key parameters in the MMA method, that the WL more strongly influences the Hurst surface than the SL, and that the combination of WL =4 and SL =4 is optimal for a 2D image; (ii) that the robustness of h (2 ,s ) to four common noises is high at large scales but variable at small scales; and (iii) that the long-term correlations in the images weaken as the intensity of Gaussian noise and salt and pepper noise is increased. Our findings greatly improve the performance of the MMA method on 2D surfaces.

Absolute and Relative Training Load and Its Relation to Fatigue in Football

PubMed Central

Zurutuza, Unai; Castellano, Julen; Echeazarra, Ibon; Casamichana, David

2017-01-01

The aim of the study was to assess the relationship of external and internal training load (TL) indicators with the objective and subjective fatigue experienced by 15 semi-professional football players, over eight complete weeks of the competition period in the 2015–2016 season, which covered microcycles from 34th to 41st. The maximum heart rate (HRmax) and maximum speed (Vmax) of all the players were previously measured in specific tests. The TL was monitored via questionnaires on rating of perceived exertion (RPE), pulsometers and GPS devices, registering the variables: total distance (TD), player load 2D (PL2D), TD at >80% of the Vmax (TD80), TD in deceleration at < -2 m⋅sec-2 (TDD <-2), TD in acceleration >2 m⋅sec-2 (TDA >2), Edwards (ED), time spent at between 50 and 80% (50–80% HRmax), 80–90% (80–90% HRmax), and >90% of the HRmax (>90% HRmax), and RPE both respiratory/thoracic (RPEres) and leg/muscular (RPEmus). All the variables were analyzed taking into account both the absolute values accumulated over the week and the normalized values in relation to individual mean competition values. Neuromuscular fatigue was measured objectively using the countermovement jump test and subjectively via the Total Quality Recovery (TQR) scale questionnaire. Analytical correlation techniques were later applied within the general linear model. There is a correlation between the fatigue experienced by the player, assessed objectively and subjectively, and the load accumulated over the week, this being assessed in absolute and relative terms. Specifically, the load relative to competition correlated with the physical variables TD (-0.279), PL2D (-0.272), TDD < -2 (-0.294), TDA >2 (-0.309), and sRPEmus (-0.287). The variables related to heart rate produced a higher correlation with TQR. There is a correlation between objectively and subjectively assessed fatigue and the accumulated TL of a player over the week, with a higher sensitivity being shown when compared to the values related to the demands of competition. Monitoring load and assessing fatigue, we are closer to knowing what the prescription of an adequate dose of training should be in order for a player to be as fresh as possible and in top condition for a match. Normalizing training demands with respect to competition could be an appropriate strategy for individualizing player TL. PMID:28634456

Isotope Mass Scaling of Turbulence and Transport

NASA Astrophysics Data System (ADS)

McKee, George; Yan, Zheng; Gohil, Punit; Luce, Tim; Rhodes, Terry

2017-10-01

The dependence of turbulence characteristics and transport scaling on the fuel ion mass has been investigated in a set of hydrogen (A = 1) and deuterium (A = 2) plasmas on DIII-D. Normalized energy confinement time (B *τE) is two times lower in hydrogen (H) plasmas compare to similar deuterium (D) plasmas. Dimensionless parameters other than ion mass (A) , including ρ*, q95, Te /Ti , βN, ν*, and Mach number were maintained nearly fixed. Matched profiles of electron density, electron and ion temperature, and toroidal rotation were well matched. The normalized turbulence amplitude (ñ / n) is approximately twice as large in H as in D, which may partially explain the increased transport and reduced energy confinement time. Radial correlation lengths of low-wavenumber density turbulence in hydrogen are similar to or slightly larger than correlation lengths in the deuterium plasmas and generally scale with the ion gyroradius, which were maintained nearly fixed in this dimensionless scan. Predicting energy confinement in D-T burning plasmas requires an understanding of the large and beneficial isotope scaling of transport. Supported by USDOE under DE-FG02-08ER54999 and DE-FC02-04ER54698.

Assessment of Myocardial Infarct Size by Three-Dimensional and Two-Dimensional Speckle Tracking Echocardiography: A Comparative Study to Single Photon Emission Computed Tomography.

PubMed

Wang, Qiushuang; Huang, Dangsheng; Zhang, Liwei; Shen, Dong; Ouyang, Qiaohong; Duan, Zhongxiang; An, Xiuzhi; Zhang, Meiqing; Zhang, Chunhong; Yang, Feifei; Zhi, Guang

2015-10-01

To compare three-dimensional (3D) and two-dimensional (2D) speckle tracking echocardiography (STE) techniques in the assessment of left ventricular function and myocardial infarct size (MIS). Thirty-two patients diagnosed with ST elevation myocardial infarction and 18 healthy control patients underwent 2D echocardiography, 3D echocardiography, and single photon emission computed tomography (SPECT). 3D left ventricular global area strain (GAS), 2D and 3D global longitudinal strain (GLS), global radial strain (GRS) as well as global circumferential strain (GCS) were analyzed to correlate with myocardial infarct size detected by SPECT. 2D and 3D left ventricular ejection fraction (LVEF) as well as 2D and 3D wall motion score index (WMSI) also were measured using conventional echocardiography. The 2D-GLS values were significantly higher than that of 3D-GLS, while 2D-GCS and GRS were significantly lower than 3D-GCS and GRS, respectively. However, no significant differences in LVEF and WMSI could be observed between 2D and 3D echocardiography. Myocardial strain indices, LVEF, and WMSI using 2D and 3D echocardiography also had good correlations with MIS as measured by SPECT. ROC curve analysis showed that the 3D and 2D myocardial indices, LVEF, and WMSI could distinguish between small and large MIS, while 2D-GLS had the highest AUC. The 2D and 3D myocardial strain indices correlated well with MIS by SPECT. Among them, the 2D-GLS showed the highest diagnostic value, while 3D-GRS and GCS had better diagnostic value than 2D-GRS and GCS. © 2015, Wiley Periodicals, Inc.

Magnetic Resonance T2-Relaxometry and 2D L-Correlated Spectroscopy in Patients with Minimal Hepatic Encephalopathy

PubMed Central

Singhal, Aparna; Nagarajan, Rajakumar; Kumar, Rajesh; Huda, Amir; Gupta, Rakesh K.; Thomas, M. Albert

2010-01-01

Purpose To evaluate T2-relaxation changes in patients with minimal hepatic encephalopathy (MHE) using T2-relaxometry and to correlate T2 values with brain metabolites evaluated using two-dimensional (2D) magnetic resonance spectroscopy (MRS). Materials and Methods Eight MHE patients and 13 healthy subjects were evaluated using T2-relaxometry, and 8 patients and 9 healthy subjects underwent 2D MRS in right frontal and left occipital regions. Whole brain T2-relaxation maps were compared between MHE and control subjects using analysis-of-covariance, with age and gender included as covariates. T2 values derived from the right frontal and left occipital lobes were correlated with the metabolite ratios. Results Multiple brain regions including anterior and mid cingulate cortices, right anterior and left posterior insular cortices, right prefrontal, medial frontal, and right superior temporal cortices showed significantly increased T2 values in MHE patients compared to control subjects. MRS showed significantly increased ratios of glutamine/glutamate (Glx) and decreased ratios of myo-inositol, taurine, choline, and myo-inositol/choline (mICh) with respect to creatine (Cr_d) in patients compared to controls. Frontal Glx/Cr_d showed significantly positive correlation with T2 values. Conclusion MHE patients showed significantly increased T2 values in multiple brain regions reflecting increased free water content and T2 values in frontal lobe correlated with the increased Glx/Cr_d ratio. PMID:19856435

One-dimensional Ising model with multispin interactions

NASA Astrophysics Data System (ADS)

Turban, Loïc

2016-09-01

We study the spin-1/2 Ising chain with multispin interactions K involving the product of m successive spins, for general values of m. Using a change of spin variables the zero-field partition function of a finite chain is obtained for free and periodic boundary conditions and we calculate the two-spin correlation function. When placed in an external field H the system is shown to be self-dual. Using another change of spin variables the one-dimensional Ising model with multispin interactions in a field is mapped onto a zero-field rectangular Ising model with first-neighbour interactions K and H. The 2D system, with size m × N/m, has the topology of a cylinder with helical BC. In the thermodynamic limit N/m\\to ∞ , m\\to ∞ , a 2D critical singularity develops on the self-duality line, \\sinh 2K\\sinh 2H=1.

Anisotropic magnification distortion of the 3D galaxy correlation. I. Real space

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

Hui, Lam; LoVerde, Marilena; Department of Physics, Columbia University, New York, New York 10027

2007-11-15

It has long been known that gravitational lensing, primarily via magnification bias, modifies the observed galaxy (or quasar) clustering. Such discussions have largely focused on the 2D angular correlation function. Here and in paper II [L. Hui, E. Gaztanaga, and M. LoVerde, arXiv:0710.4191] we explore how magnification bias distorts the 3D correlation function and power spectrum, as first considered by Matsubara [Astrophys. J. Lett. 537, L77 (2000).]. The interesting point is that the distortion is anisotropic. Magnification bias in general preferentially enhances the observed correlation in the line-of-sight (LOS) orientation, especially on large scales. For instance, at a LOS separationmore » of {approx}100 Mpc/h, where the intrinsic galaxy-galaxy correlation is rather weak, the observed correlation can be enhanced by lensing by a factor of a few, even at a modest redshift of z{approx}0.35. This effect presents an interesting opportunity as well as a challenge. The opportunity: this lensing anisotropy is distinctive, making it possible to separately measure the galaxy-galaxy, galaxy-magnification, and magnification-magnification correlations, without measuring galaxy shapes. The anisotropy is distinguishable from the well-known distortion due to peculiar motions, as will be discussed in paper II. The challenge: the magnification distortion of the galaxy correlation must be accounted for in interpreting data as precision improves. For instance, the {approx}100 Mpc/h baryon acoustic oscillation scale in the correlation function is shifted by up to {approx}3% in the LOS orientation, and up to {approx}0.6% in the monopole, depending on the galaxy bias, redshift, and number count slope. The corresponding shifts in the inferred Hubble parameter and angular diameter distance, if ignored, could significantly bias measurements of the dark energy equation of state. Lastly, magnification distortion offers a plausible explanation for the well-known excess correlations seen in pencil beam surveys.« less

Kinetic attractor phase diagrams of active nematic suspensions: the dilute regime.

PubMed

Forest, M Gregory; Wang, Qi; Zhou, Ruhai

2015-08-28

Large-scale simulations by the authors of the kinetic-hydrodynamic equations for active polar nematics revealed a variety of spatio-temporal attractors, including steady and unsteady, banded (1d) and cellular (2d) spatial patterns. These particle scale activation-induced attractors arise at dilute nanorod volume fractions where the passive equilibrium phase is isotropic, whereas all previous model simulations have focused on the semi-dilute, nematic equilibrium regime and mostly on low-moment orientation tensor and polarity vector models. Here we extend our previous results to complete attractor phase diagrams for active nematics, with and without an explicit polar potential, to map out novel spatial and dynamic transitions, and to identify some new attractors, over the parameter space of dilute nanorod volume fraction and nanorod activation strength. The particle-scale activation parameter corresponds experimentally to a tunable force dipole strength (so-called pushers with propulsion from the rod tail) generated by active rod macromolecules, e.g., catalysis with the solvent phase, ATP-induced propulsion, or light-activated propulsion. The simulations allow 2d spatial variations in all flow and orientational variables and full spherical orientational degrees of freedom; the attractors correspond to numerical integration of a coupled system of 125 nonlinear PDEs in 2d plus time. The phase diagrams with and without the polar interaction potential are remarkably similar, implying that polar interactions among the rodlike particles are not essential to long-range spatial and temporal correlations in flow, polarity, and nematic order. As a general rule, above a threshold, low volume fractions induce 1d banded patterns, whereas higher yet still dilute volume fractions yield 2d patterns. Again as a general rule, varying activation strength at fixed volume fraction induces novel dynamic transitions. First, stationary patterns saturate the instability of the isotropic state, consisting of discrete 1d banded or 2d cellular patterns depending on nanorod volume fraction. Increasing activation strength further induces a sequence of attractor bifurcations, including oscillations superimposed on the 1d and 2d stationary patterns, a uniform translational motion of 1d and 2d oscillating patterns, and periodic switching between 1d and 2d patterns. These results imply that active macromolecular suspensions are capable of long-range spatial and dynamic organization at isotropic equilibrium concentrations, provided particle-scale activation is sufficiently strong.

Thoracic Idiopathic Scoliosis Severity Is Highly Correlated with 3D Measures of Thoracic Kyphosis.

PubMed

Sullivan, T Barrett; Reighard, Fredrick G; Osborn, Emily J; Parvaresh, Kevin C; Newton, Peter O

2017-06-07

Loss of thoracic kyphosis has been associated with thoracic idiopathic scoliosis. Modern 3-dimensional (3D) imaging systems allow more accurate characterization of the scoliotic deformity than traditional radiographs. In this study, we utilized 3D calculations to characterize the association between increasing scoliosis severity and changes in the sagittal and axial planes. Patients evaluated in a scoliosis clinic and determined to have either a normal spine or idiopathic scoliosis were included in the analysis. All underwent upright, biplanar radiography with 3D reconstructions. Two-dimensional (2D) measurements of the magnitude of the thoracic major curve and the thoracic kyphosis were recorded. Image processing and MATLAB analysis were utilized to produce a 3D calculation of thoracic kyphosis and apical vertebral axial rotation. Regression analysis was performed to determine the correlation of 2D kyphosis, 3D kyphosis, and apical axial rotation with the magnitude of the thoracic major curve. The 442 patients for whom 2D and 3D data were collected had a main thoracic curve magnitude ranging from 1° to 118°. Linear regression analysis of the 2D and 3D T5-T12 kyphosis versus main thoracic curve magnitude yielded significant models (p < 0.05). The 2D model had a minimally negative slope (-0.07), a small R value (0.02), and a poor correlation coefficient (-0.14). In contrast, the 3D model had a strongly negative slope (-0.54), a high R value (0.56), and a strong correlation coefficient (-0.75). Curve magnitude also had a strong correlation with loss of 3D T1-T12 kyphosis and increasing apical axial rotation. Segmentally calculated 3D thoracic kyphosis had a strongly negative correlation with the magnitude of the main thoracic curve. With near uniformity, 3D thoracic kyphosis progressively decreased as scoliosis magnitude increased, at a rate of more than half the increase in the main thoracic curve magnitude. Analysis confirmed a surprisingly strong correlation between scoliosis severity and loss of 3D kyphosis that was absent in the 2D analysis. A similarly strong correlation between curve magnitude and apical axial rotation was evident. These findings lend further credence to the concept that scoliosis progresses in the coronal, sagittal, and axial planes simultaneously. The findings of this study suggest that 3D assessment is critical for adequate characterization of the multiplanar deformity of idiopathic scoliosis and deformity in the sagittal plane is linked to deformity in the coronal plane. Increasing severity of coronal plane curvature is associated with a progressive loss of thoracic kyphosis that should be anticipated so that the appropriate intraoperative techniques for correction of idiopathic scoliosis can be applied in all 3 planes.

Chinese Version of the EQ-5D Preference Weights: Applicability in a Chinese General Population

PubMed Central

Wu, Chunmei; Gong, Yanhong; Wu, Jiang; Zhang, Shengchao; Yin, Xiaoxv; Dong, Xiaoxin; Li, Wenzhen; Cao, Shiyi; Mkandawire, Naomie; Lu, Zuxun

2016-01-01

Objectives This study aimed to test the reliability, validity and sensitivity of Chinese version of the EQ-5D preference weights in Chinese general people, examine the differences between the China value set and the UK, Japan and Korea value sets, and provide methods for evaluating and comparing the EQ-5D value sets of different countries. Methods A random sample of 2984 community residents (15 years or older) were interviewed using a questionnaire including the EQ-5D scale. Level of agreement, convergent validity, known-groups validity and sensitivity of the EQ-5D China, United Kingdom (UK), Japan and Korea value sets were determined. Results The mean EQ-5D index scores were significantly (P<0.05) different among the UK (0.964), Japan (0.981), Korea (0.987), and China (0.985) weights. High level of agreement (intraclass correlations coefficients > 0.75) and convergent validity (Pearson’s correlation coefficients > 0.95) were found between each paired schemes. The EQ-5D index scores discriminated equally well for the four versions between levels of 10 known-groups (P< 0.05). The effect size and the relative efficiency statistics showed that the China weights had better sensitivity. Conclusions The China EQ-5D preference weights show equivalent psychometric properties with those from the UK, Japan and Korea weights while slightly more sensitive to known group differences than those from the Japan and Korea weights. Considering both psychometric and sociocultural issues, the China scheme should be a priority as an EQ-5D based measure of the health related quality of life in Chinese general population. PMID:27711169

[Semantic interference and pathological anxiety: experimental approach in generalized anxiety].

PubMed

Azaïs, F; Granger, B; Debray, Q

1994-01-01

Patients with D.S.M. III-R generalized anxiety disorder and normal controls performed a computerized Stroop color naming-task in which they named colors of threat-related, positive and neutral words. Compared to controls, generalized anxious patients revealed a longer response latency for threat-related words, without correlation with anxious measures on Spielberger State-Trait Anxiety Inventory. In normal control group, response delay to emotional words was correlated to anxious score on STAI-Trait. There was no difference between the two groups in a recognition memory task. The results suggest existence of different semantic interference in categorical and normal anxiety, without implication of explicit memory.

Correlation between a 2D Channelized Hotelling Observer and Human Observers in a Low-contrast Detection Task with Multi-slice Reading in CT

PubMed Central

Yu, Lifeng; Chen, Baiyu; Kofler, James M.; Favazza, Christopher P.; Leng, Shuai; Kupinski, Matthew A.; McCollough, Cynthia H.

2017-01-01

Purpose Model observers have been successfully developed and used to assess the quality of static 2D CT images. However, radiologists typically read images by paging through multiple 2D slices (i.e. multi-slice reading). The purpose of this study was to correlate human and model observer performance in a low-contrast detection task performed using both 2D and multi-slice reading, and to determine if the 2D model observer still correlate well with human observer performance in multi-slice reading. Methods A phantom containing 18 low-contrast spheres (6 sizes × 3 contrast levels) was scanned on a 192-slice CT scanner at 5 dose levels (CTDIvol = 27, 13.5, 6.8, 3.4, and 1.7 mGy), each repeated 100 times. Images were reconstructed using both filtered-backprojection (FBP) and an iterative reconstruction (IR) method (ADMIRE, Siemens). A 3D volume of interest (VOI) around each sphere was extracted and placed side-by-side with a signal-absent VOI to create a 2-alternative forced choice (2AFC) trial. Sixteen 2AFC studies were generated, each with 100 trials, to evaluate the impact of radiation dose, lesion size and contrast, and reconstruction methods on object detection. In total, 1600 trials were presented to both model and human observers. Three medical physicists acted as human observers and were allowed to page through the 3D volumes to make a decision for each 2AFC trial. The human observer performance was compared with the performance of a multi-slice channelized Hotelling observer (CHO_MS), which integrates multi-slice image data, and with the performance of previously validated CHO, which operates on static 2D images (CHO_2D). For comparison, the same 16 2AFC studies were also performed in a 2D viewing mode by the human observers and compared with the multi-slice viewing performance and the two CHO models. Results Human observer performance was well correlated with the CHO_2D performance in the 2D viewing mode (Pearson product-moment correlation coefficient R=0.972, 95% confidence interval (CI): 0.919 to 0.990) and with the CHO_MS performance in the multi-slice viewing mode (R=0.952, 95% CI: 0.865 to 0.984). The CHO_2D performance, calculated from the 2D viewing mode, also had a strong correlation with human observer performance in the multi-slice viewing mode (R=0.957, 95% CI: 879 to 0.985). Human observer performance varied between the multi-slice and 2D modes. One reader performed better in the multi-slice mode (p=0.013); whereas the other two readers showed no significant difference between the two viewing modes (p=0.057 and p=0.38). Conclusions A 2D CHO model is highly correlated with human observer performance in detecting spherical low contrast objects in multi-slice viewing of CT images. This finding provides some evidence for the use of a simpler, 2D CHO to assess image quality in clinically relevant CT tasks where multi-slice viewing is used. PMID:28555878

Correlation between a 2D channelized Hotelling observer and human observers in a low-contrast detection task with multislice reading in CT.

PubMed

Yu, Lifeng; Chen, Baiyu; Kofler, James M; Favazza, Christopher P; Leng, Shuai; Kupinski, Matthew A; McCollough, Cynthia H

2017-08-01

Model observers have been successfully developed and used to assess the quality of static 2D CT images. However, radiologists typically read images by paging through multiple 2D slices (i.e., multislice reading). The purpose of this study was to correlate human and model observer performance in a low-contrast detection task performed using both 2D and multislice reading, and to determine if the 2D model observer still correlate well with human observer performance in multislice reading. A phantom containing 18 low-contrast spheres (6 sizes × 3 contrast levels) was scanned on a 192-slice CT scanner at five dose levels (CTDI vol = 27, 13.5, 6.8, 3.4, and 1.7 mGy), each repeated 100 times. Images were reconstructed using both filtered-backprojection (FBP) and an iterative reconstruction (IR) method (ADMIRE, Siemens). A 3D volume of interest (VOI) around each sphere was extracted and placed side-by-side with a signal-absent VOI to create a 2-alternative forced choice (2AFC) trial. Sixteen 2AFC studies were generated, each with 100 trials, to evaluate the impact of radiation dose, lesion size and contrast, and reconstruction methods on object detection. In total, 1600 trials were presented to both model and human observers. Three medical physicists acted as human observers and were allowed to page through the 3D volumes to make a decision for each 2AFC trial. The human observer performance was compared with the performance of a multislice channelized Hotelling observer (CHO_MS), which integrates multislice image data, and with the performance of previously validated CHO, which operates on static 2D images (CHO_2D). For comparison, the same 16 2AFC studies were also performed in a 2D viewing mode by the human observers and compared with the multislice viewing performance and the two CHO models. Human observer performance was well correlated with the CHO_2D performance in the 2D viewing mode [Pearson product-moment correlation coefficient R = 0.972, 95% confidence interval (CI): 0.919 to 0.990] and with the CHO_MS performance in the multislice viewing mode (R = 0.952, 95% CI: 0.865 to 0.984). The CHO_2D performance, calculated from the 2D viewing mode, also had a strong correlation with human observer performance in the multislice viewing mode (R = 0.957, 95% CI: 879 to 0.985). Human observer performance varied between the multislice and 2D modes. One reader performed better in the multislice mode (P = 0.013); whereas the other two readers showed no significant difference between the two viewing modes (P = 0.057 and P = 0.38). A 2D CHO model is highly correlated with human observer performance in detecting spherical low contrast objects in multislice viewing of CT images. This finding provides some evidence for the use of a simpler, 2D CHO to assess image quality in clinically relevant CT tasks where multislice viewing is used. © 2017 American Association of Physicists in Medicine.

Point processes in arbitrary dimension from fermionic gases, random matrix theory, and number theory

NASA Astrophysics Data System (ADS)

Torquato, Salvatore; Scardicchio, A.; Zachary, Chase E.

2008-11-01

It is well known that one can map certain properties of random matrices, fermionic gases, and zeros of the Riemann zeta function to a unique point process on the real line \\mathbb {R} . Here we analytically provide exact generalizations of such a point process in d-dimensional Euclidean space \\mathbb {R}^d for any d, which are special cases of determinantal processes. In particular, we obtain the n-particle correlation functions for any n, which completely specify the point processes in \\mathbb {R}^d . We also demonstrate that spin-polarized fermionic systems in \\mathbb {R}^d have these same n-particle correlation functions in each dimension. The point processes for any d are shown to be hyperuniform, i.e., infinite wavelength density fluctuations vanish, and the structure factor (or power spectrum) S(k) has a non-analytic behavior at the origin given by S(k)~|k| (k \\rightarrow 0 ). The latter result implies that the pair correlation function g2(r) tends to unity for large pair distances with a decay rate that is controlled by the power law 1/rd+1, which is a well-known property of bosonic ground states and more recently has been shown to characterize maximally random jammed sphere packings. We graphically display one-and two-dimensional realizations of the point processes in order to vividly reveal their 'repulsive' nature. Indeed, we show that the point processes can be characterized by an effective 'hard core' diameter that grows like the square root of d. The nearest-neighbor distribution functions for these point processes are also evaluated and rigorously bounded. Among other results, this analysis reveals that the probability of finding a large spherical cavity of radius r in dimension d behaves like a Poisson point process but in dimension d+1, i.e., this probability is given by exp[-κ(d)rd+1] for large r and finite d, where κ(d) is a positive d-dependent constant. We also show that as d increases, the point process behaves effectively like a sphere packing with a coverage fraction of space that is no denser than 1/2d. This coverage fraction has a special significance in the study of sphere packings in high-dimensional Euclidean spaces.

Facts and Misconceptions about 2D:4D, Social and Risk Preferences

PubMed Central

Alonso, Judit; Di Paolo, Roberto; Ponti, Giovanni; Sartarelli, Marcello

2018-01-01

We study how the ratio between the length of the second and fourth digit (2D:4D) correlates with choices in social and risk preferences elicitation tasks by building a large dataset from five experimental projects with more than 800 subjects. Our results confirm the recent literature that downplays the link between 2D:4D and many domains of economic interest, such as social and risk preferences. As for the former, we find that social preferences are significantly lower when 2D:4D is above the median value only for subjects with low cognitive ability. As for the latter, we find that a high 2D:4D is not correlated with the frequency of subjects' risky choices. PMID:29487510

Prenatal testosterone and stuttering.

PubMed

Montag, Christian; Bleek, Benjamin; Breuer, Svenja; Prüss, Holger; Richardt, Kirsten; Cook, Susanne; Yaruss, J Scott; Reuter, Martin

2015-01-01

The prevalence of stuttering is much higher in males compared to females. The biological underpinnings of this skewed sex-ratio is poorly understood, but it has often been speculated that sex hormones could play an important role. The present study investigated a potential link between prenatal testosterone and stuttering. Here, an indirect indicator of prenatal testosterone levels, the Digit Ratio (2D:4D) of the hand, was used. As numerous studies have shown, hands with more "male" characteristics (putatively representing greater prenatal testosterone levels) are characterized by a longer ring finger compared to the index finger (represented as a lower 2D:4D ratio) in the general population. We searched for differences in the 2D:4D ratios between 38 persons who stutter and 36 persons who do not stutter. In a second step, we investigated potential links between the 2D:4D ratio and the multifaceted symptomatology of stuttering, as measured by the Overall Assessment of the Speaker's Experience of Stuttering (OASES), in a larger sample of 44 adults who stutter. In the first step, no significant differences in the 2D:4D were observed between individuals who stutter and individuals who do not stutter. In the second step, 2D:4D correlated negatively with higher scores of the OASES (representing higher negative experiences due to stuttering), and this effect was more pronounced for female persons who stutter. The findings indicate for the first time that prenatal testosterone may influence individual differences in psychosocial impact of this speech disorder. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prostaglandin metabolising enzymes and PGE2 are inversely correlated with vitamin D receptor and 25(OH)2D3 in breast cancer.

PubMed

Thill, Marc; Fischer, Dorothea; Hoellen, Friederike; Kelling, Katharina; Dittmer, Christine; Landt, Solveig; Salehin, Darius; Diedrich, Klaus; Friedrich, Michael; Becker, Steffi

2010-05-01

Breast cancer is associated with inflammatory processes based on an up-regulation of cyclooxygenase-2 (COX-2) expression. The antiproliferative effects of calcitriol (1,25(OH)(2)D(3)) mediated via the vitamin D receptor (VDR) render vitamin D a promising target in breast cancer therapy. First data suggest a correlation between vitamin D and prostaglandin metabolism. We determined the expression of VDR, COX-2, 15-PGDH and the prostaglandin receptors EP(2)/EP(4) in normal and malignant breast tissue by real-time PCR and Western blot analysis, as well as 25(OH)(2)D(3) and PGE(2) plasma levels from healthy and breast cancer patients. Significantly higher COX-2, lower VDR and lower EP(2) and EP(4) receptor protein levels in the malignant tissue and a significantly lower 15-PGDH protein level in normal breast tissue were detected. Breast cancer patients older than 45 years, diagnosed and sampled in the winter time had significantly lower 25(OH)(2)D(3) and higher PGE(2) serum levels. The inverse correlation between VDR and both COX-2 and 15-PGDH, as well as between PGE(2) and 25(OH)(2)D(3) levels, suggests a possible link between VDR-associated target genes and prostaglandin metabolism.

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

Avakian, Harut

Studies of the 3D structure of the nucleon encoded in Transverse Momentum Dependent distribution and fragmentation functions of partons and Generalized Parton Distributions are among the key objectives of the JLab 12 GeV upgrade and the Electron Ion Collider. Main challenges in extracting 3D partonic distributions from precision measurements of hard scattering processes include clear understanding of leading twist QCD fundamentals, higher twist effects, and also correlations of hadron production in target and current fragmentation regions. In this contribution we discuss some ongoing studies and future measurements of spin-orbit correlations at Jefferson Lab.

The General Formulation and Practical Calculation of the Diffusion Coefficient in a Lattice Containing Cavities; FORMULATION GENERALE ET CALCUL PRATIQUE DU COEFFICIENT DE DIFFUSION DANS UN RESEAU COMPORTANT DES CAVITES (in French)

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

Benoist, P.

The calculation of diffusion coefficients in a lattice necessitates the knowledge of a correct method of weighting the free paths of the different constituents. An unambiguous definition of this weighting method is given here, based on the calculation of leakages from a zone of a reactor. The formulation obtained, which is both simple and general, reduces the calculation of diffusion coefficients to that of collision probabilities in the different media; it reveals in the expression for the radial coefficient the series of the terms of angular correlation (cross terms) recently shown by several authors. This formulation is then used tomore » calculate the practical case of a classical type of lattice composed of a moderator and a fuel element surrounded by an empty space. Analytical and numerical comparison of the expressions obtained with those inferred from the theory of BEHRENS shows up the importance of several new terms some of which are linked with the transparency of the fuel element. Cross terms up to the second order are evaluated. A practical formulary is given at the end of the paper. (author) [French] Le calcul des coefficients de diffusion dans un reseau suppose la connaissance d'un mode de ponderation correct des libres parcours des differents constituants. On definit ici sans ambiguite ce mode de ponderation a partir du calcul des fuites hors d'une zone de reacteur. La formulation obtenue, simple et generale, ramene le calcul des coefficients de diffusion a celui des probabilites de collision dans les differents milieux; elle fait apparaitre dans l'expression du coefficient radial la serie des termes de correlation angulaire (termes rectangles), mis en evidence recemment par plusieurs auteurs. Cette formulation est ensuite appliquee au calcul pratique d'un reseau classique, compose d'un moderateur et d'un element combustible entoure d'une cavite; la comparaison analytique et numerique des expressions obtenues avec celles deduites de la theorie de BEHRENS fait apparaitre l'importance de plusieurs termes nouveaux, dont certains sont lies a la transparence de l'element combustible; les termes rectangles sont calcules jusqu'a l'ordre 2. Un formulaire pratique est donne a la fin de cette etude. (auteur)« less

[Correlation between serum 25-hydroxyvitamin D level and core symptoms of autism spectrum disorder in children].

PubMed

Dong, H Y; Wang, B; Li, H H; Shan, L; Jia, F Y

2017-12-02

Objective: To explore the relationship between serum 25-hydroxyvitamin D levels and core symptoms of autism spectrum disorder (ASD) in children. Method: In this cross-sectional study, ASD children 4 to 6 years of age who were diagnosed in Department of Developmental and Behavioral Pediatrics, First Hospital of Jilin university from January to May 2017 were assigned to ASD group, and children for routine growth and development assessment in Jilin province were assigned to control group. The two groups were well matched for age and sex, and none of them had received vitamin D supplementation. Serum 25-hydroxyvitamin D levels were measured by HPLC-MS/MS method. The patients of the ASD group were assessed with autism behavior checklist (ABC), childhood autism rating scale (CARS), social response scale (SRS), and autism treatment evaluation checklist (ATEC). The levels of vitamin D were divided into normal(>0.03 ng/L), insufficient (0.01-0.03 ng/L) and deficient (<0.01 ng/L). Levels of serum vitamin D between the two groups were compared by two independent sample t -test, and the difference in the percentages of normal, insufficient and deficient levels of vitamin D was tested by chi-square test, and correlations between vitamin D levels and the total scores or subscales of ABC, CARS, SRS and ATEC were analyzed by Pearson correlation analysis. Result: The 87 subjects in the ASD group included 75 males and 12 females, with a mean (±SD) age of (4.7±0.7) years. The 301 subjects in the control group included 249 males and 52 females, with a mean (±SD) age of (4.8±0.8) years. Serum vitamin D level in ASD children was significantly lower than that of the control group ( (0.021±0.008) vs . (0.036±0.016) ng/L, t= -8.17, P< 0.01), and the between-group percentage difference of normal, insufficient and deficient levels of vitamin D was statistically significant (12 (14%) vs . 186 (62%) , 67 (77%) vs . 113 (37%) , 8 (9%) vs . 2 (1%) , χ(2)=72.1, P< 0.01). There were negative correlations between serum vitamin D level in ASD children and total ABC score or ABC subscale scores (body behavior, self-care, language and social interaction)( r=- 0.531, - 0.397,-0.283,-0.248,-0.262, P= 0.000, 0.000, 0.007, 0.020, 0.014). There were negative correlations between serum vitamin D level in ASD children and total CARS score and CARS subscale scores (imitation, nonverbal communication and general impression) ( r=- 0.352, - 0.216, - 0.248, - 0.216, P= 0.001, 0.046, 0.021, 0.046). There were negative correlations between serum vitamin D level in ASD children and SRS behavior subscale or ATEC social interaction subscale ( r=- 0.536, P= 0.005, r=- 0.400, P= 0.014). Conclusion: Serum 25-hydroxyvitamin D level in children with ASD is obviously lower than that in the healthy control group, and there are negative correlations between vitamin D levels and core symptoms of ASD. Trial registration Chinese Clinical Trial Registry, ChiCTR-CCC-13004498.

Prevalence and predictors of vitamin D inadequacy amongst Lebanese osteoporotic women.

PubMed

Gannagé-Yared, Marie-Hélène; Maalouf, Ghassan; Khalife, Simon; Challita, Samir; Yaghi, Yasser; Ziade, Nelly; Chalfoun, Amal; Norquist, Josephine; Chandler, Julie

2009-02-01

In Middle-Eastern countries, more particularly in Lebanon, the incidence of vitamin D deficiency has been found to be surprisingly high in schoolchildren and young individuals. However, the prevalence and risk factors for vitamin D inadequacy amongst Lebanese osteoporotic women seeking medical health care has never been studied. We analysed vitamin D-inadequacy risk factors among the 251 Lebanese postmenopausal osteoporotic women (from both Muslim and Christian communities) who participated in a vitamin D international epidemiological study. Vitamin D inadequacy prevalence (25-hydroxyvitamin D (25(OH)D) , 30 ng/ml) was 84.9%. 25(OH)D was negatively correlated with BMI (r 20.41; P<0.001) and positively correlated with educational level (r 0.37; P<0.001) and self-reported general health (r 0.17; P<0.01). No significant correlation was found with age and no seasonal variation was observed. There was no significant correlation between 25(OH)D and sun exposure index or vitamin D-rich food consumption. However, 25(OH)D strongly correlated with vitamin D supplement intake (r 0.48; P<0.0001). Muslim community participants had lower 25(OH)D levels compared with their Christian counterparts (P<0.001). They also had higher BMI, lower educational level and vitamin D supplement consumption and followed more frequently a dress code covering the arms (P<0.0001 for all variables). In a multivariate model, in Muslims, inadequate vitamin D supplements and a dress code covering the arms are the independent predictors of 25(OH)D inadequacy (P<0.001 for both variables). However, in Christians, the predictors are inadequate vitamin D supplements, high BMI and low educational level (P<0.001; P=002 and P=0.02 respectively). There is an urgent need to increase vitamin D supplement use in Middle-Eastern osteoporotic women, more particularly in those from the Muslim community.

Dopamine D2 Receptor Levels in Striatum, Thalamus, Substantia Nigra, Limbic Regions, and Cortex in Schizophrenic Subjects

PubMed Central

Kessler, Robert M; Woodward, Neil D; Riccardi, Patrizia; Li, Rui; Ansari, M Sib; Anderson, Sharlett; Dawant, Benoit; Zald, David; Meltzer, Herbert Y

2009-01-01

Background Studies in schizophrenics have reported dopaminergic abnormalities in striatum, substantia nigra, thalamus, anterior cingulate, hippocampus and cortex which have been related to positive symptoms and cognitive impairments. Methods [18F]fallypride PET studies were performed in off medication or never medicated schizophrenic subjects [N = 11, 6 M, 5 F; mean age of 30.5 ± 8.0 (S.D.); 4 drug naive] and age matched healthy subjects [N = 11, 5M, 6F, mean age of 31.6 ± 9.2 (S.D.)] to examine dopamine D2 receptor (DA D2r) levels in the caudate, putamen, ventral striatum, medial thalamus, posterior thalamus, substantia nigra, amygdala, temporal cortex, anterior cingulate, and hippocampus. Results In schizophrenic subjects increased DA D2r levels were seen in the substantia nigra bilaterally; decreased levels were seen in the left medial thalamus. Correlations of symptoms with region of interest data demonstrated a significant correlation of disorganized thinking/nonparanoid delusions with the right temporal cortex region of interest (r = 0.94, P = 0.0001) which remained significant after correction for multiple comparisons (P<0.03). Correlations of symptoms with parametric images of DA D2r levels revealed no significant clusters of correlations with negative symptoms, but significant clusters of positive correlations of total positive symptoms, delusions and bizarre behavior with the lateral and anterior temporal cortex, and hallucinations with the left ventral striatum. Conclusions The results of this study demonstrate abnormal DA D2r mediated neurotransmission in the substantia nigra consistent with nigral dysfunction in schizophrenia and suggest that both temporal cortical and ventral striatal DA D2r mediate positive symptoms. PMID:19251247

Correlation between genetic features of the mef(A)-msr(D) locus and erythromycin resistance in Streptococcus pyogenes.

PubMed

Vitali, Luca Agostino; Di Luca, Maria Chiara; Prenna, Manuela; Petrelli, Dezemona

2016-01-01

We investigated the correlation between the genetic variation within mef(A)-msr(D) determinants of efflux-mediated erythromycin resistance in Streptococcus pyogenes and the level of erythromycin resistance. Twenty-eight mef(A)-positive strains were selected according to erythromycin MIC (4-32 μg/mL), and their mef(A)-msr(D) regions were sequenced. Strains were classified according to the bacteriophage carrying mef(A)-msr(D). A new Φm46.1 genetic variant was found in 8 strains out of 28 and named VP_00501.1. Degree of allelic variation was higher in mef(A) than in msr(D). Hotspots for recombination were mapped within the locus that could have shaped the apparent mosaic structure of the region. There was a general correlation between mef(A)-msr(D) sequence and erythromycin resistance level. However, lysogenic conversion of susceptible strains by mef(A)-msr(D)-carrying Φm46.1 indicated that key determinants may not all reside within the mef(A)-msr(D) locus and that horizontal gene transfer could contribute to changes in the level of antibiotic resistance in S. pyogenes. Copyright © 2016 Elsevier Inc. All rights reserved.

Revisiting Geschwind's hypothesis on brain lateralisation: a functional MRI study of digit ratio (2D:4D) and sex interaction effects on spatial working memory.

PubMed

Kalmady, Sunil Vasu; Agarwal, Sri Mahavir; Shivakumar, Venkataram; Jose, Dania; Venkatasubramanian, Ganesan; Reddy, Y C Janardhan

2013-01-01

The Geschwind-Behan-Galaburda (GBG) hypothesis links cerebral lateralisation with prenatal testosterone exposure. Digit ratio measures in adults have been established as potential markers of foetal sex hormonal milieu. The aim of the study was to evaluate the sex-dependent interaction of digit ratio measures and cerebral lateralization as well as their neurohemodynamic correlates using functional MRI (fMRI). Digit ratio measures-ratio of index finger (2D) length to ring finger (4D) length (2D:4D) and difference between 2D:4D of two hands, i.e., right minus left (DR-L)-were calculated using high resolution digital images in 70 right-handed participants (42 men) based on reliable and valid method. fMRI was acquired during the performance of a spatial working memory task in a subset of 25 individuals (14 men), and analysed using Statistical Parametric Mapping 8 (SPM8) and the Laterality Index toolbox for SPM8. Men had significantly less bilateral 2D:4D than women. There was a significant negative correlation between right 2D:4D and 2-Back task accuracy (2BACC) in women. A significant sex-by-right 2D:4D interaction was observed in left parahippocampal gyrus activation. Additionally, sex-by-DR-L interaction was observed in left IPL activation. DR-L showed a significant positive correlation with the whole brain Laterality Index (LI), and LI, in turn, demonstrated a significant negative correlation with 2BACC. Our study observations suggest several novel sex-differential relationships between 2D:4D measures and fMRI activation during spatial working memory task performance. Given the pre-existing background data supporting digit ratio measures as putative indicator of prenatal sex hormonal milieu, our study findings add support to the Geschwind-Behan-Galaburda (GBG) hypothesis.

Two-dimensional fluorescence correlation spectroscopy: resolution of fluorescence of tryptophan residues in horse heart myoglobin.

PubMed

Nakashima, Kenichi; Yuda, Kazuki; Ozaki, Yukihiro; Noda, Isao

2003-11-01

Generalized two-dimensional (2D) fluorescence correlation spectroscopy has been used to resolve fluorescence of two tryptophan (Trp) residues in horse heart myoglobin. Fluorescence quenching is employed as a perturbation mode for causing intensity changes in the fluorescence (quenching perturbation). Two kinds of quenchers, iodide ion and acrylamide, are used for inducing fluorescence intensity change. This technique works because the Trp residue located at the 7th position (W7) is known to be easily accessible to the quencher, whereas that located at the 14th position (W14) is not. By this technique, the fluorescence spectra of the two Trp residues were clearly resolved. From asynchronous maps, it was also shown that the quenching of W7 fluorescence is brought about prior to the quenching of W14 fluorescence. This result is consistent with the structure of horse heart myoglobin that was proposed earlier. Furthermore, it was elucidated that the present 2D analysis is not interfered with by Raman bands of the solvents, which sometimes brings difficulty into conventional fluorescence analysis.

2D-3D rigid registration to compensate for prostate motion during 3D TRUS-guided biopsy.

PubMed

De Silva, Tharindu; Fenster, Aaron; Cool, Derek W; Gardi, Lori; Romagnoli, Cesare; Samarabandu, Jagath; Ward, Aaron D

2013-02-01

Three-dimensional (3D) transrectal ultrasound (TRUS)-guided systems have been developed to improve targeting accuracy during prostate biopsy. However, prostate motion during the procedure is a potential source of error that can cause target misalignments. The authors present an image-based registration technique to compensate for prostate motion by registering the live two-dimensional (2D) TRUS images acquired during the biopsy procedure to a preacquired 3D TRUS image. The registration must be performed both accurately and quickly in order to be useful during the clinical procedure. The authors implemented an intensity-based 2D-3D rigid registration algorithm optimizing the normalized cross-correlation (NCC) metric using Powell's method. The 2D TRUS images acquired during the procedure prior to biopsy gun firing were registered to the baseline 3D TRUS image acquired at the beginning of the procedure. The accuracy was measured by calculating the target registration error (TRE) using manually identified fiducials within the prostate; these fiducials were used for validation only and were not provided as inputs to the registration algorithm. They also evaluated the accuracy when the registrations were performed continuously throughout the biopsy by acquiring and registering live 2D TRUS images every second. This measured the improvement in accuracy resulting from performing the registration, continuously compensating for motion during the procedure. To further validate the method using a more challenging data set, registrations were performed using 3D TRUS images acquired by intentionally exerting different levels of ultrasound probe pressures in order to measure the performance of our algorithm when the prostate tissue was intentionally deformed. In this data set, biopsy scenarios were simulated by extracting 2D frames from the 3D TRUS images and registering them to the baseline 3D image. A graphics processing unit (GPU)-based implementation was used to improve the registration speed. They also studied the correlation between NCC and TREs. The root-mean-square (RMS) TRE of registrations performed prior to biopsy gun firing was found to be 1.87 ± 0.81 mm. This was an improvement over 4.75 ± 2.62 mm before registration. When the registrations were performed every second during the biopsy, the RMS TRE was reduced to 1.63 ± 0.51 mm. For 3D data sets acquired under different probe pressures, the RMS TRE was found to be 3.18 ± 1.6 mm. This was an improvement from 6.89 ± 4.1 mm before registration. With the GPU based implementation, the registrations were performed with a mean time of 1.1 s. The TRE showed a weak correlation with the similarity metric. However, the authors measured a generally convex shape of the metric around the ground truth, which may explain the rapid convergence of their algorithm to accurate results. Registration to compensate for prostate motion during 3D TRUS-guided biopsy can be performed with a measured accuracy of less than 2 mm and a speed of 1.1 s, which is an important step toward improving the targeting accuracy of a 3D TRUS-guided biopsy system.

Association between Intake of Sugar-Sweetened Beverages and Circulating 25-Hydroxyvitamin D Concentration among Premenopausal Women

PubMed Central

Duchaine, Caroline S.; Diorio, Caroline

2014-01-01

Intake of sugar-sweetened beverages has increased in North America and seems to have several adverse health effects possibly through decreased circulating 25-hydroxyvitamin D (25(OH)D) concentrations. The aim of this cross-sectional study was to evaluate the association between sugar-sweetened beverages intake and 25(OH)D concentrations among premenopausal women. Intake of sugar-sweetened beverages including colas, other carbonated beverages and sweet fruit drinks was assessed using a validated food frequency questionnaire among 741 premenopausal women. Plasma concentrations of 25(OH)D were quantified by radioimmunoassay. The association between sugar-sweetened beverages intake and 25(OH)D concentrations was evaluated using multivariate generalized linear models and Spearman correlations. A higher intake of colas was associated with lower mean 25(OH)D levels (67.0, 63.7, 64.7 and 58.5 nmol/L for never, <1, 1–3 and >3 servings/week, respectively; r = −0.11 (p = 0.004)). A correlation was observed between intake of other carbonated beverages and 25(OH)D concentrations but was not statistically significant (r = −0.06 (p = 0.10)). No association was observed between intake of sweet fruit drinks and 25(OH)D concentrations. This study suggests that high intake of colas may decrease 25(OH)D levels in premenopausal women. Considering the high consumption of these drinks in the general population and the possible consequences of vitamin D deficiency on health, this finding needs further investigation. PMID:25072269

Association between intake of sugar-sweetened beverages and circulating 25-hydroxyvitamin D concentration among premenopausal women.

PubMed

Duchaine, Caroline S; Diorio, Caroline

2014-07-28

Intake of sugar-sweetened beverages has increased in North America and seems to have several adverse health effects possibly through decreased circulating 25-hydroxyvitamin D (25(OH)D) concentrations. The aim of this cross-sectional study was to evaluate the association between sugar-sweetened beverages intake and 25(OH)D concentrations among premenopausal women. Intake of sugar-sweetened beverages including colas, other carbonated beverages and sweet fruit drinks was assessed using a validated food frequency questionnaire among 741 premenopausal women. Plasma concentrations of 25(OH)D were quantified by radioimmunoassay. The association between sugar-sweetened beverages intake and 25(OH)D concentrations was evaluated using multivariate generalized linear models and Spearman correlations. A higher intake of colas was associated with lower mean 25(OH)D levels (67.0, 63.7, 64.7 and 58.5 nmol/L for never, <1, 1-3 and >3 servings/week, respectively; r = -0.11 (p = 0.004)). A correlation was observed between intake of other carbonated beverages and 25(OH)D concentrations but was not statistically significant (r = -0.06 (p = 0.10)). No association was observed between intake of sweet fruit drinks and 25(OH)D concentrations. This study suggests that high intake of colas may decrease 25(OH)D levels in premenopausal women. Considering the high consumption of these drinks in the general population and the possible consequences of vitamin D deficiency on health, this finding needs further investigation.

Direct comparison of cardiac magnetic resonance feature tracking and 2D/3D echocardiography speckle tracking for evaluation of global left ventricular strain.

PubMed

Obokata, Masaru; Nagata, Yasufumi; Wu, Victor Chien-Chia; Kado, Yuichiro; Kurabayashi, Masahiko; Otsuji, Yutaka; Takeuchi, Masaaki

2016-05-01

Cardiac magnetic resonance (CMR) feature tracking (FT) with steady-state free precession (SSFP) has advantages over traditional myocardial tagging to analyse left ventricular (LV) strain. However, direct comparisons of CMRFT and 2D/3D echocardiography speckle tracking (2/3DEST) for measurement of LV strain are limited. The aim of this study was to investigate the feasibility and reliability of CMRFT and 2D/3DEST for measurement of global LV strain. We enrolled 106 patients who agreed to undergo both CMR and 2D/3DE on the same day. SSFP images at multiple short-axis and three apical views were acquired. 2DE images from three levels of short-axis, three apical views, and 3D full-volume datasets were also acquired. Strain data were expressed as absolute values. Feasibility was highest in CMRFT, followed by 2DEST and 3DEST. Analysis time was shortest in 3DEST, followed by CMRFT and 2DEST. There was good global longitudinal strain (GLS) correlation between CMRFT and 2D/3DEST (r = 0.83 and 0.87, respectively) with the limit of agreement (LOA) ranged from ±3.6 to ±4.9%. Excellent global circumferential strain (GCS) correlation between CMRFT and 2D/3DEST was observed (r = 0.90 and 0.88) with LOA of ±6.8-8.5%. Global radial strain showed fair correlations (r = 0.69 and 0.82, respectively) with LOA ranged from ±12.4 to ±16.3%. CMRFT GCS showed least observer variability with highest intra-class correlation. Although not interchangeable, the high GLS and GCS correlation between CMRFT and 2D/3DEST makes CMRFT a useful modality for quantification of global LV strain in patients, especially those with suboptimal echo image quality. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Galactic cannibalism. IV. The evidence-correlations between dynamical time scales and Bautz-Morgan type

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

McGlynn, T.A.; Ostriker, J.P.

1980-11-01

If the luminosity of supergiant cD galaxies in particular, and the Bautz-Morgan sequence of galaxy types in general, is produced by dynamical evolutionary processes, then one expects to find a correlation between dynamical times and ..delta..M/sub 12/, the magnitude difference between first and second brightest cluster members.

Vaccine-induced antibodies to herpes simplex virus glycoprotein D epitopes involved in virus entry and cell-to-cell spread correlate with protection against genital disease in guinea pigs

PubMed Central

Brooks, Benjamin D.; Friedman, Harvey M.

2018-01-01

Herpes simplex virus type 2 (HSV-2) glycoprotein D (gD2) subunit antigen is included in many preclinical candidate vaccines. The rationale for including gD2 is to produce antibodies that block crucial gD2 epitopes involved in virus entry and cell-to-cell spread. HSV-2 gD2 was the only antigen in the Herpevac Trial for Women that protected against HSV-1 genital infection but not HSV-2. In that trial, a correlation was detected between gD2 ELISA titers and protection against HSV-1, supporting the importance of antibodies. A possible explanation for the lack of protection against HSV-2 was that HSV-2 neutralization titers were low, four-fold lower than to HSV-1. Here, we evaluated neutralization titers and epitope-specific antibody responses to crucial gD2 epitopes involved in virus entry and cell-to-cell spread as correlates of immune protection against genital lesions in immunized guinea pigs. We detected a strong correlation between neutralizing antibodies and protection against genital disease. We used a high throughput biosensor competition assay to measure epitope-specific responses to seven crucial gD2 linear and conformational epitopes involved in virus entry and spread. Some animals produced antibodies to most crucial epitopes while others produced antibodies to few. The number of epitopes recognized by guinea pig immune serum correlated with protection against genital lesions. We confirmed the importance of antibodies to each crucial epitope using monoclonal antibody passive transfer that improved survival and reduced genital disease in mice after HSV-2 genital challenge. We re-evaluated our prior study of epitope-specific antibody responses in women in the Herpevac Trial. Humans produced antibodies that blocked significantly fewer crucial gD2 epitopes than guinea pigs, and antibody responses in humans to some linear epitopes were virtually absent. Neutralizing antibody titers and epitope-specific antibody responses are important immune parameters to evaluate in future Phase I/II prophylactic human vaccine trials that contain gD2 antigen. PMID:29791513

Vaccine-induced antibodies to herpes simplex virus glycoprotein D epitopes involved in virus entry and cell-to-cell spread correlate with protection against genital disease in guinea pigs.

PubMed

Hook, Lauren M; Cairns, Tina M; Awasthi, Sita; Brooks, Benjamin D; Ditto, Noah T; Eisenberg, Roselyn J; Cohen, Gary H; Friedman, Harvey M

2018-05-01

Herpes simplex virus type 2 (HSV-2) glycoprotein D (gD2) subunit antigen is included in many preclinical candidate vaccines. The rationale for including gD2 is to produce antibodies that block crucial gD2 epitopes involved in virus entry and cell-to-cell spread. HSV-2 gD2 was the only antigen in the Herpevac Trial for Women that protected against HSV-1 genital infection but not HSV-2. In that trial, a correlation was detected between gD2 ELISA titers and protection against HSV-1, supporting the importance of antibodies. A possible explanation for the lack of protection against HSV-2 was that HSV-2 neutralization titers were low, four-fold lower than to HSV-1. Here, we evaluated neutralization titers and epitope-specific antibody responses to crucial gD2 epitopes involved in virus entry and cell-to-cell spread as correlates of immune protection against genital lesions in immunized guinea pigs. We detected a strong correlation between neutralizing antibodies and protection against genital disease. We used a high throughput biosensor competition assay to measure epitope-specific responses to seven crucial gD2 linear and conformational epitopes involved in virus entry and spread. Some animals produced antibodies to most crucial epitopes while others produced antibodies to few. The number of epitopes recognized by guinea pig immune serum correlated with protection against genital lesions. We confirmed the importance of antibodies to each crucial epitope using monoclonal antibody passive transfer that improved survival and reduced genital disease in mice after HSV-2 genital challenge. We re-evaluated our prior study of epitope-specific antibody responses in women in the Herpevac Trial. Humans produced antibodies that blocked significantly fewer crucial gD2 epitopes than guinea pigs, and antibody responses in humans to some linear epitopes were virtually absent. Neutralizing antibody titers and epitope-specific antibody responses are important immune parameters to evaluate in future Phase I/II prophylactic human vaccine trials that contain gD2 antigen.

Dopamine D2 gene expression interacts with environmental enrichment to impact lifespan and behavior.

PubMed

Thanos, Panayotis K; Hamilton, John; O'Rourke, Joseph R; Napoli, Anthony; Febo, Marcelo; Volkow, Nora D; Blum, Kenneth; Gold, Mark

2016-04-12

Aging produces cellular, molecular, and behavioral changes affecting many areas of the brain. The dopamine (DA) system is known to be vulnerable to the effects of aging, which regulate behavioral functions such as locomotor activity, body weight, and reward and cognition. In particular, age-related DA D2 receptor (D2R) changes have been of particular interest given its relationship with addiction and other rewarding behavioral properties. Male and female wild-type (Drd2 +/+), heterozygous (Drd2 +/-) and knockout (Drd2 -/-) mice were reared post-weaning in either an enriched environment (EE) or a deprived environment (DE). Over the course of their lifespan, body weight and locomotor activity was assessed. While an EE was generally found to be correlated with longer lifespan, these increases were only found in mice with normal or decreased expression of the D2 gene. Drd2 +/+ EE mice lived nearly 16% longer than their DE counterparts. Drd2 +/+ and Drd2 +/- EE mice lived 22% and 21% longer than Drd2 -/- EE mice, respectively. Moreover, both body weight and locomotor activity were moderated by environmental factors. In addition, EE mice show greater behavioral variability between genotypes compared to DE mice with respect to body weight and locomotor activity.

Positron spectroscopy studies of zeolites

NASA Astrophysics Data System (ADS)

Hung, Ku-Jung

The lineshapes of two-dimensional angular correlation of electron-positron annihilation radiation (2D-ACAR) in alumina and several zeolites were measured as a function of internal surface areas. In all cases, the lineshape parameter S from 2D-ACAR spectra were found to vary proportionally with internal surface area. In order to investigate the Bronsted acidity in NaHY zeolite, the lineshape parameter evaluation from 2D-ACAR measurements for varied acidity in NaHY zeolites by ion-exchange and thermal desorption were presented. The result from this investigation has demonstrated that the Bronsted acidity in NaHY zeolite was found to vary linearly with the lineshape parameter of the angular correlation spectrum of the sample. The lineshapes of 2D-ACAR spectra were determined for different base adsorbed HY-zeolite samples under a temperature controlled heating system in order to investigate, in-situ, the acid strength and number of Bronsted acid sites in the sample. Results have shown that the lineshape parameter of the angular correlation spectrum of the sample increases with the strength of adsorbed base and decreases with the number of Bronsted acid sites in the sample. This indicated that the lineshape parameter is sensitive to all of the strengths and concentrations of Bronsted acid sites in the HY-zeolite samples. The result from this study has also demonstrated that the large size base, pyridine, would reduce the possibility of positronium formation in the sample by filling the cage to eliminate the internal surface areas where the positroniums are likely to form. However, the small size base, ammonia, did not show any effect on the internal surface areas. Owing to the fact that this technique monitors only the Bronsted acid sites that situate on the surface which relates to the catalytic activity, there is little ambiguity about the location of the source of information obtained. The findings presented in this dissertation point out the fact that such lineshape measurement of 2D-ACAR can well be an effective in-situ microprobe that could have important practical applications in internal surface characterization of zeolite catalysts in general.

Population norms for the EQ-5D-3L: a cross-country analysis of population surveys for 20 countries.

PubMed

Janssen, M F; Szende, A; Cabases, J; Ramos-Goñi, J M; Vilagut, G; König, H H

2018-02-14

This study provides EQ-5D population norms for 20 countries (N = 163,838), which can be used to compare profiles for patients with specific conditions with data for the average person in the general population in a similar age and/or gender group. Descriptive EQ-5D data are provided for the total population, by gender and by seven age groups. Provided index values are based on European VAS for all countries, based on TTO for 11 countries and based on VAS for 10 countries. Important differences exist in EQ-5D reported health status across countries after standardizing for population structure. Self-reported health according to all five dimensions and EQ VAS generally decreased with increasing age and was lower for females. Mean self-rated EQ VAS scores varied from 70.4 to 83.3 in the total population by country. The prior living standards (GDP per capita) in the countries studied are correlated most with the EQ VAS scores (0.58), while unemployment appeared to be significantly correlated in people over the age of 45 only. A country's expenditure on health care correlated moderately with higher ratings on the EQ VAS (0.55). EQ-5D norms can be used as reference data to assess the burden of disease of patients with specific conditions. Such information, in turn, can inform policy-making and assist in setting priorities in health care.

Low second to fourth digit ratio in Dupuytren disease.

PubMed

Yokoi, Takuya; Uemura, Takuya; Kazuki, Kenichi; Onode, Ema; Shintani, Kosuke; Okada, Mitsuhiro; Nakamura, Hiroaki

2017-08-01

The ratio of the lengths of the second and fourth digits (2D:4D) has been described as reflecting endogenous prenatal androgen exposure. In general, 2D:4D is lower in men than in women and has potential as a biomarker or predictor for various diseases, athletic ability, and academic performance. Dupuytren disease has digital flexion contractures and is known to predominate in men, but the pathogenesis of the disease remains unclear. To clarify the relationships between Dupuytren disease and endogenous androgens, we performed a retrospective analysis of hand radiographs to investigate 2D:4D in Dupuytren disease. The study included male patients with Dupuytren disease (n = 22) and a control group (n = 18) of male patients with carpal tunnel syndrome. Only unaffected hands, without contractures or osteoarthritis, were evaluated for the purpose of radiographic assessment. The lengths of the phalanx and metacarpal bones in the second and fourth digits were measured by 2 independent observers who each performed 2 sets of measurements separated by a minimum 1-week interval. The 2D:4D was calculated separately for the phalanges and metacarpals, and a combined (phalanx + metacarpal) 2D:4D was also calculated. The reliability of the observer measurements was established using the intraclass correlation coefficient, and both the intra- and interobserver reliability showed excellent agreement. We found that compared with control group, the Dupuytren disease group had significantly lower phalanx and combined 2D:4D. These findings suggest that endogenous prenatal androgens could contribute to the development of Dupuytren disease, leading to its characteristic clinical presentation predominantly in men and affecting the ulnar rays.

[Use of the 2D:4D digit ratio as a biological marker of specific language disorders].

PubMed

Font-Jordà, Antònia; Gamundí, Antoni; Nicolau Llobera, María Cristina; Aguilar-Mediavilla, Eva

2018-04-03

The finding of biological markers of specific language impairment would facilitate their detection and early intervention. In this sense, the 2D:4D finger ratio is considered an indirect indicator of prenatal exposure to testosterone. Previous studies have related it to linguistic competence and aggressive behaviour, and could be a candidate for a biological marker of language impairment. The aim was to compare the value of the 2D:4D ratio in children with Specific Language Impairment (SLI) with those of children with typical language development, as well as to establish to what extent this biological index correlates with the behaviour (linguistic, cognitive, social,...) in both groups. 2D:4D ratio, language, cognition and social behaviour were compared in a group of children with SLI (n=15), with a group of children without language difficulties (n=16) of the same age (between 5-8 years), gender (male), and socio-cultural level. Children with SLI showed significantly higher values of 2D:4D ratio of the right hand, and a negative correlation between this ratio and their linguistic competence. Although the children with SLI showed impaired adaptive abilities, but not more aggressive behaviour, these measurements did not correlate with the 2D:4D index. Nevertheless, social behaviour correlated with language and cognition competence. A higher value of the biological 2D:4D ration (lower intrauterine exposure to testosterone) seems to be associated with language difficulties in boys with SLI, but not with their behavioural difficulties. Their behavioural difficulties seem to be a consequence of their linguistic difficulties and their level of cognition. Copyright © 2018. Publicado por Elsevier España, S.L.U.

Square-antiprismatic eight-coordinate complexes of divalent first-row transition metal cations: a density functional theory exploration of the electronic-structural landscape.

PubMed

Conradie, Jeanet; Patra, Ashis K; Harrop, Todd C; Ghosh, Abhik

2015-02-16

Density functional theory (in the form of the PW91, BP86, OLYP, and B3LYP exchange-correlation functionals) has been used to map out the low-energy states of a series of eight-coordinate square-antiprismatic (D2d) first-row transition metal complexes, involving Mn(II), Fe(II), Co(II), Ni(II), and Cu(II), along with a pair of tetradentate N4 ligands. Of the five complexes, the Mn(II) and Fe(II) complexes have been synthesized and characterized structurally and spectroscopically, whereas the other three are as yet unknown. Each N4 ligand consists of a pair of terminal imidazole units linked by an o-phenylenediimine unit. The imidazole units are the strongest ligands in these complexes and dictate the spatial disposition of the metal three-dimensional orbitals. Thus, the dx(2)-y(2) orbital, whose lobes point directly at the coordinating imidazole nitrogens, has the highest orbital energy among the five d orbitals, whereas the dxy orbital has the lowest orbital energy. In general, the following orbital ordering (in order of increasing orbital energy) was found to be operative: dxy < dxz = dyz ≤ dz(2) < dx(2)-y(2). The square-antiprism geometry does not lead to large energy gaps between the d orbitals, which leads to an S = 2 ground state for the Fe(II) complex. Nevertheless, the dxy orbital has significantly lower energy relative to that of the dxz and dyz orbitals. Accordingly, the ground state of the Fe(II) complex corresponds unambiguously to a dxy(2)dxz(1)dyz(1)dz(2)(1)dx(2)-y(2)(1) electronic configuration. Unsurprisingly, the Mn(II) complex has an S = 5/2 ground state and no low-energy d-d excited states within 1.0 eV of the ground state. The Co(II) complex, on the other hand, has both a low-lying S = 1/2 state and multiple low-energy S = 3/2 states. Very long metal-nitrogen bonds are predicted for the Ni(II) and Cu(II) complexes; these bonds may be too fragile to survive in solution or in the solid state, and the complexes may therefore not be isolable. Overall, the different exchange-correlation functionals provided a qualitatively consistent and plausible picture of the low-energy d-d excited states of the complexes.

Martingales, nonstationary increments, and the efficient market hypothesis

NASA Astrophysics Data System (ADS)

McCauley, Joseph L.; Bassler, Kevin E.; Gunaratne, Gemunu H.

2008-06-01

We discuss the deep connection between nonstationary increments, martingales, and the efficient market hypothesis for stochastic processes x(t) with arbitrary diffusion coefficients D(x,t). We explain why a test for a martingale is generally a test for uncorrelated increments. We explain why martingales look Markovian at the level of both simple averages and 2-point correlations. But while a Markovian market has no memory to exploit and cannot be beaten systematically, a martingale admits memory that might be exploitable in higher order correlations. We also use the analysis of this paper to correct a misstatement of the ‘fair game’ condition in terms of serial correlations in Fama’s paper on the EMH. We emphasize that the use of the log increment as a variable in data analysis generates spurious fat tails and spurious Hurst exponents.

A Powerful Procedure for Pathway-Based Meta-analysis Using Summary Statistics Identifies 43 Pathways Associated with Type II Diabetes in European Populations.

PubMed

Zhang, Han; Wheeler, William; Hyland, Paula L; Yang, Yifan; Shi, Jianxin; Chatterjee, Nilanjan; Yu, Kai

2016-06-01

Meta-analysis of multiple genome-wide association studies (GWAS) has become an effective approach for detecting single nucleotide polymorphism (SNP) associations with complex traits. However, it is difficult to integrate the readily accessible SNP-level summary statistics from a meta-analysis into more powerful multi-marker testing procedures, which generally require individual-level genetic data. We developed a general procedure called Summary based Adaptive Rank Truncated Product (sARTP) for conducting gene and pathway meta-analysis that uses only SNP-level summary statistics in combination with genotype correlation estimated from a panel of individual-level genetic data. We demonstrated the validity and power advantage of sARTP through empirical and simulated data. We conducted a comprehensive pathway-based meta-analysis with sARTP on type 2 diabetes (T2D) by integrating SNP-level summary statistics from two large studies consisting of 19,809 T2D cases and 111,181 controls with European ancestry. Among 4,713 candidate pathways from which genes in neighborhoods of 170 GWAS established T2D loci were excluded, we detected 43 T2D globally significant pathways (with Bonferroni corrected p-values < 0.05), which included the insulin signaling pathway and T2D pathway defined by KEGG, as well as the pathways defined according to specific gene expression patterns on pancreatic adenocarcinoma, hepatocellular carcinoma, and bladder carcinoma. Using summary data from 8 eastern Asian T2D GWAS with 6,952 cases and 11,865 controls, we showed 7 out of the 43 pathways identified in European populations remained to be significant in eastern Asians at the false discovery rate of 0.1. We created an R package and a web-based tool for sARTP with the capability to analyze pathways with thousands of genes and tens of thousands of SNPs.

A Powerful Procedure for Pathway-Based Meta-analysis Using Summary Statistics Identifies 43 Pathways Associated with Type II Diabetes in European Populations

PubMed Central

Zhang, Han; Wheeler, William; Hyland, Paula L.; Yang, Yifan; Shi, Jianxin; Chatterjee, Nilanjan; Yu, Kai

2016-01-01

Meta-analysis of multiple genome-wide association studies (GWAS) has become an effective approach for detecting single nucleotide polymorphism (SNP) associations with complex traits. However, it is difficult to integrate the readily accessible SNP-level summary statistics from a meta-analysis into more powerful multi-marker testing procedures, which generally require individual-level genetic data. We developed a general procedure called Summary based Adaptive Rank Truncated Product (sARTP) for conducting gene and pathway meta-analysis that uses only SNP-level summary statistics in combination with genotype correlation estimated from a panel of individual-level genetic data. We demonstrated the validity and power advantage of sARTP through empirical and simulated data. We conducted a comprehensive pathway-based meta-analysis with sARTP on type 2 diabetes (T2D) by integrating SNP-level summary statistics from two large studies consisting of 19,809 T2D cases and 111,181 controls with European ancestry. Among 4,713 candidate pathways from which genes in neighborhoods of 170 GWAS established T2D loci were excluded, we detected 43 T2D globally significant pathways (with Bonferroni corrected p-values < 0.05), which included the insulin signaling pathway and T2D pathway defined by KEGG, as well as the pathways defined according to specific gene expression patterns on pancreatic adenocarcinoma, hepatocellular carcinoma, and bladder carcinoma. Using summary data from 8 eastern Asian T2D GWAS with 6,952 cases and 11,865 controls, we showed 7 out of the 43 pathways identified in European populations remained to be significant in eastern Asians at the false discovery rate of 0.1. We created an R package and a web-based tool for sARTP with the capability to analyze pathways with thousands of genes and tens of thousands of SNPs. PMID:27362418

Structure-Based Characterization of Multiprotein Complexes

PubMed Central

Wiederstein, Markus; Gruber, Markus; Frank, Karl; Melo, Francisco; Sippl, Manfred J.

2014-01-01

Summary Multiprotein complexes govern virtually all cellular processes. Their 3D structures provide important clues to their biological roles, especially through structural correlations among protein molecules and complexes. The detection of such correlations generally requires comprehensive searches in databases of known protein structures by means of appropriate structure-matching techniques. Here, we present a high-speed structure search engine capable of instantly matching large protein oligomers against the complete and up-to-date database of biologically functional assemblies of protein molecules. We use this tool to reveal unseen structural correlations on the level of protein quaternary structure and demonstrate its general usefulness for efficiently exploring complex structural relationships among known protein assemblies. PMID:24954616

Hydrogen/deuterium (H/D) exchange of gelatinized starch studied by two-dimensional (2D) near-infrared (NIR) correlation spectroscopy

NASA Astrophysics Data System (ADS)

Shinzawa, Hideyuki; Mizukado, Junji

2018-05-01

Hydrogen/deuterium (H/D) exchange of gelatinized starch was probed by in-situ near-infrared (NIR) monitoring coupled with two-dimensional (2D) correlation spectroscopy. Gelatinized starch undergoes spontaneous H/D exchange in D2O. During the substitution, the exchange rate essentially becomes different depending on solvent accessibility of various parts of the molecule. Thus, by analyzing the change in the NIR feature observed during the substitution, it becomes possible to sort out local structure and dynamics of the system. 2D correlation analysis of the time-dependent NIR spectra reveals the presence of different local structure of the starch, each having different solvent accessibility. For example, during the H/D exchange, the D2O is first absorbed by starch molecules especially around the surface area between the starch and water, where the water molecules are weakly interacted with the starch molecules. This absorption is quickly followed by the development of HDO species. Further absorption of the D2O results in the penetration of the molecules inside the starch and eventually develops the relatively strong interaction between the HDO and starch molecules because of the presence of dominant starch molecules.

Awareness of Diagnostic Error among Japanese Residents: a Nationwide Study.

PubMed

Nishizaki, Yuji; Shinozaki, Tomohiro; Kinoshita, Kensuke; Shimizu, Taro; Tokuda, Yasuharu

2018-04-01

Residents' understanding of diagnostic error may differ between countries. We sought to explore the relationship between diagnostic error knowledge and self-study, clinical knowledge, and experience. Our nationwide study involved postgraduate year 1 and 2 (PGY-1 and -2) Japanese residents. The Diagnostic Error Knowledge Assessment Test (D-KAT) and General Medicine In-Training Examination (GM-ITE) were administered at the end of the 2014 academic year. D-KAT scores were compared with the benchmark scores of US residents. Associations between D-KAT score and gender, PGY, emergency department (ED) rotations per month, mean number of inpatients handled at any given time, and mean daily minutes of self-study were also analyzed, both with and without adjusting for GM-ITE scores. Student's t test was used for comparisons with linear mixed models and structural equation models (SEM) to explore associations with D-KAT or GM-ITE scores. The mean D-KAT score among Japanese PGY-2 residents was significantly lower than that of their US PGY-2 counterparts (6.2 vs. 8.3, p < 0.001). GM-ITE scores correlated with ED rotations (≥6 rotations: 2.14; 0.16-4.13; p = 0.03), inpatient caseloads (5-9 patients: 1.79; 0.82-2.76; p < 0.001), and average daily minutes of self-study (≥91 min: 2.05; 0.56-3.53; p = 0.01). SEM revealed that D-KAT scores were directly associated with GM-ITE scores (ß = 0.37, 95% CI: 0.34-0.41) and indirectly associated with ED rotations (ß = 0.06, 95% CI: 0.02-0.10), inpatient caseload (ß = 0.04, 95% CI: 0.003-0.08), and average daily minutes of study (ß = 0.13, 95% CI: 0.09-0.17). Knowledge regarding diagnostic error among Japanese residents was poor compared with that among US residents. D-KAT scores correlated strongly with GM-ITE scores, and the latter scores were positively associated with a greater number of ED rotations, larger caseload (though only up to 15 patients), and more time spent studying.

Ab initio study of the diatomic fluorides FeF, CoF, NiF, and CuF.

PubMed

Koukounas, Constantine; Mavridis, Aristides

2008-11-06

The late-3d transition-metal diatomic fluorides MF = FeF, CoF, NiF, and CuF have been studied using variational multireference (MRCI) and coupled-cluster [RCCSD(T)] methods, combined with large to very large basis sets. We examined a total of 35 (2S+1)|Lambda| states, constructing as well 29 full potential energy curves through the MRCI method. All examined states are ionic, diabatically correlating to M(+)+F(-)((1)S). Notwithstanding the "eccentric" character of the 3d transition metals and the difficulties to accurately be described with all-electron ab initio methods, our results are, in general, in very good agreement with available experimental numbers.

Accuracy-enhanced constitutive parameter identification using virtual fields method and special stereo-digital image correlation

NASA Astrophysics Data System (ADS)

Zhang, Zhongya; Pan, Bing; Grédiac, Michel; Song, Weidong

2018-04-01

The virtual fields method (VFM) is generally used with two-dimensional digital image correlation (2D-DIC) or grid method (GM) for identifying constitutive parameters. However, when small out-of-plane translation/rotation occurs to the test specimen, 2D-DIC and GM are prone to yield inaccurate measurements, which further lessen the accuracy of the parameter identification using VFM. In this work, an easy-to-implement but effective "special" stereo-DIC (SS-DIC) method is proposed for accuracy-enhanced VFM identification. The SS-DIC can not only deliver accurate deformation measurement without being affected by unavoidable out-of-plane movement/rotation of a test specimen, but can also ensure evenly distributed calculation data in space, which leads to simple data processing. Based on the accurate kinematics fields with evenly distributed measured points determined by SS-DIC method, constitutive parameters can be identified by VFM with enhanced accuracy. Uniaxial tensile tests of a perforated aluminum plate and pure shear tests of a prismatic aluminum specimen verified the effectiveness and accuracy of the proposed method. Experimental results show that the constitutive parameters identified by VFM using SS-DIC are more accurate and stable than those identified by VFM using 2D-DIC. It is suggested that the proposed SS-DIC can be used as a standard measuring tool for mechanical identification using VFM.

The role of albumin and endoplasmic reticulum in pathogenesis Preeclampsia. Changes of GRP78 and placental VEGF in preeclampsia.

PubMed

Aditiawarman

2014-07-01

Preeclampsia remains the highest causes of maternal mortality in Indonesia. This disease is known as "the disease of theories" since the etiology of this disease still obscure, but it is clearly accepted that this disease is correlated with placenta. The incidence of this disease increased in dr. Soetomo General Hospital during economic crisis in Indonesia, as nutritional problem occurred, but correlation between nutrition to preeclampsia still unclear. This study was conducted to find out the influence of hypoalbuminemia caused by alteration of amino acids and changes of GRP78 and placental VEGF in preeclampsia. It was cross-sectional study among 10 patients with preeclampsia albumin ⩽ gram/dL and 9 patients with preeclampsia albumin >3g/dL. Placenta collected was homogenized and blood was separated from the cells. Placental lysat, serum and plasma were stored -87°C until laboratory analysis for GRP78 and VEGF. Data were analyzed using student t test, Manova. Pearson correlation, simple and multiple regressions. There were alterations of amino acid's profile among albumin ⩽3g/dL compare with albumin >3g/dL. GRP78 concentration on albumin ⩽3g/dL group was higher, but were not significant. Weak negative correlation between albumins to GRP78 was found. Negative correlation were found in the groups of albumin ⩽3g/dL - GRP⩽425μg/dL, but significant result only on albumin ⩽3g/dL - GRP⩽425μg/dL. Positive correlation were found in the group of albumin >3g/dL - GRP>425μg/dL. Response of Endoplasmic Reticulum Stress appeared different depends on levels of albumin (stressor) and GRP78 (stress response protein). Placental VEGF were significantly lower in albumin ⩽3g/dL (p<0.05). Correlation between GRP78 on placental VEGF was negative with coefficient correlation was 3.8%. Placental VEGF profoundly decreased as correlation between albumin and GRP78 stronger. Alteration of amino acids profile influenced Albumin concentration. Hypoalbuminemia was a stressor that induced reticulum endoplasmic response by increasing GRP78, decreasing placental VEGF. Responses of Endoplasmic Reticulum Stress depend on levels of stressor (albumin) and stress response protein (GRP78). Copyright © 2014 International Society for the Study of Hypertension in Pregnancy.

Correlation Between Arthroscopy Simulator and Video Game Performance: A Cross-Sectional Study of 30 Volunteers Comparing 2- and 3-Dimensional Video Games.

PubMed

Jentzsch, Thorsten; Rahm, Stefan; Seifert, Burkhardt; Farei-Campagna, Jan; Werner, Clément M L; Bouaicha, Samy

2016-07-01

To investigate the association between arthroscopy simulator performance and video game skills. This study compared the performances of 30 volunteers without experience performing arthroscopies in 3 different tasks of a validated virtual reality knee arthroscopy simulator with the video game experience using a questionnaire and actual performances in 5 different 2- and 3-dimensional (D) video games of varying genres on 2 different platforms. Positive correlations between knee arthroscopy simulator and video game performances (ρ = 0.63, P < .001) as well as experiences (ρ = 0.50, P = .005) were found. The strongest correlations were found for the task of catching (hooking) 6 foreign bodies (virtual rings; "triangulation") and the dribbling performance in a sports game and a first-person shooter game, as well as the meniscus resection and a tile-matching puzzle game (all ρ ≥ 0.60, P < .001). No correlations were found for any of the knee arthroscopy simulator tasks and a strategy game. Although knee arthroscopy performances do not correlate with 2-D strategy video game skills, they show a correlation with 2-D tile-matching puzzle games only for easier tasks with a rather limited focus, and highly correlate with 3-D sports and first-person shooter video games. These findings show that experienced and good 3-D gamers are better arthroscopists than nonexperienced and poor 3-D gamers. Level II, observational cross-sectional study. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Imaging Spatial Correlations of Rydberg Excitations in Cold Atom Clouds

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

Schwarzkopf, A.; Sapiro, R. E.; Raithel, G.

2011-09-02

We use direct spatial imaging of cold {sup 85}Rb Rydberg atom clouds to measure the Rydberg-Rydberg correlation function. The results are in qualitative agreement with theoretical predictions [F. Robicheaux and J. V. Hernandez, Phys. Rev. A 72, 063403 (2005)]. We determine the blockade radius for states 44D{sub 5/2}, 60D{sub 5/2}, and 70D{sub 5/2} and investigate the dependence of the correlation behavior on excitation conditions and detection delay. Experimental data hint at the existence of long-range order.

Dopamine D2 receptor levels in striatum, thalamus, substantia nigra, limbic regions, and cortex in schizophrenic subjects.

PubMed

Kessler, Robert M; Woodward, Neil D; Riccardi, Patrizia; Li, Rui; Ansari, M Sib; Anderson, Sharlett; Dawant, Benoit; Zald, David; Meltzer, Herbert Y

2009-06-15

Studies in schizophrenic patients have reported dopaminergic abnormalities in striatum, substantia nigra, thalamus, anterior cingulate, hippocampus, and cortex that have been related to positive symptoms and cognitive impairments. [(18)F]fallypride positron emission tomography studies were performed in off-medication or never-medicated schizophrenic subjects (n = 11, 6 men, 5 women; mean age of 30.5 +/- 8.0 [SD] years; 4 drug-naive) and age-matched healthy subjects (n = 11, 5 men, 6 women, mean age of 31.6 +/- 9.2 [SD]) to examine dopamine D(2) receptor (DA D(2)r) levels in the caudate, putamen, ventral striatum, medial thalamus, posterior thalamus, substantia nigra, amygdala, temporal cortex, anterior cingulate, and hippocampus. In schizophrenic subjects, increased DA D(2)r levels were seen in the substantia nigra bilaterally; decreased levels were seen in the left medial thalamus. Correlations of symptoms with ROI data demonstrated a significant correlation of disorganized thinking/nonparanoid delusions with the right temporal cortex ROI (r = .94, p = .0001), which remained significant after correction for multiple comparisons (p < .03). Correlations of symptoms with parametric images of DA D(2)r levels revealed no significant clusters of correlations with negative symptoms but significant clusters of positive correlations of total positive symptoms, delusions and bizarre behavior with the lateral and anterior temporal cortex, and hallucinations with the left ventral striatum. The results of this study demonstrate abnormal DA D(2)r-mediated neurotransmission in the substantia nigra consistent with nigral dysfunction in schizophrenia and suggest that both temporal cortical and ventral striatal DA D(2)r mediate positive symptoms.

Identification of spectral units on Phoebe

USGS Publications Warehouse

Coradini, A.; Tosi, F.; Gavrishin, A.I.; Capaccioni, F.; Cerroni, P.; Filacchione, G.; Adriani, A.; Brown, R.H.; Bellucci, G.; Formisano, V.; D'Aversa, E.; Lunine, J.I.; Baines, K.H.; Bibring, J.-P.; Buratti, B.J.; Clark, R.N.; Cruikshank, D.P.; Combes, M.; Drossart, P.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, Christophe; Hedman, M.M.; Hansen, G.B.; Hibbitts, C.A.; Showalter, M.; Griffith, C.; Strazzulla, G.

2008-01-01

We apply a multivariate statistical method to the Phoebe spectra collected by the VIMS experiment onboard the Cassini spacecraft during the flyby of June 2004. The G-mode clustering method, which permits identification of the most important features in a spectrum, is used on a small subset of data, characterized by medium and high spatial resolution, to perform a raw spectral classification of the surface of Phoebe. The combination of statistics and comparative analysis of the different areas using both the VIMS and ISS data is explored in order to highlight possible correlations with the surface geology. In general, the results by Clark et al. [Clark, R.N., Brown, R.H., Jaumann, R., Cruikshank, D.P., Nelson, R.M., Buratti, B.J., McCord, T.B., Lunine, J., Hoefen, T., Curchin, J.M., Hansen, G., Hibbitts, K., Matz, K.-D., Baines, K.H., Bellucci, G., Bibring, J.-P., Capaccioni, F., Cerroni, P., Coradini, A., Formisano, V., Langevin, Y., Matson, D.L., Mennella, V., Nicholson, P.D., Sicardy, B., Sotin, C., 2005. Nature 435, 66-69] are confirmed; but we also identify new signatures not reported before, such as the aliphatic CH stretch at 3.53 ??m and the ???4.4 ??m feature possibly related to cyanide compounds. On the basis of the band strengths computed for several absorption features and for the homogeneous spectral types isolated by the G-mode, a strong correlation of CO2 and aromatic hydrocarbons with exposed water ice, where the uniform layer covering Phoebe has been removed, is established. On the other hand, an anti-correlation of cyanide compounds with CO2 is suggested at a medium resolution scale. ?? 2007 Elsevier Inc. All rights reserved.

Classification of Acousto-Optic Correlation Signatures of Spread Spectrum Signals Using Artificial Neural Networks

DTIC Science & Technology

1989-12-01

Ohio ’aPw iorlipuab muo i 0I2, AFIT/GE/ENG/89D-10 CLASSIFICATION OF ACOUSTO - OPTIC CORRELATION SIGNATURES OF SPREAD SPECTRUM SIGNALS USING ARTIFICIAL...ENG/89D- 10 CLASSIFICATION OF ACOUSTO - OPTIC CORRELATION SIGNATURES OF SPREAD SPECTRUM SIGNALS USING ARTIFICIAL NEURAL NETWORKS THESIS John W. DeBerry...Captain, USAF AFIT/GE/ENG/89D- 10 Approved for public release; distribution unlimited. AFIT/GE/ENG/89D-10 CLASSIFICATION OF ACOUSTO - OPTIC CORRELATION

Correlation between reactive oxygen metabolites & atherosclerotic risk factors in patients with type 2 diabetes mellitus

PubMed Central

Kotani, Kazuhiko; Tsuzaki, Kokoro; Taniguchi, Nobuyuki; Sakane, Naoki

2013-01-01

Background & objectives: Oxidative stress plays important roles in the pathophysiology of type 2 diabetes mellitus (T2DM). The diacron reactive oxygen metabolites (d-ROMs) test has been used in the clinics. The present study was aimed to investigate the correlation of the oxidative stress status, as evaluated by the d-ROMs, with atherosclerotic risk factors in T2DM patients, in comparison to controls. Methods: The study included 200 subjects (100 patients with T2DM and 100 controls; 86 males/114 females; mean age 59.0 yr). Clinical variables including the body mass index, blood pressure (BP), glucose and lipid panels, in addition to the d-ROMs, were measured. Results: Patients with T2DM showed significantly higher d-ROMs levels than controls (322 ± 60 vs. 345 ± 64 U. Carr., P<0.05). A multiple linear regression analysis revealed that systolic BP (β=0.26, P<0.05) and high-density lipoprotein cholesterol (HDL-C: β= -0.30, P<0.05) were independently and significantly correlated with the d-ROMs levels in patients with T2DM, although these correlations were not significant in the controls. The gender-based analysis showed that systolic BP (β = 0.44, P<0.05) and HDL-C (β = -0.36, P<0.05) were independently and significantly correlated with the d-ROMs levels in females with T2DM, while there was a marginally significant correlation between HDL-C and the d-ROMs levels (β = -0.36, P=0.06) in males with T2DM. Interpretation & conclusions: The present findings may reinforce the importance of BP control in female patients with T2DM, as well as the management of HDL-C in male and female patients with T2DM, under the linkage between oxidative stress and atherosclerosis. PMID:23703342

Comparing Pearson, Spearman and Hoeffding's D measure for gene expression association analysis.

PubMed

Fujita, André; Sato, João Ricardo; Demasi, Marcos Angelo Almeida; Sogayar, Mari Cleide; Ferreira, Carlos Eduardo; Miyano, Satoru

2009-08-01

DNA microarrays have become a powerful tool to describe gene expression profiles associated with different cellular states, various phenotypes and responses to drugs and other extra- or intra-cellular perturbations. In order to cluster co-expressed genes and/or to construct regulatory networks, definition of distance or similarity between measured gene expression data is usually required, the most common choices being Pearson's and Spearman's correlations. Here, we evaluate these two methods and also compare them with a third one, namely Hoeffding's D measure, which is used to infer nonlinear and non-monotonic associations, i.e. independence in a general sense. By comparing three different variable association approaches, namely Pearson's correlation, Spearman's correlation and Hoeffding's D measure, we aimed at assessing the most appropriate one for each purpose. Using simulations, we demonstrate that the Hoeffding's D measure outperforms Pearson's and Spearman's approaches in identifying nonlinear associations. Our results demonstrate that Hoeffding's D measure is less sensitive to outliers and is a more powerful tool to identify nonlinear and non-monotonic associations. We have also applied Hoeffding's D measure in order to identify new putative genes associated with tp53. Therefore, we propose the Hoeffding's D measure to identify nonlinear associations between gene expression profiles.

Can diffusion-weighted imaging serve as a biomarker of fibrosis in pancreatic adenocarcinoma?

PubMed

Hecht, Elizabeth M; Liu, Michael Z; Prince, Martin R; Jambawalikar, Sachin; Remotti, Helen E; Weisberg, Stuart W; Garmon, Donald; Lopez-Pintado, Sara; Woo, Yanghee; Kluger, Michael D; Chabot, John A

2017-08-01

To assess the relationship between diffusion-weighted imaging (DWI) and intravoxel incoherent motion (IVIM)-derived quantitative parameters (apparent diffusion coefficient [ADC], perfusion fraction [f], D slow , diffusion coefficient [D], and D fast , pseudodiffusion coefficient [D*]) and histopathology in pancreatic adenocarcinoma (PAC). Subjects with suspected surgically resectable PAC were prospectively enrolled in this Health Insurance Portability and Accountability Act (HIPAA)-compliant, Institutional Review Board-approved study. Imaging was performed at 1.5T with a respiratory-triggered echo planar DWI sequence using 10 b values. Two readers drew regions of interest (ROIs) over the tumor and adjacent nontumoral tissue. Monoexponential and biexponential fits were used to derive ADC 2b , ADC all , f, D, and D*, which were compared to quantitative histopathology of fibrosis, mean vascular density, and cellularity. Two biexponential IVIM models were investigated and compared: 1) nonlinear least-square fitting based on the Levenberg-Marquardt algorithm, and 2) linear fit using a fixed D* (20 mm 2 /s). Statistical analysis included Student's t-test, Pearson correlation (P < 0.05 was considered significant), intraclass correlation, and coefficients of variance. Twenty subjects with PAC were included in the final cohort. Negative correlation between D and fibrosis (Reader 2: r = -0.57 P = 0.01; pooled P = -0.46, P = 0.04) was observed with a trend toward positive correlation between f and fibrosis (r = 0.44, P = 0.05). ADC 2b was significantly lower in PAC with dense fibrosis than with loose fibrosis ADC 2b (P = 0.03). Inter- and intrareader agreement was excellent for ADC, D, and f. In PAC, D negatively correlates with fibrosis, with a trend toward positive correlation with f suggesting both perfusion and diffusion effects contribute to stromal desmoplasia. ADC 2b is significantly lower in tumors with dense fibrosis and may serve as a biomarker of fibrosis architecture. 1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:393-402. © 2017 International Society for Magnetic Resonance in Medicine.

Generalized interferometry - I: theory for interstation correlations

NASA Astrophysics Data System (ADS)

Fichtner, Andreas; Stehly, Laurent; Ermert, Laura; Boehm, Christian

2017-02-01

We develop a general theory for interferometry by correlation that (i) properly accounts for heterogeneously distributed sources of continuous or transient nature, (ii) fully incorporates any type of linear and nonlinear processing, such as one-bit normalization, spectral whitening and phase-weighted stacking, (iii) operates for any type of medium, including 3-D elastic, heterogeneous and attenuating media, (iv) enables the exploitation of complete correlation waveforms, including seemingly unphysical arrivals, and (v) unifies the earthquake-based two-station method and ambient noise correlations. Our central theme is not to equate interferometry with Green function retrieval, and to extract information directly from processed interstation correlations, regardless of their relation to the Green function. We demonstrate that processing transforms the actual wavefield sources and actual wave propagation physics into effective sources and effective wave propagation. This transformation is uniquely determined by the processing applied to the observed data, and can be easily computed. The effective forward model, that links effective sources and propagation to synthetic interstation correlations, may not be perfect. A forward modelling error, induced by processing, describes the extent to which processed correlations can actually be interpreted as proper correlations, that is, as resulting from some effective source and some effective wave propagation. The magnitude of the forward modelling error is controlled by the processing scheme and the temporal variability of the sources. Applying adjoint techniques to the effective forward model, we derive finite-frequency Fréchet kernels for the sources of the wavefield and Earth structure, that should be inverted jointly. The structure kernels depend on the sources of the wavefield and the processing scheme applied to the raw data. Therefore, both must be taken into account correctly in order to make accurate inferences on Earth structure. Not making any restrictive assumptions on the nature of the wavefield sources, our theory can be applied to earthquake and ambient noise data, either separately or combined. This allows us (i) to locate earthquakes using interstation correlations and without knowledge of the origin time, (ii) to unify the earthquake-based two-station method and noise correlations without the need to exclude either of the two data types, and (iii) to eliminate the requirement to remove earthquake signals from noise recordings prior to the computation of correlation functions. In addition to the basic theory for acoustic wavefields, we present numerical examples for 2-D media, an extension to the most general viscoelastic case, and a method for the design of optimal processing schemes that eliminate the forward modelling error completely. This work is intended to provide a comprehensive theoretical foundation of full-waveform interferometry by correlation, and to suggest improvements to current passive monitoring methods.

Cathepsin D in normal and neoplastic thyroid tissues.

PubMed

Kraimps, J L; Métayé, T; Millet, C; Margerit, D; Ingrand, P; Goujon, J M; Levillain, P; Babin, P; Begon, F; Barbier, J

1995-12-01

Cathepsin D is a widely distributed lysosomal acidic endopeptidase. It is an estrogen-regulated protein that is a prognostic factor in breast cancer. The aim of this study was to measure cathepsin D concentrations in thyroid tissues and to correlate these concentrations with clinical and pathologic parameters. Cathepsin D and thyroglobulin concentrations were measured in the cytosol of normal thyroid tissues (n = 14), benign nodules (n = 6), and thyroid carcinomas (n = 32) with an immunoradiometric assay. Statistical analysis was based on the Kruskal-Wallis and Wilcoxon tests and on the Spearman rank correlation coefficient. The mean level of cathepsin D, expressed as picomoles per milligram protein minus thyroglobulin, was higher in the 32 carcinomas, 29.1 +/- 15.5, than in the 14 normal thyroid tissues, 8.4 +/- 2.5 (p < 0.001) or in the 6 benign nodules, 11.2 +/- 7.3 (p = 0.003). Cathepsin D concentrations correlated with tumor size; Spearman rank correlation coefficient was rs = 0.44 (p = 0.012). No significant difference was found regarding histologic type. Cathepsin D concentrations were inversely correlated with the thyroglobulin level in the tumor; Spearman rank correlation coefficient was rs = -0.60 (p < 0.001). Cathepsin D concentration is higher in thyroid carcinoma than in normal thyroid tissue. Increased cathepsin D concentrations correlate with thyroid tumor size but not with histologic type. Further studies should be done to confirm the potential prognostic value of cathepsin D in patients with thyroid carcinomas.

Exploring the Wisdom Structure: Validation of the Spanish New Short Three-Dimensional Wisdom Scale (3D-WS) and Its Explanatory Power on Psychological Health-Related Variables.

PubMed

García-Campayo, Javier; Del Hoyo, Yolanda L; Barceló-Soler, Alberto; Navarro-Gil, Mayte; Borao, Luis; Giarin, Veronica; Tovar-Garcia, R Raziel; Montero-Marin, Jesus

2018-01-01

Introduction: Personal wisdom has demonstrated important implications for the health of individuals. The aim of the present study was to validate a Spanish version of the Three-Dimensional Wisdom Scale (3D-WS), exploring the structure of a possible general factor, and assessing its explanatory power on psychological health-related variables. Methods: A cross-sectional study design was used, with a total sample of 624 Spanish participants recruited on the Internet and randomly split into two halves. The following instruments were applied: 3D-WS, Purpose in Life (PIL), Multidimensional State Boredom Scale (MSBS), Positive and Negative Affect Scale (PANAS), and Difficulties in Emotion Regulation Scale (DERS). Factorial structures were analyzed through exploratory and confirmatory factor analysis (EFA and CFA), and the general factor was characterized by using bifactor models. The explanatory power of the 3D-WS was established by multiple regression. Results: The original long and short versions of the 3D-WS were not replicated in the first subsample using EFA, and there was a high rate of cross-loadings. Thus, a new short 3D-WS was proposed by ordering the original items according to factorial weights. This three-correlated-factor (reflective, cognitive, and affective) proposal was tested by means of CFA in the second subsample, with adequate psychometrics and invariance, and a good fit (χ 2 /df = 1.98; CFI = 0.946; RMSEA = 0.056; 90% CI = 0.040-0.072). A bifactor structure, in which the reflective trait of wisdom was integrated into a general factor (G-Reflective) improved the model fit (χ 2 /df = 1.85; CFI = 0.959; RMSEA = 0.052; 90% CI = 0.035-0.070). The explained common variance of G-Reflective was 0.53; therefore, the new short 3D-WS should not be considered essentially unidimensional. The new short 3D-WS showed positive relationships with the PIL and PANAS-positive, and negative associations with the MSBS, PANAS-negative and DERS, contributing to explain all the referred variables. These results were consistent across subsamples. Conclusion: The new short 3D-WS appears to be a reliable instrument for measuring wisdom in the Spanish general population. The reflective facet might influence the cognitive and affective wisdom components through the G-Reflective general factor. There seems to be a high explanatory power of the 3D-WS on psychological health-related variables. This study will facilitate the development of future research and psychological knowledge regarding wisdom.

Comparison of two-dimensional and three-dimensional simulations of dense nonaqueous phase liquids (DNAPLs): Migration and entrapment in a nonuniform permeability field

NASA Astrophysics Data System (ADS)

Christ, John A.; Lemke, Lawrence D.; Abriola, Linda M.

2005-01-01

The influence of reduced dimensionality (two-dimensional (2-D) versus 3-D) on predictions of dense nonaqueous phase liquid (DNAPL) infiltration and entrapment in statistically homogeneous, nonuniform permeability fields was investigated using the University of Texas Chemical Compositional Simulator (UTCHEM), a 3-D numerical multiphase simulator. Hysteretic capillary pressure-saturation and relative permeability relationships implemented in UTCHEM were benchmarked against those of another lab-tested simulator, the Michigan-Vertical and Lateral Organic Redistribution (M-VALOR). Simulation of a tetrachloroethene spill in 16 field-scale aquifer realizations generated DNAPL saturation distributions with approximately equivalent distribution metrics in two and three dimensions, with 2-D simulations generally resulting in slightly higher maximum saturations and increased vertical spreading. Variability in 2-D and 3-D distribution metrics across the set of realizations was shown to be correlated at a significance level of 95-99%. Neither spill volume nor release rate appeared to affect these conclusions. Variability in the permeability field did affect spreading metrics by increasing the horizontal spreading in 3-D more than in 2-D in more heterogeneous media simulations. The assumption of isotropic horizontal spatial statistics resulted, on average, in symmetric 3-D saturation distribution metrics in the horizontal directions. The practical implication of this study is that for statistically homogeneous, nonuniform aquifers, 2-D simulations of saturation distributions are good approximations to those obtained in 3-D. However, additional work will be needed to explore the influence of dimensionality on simulated DNAPL dissolution.

The use (or misuse) of microsatellite allelic distances in the context of inbreeding and conservation genetics.

PubMed

Hansson, Bengt

2010-03-01

In line with inbreeding theory, genetic diversity at a set of molecular markers may explain variation in fitness-associated traits in partially inbred populations, and such associations will appear as 'genotype-fitness correlations'. An individual genetic diversity index specifically used for microsatellites is 'mean d(2)', i.e. the mean squared distance between alleles. The original hypothesis for mean d(2)-fitness correlations assumes that mean d(2) captures fitness effects at both ends of the inbreeding-outbreeding spectrum. This hypothesis received strong criticism from work showing that even a plain diversity estimate such as multi-locus heterozygosity (MLH) outperforms mean d(2) as a predictor of the inbreeding coefficient and fitness in most realistic situations. Despite this critique, the mean d(2)-approach is still used frequently in ecological and evolutionary research, producing results suggesting that mean d(2) sometimes provides a stronger prediction of fitness than does MLH. In light of the critique, such results are unexpected, but potential explanations for them may exist (at least hypothetically), including scenarios based on close linkage and recent admixture. Nevertheless, a major caveat is that it is very difficult to predict a priori if mean d(2) will improve the genotype-fitness correlation, which in turn makes objective interpretations difficult. Mean d(2)-fitness associations are potentially interesting, but the fact that we cannot easily understand them is problematic and should be thoroughly addressed in each study. Therefore, instead of hastily reached interpretations of mean d(2)-fitness correlations, conclusions need support from complementary analyses, e.g. verifying admixture of genetically structured populations.

How good is controlled attenuation parameter and fatty liver index for assessing liver steatosis in general population: correlation with ultrasound.

PubMed

Carvalhana, Sofia; Leitão, Jorge; Alves, Ana C; Bourbon, Mafalda; Cortez-Pinto, Helena

2014-07-01

Liver steatosis measurement by controlled attenuation parameter (CAP) is a non-invasive method for diagnosing steatosis, based on transient elastography. Its usefulness as screening procedure for hepatic steatosis in general population has not been previously evaluated. The aim of this study was to evaluate the diagnostic accuracy of CAP and fatty liver index (FLI) for detection and quantification of steatosis in general population. Recruitment was done from a prospective epidemiological study of the general adult population. Steatosis was evaluated using CAP, FLI and ultrasound (US). Steatosis scored according to Hamaguchi's US scoring, from 0 (S0) to 6 (S6) points. Hepatic steatosis defined by score ≥2 (S≥2) and moderate/severe steatosis by score ≥4 (S≥4). Performance of CAP and FLI for diagnosing steatosis compared with US was assessed using areas under receiver operating characteristic curves (AUROC). From 219 consecutive individuals studied, 13 (5.9%) excluded because of failure/unreliable liver stiffness measurements. Steatosis prevalence: S≥2 38.4% and S≥4 12.1%. CAP significantly correlated with steatosis (ρ = 0.73, P < 0.0001), steatosis score (ρ = 0.76; P < 0.0001), FLI (ρ = 0.69), waist circumference (ρ = 0.62), body mass index (ρ = 0.55), triglyceride (ρ = 0.49), HOMA-IR (ρ = 0.26), alcohol consumption (ρ = 0.24) and cholesterol (ρ = 0.19), not with liver stiffness measurements. Using CAP and FLI, AUROC's were 0.94 (95% CI 0.91-0.97, P < 0.001) and 0.91 for S≥2; 0.95 (95% CI 0.90-0.99, P < 0.001) and 0.93 for S≥4 respectively. Optimal cut-off value of CAP and FLI were 243 dB/m and 48 for S≥2; 303.5 dB/m and 62 for S≥4 respectively. Controlled attenuation parameter and FLI seem promising tools for screening and steatosis quantification in the general population. Larger studies are needed for validation. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

SU-E-T-72: A Retrospective Correlation Analysis On Dose-Volume Control Points and Treatment Outcomes

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

Roy, A; Nohadani, O; Refaat, T

2015-06-15

Purpose: To quantify correlation between dose-volume control points and treatment outcomes. Specifically, two outcomes are analyzed: occurrence of radiation induced dysphagia and target complications. The results inform the treatment planning process when competing dose-volume criteria requires relaxations. Methods: 32 patients, treated with whole-field sequential intensity modulated radiation therapy during 2009–2010 period, are considered for this study. Acute dysphagia that is categorized into 3 grades is observed on all patients. 3 patients are observed in grade 1, 17 patients in grade 2, and 12 patients in grade 3. Ordinal logistic regression is employed to establish correlations between grades of dysphagia andmore » dose to cervico-thoracic esophagus. Particularly, minimum (Dmin), mean (Dmean), and maximum (Dmax) dose control points are analyzed. Additionally, target complication, which includes local-regional recurrence and/or distant metastasis, is observed on 4 patients. Binary logistic regression is used to quantify correlation between target complication and four dose control points. Namely, ICRU recommended dose control points, D2, D50, D95, and D98 are analyzed. Results: For correlation with dysphagia, Dmin on cervico-thoracic esophagus is statistically significant (p-value = 0.005). Additionally, Dmean on cervico-thoracic esophagus is also significant in association with dysphagia (p-value = 0.012). However, no correlation was observed between Dmax and dysphagia (p-value = 0.263). For target complications, D50 on the target is a statistically significant dose control point (p-value = 0.032). No correlations were observed between treatment complications and D2 (p-value = 0.866), D95 (p-value = 0.750), and D98 (p-value = 0.710) on the target. Conclusion: Significant correlations are observed between radiation induced dysphagia and Dmean (and Dmin) to cervico-thoracic esophagus. Additionally, correlation between target complications and median dose to target (D50) is observed. Quantification of these correlations can inform treatment planners when any competing objectives requires relaxation of target D50 or Dmean (or Dmin) to cervico-thoracic esophagus.« less

A novel improved method for analysis of 2D diffusion relaxation data—2D PARAFAC-Laplace decomposition

NASA Astrophysics Data System (ADS)

Tønning, Erik; Polders, Daniel; Callaghan, Paul T.; Engelsen, Søren B.

2007-09-01

This paper demonstrates how the multi-linear PARAFAC model can with advantage be used to decompose 2D diffusion-relaxation correlation NMR spectra prior to 2D-Laplace inversion to the T2- D domain. The decomposition is advantageous for better interpretation of the complex correlation maps as well as for the quantification of extracted T2- D components. To demonstrate the new method seventeen mixtures of wheat flour, starch, gluten, oil and water were prepared and measured with a 300 MHz nuclear magnetic resonance (NMR) spectrometer using a pulsed gradient stimulated echo (PGSTE) pulse sequence followed by a Carr-Purcell-Meiboom-Gill (CPMG) pulse echo train. By varying the gradient strength, 2D diffusion-relaxation data were recorded for each sample. From these double exponentially decaying relaxation data the PARAFAC algorithm extracted two unique diffusion-relaxation components, explaining 99.8% of the variation in the data set. These two components were subsequently transformed to the T2- D domain using 2D-inverse Laplace transformation and quantitatively assigned to the oil and water components of the samples. The oil component was one distinct distribution with peak intensity at D = 3 × 10 -12 m 2 s -1 and T2 = 180 ms. The water component consisted of two broad populations of water molecules with diffusion coefficients and relaxation times centered around correlation pairs: D = 10 -9 m 2 s -1, T2 = 10 ms and D = 3 × 10 -13 m 2 s -1, T2 = 13 ms. Small spurious peaks observed in the inverse Laplace transformation of original complex data were effectively filtered by the PARAFAC decomposition and thus considered artefacts from the complex Laplace transformation. The oil-to-water ratio determined by PARAFAC followed by 2D-Laplace inversion was perfectly correlated with known oil-to-water ratio of the samples. The new method of using PARAFAC prior to the 2D-Laplace inversion proved to have superior potential in analysis of diffusion-relaxation spectra, as it improves not only the interpretation, but also the quantification.

The relationship between second-to-fourth digit (2D:4D) ratios and problematic and pathological Internet use among Turkish university students.

PubMed

Canan, Fatih; Karaca, Servet; Düzgün, Melike; Erdem, Ayşe Merve; Karaçaylı, Esranur; Topan, Nur Begüm; Lee, Sang-Kyu; Zhai, Zu Wei; Kuloğlu, Murat; Potenza, Marc N

2017-03-01

Background and aims The ratio of the second and fourth fingers (2D:4D ratio) is a sexually dimorphic trait, with men tending to have lower values than women. This ratio has been related to prenatal testosterone concentrations and addictive behaviors including problematic video-gaming. We aimed to investigate the possible association between 2D:4D ratios and Internet addiction and whether such a relationship would be independent of impulsivity. Methods A total of 652 university students (369 women, 283 men), aged 17-27 years, were enrolled in the study. Problematic and pathological Internet use (PPIU) was assessed using the Internet Addiction Test (IAT). The participants also completed the Barratt Impulsiveness Scale (version 11; BIS-11) and had their 2D:4D ratios measured. Results 2D:4D ratios were not significantly different in women with PPIU and in those with adaptive Internet use (AIU). Men with PPIU exhibited lower 2D:4D ratios on both hands when compared with those with AIU. Correlation analysis revealed that 2D:4D ratios on both hands were negatively correlated with IAT scores among men, but not among women. The multiple linear regression analysis revealed that age, duration of weekly Internet use, impulsiveness, and 2D:4D ratios on the right hand were independently associated with IAT scores among men, and impulsivity did not mediate the relationship between 2D:4D ratios and PPIU. Conclusions For men, 2D:4D ratios on the right hand were inversely correlated with Internet addiction severity even after controlling for individual differences in impulsivity. These findings suggest that high prenatal testosterone levels may contribute to the occurrence of PPIU among men.

The relationship between second-to-fourth digit (2D:4D) ratios and problematic and pathological Internet use among Turkish university students

PubMed Central

Canan, Fatih; Karaca, Servet; Düzgün, Melike; Erdem, Ayşe Merve; Karaçaylı, Esranur; Topan, Nur Begüm; Lee, Sang-Kyu; Zhai, Zu Wei; Kuloğlu, Murat; Potenza, Marc N.

2017-01-01

Background and aims The ratio of the second and fourth fingers (2D:4D ratio) is a sexually dimorphic trait, with men tending to have lower values than women. This ratio has been related to prenatal testosterone concentrations and addictive behaviors including problematic video-gaming. We aimed to investigate the possible association between 2D:4D ratios and Internet addiction and whether such a relationship would be independent of impulsivity. Methods A total of 652 university students (369 women, 283 men), aged 17–27 years, were enrolled in the study. Problematic and pathological Internet use (PPIU) was assessed using the Internet Addiction Test (IAT). The participants also completed the Barratt Impulsiveness Scale (version 11; BIS-11) and had their 2D:4D ratios measured. Results 2D:4D ratios were not significantly different in women with PPIU and in those with adaptive Internet use (AIU). Men with PPIU exhibited lower 2D:4D ratios on both hands when compared with those with AIU. Correlation analysis revealed that 2D:4D ratios on both hands were negatively correlated with IAT scores among men, but not among women. The multiple linear regression analysis revealed that age, duration of weekly Internet use, impulsiveness, and 2D:4D ratios on the right hand were independently associated with IAT scores among men, and impulsivity did not mediate the relationship between 2D:4D ratios and PPIU. Conclusions For men, 2D:4D ratios on the right hand were inversely correlated with Internet addiction severity even after controlling for individual differences in impulsivity. These findings suggest that high prenatal testosterone levels may contribute to the occurrence of PPIU among men. PMID:28358645

SU-E-T-491: Influence of Applicator Dimensions On Doses to Bladder, Rectum and Sigmoid in HDR Brachytherapy for Cervical Cancer

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

Dumane, V; Rhome, R; Yuan, Y

2015-06-15

Purpose: To study the influence of dimensions of the tandem and ring applicator on bladder D2cc, rectum D2cc and sigmoid D2cc in HDR treatment planning for cervical cancer. Methods: 53 plans from 13 patients treated at our institution with the tandem and ring applicator were retrospectively reviewed. Prescription doses were one of the following: 8 Gy x 3, 7 Gy x 4 and 5.5 Gy x 5. Doses to the D2ccs of the bladder, rectum and the sigmoid were recorded. These doses were normalized to their relative prescriptions doses. Correlations between the normalized bladder D2cc, rectum D2cc and sigmoid D2ccmore » were investigated and linear regression models were developed to study the dependence of these doses on the ring diameter and the applicator angle. Results: Normalized doses to the D2cc of the bladder, rectum and sigmoid showed statistically significant correlation (P < 0.05) to the applicator angle. Significant correlation was also noted for the normalized D2cc of the rectum and the sigmoid with the ring diameter. The normalized bladder D2cc was found to decrease with applicator angle on an average by 22.65% ± 4.43% while the same for the rectum and sigmoid were found to increase on an average by 14.43% ± 1.65% and 14.01% ± 1.42% respectively. Both the rectum and sigmoid D2cc reduced with increasing ring diameter by 12.93% ± 1.95% and 11.27% ± 1.79%. No correlation was observed between the normalized bladder D2cc and the ring diameter. Conclusion: Preliminary regression models developed in this study can potentially aid in the choice of the appropriate applicator angle and ring diameter for tandem and ring implant so as to optimize doses to the bladder, rectum and sigmoid.« less

Random Survival Forest in practice: a method for modelling complex metabolomics data in time to event analysis.

PubMed

Dietrich, Stefan; Floegel, Anna; Troll, Martina; Kühn, Tilman; Rathmann, Wolfgang; Peters, Anette; Sookthai, Disorn; von Bergen, Martin; Kaaks, Rudolf; Adamski, Jerzy; Prehn, Cornelia; Boeing, Heiner; Schulze, Matthias B; Illig, Thomas; Pischon, Tobias; Knüppel, Sven; Wang-Sattler, Rui; Drogan, Dagmar

2016-10-01

The application of metabolomics in prospective cohort studies is statistically challenging. Given the importance of appropriate statistical methods for selection of disease-associated metabolites in highly correlated complex data, we combined random survival forest (RSF) with an automated backward elimination procedure that addresses such issues. Our RSF approach was illustrated with data from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study, with concentrations of 127 serum metabolites as exposure variables and time to development of type 2 diabetes mellitus (T2D) as outcome variable. Out of this data set, Cox regression with a stepwise selection method was recently published. Replication of methodical comparison (RSF and Cox regression) was conducted in two independent cohorts. Finally, the R-code for implementing the metabolite selection procedure into the RSF-syntax is provided. The application of the RSF approach in EPIC-Potsdam resulted in the identification of 16 incident T2D-associated metabolites which slightly improved prediction of T2D when used in addition to traditional T2D risk factors and also when used together with classical biomarkers. The identified metabolites partly agreed with previous findings using Cox regression, though RSF selected a higher number of highly correlated metabolites. The RSF method appeared to be a promising approach for identification of disease-associated variables in complex data with time to event as outcome. The demonstrated RSF approach provides comparable findings as the generally used Cox regression, but also addresses the problem of multicollinearity and is suitable for high-dimensional data. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

[Confirmatory factor analysis of the short French version of the Center for Epidemiological Studies of Depression Scale (CES-D10) in adolescents].

PubMed

Cartierre, N; Coulon, N; Demerval, R

2011-09-01

Screening depressivity among adolescents is a key public health priority. In order to measure the severity of depressive symptomatology, a four-dimensional 20 items scale called "Center for Epidemiological Studies-Depression Scale" (CES-D) was developed. A shorter 10-item version was developed and validated (Andresen et al.). For this brief version, several authors supported a two-factor structure - Negative and Positive affect - but the relationship between the two reversed-worded items of the Positive affect factor could be better accounted for by correlated errors. The aim of this study is triple: firstly to test a French version of the CES-D10 among adolescents; secondly to test the relevance of a one-dimensional structure by considering error correlation for Positive affect items; finally to examine the extent to which this structural model is invariant across gender. The sample was composed of 269 French middle school adolescents (139 girls and 130 boys, mean age: 13.8, SD=0.65). Confirmatory Factorial Analyses (CFA) using the LISREL 8.52 were conducted in order to assess the adjustment to the data of three factor models: a one-factor model, a two-factor model (Positive and Negative affect) and a one-factor model with specification of correlated errors between the two reverse-worded items. Then, multigroup analysis was conducted to test the scale invariance for girls and boys. Internal consistency of the CES-D10 was satisfying for the adolescent sample (α=0.75). The best fitting model is the one-factor model with correlated errors between the two items of the previous Positive affect factor (χ(2)/dl=2.50; GFI=0.939; CFI=0.894; RMSEA=0.076). This model presented a better statistical fit to the data than the one-factor model without error correlation: χ(2)(diff) (1)=22.14, p<0.001. Then, the one-factor model with correlated errors was analyzed across separate samples of girls and boys. The model explains the data somewhat better for boys than for girls. The model's overall χ(2)(68) without equality constraints from the multigroup analysis was 107.98. The χ(2)(89) statistic for the model with equality-constrained factor loadings was 121.31. The change in the overall Chi(2) is not statistically significant. This result implies that the model is, therefore, invariant across gender. The mean scores were higher for girls than boys: 9.69 versus 7.19; t(267)=4.13, p<0.001. To conclude, and waiting for further research using the French version of the CES-D10 for adolescents, it appears that this short scale is generally acceptable and can be a useful tool for both research and practice. The scale invariance across gender has been demonstrated but the invariance across age must be tested too. Copyright © 2011 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

Validation of the Center for Epidemiological Studies Depression Scale among Korean Adolescents.

PubMed

Heo, Eun-Hye; Choi, Kyeong-Sook; Yu, Je-Chun; Nam, Ji-Ae

2018-02-01

The Center for Epidemiological Studies Depression Scale (CES-D) is designed to measure the current level of depressive symptomatology in the general population. However, no review has examined whether the scale is reliable and valid among children and adolescents in Korea. The purpose of this study was to test whether the Korean form of the CES-D is valid in adolescents. Data were obtained from 1,884 adolescents attending grades 1-3 in Korean middle schools. Reliability was evaluated by internal consistency (Cronbach's alpha). Concurrent validity was evaluated by a correlation analysis between the CES-D and other scales. Construct validity was evaluated by exploratory factor and confirmatory factor analyses. The internal consistency coefficient for the entire group was 0.88. The CES-D was positively correlated with scales that measure negative psychological constructs, such as the State Anxiety Inventory for Children, the Korean Social Anxiety Scale for Children and Adolescents, and the Reynold Suicidal Ideation Questionnaire, but it was negatively correlated with scales that measure positive psychological constructs, such as the Korean version of the Rosenberg Self-Esteem Scale and the Connor-Davidson Resilience Scale-2. The CES-D was examined by three-dimensional exploratory factor analysis, and the three-factor structure of the scale explained 53.165% of the total variance. The variance explained by factor I was 24.836%, that explained by factor II was 15.988%, and that explained by factor III was 12.341%. The construct validity of the CES-D was tested by confirmatory factor analysis, and we applied the entire group's data using a three-factor hierarchical model. The fit index showed a level similar to those of other countries' adolescent samples. The CES-D has high internal consistency and addresses psychological constructs similar to those addressed by other scales. The CES-D showed a three-factor structure in an exploratory factor analysis. The present findings suggest that the CES-D is a useful and reliable tool for measuring depression in Korean adolescents.

Construct validity of SF-6D health state utility values in an employed population.

PubMed

Baxter, Siyan; Sanderson, Kristy; Venn, Alison; Otahal, Petr; Palmer, Andrew J

2015-04-01

Health utility values permit cost utility analysis in workplace health promotion; however, utility measures of working populations have not been validated. To investigate construct validity of SF-6D health utility in a public service workforce. SF-12v2 Health Survey was administered to 3,408 randomly selected public service employees in Australia in 2010. SF-12 scores were converted to SF-6D health utility values. Associations and correlates of SF-6D with health, socio-demographic and work characteristics [comorbidities, body mass index (BMI), Kessler-10 psychological distress (K10), education, salary, effort-reward imbalance (ERI), absenteeism] were explored. Ceiling effects were analysed. Nationally representative employee SF-6D values from the Household, Income and Labour Dynamics in Australia (HILDA) survey (n = 11,234) were compared. All analyses were stratified by sex. Mean (SE) age was 45.7 (0.35) males; 44.5 (0.22) females. Females represented 72 % of the sample. Mean (SE) health utility 0.792 (0.004); 0.771 (0.003) was higher in males. SF-6D demonstrated both a significant inverse association (p < 0.01) and negative correlations (female; male) with K10 (r = -0.63; r = -0.66), comorbidity count (r = -0.40; r = -0.33), ERI (r = -0.37; r = -0.34) and absenteeism (p < 0.005, r = -0.25; r = -0.21). Mean (SE) SF-6D in HILDA was 0.792 (0.002); 0.775 (0.003) males; females. Correlates and associations in all samples were similar. The general employed demonstrated a significant inverse association with age and positive association with salary. SF-6D was independent of BMI. Psychological distress, comorbidity, effort-reward imbalance and absenteeism are negatively associated with employee health. SF-6D is a valid measure of perceived health states in working populations.

[A survey of correlation between serum 25-hydroxyvitamin D levels and dyslipidemia rlsk among middle-aged individuals in Beijing].

PubMed

Zhang, L L; Lu, Y H; Cheng, X L; Liu, M Y; Sun, B R; Li, C L

2016-08-01

To evaluate vitamin D status in middle-aged subjects in Beijing and explore the correlation between serum 25-hydroxyvitamin D[25(OH)D] levels and dyslipidemia. A total of 448 individuals over 40 years old were enrolled in the cross-sectional survey. The general information, blood biochemical and lipid profiles and serum 25(OH)D levels were collected. The subjects were either divided into two groups (the dyslipidemia group and the non-dyslipidemia group) based on the lipid levels, or four groups according to quartiles of 25(OH)D levels. The association between 25(OH)D levels and dyslipidemia risk was analyzed by a logistic regression analysis. A total of 234 cases were in dyslipidemia group, which accounted for 52.23% of the subjects. The serum 25(OH)D levels were significantly lower in the dyslipidemia group than in the non-dyslipidemia group both in men and in women (all P<0.05). The median serum 25(OH)D level in the total subjects was 15.7 (12.2, 20.1)μg/L with 91.1% subjects of serum 25(OH)D level<30 μg/L. The proportion of subjects with dyslipidemia (high TC, high TG, high LDL-C, or low HDL-C) increased with the decrease of 25(OH)D level quartiles (P<0.05). After adjustment of confounding factors, the logistic regression analysis showed that subjects in the lowest 25(OH) D quartile group had 143% higher risks for dyslipidemia than those in the highest quartile group. These findings indicate that 25(OH)D insufficiency is highly prevalent among middle-aged individuals and it may be associated with the risk of dyslipidemia.

Psychometric evaluation of the Chinese version of the Child Health Utility 9D (CHU9D-CHN): a school-based study in China.

PubMed

Yang, Peirong; Chen, Gang; Wang, Peng; Zhang, Kejian; Deng, Feng; Yang, Haifeng; Zhuang, Guihua

2018-05-05

The Child Health Utility 9D (CHU9D), a new generic preference-based health-related quality of life (HRQoL) instrument, was developed specifically for the application in cost-effectiveness analyses of treatments and interventions for children and adolescents. The main objective of this study was to examine the psychometric property of the Chinese version of CHU9D (CHU9D-CHN) in a large school-based sample in China. Data were collected using a multi-stage sampling method from third-to-ninth-grade students in Shaanxi Province, China. Participants self-completed a hard-copy questionnaire including the CHU9D-CHN instrument, the Pediatric Quality of Life Inventory™ 4.0 Generic Core Scales (PedsQL), information on socio-demographic characteristics and self-reported health status. The psychometric properties of the CHU9D-CHN, including the internal consistency, 2-week test-retest reliability, convergent and known-groups validity were studied. A total of 1912 students participated in the survey. The CHU9D-CHN internal consistency and test-retest reliability were good to excellent with a Cronbach's alpha of 0.77 and an intra-class correlation coefficient of 0.65, respectively. The CHU9D utility scores moderately correlated with the PedsQL total scores (r = .57, P < .001), demonstrating good convergent validity. Difference of the CHU9D utility scores among the different participants with levels of self-reported general health, health services utilisation and left-behind status demonstrated good construct validity. The findings demonstrated adequate psychometric performance for the CHU9D-CHN. The CHU9D-CHN was a satisfactory, reliable and valid instrument to measure and value HRQoL for children and adolescents in China.

Texture analysis on the fluence map to evaluate the degree of modulation for volumetric modulated arc therapy.

PubMed

Park, So-Yeon; Kim, Il Han; Ye, Sung-Joon; Carlson, Joel; Park, Jong Min

2014-11-01

Texture analysis on fluence maps was performed to evaluate the degree of modulation for volumetric modulated arc therapy (VMAT) plans. A total of six textural features including angular second moment, inverse difference moment, contrast, variance, correlation, and entropy were calculated for fluence maps generated from 20 prostate and 20 head and neck VMAT plans. For each of the textural features, particular displacement distances (d) of 1, 5, and 10 were adopted. To investigate the deliverability of each VMAT plan, gamma passing rates of pretreatment quality assurance, and differences in modulating parameters such as multileaf collimator (MLC) positions, gantry angles, and monitor units at each control point between VMAT plans and dynamic log files registered by the Linac control system during delivery were acquired. Furthermore, differences between the original VMAT plan and the plan reconstructed from the dynamic log files were also investigated. To test the performance of the textural features as indicators for the modulation degree of VMAT plans, Spearman's rank correlation coefficients (rs) with the plan deliverability were calculated. For comparison purposes, conventional modulation indices for VMAT including the modulation complexity score for VMAT, leaf travel modulation complexity score, and modulation index supporting station parameter optimized radiation therapy (MISPORT) were calculated, and their correlations were analyzed in the same way. There was no particular textural feature which always showed superior correlations with every type of plan deliverability. Considering the results comprehensively, contrast (d = 1) and variance (d = 1) generally showed considerable correlations with every type of plan deliverability. These textural features always showed higher correlations to the plan deliverability than did the conventional modulation indices, except in the case of modulating parameter differences. The rs values of contrast to the global gamma passing rates with criteria of 2%/2 mm, 2%/1 mm, and 1%/2 mm were 0.536, 0.473, and 0.718, respectively. The respective values for variance were 0.551, 0.481, and 0.688. In the case of local gamma passing rates, the rs values of contrast were 0.547, 0.578, and 0.620, respectively, and those of variance were 0.519, 0.527, and 0.569. All of the rs values in those cases were statistically significant (p < 0.003). In the cases of global and local gamma passing rates, MISPORT showed the highest correlations among the conventional modulation indices. For global passing rates, rs values of MISPORT were -0.420, -0.330, and -0.632, respectively, and those for local passing rates were -0.455, -0.490 and -0.502. The values of rs of contrast, variance, and MISPORT with the MLC errors were -0.863, -0.828, and 0.795, respectively, all with statistical significances (p < 0.001). The correlations with statistical significances between variance and dose-volumetric differences were observed more frequently than the others. The contrast (d = 1) and variance (d = 1) calculated from fluence maps of VMAT plans showed considerable correlations with the plan deliverability, indicating their potential use as indicators for assessing the degree of modulation of VMAT plans. Both contrast and variance consistently showed better performance than the conventional modulation indices for VMAT.

Enkephalin and dynorphin neuropeptides are differently correlated with locomotor hypersensitivity and levodopa-induced dyskinesia in parkinsonian rats.

PubMed

Sgroi, Stefania; Capper-Loup, Christine; Paganetti, Paolo; Kaelin-Lang, Alain

2016-06-01

The opioidergic neuropeptides dynorphin (DYN) and enkephalin (ENK) and the D1 and D2 dopaminergic receptors (D1R, D2R) are involved in the striatal control of motor and behavioral function. In Parkinson's disease, motor disturbances such as "on-off" motor fluctuations and involuntary movements (dyskinesia) are severe complications that often arise after chronic l-dihydroxyphenylalanine (l-DOPA) treatment. Changes in the striatal expression of preproENK (PPENK), proDYN (PDYN), D1R, and D2R mRNA have been observed in parkinsonian animals treated with l-DOPA. Enhanced opioidergic transmission has been found in association with l-DOPA-induced dyskinesia, but the connection of PPENK, PDYN, D1R, and D2R mRNA expression with locomotor activity remains unclear. In this study, we measured PPENK, PDYN, D1R and D2R mRNA levels by in situ hybridization in the striatum of 6-OHDA hemi-parkinsonian rats treated with l-DOPA (PD+l-DOPA group), along with two control groups (PD+saline and naive+l-DOPA). We found different levels of expression of PPENK, PDYN, D1R and D2R mRNA across the experimental groups and correlated the changes in mRNA expression with dyskinesia and locomotor variables assessed by open field test during several phases of l-DOPA treatment. Both PDYN and PPENK mRNA levels were correlated with the severity of dyskinesia, while PPENK mRNA levels were also correlated with the frequency of contralateral rotational movements and with locomotor variables. Moreover, a strong correlation was found between D1R mRNA expression and D2R mRNA expression in the PD+l-DOPA group. These findings suggest that, in parkinsonian animals treated with l-DOPA, high levels of PPENK are a prerequisite for a locomotor sensitization to l-DOPA treatment, while PDYN overexpression is responsible only for the development of dyskinesia. Copyright © 2016 Elsevier Inc. All rights reserved.

Quantitative analyses of factors related to anxiety and depression in patients with retinitis pigmentosa.

PubMed

Sainohira, Mayumi; Yamashita, Takehiro; Terasaki, Hiroto; Sonoda, Shozo; Miyata, Kazunori; Murakami, Yusuke; Ikeda, Yasuhiro; Morimoto, Takeshi; Endo, Takao; Fujikado, Takashi; Kamo, Junko; Sakamoto, Taiji

2018-01-01

The purpose of this study is to determine the factors related to anxiety and depression in patients with retinitis pigmentosa (RP). The status of anxiety and depression was determined in RP patients with the Hospital Anxiety and Depression Scale (HADS) questionnaire which consisted of subscales for HADS-anxiety (HADS-A) and HADS-depression (HADS-D). The vision-specific quality of life (VSQOL) was assessed with the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ25). The correlations between the HADS-A or HADS-D scores and vision-related clinical parameters such as the best-corrected visual acuity (BCVA), Functional Acuity Score, Functional Field Score, Functional Vision Score, the NEI- VFQ25 subscale score were determined. The socioeconomic status, such as the work status and membership in the RP society, was investigated to determine the factors related to the HADS-A and HADS-D scores. One hundred and twelve RP patients (46 men and 66 women) with mean age of 60.7±15.4 (standard deviation) years were studied. The HADS-A score was not significantly correlated with any visual functions but was significantly correlated with the general health condition (r = -0.34, P<0.001) and the role limitation (r = -0.20, P = 0.03) of the NEI-VFQ25 subscale. The HADS-D score was significantly correlated with all the visual functions (r = -0.38 to 0.29, P<0.001), the NEI-VFQ25 subscale score (r = - 0.58 to -0.33, P<0.001) by Spearman's correlations. The HADS-A score was significantly higher in the members of the RP society than in non-members (P = 0.013). The mean HADS-D score of employed individuals was significantly lower than that of unemployed ones (P = 0.001) by the Mann-Whitney U test. The results indicate that visual function impairments and vision-related quality of life are associated with a depressive state, and the general health condition is related to anxiety in RP patients. Being employed may be strongly correlated with the degree of depression in RP patients.

Investigating shared aetiology between type 2 diabetes and major depressive disorder in a population based cohort.

PubMed

Clarke, Toni-Kim; Obsteter, Jana; Hall, Lynsey S; Hayward, Caroline; Thomson, Pippa A; Smith, Blair H; Padmanabhan, Sandosh; Hocking, Lynne J; Deary, Ian J; Porteous, David J; McIntosh, Andrew M

2017-04-01

Type II diabetes (T2D) and major depressive disorder (MDD) are often co-morbid. The reasons for this co-morbidity are unclear. Some studies have highlighted the importance of environmental factors and a causal relationship between T2D and MDD has also been postulated. In the present study we set out to investigate the shared aetiology between T2D and MDD using Mendelian randomization in a population based sample, Generation Scotland: the Scottish Family Health Study (N = 21,516). Eleven SNPs found to be associated with T2D were tested for association with MDD and psychological distress (General Health Questionnaire scores). We also assessed causality and genetic overlap between T2D and MDD using polygenic risk scores (PRS) assembled from the largest available GWAS summary statistics to date. No single T2D risk SNP was associated with MDD in the MR analyses and we did not find consistent evidence of genetic overlap between MDD and T2D in the PRS analyses. Linkage disequilibrium score regression analyses supported these findings as no genetic correlation was observed between T2D and MDD (rG = 0.0278 (S.E. 0.11), P-value = 0.79). As suggested by previous studies, T2D and MDD covariance may be better explained by environmental factors. Future studies would benefit from analyses in larger cohorts where stratifying by sex and looking more closely at MDD cases demonstrating metabolic dysregulation is possible. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc.

Comparison of two- and three-dimensional assessment methods of nasolabial appearance in cleft lip and palate patients: Do the assessment methods measure the same outcome?

PubMed

Mosmuller, David G M; Maal, Thomas J; Prahl, Charlotte; Tan, Robin A; Mulder, Frans J; Schwirtz, Roderic M F; de Vet, Henrica C W; Bergé, Stefaan J; Don Griot, J P W

2017-08-01

For the assessment of the nasolabial appearance in cleft patients, a widely accepted, reliable scoring system is not available. In this study four different methods of assessment are compared, including 2D and 3D asymmetry and aesthetic assessments. The data and ratings from an earlier study using the Asher-McDade aesthetic index on 3D photographs and the outcomes of 3D facial distance mapping were compared to a 2D aesthetic assessment, the Cleft Aesthetic Rating Scale, and to SymNose, a computerized 2D asymmetry assessment technique. The reliability and correlation between the four assessment techniques were tested using a sample of 79 patients. The 3D asymmetry assessment had the highest reliability and could be performed by just one observer (Intraclass correlation coefficient (ICC): 0.99). The 2D asymmetry assessment of the nose was highly reliable when performed by just one observer (ICC: 0.89). However, for the 2D asymmetry assessment of the lip more observers were needed. For the 2D aesthetic assessments 3 observers were needed. The 3D aesthetic assessment had the lowest single-observer reliability (ICC: 0.38-0.56) of all four techniques. The agreement between the different assessment methods is poor to very poor. The highest correlation (R: 0.48) was found between 2D and 3D aesthetic assessments. Remarkably, the lowest correlations were found between 2D and 3D asymmetry assessments (0.08-0.17). Different assessment methods are not in agreement and seem to measure different nasolabial aspects. More research is needed to establish exactly what each assessment technique measures and which measurements or outcomes are relevant for the patients. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Recognizing familiar objects by hand and foot: Haptic shape perception generalizes to inputs from unusual locations and untrained body parts.

PubMed

Lawson, Rebecca

2014-02-01

The limits of generalization of our 3-D shape recognition system to identifying objects by touch was investigated by testing exploration at unusual locations and using untrained effectors. In Experiments 1 and 2, people found identification by hand of real objects, plastic 3-D models of objects, and raised line drawings placed in front of themselves no easier than when exploration was behind their back. Experiment 3 compared one-handed, two-handed, one-footed, and two-footed haptic object recognition of familiar objects. Recognition by foot was slower (7 vs. 13 s) and much less accurate (9 % vs. 47 % errors) than recognition by either one or both hands. Nevertheless, item difficulty was similar across hand and foot exploration, and there was a strong correlation between an individual's hand and foot performance. Furthermore, foot recognition was better with the largest 20 of the 80 items (32 % errors), suggesting that physical limitations hampered exploration by foot. Thus, object recognition by hand generalized efficiently across the spatial location of stimuli, while object recognition by foot seemed surprisingly good given that no prior training was provided. Active touch (haptics) thus efficiently extracts 3-D shape information and accesses stored representations of familiar objects from novel modes of input.

Impact of diabetes-related gene polymorphisms on the clinical characteristics of type 2 diabetes Chinese Han population.

PubMed

Li, Jing; Wei, Jiachen; Xu, Pengcheng; Yan, Mengdan; Li, Jingjie; Chen, Zhengshuai; Jin, Tianbo

2016-12-20

We investigated the correlation between type 2 diabetes (T2D)-related genes and the clinical characteristics of T2D in the Chinese Han population. Our study included 319 patients and 387 controls. Age, gender, clinical features, medications intake and biochemical blood profiles were analyzed. Genotyping was performed on a total of 18 single nucleotide polymorphisms previously reported to be associated with T2D. Our analyses revealed that the CT genotype of ARHGAP22 rs4838605 is associated with T2D risk. Upon analyzing the subjects' clinical characteristics, we found that for rs2811893, the TT genotype correlated with high creatinine levels, while the AA genotype of rs17045754 and the TT genotype of rs4838605 correlated with elevated triglyceride levels. In addition, the AA genotype of rs17376456 and the TT genotype of rs6214 (p = 0.006) correlated with elevated hemoglobin A1c levels. Lastly, those carrying the TT genotype of rs7772697 and the CA genotype of rs3918227 exhibited higher mean body mass index and Cystatin C than controls. Our results showing that the ARHGAP22 gene is associated with an increased risk of T2D, and that seven SNPs in MYSM1, PLXDC2, ARHGAP22 and HS6ST3 promote T2D progression and could help predict the clinical course of T2D in patients at risk.

Tensor models, Kronecker coefficients and permutation centralizer algebras

NASA Astrophysics Data System (ADS)

Geloun, Joseph Ben; Ramgoolam, Sanjaye

2017-11-01

We show that the counting of observables and correlators for a 3-index tensor model are organized by the structure of a family of permutation centralizer algebras. These algebras are shown to be semi-simple and their Wedderburn-Artin decompositions into matrix blocks are given in terms of Clebsch-Gordan coefficients of symmetric groups. The matrix basis for the algebras also gives an orthogonal basis for the tensor observables which diagonalizes the Gaussian two-point functions. The centres of the algebras are associated with correlators which are expressible in terms of Kronecker coefficients (Clebsch-Gordan multiplicities of symmetric groups). The color-exchange symmetry present in the Gaussian model, as well as a large class of interacting models, is used to refine the description of the permutation centralizer algebras. This discussion is extended to a general number of colors d: it is used to prove the integrality of an infinite family of number sequences related to color-symmetrizations of colored graphs, and expressible in terms of symmetric group representation theory data. Generalizing a connection between matrix models and Belyi maps, correlators in Gaussian tensor models are interpreted in terms of covers of singular 2-complexes. There is an intriguing difference, between matrix and higher rank tensor models, in the computational complexity of superficially comparable correlators of observables parametrized by Young diagrams.

Generalized Two-Dimensional Perturbation Correlation Infrared Spectroscopy reveals Mechanisms for the Development of Surface Charge and Recalcitrance in Plant-derived Biochars

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

Harvey, Omar R.; Herbert, Bruce; Kuo, Li-Jung

2012-09-05

Fundamental knowledge of how biochars develop surface-charge and resistance to environmental degradation (or recalcitrance) is crucial to their production for customized applications or, understanding their functions in the environment. Two-dimensional perturbation-based correlation infrared spectroscopy (2D-PCIS) was used to study the biochar formation process in three taxonomically-different plant biomass, under oxygen-limited conditions along a heat-treatment-temperature gradient (HTT; 200-650 oC). Results from 2D-PCIS pointed to the systematic, HTT-induced defragmenting of lignocellulose H-bonding network, and demethylenation/demethylation, oxidation or dehydroxylation/dehydrogenation of lignocellulose fragments as the primary reactions controlling biochar properties along the HTT gradient. The cleavage of OH O-type H-bonds, oxidation of free primarymore » hydroxyls (HTT≤500 oC), and their subsequent dehydrogenation/dehydroxylation (HTT>500 oC) controlled surface charge on the biochars; while the dehydrogenation of methylene groups, which yielded increasingly condensed structures (R-CH2-R →R=CH-R →R=C=R), controlled biochar recalcitrance. Variations in biochar properties across plant biomass type were attributable to taxa-specific transformations. For example, apparent inefficiencies in the cleavage of wood-specific H-bonds, and their subsequent oxidation to carboxyls, lead to lower surface charge in wood biochars (compared to grass biochars). Both non-taxa and taxa-specific transformations highlighted by 2D-PCIS could have significant implications for biochar functioning in fire-impacted or biochar-amended systems.« less

Analysis of chronic aortic regurgitation by 2D and 3D echocardiography and cardiac MRI

PubMed Central

Stoebe, Stephan; Metze, Michael; Jurisch, Daniel; Tayal, Bhupendar; Solty, Kilian; Laufs, Ulrich; Pfeiffer, Dietrich; Hagendorff, Andreas

2018-01-01

Purpose The study compares the feasibility of the quantitative volumetric and semi-quantitative approach for quantification of chronic aortic regurgitation (AR) using different imaging modalities. Methods Left ventricular (LV) volumes, regurgitant volumes (RVol) and regurgitant fractions (RF) were assessed retrospectively by 2D, 3D echocardiography and cMRI in 55 chronic AR patients. Semi-quantitative parameters were assessed by 2D echocardiography. Results 22 (40%) patients had mild, 25 (46%) moderate and 8 (14%) severe AR. The quantitative volumetric approach was feasible using 2D, 3D echocardiography and cMRI, whereas the feasibility of semi-quantitative parameters varied considerably. LV volume (LVEDV, LVESV, SVtot) analyses showed good correlations between the different imaging modalities, although significantly increased LV volumes were assessed by cMRI. RVol was significantly different between 2D/3D echocardiography and 2D echocardiography/cMRI but was not significantly different between 3D echocardiography/cMRI. RF was not statistically different between 2D echocardiography/cMRI and 3D echocardiography/cMRI showing poor correlations (r < 0.5) between the different imaging modalities. For AR grading by RF, moderate agreement was observed between 2D/3D echocardiography and 2D echocardiography/cMRI and good agreement was observed between 3D echocardiography/cMRI. Conclusion Semi-quantitative parameters are difficult to determine by 2D echocardiography in clinical routine. The quantitative volumetric RF assessment seems to be feasible and can be discussed as an alternative approach in chronic AR. However, RVol and RF did not correlate well between the different imaging modalities. The best agreement for grading of AR severity by RF was observed between 3D echocardiography and cMRI. LV volumes can be verified by different approaches and different imaging modalities. PMID:29519957

Spatiotemporal differences in the c-fos pathway between C57BL/6J and DBA/2J mice following flurothyl-induced seizures: a dissociation of hippocampal Fos from seizure activity

PubMed Central

Kadiyala, Sridhar B.; Papandrea, Dominick; Tuz, Karina; Anderson, Tara M.; Jayakumar, Sachidhanand; Herron, Bruce J.; Ferland, Russell J.

2014-01-01

Significant differences in seizure characteristics between inbred mouse strains highlight the importance of genetic predisposition to epilepsy. Here, we examined the genetic differences between the seizure-resistant C57BL/6J (B6) mouse strain and the seizure-susceptible DBA/2J (D2) strain in the phospho-Erk and Fos pathways to examine seizure-induced neuronal activity to uncover potential mechanistic correlates to these disparate seizure responsivities. Expression of neural activity markers was examined following 1, 5, or 8 seizures, or after 8 seizures, a 28 day rest period, and a final flurothyl rechallenge. Two brain regions, the hippocampus and ventromedial nucleus of the hypothalamus (VMH), had significantly different Fos expression profiles following seizures. Fos expression was highly robust in B6 hippocampus following one seizure and remained elevated following multiple seizures. Conversely, there was an absence of Fos (and phospho-Erk) expression in D2 hippocampus following one generalized seizure that increased with multiple seizures. This lack of Fos expression occurred despite intracranial electroencephalographic recordings indicating that the D2 hippocampus propagated ictal discharge during the first flurothyl seizure suggesting a dissociation of seizure discharge from Fos and phospho-Erk expression. Global transcriptional analysis confirmed a dysregulation of the c-fos pathway in D2 mice following 1 seizure. Moreover, global analysis of RNA expression differences between B6 and D2 hippocampus revealed a unique pattern of transcripts that were co-regulated with Fos in D2 hippocampus following 1 seizure. These expression differences could, in part, account for D2’s seizure susceptibility phenotype. Following 8 seizures, a 28 day rest period, and a final flurothyl rechallenge, ~85% of B6 mice develop a more complex seizure phenotype consisting of a clonic-forebrain seizure that uninterruptedly progresses into a brainstem seizure. This seizure phenotype in B6 mice is highly correlated with bilateral Fos expression in the VMH and was not observed in D2 mice, which always express clonic-forebrain seizures upon flurothyl retest. Overall, these results illustrate specific differences in protein and RNA expression in different inbred strains following seizures that precede the reorganizational events that affect seizure susceptibility and changes in seizure semiology over time. PMID:25524858

Spatiotemporal differences in the c-fos pathway between C57BL/6J and DBA/2J mice following flurothyl-induced seizures: A dissociation of hippocampal Fos from seizure activity.

PubMed

Kadiyala, Sridhar B; Papandrea, Dominick; Tuz, Karina; Anderson, Tara M; Jayakumar, Sachidhanand; Herron, Bruce J; Ferland, Russell J

2015-01-01

Significant differences in seizure characteristics between inbred mouse strains highlight the importance of genetic predisposition to epilepsy. Here, we examined the genetic differences between the seizure-resistant C57BL/6J (B6) mouse strain and the seizure-susceptible DBA/2J (D2) strain in the phospho-Erk and Fos pathways to examine seizure-induced neuronal activity to uncover potential mechanistic correlates to these disparate seizure responsivities. Expression of neural activity markers was examined following 1, 5, or 8 seizures, or after 8 seizures, a 28 day rest period, and a final flurothyl rechallenge. Two brain regions, the hippocampus and ventromedial nucleus of the hypothalamus (VMH), had significantly different Fos expression profiles following seizures. Fos expression was highly robust in B6 hippocampus following one seizure and remained elevated following multiple seizures. Conversely, there was an absence of Fos (and phospho-Erk) expression in D2 hippocampus following one generalized seizure that increased with multiple seizures. This lack of Fos expression occurred despite intracranial electroencephalographic recordings indicating that the D2 hippocampus propagated ictal discharge during the first flurothyl seizure suggesting a dissociation of seizure discharge from Fos and phospho-Erk expression. Global transcriptional analysis confirmed a dysregulation of the c-fos pathway in D2 mice following 1 seizure. Moreover, global analysis of RNA expression differences between B6 and D2 hippocampus revealed a unique pattern of transcripts that were co-regulated with Fos in D2 hippocampus following 1 seizure. These expression differences could, in part, account for D2's seizure susceptibility phenotype. Following 8 seizures, a 28 day rest period, and a final flurothyl rechallenge, ∼85% of B6 mice develop a more complex seizure phenotype consisting of a clonic-forebrain seizure that uninterruptedly progresses into a brainstem seizure. This seizure phenotype in B6 mice is highly correlated with bilateral Fos expression in the VMH and was not observed in D2 mice, which always express clonic-forebrain seizures upon flurothyl retest. Overall, these results illustrate specific differences in protein and RNA expression in different inbred strains following seizures that precede the reorganizational events that affect seizure susceptibility and changes in seizure semiology over time. Copyright © 2014 Elsevier B.V. All rights reserved.

Genetic parameters for oocyte number and embryo production within a bovine ovum pick-up-in vitro production embryo-production program.

PubMed

Merton, J S; Ask, B; Onkundi, D C; Mullaart, E; Colenbrander, B; Nielen, M

2009-10-15

Genetic factors influencing the outcome of bovine ovum pick-up-in vitro production (OPU-IVP) and its relation to female fertility were investigated. For the first time, genetic parameters were estimated for the number of cumulus-oocyte complexes (Ncoc), quality of cumulus-oocyte complexes (Qcoc), number and proportion of cleaved embryos at Day 4 (Ncleav(D4), Pcleav(D4)), and number and proportion of total and transferable embryos at Day 7 of culture (Nemb(D7), Pemb(D7) and NTemb(D7), PTemb(D7), respectively). Data were recorded by CRV (formally Holland Genetics) from the OPU-IVP program from January 1995 to March 2006. Data were collected from 1508 Holstein female donors, both cows and pregnant virgin heifers, with a total of 18,702 OPU sessions. Data were analyzed with repeated-measure sire models with permanent environment effect using ASREML (Holstein Friesian). Estimates of heritability were 0.25 for Ncoc, 0.09 for Qcoc, 0.19 for Ncleav(D4), 0.21 for Nemb(D7), 0.16 for NTemb(D7), 0.07 for Pcleav(D4), 0.12 for Pemb(D7), and 0.10 for PTemb(D7). Genetic correlation between Ncoc and Qcoc was close to zero, whereas genetic correlations between Ncoc and the number of embryos were positive and moderate to high for Nemb(D7) (0.47), NTemb(D7) (0.52), and Ncleav(D4) (0.85). Genetic correlations between Ncoc and percentages of embryos (Pcleav(D4), Pemb(D7), and PTemb(D7)) were all close to zero. Phenotypic correlations were in line with genetic correlations. Genetic and phenotypic correlations between Qcoc and all other traits were not significant except for the phenotypic correlations between Qcoc and number of embryos, which were negative and low to moderate for Nemb(D7) (-0.20), NTemb(D7) (-0.24), and Ncleav(D4) (-0.43). Results suggest that cumulus-oocyte complex (COC) quality, based on cumulus investment, is independent from the total number of COCs collected via OPU and that in general, a higher number of COCs will lead to a higher number of embryos produced. The correlation between the estimated breeding values for Ncoc and PTemb(D7) of sires in this study and the sires breeding index for female-fertility based on the Dutch cattle population was close to zero. This study revealed OPU-IVP traits (Nemb(D7), NTemb(D7), and Ncoc) that could be of potential value for selection. Introduction of such traits in breeding programs would enhance the number of offspring from superior donors as well as improve the cost efficiency of OPU-IVP programs.

Microfluidics for Cancer Nanomedicine: From Fabrication to Evaluation.

PubMed

Zhang, Hao; Zhu, Yifeng; Shen, Youqing

2018-05-27

Self-assembled drug delivery systems (sDDSs), made from nanocarriers and drugs, are one of the major types of nanomedicines, many of which are in clinical use, under preclinical investigation, or in clinical trials. One of the hurdles of this type of nanomedicine in real applications is the inherent complexity of their fabrication processes, which generally lack precise control over the sDDS structures and the batch-to-batch reproducibility. Furthermore, the classic 2D in vitro cell model, monolayer cell culture, has been used to evaluate sDDSs. However, 2D cell culture cannot adequately replicate in vivo tissue-level structures and their highly complex dynamic 3D environments, nor can it simulate their functions. Thus, evaluations using 2D cell culture often cannot correctly correlate with sDDS behaviors and effects in humans. Microfluidic technology offers novel solutions to overcome these problems and facilitates studying the structure-performance relationships for sDDS developments. In this Review, recent advances in microfluidics for 1) fabrication of sDDSs with well-defined physicochemical properties, such as size, shape, rigidity, and drug-loading efficiency, and 2) fabrication of 3D-cell cultures as "tissue/organ-on-a-chip" platforms for evaluations of sDDS biological performance are in focus. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Baryon acoustic oscillations in the Ly α forest of BOSS DR11 quasars

DOE PAGES

Delubac, Timothée; Bautista, Julian E.; Busca, Nicolás G.; ...

2015-01-26

We report a detection of the baryon acousticoscillation (BAO) feature in the flux-correlation function of the Lyα forest of high-redshift quasars with a statistical significance of five standard deviations. The study uses 137,562 quasars in the redshift range 2.1 ≤ z ≤ 3.5 from the data release 11 (DR11) of the Baryon Oscillation Spectroscopic Survey (BOSS) of SDSS-III. This sample contains three times the number of quasars used in previous studies. The measured position of the BAO peak determines the angular distance, D A(z = 2.34) and expansion rate, H(z = 2.34), both on a scale set by the sound horizon at the drag epoch, r d. We find D A/r d = 11.28 ± 0.65(1σ)more » $$+2.8\\atop{-1.2}$$(2σ) and D H/r d = 9.18 ± 0.28(1σ) ± 0.6(2σ) where D H = c/H. The optimal combination, ~D$$0.7\\atop{H}$$ D$0.3\\atop{A}/r d is determined with a precision of ~2%. For the value r d = 147.4 Mpc, consistent with the cosmic microwave background power spectrum measured by Planck, we find D A(z = 2.34) = 1662 ± 96(1σ) Mpc and H(z = 2.34) = 222 ± 7(1σ) km s -1 Mpc -1. Tests with mock catalogs and variations of our analysis procedure have revealed no systematic uncertainties comparable to our statistical errors. Our results agree with the previously reported BAO measurement at the same redshift using the quasar-Lyα forest cross-correlation. The autocorrelation and cross-correlation approaches are complementary because of the quite different impact of redshift-space distortion on the two measurements. The combined constraints from the two correlation functions imply values of D A/r d that are 7% lower and 7% higher for D H/r d than the predictions of a flat ΛCDM cosmological model with the best-fit Planck parameters. With our estimated statistical errors, the significance of this discrepancy is ≈2.5σ.« less

Influence of genetic background, salinity, and inoculum size on growth of the ichthyotoxic golden alga (Prymnesium parvum)

USGS Publications Warehouse

Rashel, Rakib H.; Patino, Reynaldo

2017-01-01

Salinity (5–30) effects on golden alga growth were determined at a standard laboratory temperature (22 °C) and one associated with natural blooms (13 °C). Inoculum-size effects were determined over a wide size range (100–100,000 cells ml−1). A strain widely distributed in the USA, UTEX-2797 was the primary study subject but another of limited distribution, UTEX-995 was used to evaluate growth responses in relation to genetic background. Variables examined were exponential growth rate (r), maximum cell density (max-D) and, when inoculum size was held constant (100 cells ml−1), density at onset of exponential growth (early-D). In UTEX-2797, max-D increased as salinity increased from 5 to ∼10–15 and declined thereafter regardless of temperature but r remained generally stable and only declined at salinity of 25–30. In addition, max-D correlated positively with r and early-D, the latter also being numerically highest at salinity of 15. In UTEX-995, max-D and r responded similarly to changes in salinity − they remained stable at salinity of 5–10 and 5–15, respectively, and declined at higher salinity. Also, max-D correlated with r but not early-D. Inoculum size positively and negatively influenced max-D and r, respectively, in both strains and these effects were significant even when the absolute size difference was small (100 versus 1000 cells ml−1). When cultured under similar conditions, UTEX-2797 grew faster and to much higher density than UTEX-995. In conclusion, (1) UTEX-2797’s superior growth performance may explain its relatively wide distribution in the USA, (2) the biphasic growth response of UTEX-2797 to salinity variation, with peak abundance at salinity of 10–15, generally mirrors golden alga abundance-salinity associations in US inland waters, and (3) early cell density – whether artificially manipulated or naturally attained – can influence UTEX-2797 bloom potential.

Subjective and objective appearance of head and neck cancer patients following microsurgical reconstruction and associated quality of life─A cross-sectional study.

PubMed

Kansy, Katinka; Hoffmann, Jürgen; Alhalabi, Obada; Mistele, Nicole; Freier, Kolja; Mertens, Christian; Freudlsperger, Christian; Engel, Michael

2018-06-01

Depending on the site and size of head and neck cancer, the disease affects patients' appearance and subsequently their quality of life. The aim of this study was to correlate subjective and objective evaluation of facial appearance and associated quality of life following ablative tumor surgery and microsurgical reconstruction. A total of 99 patients with combined ablative and reconstructive microsurgical procedure for head and neck malignancy and seven patients with non-malignant disease were examined by three-dimensional (3D) (photogrammetry at least 6 months post-surgery and were evaluated by two-dimensional (2D) and 3D means for symmetry and facial proportions. Measurements were correlated with subjective reporting from the University of Washington Quality of Life Questionnaire and observer ratings. Of the 106 patients, three patients scored themselves as significantly disfigured (2.8%), 19 were bothered by their appearance (17.9%), 27 (25.5%) reported no change, and 57 (53.8%) reported minor changes in their appearance. On 2D evaluation, 10 patients (9.4%) showed severely abnormal facial proportions. On 3D analysis, 17 patients showed major asymmetry. There was a high correlation (0.67) between patient and observer subjective rating (p < 0.05). While 2D evaluation alone showed no significant correlation with subjective rating, 3D evaluation showed a moderate correlation (0.37; p < 0.05). The best results were achieved by combining 2D and 3D measurements (0.5; p < 0.05). Young female patients were most critical about their appearance. Following combined ablative and microsurgical reconstructive procedures, patients have a realistic perception of their appearance compared with observer ratings and a combination of 2D and 3D objective evaluation. Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Exploring 4D quantum Hall physics with a 2D topological charge pump

NASA Astrophysics Data System (ADS)

Lohse, Michael; Schweizer, Christian; Price, Hannah M.; Zilberberg, Oded; Bloch, Immanuel

2018-01-01

The discovery of topological states of matter has greatly improved our understanding of phase transitions in physical systems. Instead of being described by local order parameters, topological phases are described by global topological invariants and are therefore robust against perturbations. A prominent example is the two-dimensional (2D) integer quantum Hall effect: it is characterized by the first Chern number, which manifests in the quantized Hall response that is induced by an external electric field. Generalizing the quantum Hall effect to four-dimensional (4D) systems leads to the appearance of an additional quantized Hall response, but one that is nonlinear and described by a 4D topological invariant—the second Chern number. Here we report the observation of a bulk response with intrinsic 4D topology and demonstrate its quantization by measuring the associated second Chern number. By implementing a 2D topological charge pump using ultracold bosonic atoms in an angled optical superlattice, we realize a dynamical version of the 4D integer quantum Hall effect. Using a small cloud of atoms as a local probe, we fully characterize the nonlinear response of the system via in situ imaging and site-resolved band mapping. Our findings pave the way to experimentally probing higher-dimensional quantum Hall systems, in which additional strongly correlated topological phases, exotic collective excitations and boundary phenomena such as isolated Weyl fermions are predicted.

Exploring 4D quantum Hall physics with a 2D topological charge pump.

PubMed

Lohse, Michael; Schweizer, Christian; Price, Hannah M; Zilberberg, Oded; Bloch, Immanuel

2018-01-03

The discovery of topological states of matter has greatly improved our understanding of phase transitions in physical systems. Instead of being described by local order parameters, topological phases are described by global topological invariants and are therefore robust against perturbations. A prominent example is the two-dimensional (2D) integer quantum Hall effect: it is characterized by the first Chern number, which manifests in the quantized Hall response that is induced by an external electric field. Generalizing the quantum Hall effect to four-dimensional (4D) systems leads to the appearance of an additional quantized Hall response, but one that is nonlinear and described by a 4D topological invariant-the second Chern number. Here we report the observation of a bulk response with intrinsic 4D topology and demonstrate its quantization by measuring the associated second Chern number. By implementing a 2D topological charge pump using ultracold bosonic atoms in an angled optical superlattice, we realize a dynamical version of the 4D integer quantum Hall effect. Using a small cloud of atoms as a local probe, we fully characterize the nonlinear response of the system via in situ imaging and site-resolved band mapping. Our findings pave the way to experimentally probing higher-dimensional quantum Hall systems, in which additional strongly correlated topological phases, exotic collective excitations and boundary phenomena such as isolated Weyl fermions are predicted.

Exploring personality traits related to dopamine D2/3 receptor availability in striatal subregions of humans.

PubMed

Caravaggio, Fernando; Fervaha, Gagan; Chung, Jun Ku; Gerretsen, Philip; Nakajima, Shinichiro; Plitman, Eric; Iwata, Yusuke; Wilson, Alan; Graff-Guerrero, Ariel

2016-04-01

While several studies have examined how particular personality traits are related to dopamine D2/3 receptor (D2/3R) availability in the striatum of humans, few studies have reported how multiple traits measured in the same persons are differentially related to D2/3R availability in different striatal sub-regions. We examined how personality traits measured with the Karolinska Scales of Personality are related to striatal D2/3R availability measured with [(11)C]-raclopride in 30 healthy humans. Based on previous the literature, five personality traits were hypothesized to be most likely related to D2/3R availability: impulsiveness, monotony avoidance, detachment, social desirability, and socialization. We found self-reported impulsiveness was negatively correlated with D2/3R availability in the ventral striatum and globus pallidus. After controlling for age and gender, monotony avoidance was also negatively correlated with D2/3R availability in the ventral striatum and globus pallidus. Socialization was positively correlated with D2/3R availability in the ventral striatum and putamen. After controlling for age and gender, the relationship between socialization and D2/3R availability in these regions survived correction for multiple comparisons (p-threshold=.003). Thus, within the same persons, different personality traits are differentially related to in vivo D2/3R availability in different striatal sub-regions. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

On exact correlation functions of chiral ring operators in 2 d N=(2, 2) SCFTs via localization

NASA Astrophysics Data System (ADS)

Chen, Jin

2018-03-01

We study the extremal correlation functions of (twisted) chiral ring operators via superlocalization in N=(2, 2) superconformal field theories (SCFTs) with central charge c ≥ 3, especially for SCFTs with Calabi-Yau geometric phases. We extend the method in arXiv: 1602.05971 with mild modifications, so that it is applicable to disentangle operators mixing on S 2 in nilpotent (twisted) chiral rings of 2 d SCFTs. With the extended algorithm and technique of localization, we compute exactly the extremal correlators in 2 d N=(2, 2) (twisted) chiral rings as non-holomorphic functions of marginal parameters of the theories. Especially in the context of Calabi-Yau geometries, we give an explicit geometric interpretation to our algorithm as the Griffiths transversality with projection on the Hodge bundle over Calabi-Yau complex moduli. We also apply the method to compute extremal correlators in Kähler moduli, or say twisted chiral rings, of several interesting Calabi-Yau manifolds. In the case of complete intersections in toric varieties, we provide an alternative formalism for extremal correlators via localization onto Higgs branch. In addition, as a spinoff we find that, from the extremal correlators of the top element in twisted chiral rings, one can extract chiral correlators in A-twisted topological theories.

Studies on spatial modes and the correlation anisotropy of entangled photons generated from 2D quadratic nonlinear photonic crystals

NASA Astrophysics Data System (ADS)

Luo, X. W.; Xu, P.; Sun, C. W.; Jin, H.; Hou, R. J.; Leng, H. Y.; Zhu, S. N.

2017-06-01

Concurrent spontaneous parametric down-conversion (SPDC) processes have proved to be an appealing approach for engineering the path-entangled photonic state with designable and tunable spatial modes. In this work, we propose a general scheme to construct high-dimensional path entanglement and demonstrate the basic properties of concurrent SPDC processes from domain-engineered quadratic nonlinear photonic crystals, including the spatial modes and the photon flux, as well as the anisotropy of spatial correlation under noncollinear quasi-phase-matching geometry. The overall understanding about the performance of concurrent SPDC processes will give valuable references to the construction of compact path entanglement and the development of new types of photonic quantum technologies.

IRFK2D: a computer program for simulating intrinsic random functions of order k

NASA Astrophysics Data System (ADS)

Pardo-Igúzquiza, Eulogio; Dowd, Peter A.

2003-07-01

IRFK2D is an ANSI Fortran-77 program that generates realizations of an intrinsic function of order k (with k equal to 0, 1 or 2) with a permissible polynomial generalized covariance model. The realizations may be non-conditional or conditioned to the experimental data. The turning bands method is used to generate realizations in 2D and 3D from simulations of an intrinsic random function of order k along lines that span the 2D or 3D space. The program generates two output files, the first containing the simulated values and the second containing the theoretical generalized variogram for different directions together with the theoretical model. The experimental variogram is calculated from the simulated values while the theoretical variogram is the specified generalized covariance model. The generalized variogram is used to assess the quality of the simulation as measured by the extent to which the generalized covariance is reproduced by the simulation. The examples given in this paper indicate that IRFK2D is an efficient implementation of the methodology.

Quantifying frontal plane knee motion during single limb squats: reliability and validity of 2-dimensional measures.

PubMed

Gwynne, Craig R; Curran, Sarah A

2014-12-01

Clinical assessment of lower limb kinematics during dynamic tasks may identify individuals who demonstrate abnormal movement patterns that may lead to etiology of exacerbation of knee conditions such as patellofemoral joint (PFJt) pain. The purpose of this study was to determine the reliability, validity and associated measurement error of a clinically appropriate two-dimensional (2-D) procedure of quantifying frontal plane knee alignment during single limb squats. Nine female and nine male recreationally active subjects with no history of PFJt pain had frontal plane limb alignment assessed using three-dimensional (3-D) motion analysis and digital video cameras (2-D analysis) while performing single limb squats. The association between 2-D and 3-D measures was quantified using Pearson's product correlation coefficients. Intraclass correlation coefficients (ICCs) were determined for within- and between-session reliability of 2-D data and standard error of measurement (SEM) was used to establish measurement error. Frontal plane limb alignment assessed with 2-D analysis demonstrated good correlation compared with 3-D methods (r = 0.64 to 0.78, p < 0.001). Within-session (0.86) and between-session ICCs (0.74) demonstrated good reliability for 2-D measures and SEM scores ranged from 2° to 4°. 2-D measures have good consistency and may provide a valid measure of lower limb alignment when compared to existing 3-D methods. Assessment of lower limb kinematics using 2-D methods may be an accurate and clinically useful alternative to 3-D motion analysis when identifying individuals who demonstrate abnormal movement patterns associated with PFJt pain. 2b.

Measuring upper limb function in children with hemiparesis with 3D inertial sensors.

PubMed

Newman, Christopher J; Bruchez, Roselyn; Roches, Sylvie; Jequier Gygax, Marine; Duc, Cyntia; Dadashi, Farzin; Massé, Fabien; Aminian, Kamiar

2017-12-01

Upper limb assessments in children with hemiparesis rely on clinical measurements, which despite standardization are prone to error. Recently, 3D movement analysis using optoelectronic setups has been used to measure upper limb movement, but generalization is hindered by time and cost. Body worn inertial sensors may provide a simple, cost-effective alternative. We instrumented a subset of 30 participants in a mirror therapy clinical trial at baseline, post-treatment, and follow-up clinical assessments, with wireless inertial sensors positioned on the arms and trunk to monitor motion during reaching tasks. Inertial sensor measurements distinguished paretic and non-paretic limbs with significant differences (P < 0.01) in movement duration, power, range of angular velocity, elevation, and smoothness (normalized jerk index and spectral arc length). Inertial sensor measurements correlated with functional clinical tests (Melbourne Assessment 2); movement duration and complexity (Higuchi fractal dimension) showed moderate to strong negative correlations with clinical measures of amplitude, accuracy, and fluency. Inertial sensor measurements reliably identify paresis and correlate with clinical measurements; they can therefore provide a complementary dimension of assessment in clinical practice and during clinical trials aimed at improving upper limb function.

Correlation of major components of ocular astigmatism in myopic patients.

PubMed

Mohammadpour, Mehrdad; Heidari, Zahra; Khabazkhoob, Mehdi; Amouzegar, Afsaneh; Hashemi, Hassan

2016-02-01

To investigate the correlation of major components of ocular astigmatism in myopic patients in an academic hospital. This cross-sectional study was conducted on 376 eyes of 188 patients who were referred to Farabi Eye Hospital for refractive surgery. Preoperative examinations including refraction and corneal topography were performed for all candidates to measure refractive and corneal astigmatism. Ocular residual astigmatism was calculated using vector analysis. Pearson's correlation and ANOVA analysis were used to evaluate the strength of the association between different types of astigmatism. Both eyes were defined as cluster and the Generalized Estimating Equations (GEE) analysis were performed. Mean age of 119 women (63.3%) and 69 men (36.7%) was 27.8 ± 5.7 years. Mean refractive error based on spherical equivalent was -3.59 ± 1.95D (range, -0.54 to -10.22D). Mean refractive and corneal astigmatism was 1.97 ± 1.3D and 1.85 ± 1.01D, respectively. Mean amount of ORA was 0.65 ± 0.36D.There was a significant correlation between ORA and refractive astigmatism(r=0.23, p<0.001), corneal and refractive astigmatism (r=0.91, p<0.001) and a weak correlation between ORA and corneal astigmatism (r=0.13, p=0.014). There was a significant correlation between J0 and J45 values of ORA and corneal astigmatism (p<0.001). There is a significant correlation between ORA and refractive astigmatism, refractive and corneal astigmatism and a weak correlation between ORA and corneal astigmatism in refractive surgery candidates. Identifying the type of astigmatism and preoperative measurement of ocular residual astigmatism is highly recommended prior to any refractive surgery, especially in cases with significant astigmatism. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electronic structure and dissociation curves for the ground states of Tl/sub 2/ and Tl/sub 2//sup +/ from relativistic effective potential calculations

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

Christiansen, P.A.; Pitzer, K.S.

The dissociation curves for the ground states of Tl/sub 2/ and Tl/sub 2//sup +/ were computed using a generalization of the molecular relativistic ..omega..--..omega.. coupling formalism of Lee, Ermler, and Pitzer. Relativistic effects, as represented by the Dirac equation, were introduced using effective potentials generated from atomic Dirac--nFock wave functions using a generalization of the improved effective potential formulation of Christiansen, Lee, and Pitzer. Our calculations show that the ground state of Tl/sub 2//sup +/ is 1/2/sub g/ with computed D/sub e/ and R/sub e/ values of 0.58 eV and 3.84 A. For Tl/sub 2/ we find that the groundmore » state is 0/sub u//sup -/ but the 0/sub g//sup +/ and the 1/sub u/ states are only slightly higher in energy; the potential curves for these states are repulsive to about 3.5 A and then essentially flat beyond that radius. While corrections for correlation will increase D/sub e/ somewhat, Tl/sub 2/ is only weakly bound in any of these states which dissociate to normal atoms. The cause is undoubtedly related to the large spin-orbit splitting between the 6p/sub 1/2/ and 6p/sub 3/2/ thallium spinors.« less

Low-power adiabatic sequences for in-vivo localized two-dimensional chemical shift correlated MR spectroscopy

PubMed Central

Andronesi, Ovidiu C.; Ramadan, Saadallah; Mountford, Carolyn E.; Sorensen, A. Gregory

2011-01-01

Novel low-power adiabatic sequences are demonstrated for in-vivo localized two-dimensional (2D) correlated MR spectroscopy, such as COSY (Correlated Spectroscopy) and TOCSY (Total Correlated Spectroscopy). The design is based on three new elements for in-vivo 2D MRS: the use of gradient modulated constant adiabaticity GOIA-W(16,4) pulses for i) localization (COSY and TOCSY) and ii) mixing (TOCSY), and iii) the use of longitudinal mixing (z-filter) for magnetization transfer during TOCSY. GOIA-W(16,4) provides accurate signal localization, and more importantly, lowers the SAR for both TOCSY mixing and localization. Longitudinal mixing improves considerably (five-folds) the efficiency of TOCSY transfer. These are markedly different from previous 1D editing TOCSY sequences using spatially non-selective pulses and transverse mixing. Fully adiabatic (adiabatic mixing with adiabatic localization) and semi-adiabatic (adiabatic mixing with non-adiabatic localization) methods for 2D TOCSY are compared. Results are presented for simulations, phantoms, and in-vivo 2D spectra from healthy volunteers and patients with brain tumors obtained on 3T clinical platforms equipped with standard hardware. To the best of our knowledge this is the first demonstration of in-vivo adiabatic 2D TOCSY and fully adiabatic 2D COSY. It is expected that these methodological developments will advance the in-vivo applicability of multi(spectrally)dimensional MRS to reliably identify metabolic biomarkers. PMID:20890988

Climatic interpretation of tree-ring methoxyl d2H time-series from a central alpine larch forest

NASA Astrophysics Data System (ADS)

Riechelmann, Dana F. C.; Greule, Markus; Siegwolf, Rolf T. W.; Esper, Jan; Keppler, Frank

2017-04-01

We measured stable hydrogen isotope ratios of lignin methoxyl groups (d2HLM) in high elevation larch trees (Larix decidua Mill.) from the Simplon Valley in southern Switzerland. Thirty-seven larch trees were sampled and five individuals analysed for their d2HLM values at annual (1971-2009) and pentadal resolution (1746-2009). Testing the climate response of the d2HLM series, the annually resolved series show a positive correlation of r = 0.60 with June/July precipitation and weaker but negative correlation with June/July temperature. In addition, a negative correlation with June-August d2H in precipitation of the nearby GNIP station in Locarno is observed. The pentadally resolved d2HLM series show no significant correlation to climate parameters. The positive correlation of the annually resolved data to summer precipitation is uncommon to d2H measurements from tree-rings (Feakins et al., 2013; Helle and Schleser, 2004; McCarroll and Loader, 2004; Mischel et al., 2015; White et al., 1994). However, we explain the positive association with warm season hydroclimate as follows: methoxyl groups of lignin are directly formed from tissues in the xylem water. More precipitation during June and July, which are on average relatively dry month, results in higher d2H values of the xylem water and therefore, higher d2H value in the lignin methoxyl groups. Therefore, we suggest that d2HLM values of high elevation larch trees might likely serve as a summer precipitation proxy. References: Feakins, S.J., Ellsworth, P.V., Sternberg, L.d.S.L., 2013. Lignin methoxyl hydrogen isotope rations in a coastal ecosystem. Geochimica et Cosmochimica Acta, 121: 54-66. Helle, G., Schleser, G.H., 2004. Interpreting Climate Proxies from Tree-rings. In: Fischer, H., Floeser, G., Kumke, T., Lohmann, G., Miller, H., Negendank, J.F.W., et al., editors. The Climate in Historical Times. Springer Berlin Heidelberg, pp. 129-148. McCarroll, D., Loader, N.J., 2004. Stable isotopes in tree rings. Quaternary Science Reviews, 23: 771-801. Mischel, M., Esper, J., Keppler, F., Greule, M., Werner, W., 2015. d2H, d13C and d18O from whole wood, a-cellulose and lignin methoxyl groups in Pinus sylvestris: a multi-parameter approach. Isotopes in Environmental and Health Studies, 1-16. White, J.W.C., Lawrence, J.R., Broecker, W.S., 1994. Modeling and interpreting D/H ratios in tree rings: A test case of white pine in the northeastern United States. Geochimica et Cosmochimica Acta, 58: 851-862.

The stationary points and structure of high-energy scattering amplitude

NASA Astrophysics Data System (ADS)

Samokhin, A. P.; Petrov, V. A.

2018-06-01

The ISR and the 7 TeV LHC data indicate that the differential cross-section of elastic proton-proton scattering remains almost energy-independent at the transferred momentum t ≈ - 0.21GeV2 at the level of ≈ 7.5 mb /GeV2. This property of dσ / dt (the "first" stationary point) appears due to the correlated growth of the total cross-section and the local slope parameter and can be expressed as a relation between the latter quantities. We anticipate that this property will be true up to 13 TeV. This enables us to normalize the preliminary TOTEM data for dσ / dt at 13 TeV and 0.05 < | t | < 3.4GeV2 and predict the values of dσ / dt at this energy. These data give an evidence of the second stationary point at t ≈ - 2.3GeV2 at the level of ≈ 33 nb /GeV2. The energy evolution of dσ / dt looks as if the high energy elastic scattering amplitude is a sum of two similar terms. We argue that the existence of the two stationary points and the two-component structure of the high energy elastic scattering amplitude are general properties for all elastic processes.

Structure-based characterization of multiprotein complexes.

PubMed

Wiederstein, Markus; Gruber, Markus; Frank, Karl; Melo, Francisco; Sippl, Manfred J

2014-07-08

Multiprotein complexes govern virtually all cellular processes. Their 3D structures provide important clues to their biological roles, especially through structural correlations among protein molecules and complexes. The detection of such correlations generally requires comprehensive searches in databases of known protein structures by means of appropriate structure-matching techniques. Here, we present a high-speed structure search engine capable of instantly matching large protein oligomers against the complete and up-to-date database of biologically functional assemblies of protein molecules. We use this tool to reveal unseen structural correlations on the level of protein quaternary structure and demonstrate its general usefulness for efficiently exploring complex structural relationships among known protein assemblies. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Multiple nitrogen isotope recorders for surface ocean nitrate utilization in the Subarctic North Pacific and the Bering Sea

NASA Astrophysics Data System (ADS)

Ren, H. A.; Anderson, R.; Sigman, D. M.; Studer, A.; Winckler, G.; Haugh, G.; Serno, S.; Gersonde, R.

2017-12-01

Sedimentary nitrogen isotopes have been developed as a proxy to reconstruct the degree of nitrate utilization in the polar surface oceans. But its application could be compromised by 1) uncertainties on the biological production, transport, and preservation of the organic material in the sediments, and 2) potential changes in the isotopic composition of the nitrate source, that is remotely controlled by processes in other regions. In this study, we map and compare spatial patterns of three d15N recorders (bulk sedimentary nitrogen, the organic nitrogen within cleaned diatom frustules or diatom-bound N, and within planktonic foraminifera tests or foraminifera-bound N) from multicore surface sediments across the Subarctic North Pacific (SNP) and the Bering Sea between 60°N and 35°N. Diatom-bound d15N varies between 3.5 and 8.5‰. Its spatial variation is reversely correlated with changes in the surface nitrate concentration, and is consistent with the expected d15N change of the export production in a simple nitrate assimilation model. Similar to previous findings, diatom-bound d15N is generally 2 4‰ higher than the modeled d15N value of the export production, likely reflecting a biomass to frustual-bound N difference. However, the greater d15N elevation observed in the eastern open SNP may be best explained by lateral transport of residual surface nitrate enriched in 15N from the western SNP. The d15N of Neogloboquadrina pachyderma (sinistral) is similar to the diatom-bound d15N within 1‰. Bulk sedimentary d15N generally agrees with diatom-bound d15N, but is more variable. It is higher than diatom-bound d15N in the eastern and western transect close to the shelf area, likely reflecting a terrigenous source, while exceptionally low d15N values were found on the Bering Sea shelf, possibly due to contamination by mineral-associated inorganic N.

Compound Specific δD Values Across a Tropical Precipitation Gradient: Implications for Low-latitude Paleoclimate Reconstructions

NASA Astrophysics Data System (ADS)

Douglas, P. M.; Pagani, M.; Brenner, M.; Curtis, J. H.; Hodell, D. A.

2009-12-01

Hydrogen isotopes (δD) of terrestrial and aquatic plant lipids have been used to reconstruct past continental hydrological change in low-latitude settings. Generally, lipid δD values correlate strongly with the isotopic composition of precipitation, although evapotranspiration and biosynthetic fractionation are important influences on the δD of leaf waxes. Few studies have focused on constraining the controls on δD values of lipids in the tropics, where high evaporation rates impact both leaf and lake water isotopic composition. We measured δD values in surface waters and lipids extracted from leaves, lake sediments and soils along a latitudinal transect across Mexico, Guatemala and Honduras, a region with distinct dry and wet seasons. The δD values of leaf waxes extracted from lake sediments are positively correlated with surface water δD values (r = 0.73). The apparent fractionation between stream waters (inferred to represent plant source water) and leaf waxes (ɛlw) is negatively correlated with mean annual precipitation (r = -0.89), likely due to greater evapotranspiration and D-enriched leaf water in drier climates. δD values of leaf waxes extracted directly from leaves collected during the rainy season (August 2008) are similarly correlated with surface water δD values (r = 0.85). Leaf ɛlw values, however, are not significantly correlated with mean annual precipitation. It is possible that the correlation between ɛlw and mean annual precipitation in lake sediment leaf waxes is related to seasonal variability in evapotranspiration. Specifically, lake sediment leaf waxes could predominantly represent production during the dry season when evapotranspiration effects are strongest and when many tropical tree species shed their leaves. Possible seasonal variability in fractionation between source water and leaf wax lipids should be taken into account when interpreting leaf wax δD records from tropical locations, both in terms of controlling for long-term variability in seasonality and when comparing records from different sites. Overall, the results of this research indicate that both the isotopic composition of precipitation and the intensity of evapotranspiration control the δD of terrestrial plant leaf waxes in the tropics.

Itinerant quantum multicriticality of two-dimensional Dirac fermions

NASA Astrophysics Data System (ADS)

Roy, Bitan; Goswami, Pallab; Juričić, Vladimir

2018-05-01

We analyze emergent quantum multicriticality for strongly interacting, massless Dirac fermions in two spatial dimensions (d =2 ) within the framework of Gross-Neveu-Yukawa models, by considering the competing order parameters that give rise to fully gapped (insulating or superconducting) ground states. We focus only on those competing orders which can be rotated into each other by generators of an exact or emergent chiral symmetry of massless Dirac fermions, and break O(S1) and O(S2) symmetries in the ordered phase. Performing a renormalization-group analysis by using the ɛ =(3 -d ) expansion scheme, we show that all the coupling constants in the critical hyperplane flow toward a new attractive fixed point, supporting an enlarged O(S1+S2) chiral symmetry. Such a fixed point acts as an exotic quantum multicritical point (MCP), governing the continuous semimetal-insulator as well as insulator-insulator (for example, antiferromagnet to valence bond solid) quantum phase transitions. In comparison with the lower symmetric semimetal-insulator quantum critical points, possessing either O(S1) or O(S2) chiral symmetry, the MCP displays enhanced correlation length exponents, and anomalous scaling dimensions for both fermionic and bosonic fields. We discuss the scaling properties of the ratio of bosonic and fermionic masses, and the increased dc resistivity at the MCP. By computing the scaling dimensions of different local fermion bilinears in the particle-hole channel, we establish that most of the four fermion operators or generalized density-density correlation functions display faster power-law decays at the MCP compared to the free fermion and lower symmetric itinerant quantum critical points. Possible generalization of this scenario to higher-dimensional Dirac fermions is also outlined.

Assessment of left ventricular size and function by 3-dimensional transthoracic echocardiography: Impact of the echocardiography platform and analysis software.

PubMed

Castel, Anne Laure; Toledano, Manuel; Tribouilloy, Christophe; Delelis, François; Mailliet, Amandine; Marotte, Nathalie; Guerbaai, Raphaëlle A; Levy, Franck; Graux, Pierre; Ennezat, Pierre-Vladimir; Maréchaux, Sylvestre

2018-05-27

Whether echocardiography platform and analysis software impact left ventricular (LV) volumes, ejection fraction (EF), and stroke volume (SV) by transthoracic tridimensional echocardiography (3DE) has not yet been assessed. Hence, our aim was to compare 3DE LV end-diastolic and end-systolic volumes (EDV and ESV), LVEF, and SV obtained with echocardiography platform from 2 different manufacturers. 3DE was performed in 84 patients (65% of screened consecutive patients), with equipment from 2 different manufacturers, with subsequent off-line postprocessing to obtain parameters of LV function and size (Philips QLAB 3DQ and General Electric EchoPAC 4D autoLVQ). Twenty-five patients with clinical indication for cardiac magnetic resonance imaging served as a validation subgroup. LVEDV and LVESV from 2 vendors were highly correlated (r = 0.93), but compared with 4D autoLVQ, the use of Qlab 3DQ resulted in lower LVEDV and LVESV (bias: 11 mL, limits of agreement: -25 to +47 and bias: 6 mL, limits of agreement: -22 to +34, respectively). The agreement between LVEF values of each software was poor (intraclass correlation coefficient 0.62) despite no or minimal bias. SVs were also lower with Qlab 3DQ advanced compared with 4D autoLVQ, and both were poorly correlated (r = 0.66). Consistently, the underestimation of LVEDV, LVESV, and SV by 3DE compared with cardiac magnetic resonance imaging was more pronounced with Philips QLAB 3DQ advanced than with 4D autoLVQ. The echocardiography platform and analysis software significantly affect the values of LV parameters obtained by 3DE. Intervendor standardization and improvements in 3DE modalities are needed to broaden the use of LV parameters obtained by 3DE in clinical practice. Copyright © 2018. Published by Elsevier Inc.

Stereoscopic depth increases intersubject correlations of brain networks.

PubMed

Gaebler, Michael; Biessmann, Felix; Lamke, Jan-Peter; Müller, Klaus-Robert; Walter, Henrik; Hetzer, Stefan

2014-10-15

Three-dimensional movies presented via stereoscopic displays have become more popular in recent years aiming at a more engaging viewing experience. However, neurocognitive processes associated with the perception of stereoscopic depth in complex and dynamic visual stimuli remain understudied. Here, we investigate the influence of stereoscopic depth on both neurophysiology and subjective experience. Using multivariate statistical learning methods, we compare the brain activity of subjects when freely watching the same movies in 2D and in 3D. Subjective reports indicate that 3D movies are more strongly experienced than 2D movies. On the neural level, we observe significantly higher intersubject correlations of cortical networks when subjects are watching 3D movies relative to the same movies in 2D. We demonstrate that increases in intersubject correlations of brain networks can serve as neurophysiological marker for stereoscopic depth and for the strength of the viewing experience. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Correlation between white matter microstructure and executive functions suggests early developmental influence on long fibre tracts in preterm born adolescents.

PubMed

Vollmer, Brigitte; Lundequist, Aiko; Mårtensson, Gustaf; Nagy, Zoltan; Lagercrantz, Hugo; Smedler, Ann-Charlotte; Forssberg, Hans

2017-01-01

Executive functions are frequently a weakness in children born preterm. We examined associations of executive functions and general cognitive abilities with brain structure in preterm born adolescents who were born with appropriate weight for gestational age and who have no radiological signs of preterm brain injury on neuroimaging. The Stockholm Neonatal Project (SNP) is a longitudinal, population-based study of children born preterm (<36 weeks of gestation) with very low birth weight (<1501g) between 1988-1993. At age 18 years (mean 18 years, SD 2 weeks) 134 preterm born and 94 full term participants underwent psychological assessment (general intelligence, executive function measures). Of these, 71 preterm and 63 full term participants underwent Magnetic Resonance Imaging (MRI) at mean 15.2 years (range 12-18 years), including 3D T1-weighted images for volumetric analyses and Diffusion Tensor Imaging (DTI) for assessment of white matter microstructure. Group comparisons of regional grey and white matter volumes and fractional anisotropy (FA, as a measure of white matter microstructure) and, within each group, correlation analyses of cognitive measures with MRI metrics were carried out. Significant differences in grey and white matter regional volumes and widespread differences in FA were seen between the two groups. No significant correlations were found between cognitive measures and brain volumes in any group after correction for multiple comparisons. However, there were significant correlations between FA in projection fibres and long association fibres, linking frontal, temporal, parietal, and occipital lobes, and measures of executive function and general cognitive abilities in the preterm born adolescents, but not in the term born adolescents. In persons born preterm, in the absence of perinatal brain injury on visual inspection of MRI, widespread alterations in regional brain tissue volumes and microstructure are present in adolescence/young adulthood. Importantly, these alterations in WM tracts are correlated with measures of executive function and general cognitive abilities. Our findings suggest that disturbance of neural pathways, rather than changes in regional brain volumes, are involved in the impaired cognitive functions.

Compositional variation in minerals of the chevkinite group

USGS Publications Warehouse

Macdonald, R.; Belkin, H.E.

2002-01-01

The composition of chevkinite and perrierite, the most common members of the chevkinite group, is closely expressed by the formula A4BC2D2Si4O22, where A = (La,Ce,Ca,Sr,Th), B = Fe2+, C = (Fe2+,Fe3+,Ti,Al,Zr,Nb) and D = Ti. The A site is dominated by a strong negative correlation between (Ca+Sr) and the REE. Chondrite-normalized REE patterns are very variable, e.g. in LREE/HREE and Eu/Eu*. The C site is dominated by Ti, Al and Fe2+, in very variable proportions. Most chevkinites and perrierites are close to stoichiometric, with cation sums between 12.9 and 13.5, compared to the theoretical 13. There is no single, generally applicable charge balancing substitution scheme in the group; however, the general relationship (Ca+Sr)A + TiC + REEA + M3C+2+ defines a linear array with r2 = 0.91. Chevkinite and perrierite are shown to be compositionally distinct on the basis of CaO, FeO* Al2O3 and Ce2O3 abundances. Chevkinite forms mainly in chemically evolved parageneses, such as syenites, rhyolites and fenites associated with carbonatite complexes. Perrierite is more commonly recorded from igneous rocks of mafic to intermediate composition. The compositional characteristics and possible structural formulae of other members of the chevkinite group are reviewed briefly.

Diagnosing cysts with correlation coefficient images from 2-dimensional freehand elastography.

PubMed

Booi, Rebecca C; Carson, Paul L; O'Donnell, Matthew; Richards, Michael S; Rubin, Jonathan M

2007-09-01

We compared the diagnostic potential of using correlation coefficient images versus elastograms from 2-dimensional (2D) freehand elastography to characterize breast cysts. In this preliminary study, which was approved by the Institutional Review Board and compliant with the Health Insurance Portability and Accountability Act, we imaged 4 consecutive human subjects (4 cysts, 1 biopsy-verified benign breast parenchyma) with freehand 2D elastography. Data were processed offline with conventional 2D phase-sensitive speckle-tracking algorithms. The correlation coefficient in the cyst and surrounding tissue was calculated, and appearances of the cysts in the correlation coefficient images and elastograms were compared. The correlation coefficient in the cysts was considerably lower (14%-37%) than in the surrounding tissue because of the lack of sufficient speckle in the cysts, as well as the prominence of random noise, reverberations, and clutter, which decorrelated quickly. Thus, the cysts were visible in all correlation coefficient images. In contrast, the elastograms associated with these cysts each had different elastographic patterns. The solid mass in this study did not have the same high decorrelation rate as the cysts, having a correlation coefficient only 2.1% lower than that of surrounding tissue. Correlation coefficient images may produce a more direct, reliable, and consistent method for characterizing cysts than elastograms.

JT15D simulated flight data evaluation

NASA Technical Reports Server (NTRS)

Holm, R. G.

1984-01-01

The noise characteristics of the JT15D turbofan engine was analyzed with the objectives of: (1) assessing the state-of-art ability to simulate flight acoustic data using test results acquired in wind tunnel and outdoor (turbulence controlled) environments; and (2) predicting the farfield noise directivity of the blade passage frequency (BPF) tonal components using results from rotor blade mounted dynamic pressure instrumentation. Engine rotor tip speeds at subsonic, transonic, and supersonic conditions were evaluated. The ability to simulate flight results was generally within 2-3 dB for both outdoor and wind tunnel acoustic results. Some differences did occur in the broadband noise level and in the multiple-pure-tone harmonics at supersonic tip speeds. The prediction of blade passage frequency tone directivity from dynamic pressure measurements was accomplished for the three tip speed conditions. Predictions were made of the random and periodic components of the tone directivity. The technique for estimating the random tone component used hot wire data to establish a correlation between dynamic pressure and turbulence intensity. This prediction overestimated the tone level by typically 10 dB with the greatest overestimates occurring at supersonic conditions.

H4: A challenging system for natural orbital functional approximations

NASA Astrophysics Data System (ADS)

Ramos-Cordoba, Eloy; Lopez, Xabier; Piris, Mario; Matito, Eduard

2015-10-01

The correct description of nondynamic correlation by electronic structure methods not belonging to the multireference family is a challenging issue. The transition of D2h to D4h symmetry in H4 molecule is among the most simple archetypal examples to illustrate the consequences of missing nondynamic correlation effects. The resurgence of interest in density matrix functional methods has brought several new methods including the family of Piris Natural Orbital Functionals (PNOF). In this work, we compare PNOF5 and PNOF6, which include nondynamic electron correlation effects to some extent, with other standard ab initio methods in the H4 D4h/D2h potential energy surface (PES). Thus far, the wrongful behavior of single-reference methods at the D2h-D4h transition of H4 has been attributed to wrong account of nondynamic correlation effects, whereas in geminal-based approaches, it has been assigned to a wrong coupling of spins and the localized nature of the orbitals. We will show that actually interpair nondynamic correlation is the key to a cusp-free qualitatively correct description of H4 PES. By introducing interpair nondynamic correlation, PNOF6 is shown to avoid cusps and provide the correct smooth PES features at distances close to the equilibrium, total and local spin properties along with the correct electron delocalization, as reflected by natural orbitals and multicenter delocalization indices.

Discrimination of Fritillary according to geographical origin with Fourier transform infrared spectroscopy and two-dimensional correlation IR spectroscopy.

PubMed

Hua, Rui; Sun, Su-Qin; Zhou, Qun; Noda, Isao; Wang, Bao-Qin

2003-09-19

Fritillaria is a traditional Chinese herbal medicine for eliminating phlegm and relieving a cough with a long history in China and some other Asian countries. The objective of this study is to develop a nondestructive and accurate method to discriminate Fritillaria of different geographical origins, which is a troublesome work by existing analytical methods. We conducted a systematic study on five kinds of Fritillaria by Fourier transform infrared spectroscopy, second derivative infrared spectroscopy, and two-dimensional (2D) correlation infrared spectroscopy under thermal perturbation. Because Fritillaria consist of a large amount of starch, the conventional IR spectra of different Fritillaria only have very limited spectral feature differences. Based on these differences, we can separate different Fritillaria to a limited extent, but this method was deemed not very practical. The second derivative IR spectra of Fritillaria could enhance spectrum resolution, amplify the differences between the IR spectra of different Fritillaria, and provide some dissimilarity in their starch content, when compared with the spectrum of pure starch. Finally, we applied thermal perturbation to Fritillaria and analyzed the resulting spectra by the 2D correlation method to distinguish different Fritillaria easily and clearly. The distinction of very similar Fritillaria was possible because the spectral resolution was greatly enhanced by the 2D correlation spectroscopy. In addition, with the dynamic information of molecular structure provided by 2D correlation IR spectra, we studied the differences in the stability of active components of Fritillaria. The differences embodied mainly on the intensity ratio of the auto-peak at 985 cm(-1) and other auto-peaks. The 2D correlation IR spectroscopy (2D IR) of Fritillaria can be a new and powerful method to discriminate Fritillaria.

Prostaglandin metabolizing enzymes in correlation with vitamin D receptor in benign and malignant breast cell lines.

PubMed

Thill, Marc; Fischer, Dorothea; Becker, Steffi; Cordes, Tim; Dittmer, Christine; Diedrich, Klaus; Salehin, Darius; Friedrich, Michael

2009-09-01

The antiproliferative effects of calcitriol (1,25(OH)2D3) mediated via the vitamin D receptor (VDR), render the biologically active form of vitamin D a promising target in breast cancer therapy. Furthermore, breast cancer is associated with inflammatory processes based on an up-regulation of cyclooxygenase-2 (COX-2) expression, the prostaglandin E2 (PGE2) synthesizing enzyme. The PGE2 metabolizing enzyme, 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is described as a tumor suppressor in cancer. First references suggest a correlation between vitamin D and prostaglandin metabolism through the impact of 1,25(OH)2D3 on the expression of COX-2 and 15-PGDH. The expression of VDR, COX-2 and 15-PGDH in benign MCF-10F and malignant MCF-7 breast cells was determined by real-time PCR (RT-PCR) and Western blot analysis. Although the RT-PCR data were divergent from those obtained from the Western blot analysis, the COX-2 protein expression was MCF-7 2-fold higher in the MCF-7 compared to the MCF-10F cells. Moreover, a correlation of 15-PGDH to VDR by RT-PCR was found in both cell lines. The VDR protein levels were inversely correlated to the 15-PGDH protein levels and revealed that the MCF-10F cells had the highest VDR expression. A possible link between VDR-associated target genes and prostaglandin metabolism is suggested.

Rapid identification of Chinese Sauce liquor from different fermentation positions with FT-IR spectroscopy

NASA Astrophysics Data System (ADS)

Li, Changwen; Wei, Jiping; Zhou, Qun; Sun, Suqin

2008-07-01

FT-IR and two-dimensional correlation spectroscopy (2D-IR) technology were applied to discriminate Chinese Sauce liquor from different fermentation positions (top, middle and bottom of fermentation cellar) for the first time. The liquors at top, middle and bottom of fermentation cellar, possessed the characteristic peaks at 1731 cm -1, 1733 cm -1 and 1602 cm -1, respectively. In the 2D correlation infrared spectra, the differences were amplified. A strong auto-peak at 1725 cm -1 showed in the 2D spectra of the Top Liquor, which indicated that the liquor might contain some ester compounds. Different from Top Liquor, three auto-peaks at 1695, 1590 and 1480 cm -1 were identified in 2D spectra of Middle Liquor, which were the characteristic absorption of acid, lactate. In 2D spectra of Bottom Liquor, two auto-peaks at 1570 and 1485 cm -1 indicated that lactate was the major component. As a result, FT-IR and 2D-IR correlation spectra technology provided a rapid and effective method for the quality analysis of the Sauce liquor.

Detection of diluted contaminants on chicken carcasses using a two-dimensional scatter plot based on a two-dimensional hyperspectral correlation spectrum.

PubMed

Wu, Wei; Chen, Gui-Yun; Wu, Ming-Qing; Yu, Zhen-Wei; Chen, Kun-Jie

2017-03-20

A two-dimensional (2D) scatter plot method based on the 2D hyperspectral correlation spectrum is proposed to detect diluted blood, bile, and feces from the cecum and duodenum on chicken carcasses. First, from the collected hyperspectral data, a set of uncontaminated regions of interest (ROIs) and four sets of contaminated ROIs were selected, whose average spectra were treated as the original spectrum and influenced spectra, respectively. Then, the difference spectra were obtained and used to conduct correlation analysis, from which the 2D hyperspectral correlation spectrum was constructed using the analogy method of 2D IR correlation spectroscopy. Two maximum auto-peaks and a pair of cross peaks appeared at 656 and 474 nm. Therefore, 656 and 474 nm were selected as the characteristic bands because they were most sensitive to the spectral change induced by the contaminants. The 2D scatter plots of the contaminants, clean skin, and background in the 474- and 656-nm space were used to distinguish the contaminants from the clean skin and background. The threshold values of the 474- and 656-nm bands were determined by receiver operating characteristic (ROC) analysis. According to the ROC results, a pixel whose relative reflectance at 656 nm was greater than 0.5 and relative reflectance at 474 nm was lower than 0.3 was judged as a contaminated pixel. A region with more than 50 pixels identified was marked in the detection graph. This detection method achieved a recognition rate of up to 95.03% at the region level and 31.84% at the pixel level. The false-positive rate was only 0.82% at the pixel level. The results of this study confirm that the 2D scatter plot method based on the 2D hyperspectral correlation spectrum is an effective method for detecting diluted contaminants on chicken carcasses.

A generalized method for high throughput in-situ experiment data analysis: An example of battery materials exploration

NASA Astrophysics Data System (ADS)

Aoun, Bachir; Yu, Cun; Fan, Longlong; Chen, Zonghai; Amine, Khalil; Ren, Yang

2015-04-01

A generalized method is introduced to extract critical information from series of ranked correlated data. The method is generally applicable to all types of spectra evolving as a function of any arbitrary parameter. This approach is based on correlation functions and statistical scedasticity formalism. Numerous challenges in analyzing high throughput experimental data can be tackled using the herein proposed method. We applied this method to understand the reactivity pathway and formation mechanism of a Li-ion battery cathode material during high temperature synthesis using in-situ high-energy X-ray diffraction. We demonstrate that Pearson's correlation function can easily unravel all major phase transition and, more importantly, the minor structural changes which cannot be revealed by conventionally inspecting the series of diffraction patterns. Furthermore, a two-dimensional (2D) reactivity pattern calculated as the scedasticity along all measured reciprocal space of all successive diffraction pattern pairs unveils clearly the structural evolution path and the active areas of interest during the synthesis. The methods described here can be readily used for on-the-fly data analysis during various in-situ operando experiments in order to quickly evaluate and optimize experimental conditions, as well as for post data analysis and large data mining where considerable amount of data hinders the feasibility of the investigation through point-by-point inspection.

A generalized method for high throughput in-situ experiment data analysis: An example of battery materials exploration

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

Aoun, Bachir; Yu, Cun; Fan, Longlong

A generalized method is introduced to extract critical information from series of ranked correlated data. The method is generally applicable to all types of spectra evolving as a function of any arbitrary parameter. This approach is based on correlation functions and statistical scedasticity formalism. Numerous challenges in analyzing high throughput experimental data can be tackled using the herein proposed method. We applied this method to understand the reactivity pathway and formation mechanism of a Li-ion battery cathode material during high temperature synthesis using in-situ highenergy X-ray diffraction. We demonstrate that Pearson's correlation function can easily unravel all major phase transitionmore » and, more importantly, the minor structural changes which cannot be revealed by conventionally inspecting the series of diffraction patterns. Furthermore, a two-dimensional (2D) reactivity pattern calculated as the scedasticity along all measured reciprocal space of all successive diffraction pattern pairs unveils clearly the structural evolution path and the active areas of interest during the synthesis. The methods described here can be readily used for on-the-fly data analysis during various in-situ operando experiments in order to quickly evaluate and optimize experimental conditions, as well as for post data analysis and large data mining where considerable amount of data hinders the feasibility of the investigation through point-by-point inspection.« less

Spin Hartree-Fock approach to studying quantum Heisenberg antiferromagnets in low dimensions

NASA Astrophysics Data System (ADS)

Werth, A.; Kopietz, P.; Tsyplyatyev, O.

2018-05-01

We construct a new mean-field theory for a quantum (spin-1/2) Heisenberg antiferromagnet in one (1D) and two (2D) dimensions using a Hartree-Fock decoupling of the four-point correlation functions. We show that the solution to the self-consistency equations based on two-point correlation functions does not produce any unphysical finite-temperature phase transition, in accord with the Mermin-Wagner theorem, unlike the common approach based on the mean-field equation for the order parameter. The next-neighbor spin-spin correlation functions, calculated within this approach, reproduce closely the strong renormalization by quantum fluctuations obtained via a Bethe ansatz in 1D and a small renormalization of the classical antiferromagnetic state in 2D. The heat capacity approximates with reasonable accuracy the full Bethe ansatz result at all temperatures in 1D. In 2D, we obtain a reduction of the peak height in the heat capacity at a finite temperature that is accessible by high-order 1 /T expansions.

Solid-state NMR covariance of homonuclear correlation spectra.

PubMed

Hu, Bingwen; Amoureux, Jean-Paul; Trebosc, Julien; Deschamps, Michael; Tricot, Gregory

2008-04-07

Direct covariance NMR spectroscopy, which does not involve a Fourier transformation along the indirect dimension, is demonstrated to obtain homonuclear correlation two-dimensional (2D) spectra in the solid state. In contrast to the usual 2D Fourier transform (2D-FT) NMR, in a 2D covariance (2D-Cov) spectrum the spectral resolution in the indirect dimension is determined by the resolution along the detection dimension, thereby largely reducing the time-consuming indirect sampling requirement. The covariance method does not need any separate phase correction or apodization along the indirect dimension because it uses those applied in the detection dimension. We compare in detail the specifications obtained with 2D-FT and 2D-Cov, for narrow and broad resonances. The efficiency of the covariance data treatment is demonstrated in organic and inorganic samples that are both well crystallized and amorphous, for spin -1/2 nuclei with 13C, 29Si, and 31P through-space or through-bond homonuclear 2D correlation spectra. In all cases, the experimental time has been reduced by at least a factor of 10, without any loss of resolution and signal to noise ratio, with respect to what is necessary with the 2D-FT NMR. According to this method, we have been able to study the silicate network of glasses by 2D NMR within reasonable experimental time despite the very long relaxation time of the 29Si nucleus. The main limitation of the 2D-Cov data treatment is related to the introduction of autocorrelated peaks onto the diagonal, which does not represent any actual connectivity.

Anomalous dimension in a two-species reaction-diffusion system

NASA Astrophysics Data System (ADS)

Vollmayr-Lee, Benjamin; Hanson, Jack; McIsaac, R. Scott; Hellerick, Joshua D.

2018-01-01

We study a two-species reaction-diffusion system with the reactions A+A\\to (0, A) and A+B\\to A , with general diffusion constants D A and D B . Previous studies showed that for dimensions d≤slant 2 the B particle density decays with a nontrivial, universal exponent that includes an anomalous dimension resulting from field renormalization. We demonstrate via renormalization group methods that the scaled B particle correlation function has a distinct anomalous dimension resulting in the asymptotic scaling \\tilde CBB(r, t) ˜ tφf(r/\\sqrt{t}) , where the exponent ϕ results from the renormalization of the square of the field associated with the B particles. We compute this exponent to first order in \

Measurement of vitamin D3 metabolites in smelter workers exposed to lead and cadmium

PubMed Central

Chalkley, S. R.; Richmond, J.; Barltrop, D.

1998-01-01

OBJECTIVES: To investigate the effects of lead and cadmium on the metabolic pathway of vitamin D3. METHODS: Blood and urinary cadmium and urinary total proteins were measured in 59 smelter workers occupationally exposed to lead and cadmium. In 19 of these workers, the plasma vitamin D3 metabolites, (25-hydroxycholecalciferol (25 OHD3), 24R, 25-dihydroxycholecalciferol (24R,25(OH)2D3) and 1 alpha,25- dihydroxycholecalciferol (1 alpha, 25(OH)2D3)) were measured together with blood lead. Vitamin D3 metabolites were measured by radioimmunoassay, (RIA), lead and cadmium by atomic absorption spectrophotometry, and total proteins with a test kit. RESULTS: Ranges for plasma 25(OH)D3, 24R,25(OH)2D3 and 1 alpha,25(OH)2D3 were 1.0-51.9 ng/ml, 0.6-5.8 ng/ml, and 0.1-75.7 pg/ml, respectively. Ranges for blood lead were 1-3.7 mumol/l, (21-76 micrograms/dl), blood cadmium 6- 145 nmol/l, and urinary cadmium 3-161 nmol/l. Total proteins in random urine samples were 2.1-32.6 mg/dl. Concentrations of lead and cadmium in blood showed no correlation (correlation coefficient -0.265) but there was a highly significant correlation between blood and urinary cadmium. Concentrations for 24R,25(OH)2D3 were depressed below the normal range as blood and urinary cadmium increased, irrespective of lead concentrations. High cadmium concentrations were associated with decreased plasma 1 alpha,25(OH)2D3 when lead concentrations were < 1.9 mumol/l and with above normal plasma 1 alpha,25(OH)2D3 when lead concentrations were > 1.9 mumol/l, Kruskal-Wallis analysis of variance (K-W ANOVA) chi 2 = 10.3, p = 0.006. Plasma 25(OH)D3 was negatively correlated with both urinary total proteins and urinary cadmium, but showed no correlation with plasma 24R,25(OH)2D3, 1 alpha,25(OH)2D3, blood lead, or blood cadmium. CONCLUSION: Continuous long term exposure to cadmium may result in a state of equilibrium between blood and urinary cadmium. Cadmium concentrations in blood could be predicted from the cadmium concentration of the urine, (regression coefficient +0.35 SE 0.077). Exposure to cadmium alone decreased the concentrations of 1 alpha,25(OH)2D3 and 24R,25(OH)2D3, whereas exposure to both cadmium and lead increased the concentrations of 1 alpha,25(OH)2D3. It has been suggested that cadmium and lead interact with renal mitochondrial hydroxylases of the vitamin D3 endocrine complex. Perturbation of the vitamin D metabolic pathway by cadmium may result in health effect, such as osteoporosis or osteomalacia, risks which are possibly increased in the presence of lead.   PMID:9816377

PET imaging predicts future body weight and cocaine preference

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

Michaelides M.; Wang G.; Michaelides M.

Deficits in dopamine D2/D3 receptor (D2R/D3R) binding availability using PET imaging have been reported in obese humans and rodents. Similar deficits have been reported in cocaine-addicts and cocaine-exposed primates. We found that D2R/D3R binding availability negatively correlated with measures of body weight at the time of scan (ventral striatum), at 1 (ventral striatum) and 2 months (dorsal and ventral striatum) post scan in rats. Cocaine preference was negatively correlated with D2R/D3R binding availability 2 months (ventral striatum) post scan. Our findings suggest that inherent deficits in striatal D2R/D3R signaling are related to obesity and drug addiction susceptibility and that ventralmore » and dorsal striatum serve dissociable roles in maintaining weight gain and cocaine preference. Measuring D2R/D3R binding availability provides a way for assessing susceptibility to weight gain and cocaine abuse in rodents and given the translational nature of PET imaging, potentially primates and humans.« less

Acute exercise and physiological insulin induce distinct phosphorylation signatures on TBC1D1 and TBC1D4 proteins in human skeletal muscle

PubMed Central

Treebak, Jonas T; Pehmøller, Christian; Kristensen, Jonas M; Kjøbsted, Rasmus; Birk, Jesper B; Schjerling, Peter; Richter, Erik A; Goodyear, Laurie J; Wojtaszewski, Jørgen F P

2014-01-01

We investigated the phosphorylation signatures of two Rab-GTPase activating proteins TBC1D1 and TBC1D4 in human skeletal muscle in response to physical exercise and physiological insulin levels induced by a carbohydrate rich meal using a paired experimental design. Eight healthy male volunteers exercised in the fasted or fed state and muscle biopsies were taken before and immediately after exercise. We identified TBC1D1/4 phospho-sites that (1) did not respond to exercise or postprandial increase in insulin (TBC1D4: S666), (2) responded to insulin only (TBC1D4: S318), (3) responded to exercise only (TBC1D1: S237, S660, S700; TBC1D4: S588, S751), and (4) responded to both insulin and exercise (TBC1D1: T596; TBC1D4: S341, T642, S704). In the insulin-stimulated leg, Akt phosphorylation of both T308 and S473 correlated significantly with multiple sites on both TBC1D1 (T596) and TBC1D4 (S318, S341, S704). Interestingly, in the exercised leg in the fasted state TBC1D1 phosphorylation (S237, T596) correlated significantly with the activity of the α2/β2/γ3 AMPK trimer, whereas TBC1D4 phosphorylation (S341, S704) correlated with the activity of the α2/β2/γ1 AMPK trimer. Our data show differential phosphorylation of TBC1D1 and TBC1D4 in response to physiological stimuli in human skeletal muscle and support the idea that Akt and AMPK are upstream kinases. TBC1D1 phosphorylation signatures were comparable between in vitro contracted mouse skeletal muscle and exercised human muscle, and we show that AMPK regulated phosphorylation of these sites in mouse muscle. Contraction and exercise elicited a different phosphorylation pattern of TBC1D4 in mouse compared with human muscle, and although different circumstances in our experimental setup may contribute to this difference, the observation exemplifies that transferring findings between species is problematic. Key points Phosphorylation signature patterns on TBC1D1 and TBC1D4 proteins in the insulin–glucose pathway were investigated in human skeletal muscle in response to physiological insulin and exercise. In response to postprandial increase in insulin, Akt phosphorylation of T308 and S473 correlated significantly with sites on TBC1D1 (T596) and TBC1D4 (S318, S341, S704). Exercise induced phosphorylation of TBC1D1 (S237, T596) that correlated significantly with activity of the α2/β2/γ3 AMPK trimer, whereas TBC1D4 phosphorylation (S341, S704) with exercise correlated with activity of the α2/β2/γ1 AMPK trimer. TBC1D1 phosphorylation signatures with exercise/muscle contraction were comparable between human and mouse skeletal muscle, and AMPK regulated phosphorylation of these sites in mouse muscle, whereas contraction and exercise elicited different TBC1D4 phosphorylation patterns in mouse compared with human muscle. Our results show differential phosphorylation of TBC1D1 and TBC1D4 in response to physiological stimuli in human skeletal muscle and indicate that Akt and AMPK may be upstream kinases. PMID:24247980

Three-dimensional mapping of soil chemical characteristics at micrometric scale: Statistical prediction by combining 2D SEM-EDX data and 3D X-ray computed micro-tomographic images

NASA Astrophysics Data System (ADS)

Hapca, Simona

2015-04-01

Many soil properties and functions emerge from interactions of physical, chemical and biological processes at microscopic scales, which can be understood only by integrating techniques that traditionally are developed within separate disciplines. While recent advances in imaging techniques, such as X-ray computed tomography (X-ray CT), offer the possibility to reconstruct the 3D physical structure at fine resolutions, for the distribution of chemicals in soil, existing methods, based on scanning electron microscope (SEM) and energy dispersive X-ray detection (EDX), allow for characterization of the chemical composition only on 2D surfaces. At present, direct 3D measurement techniques are still lacking, sequential sectioning of soils, followed by 2D mapping of chemical elements and interpolation to 3D, being an alternative which is explored in this study. Specifically, we develop an integrated experimental and theoretical framework which combines 3D X-ray CT imaging technique with 2D SEM-EDX and use spatial statistics methods to map the chemical composition of soil in 3D. The procedure involves three stages 1) scanning a resin impregnated soil cube by X-ray CT, followed by precision cutting to produce parallel thin slices, the surfaces of which are scanned by SEM-EDX, 2) alignment of the 2D chemical maps within the internal 3D structure of the soil cube, and 3) development, of spatial statistics methods to predict the chemical composition of 3D soil based on the observed 2D chemical and 3D physical data. Specifically, three statistical models consisting of a regression tree, a regression tree kriging and cokriging model were used to predict the 3D spatial distribution of carbon, silicon, iron and oxygen in soil, these chemical elements showing a good spatial agreement between the X-ray grayscale intensities and the corresponding 2D SEM-EDX data. Due to the spatial correlation between the physical and chemical data, the regression-tree model showed a great potential in predicting chemical composition in particular for iron, which is generally sparsely distributed in soil. For carbon, silicon and oxygen, which are more densely distributed, the additional kriging of the regression tree residuals improved significantly the prediction, whereas prediction based on co-kriging was less consistent across replicates, underperforming regression-tree kriging. The present study shows a great potential in integrating geo-statistical methods with imaging techniques to unveil the 3D chemical structure of soil at very fine scales, the framework being suitable to be further applied to other types of imaging data such as images of biological thin sections for characterization of microbial distribution. Key words: X-ray CT, SEM-EDX, segmentation techniques, spatial correlation, 3D soil images, 2D chemical maps.

Structural and opto-electronic properties of 2D AlSb monolayer

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

Singh, Deobrat, E-mail: deobratsingh9@gmail.com; Sonvane, Yogesh; Gupta, Sanjeev K.

2016-05-23

We have investigated dielectric function related optical properties such as refractive index, absorption coefficient of two-dimensional hexagonal system of aluminum antimony (AlSb). We have also find structural and electronic properties of AlSb which show direct/indirect band gap with planar structure, employing the density functional theory using the generalized gradient approximation (GGA) given by Perdew-Burke-Ernzerhof (PBE) functional for exchange-correlation potential. The refractive index n(ω) increases with frequency in the near infrared region but in visible region n(ω) increasing after decrease.

Biorthogonal projected energies of a Gutzwiller similarity transformed Hamiltonian.

PubMed

Wahlen-Strothman, J M; Scuseria, G E

2016-12-07

We present a method incorporating biorthogonal orbital-optimization, symmetry projection, and double-occupancy screening with a non-unitary similarity transformation generated by the Gutzwiller factor [Formula: see text], and apply it to the Hubbard model. Energies are calculated with mean-field computational scaling with high-quality results comparable to coupled cluster singles and doubles. This builds on previous work performing similarity transformations with more general, two-body Jastrow-style correlators. The theory is tested on 2D lattices ranging from small systems into the thermodynamic limit and is compared to available reference data.

Metric Tests for Curvature from Weak Lensing and Baryon Acoustic Oscillations

NASA Astrophysics Data System (ADS)

Bernstein, G.

2006-02-01

We describe a practical measurement of the curvature of the universe which, unlike current constraints, relies purely on the properties of the Robertson-Walker metric rather than any assumed model for the dynamics and content of the universe. The observable quantity is the cross-correlation between foreground mass and gravitational shear of background galaxies, which depends on the angular diameter distances dA(zl), dA(zs), and dA(zs,zl) on the degenerate triangle formed by observer, source, and lens. In a flat universe, dA(zl,zs)=dA(zs)-dA(zl), but in curved universes an additional term ~Ωk appears and alters the lensing observables even if dA(z) is fixed. We describe a method whereby weak-lensing data can be used to solve simultaneously for dA and the curvature. This method is completely insensitive to the equation of state of the contents of the universe, or amendments to general relativity that alter the gravitational deflection of light or the growth of structure. The curvature estimate is also independent of biases in the photometric redshift scale. This measurement is shown to be subject to a degeneracy among dA, Ωk, and the galaxy bias factors that may be broken by using the same imaging data to measure the angular scale of baryon acoustic oscillations. Simplified estimates of the accuracy attainable by this method indicate that ambitious weak-lensing + baryon-oscillation surveys would measure Ωk to an accuracy ~0.04f-1/2sky(σlnz/0.04)1/2, where σlnz is the photometric redshift error. The Fisher-matrix formalism developed here is also useful for predicting bounds on curvature and other characteristics of parametric dark energy models. We forecast some representative error levels and compare ours to other analyses of the weak-lensing cross-correlation method. We find both curvature and parametric constraints to be surprisingly insensitive to the systematic shear calibration errors.

Digit ratio (2D:4D) and salivary testosterone, oestradiol and cortisol levels under challenge: Evidence for prenatal effects on adult endocrine responses.

PubMed

Crewther, Blair; Cook, Christian; Kilduff, Liam; Manning, John

2015-08-01

Digit ratio (2D:4D) is a marker for prenatal sex steroids and a correlate of sporting performance. This association may exist because low 2D:4D is linked to high prenatal levels of testosterone (T) and low oestrogens (E). It was recently suggested that low 2D:4D, and particularly low right-left 2D:4D (or Dr-l), is a marker for T changes in response to physical and aggressive challenges. If correct, this link may in part explain the association between 2D:4D and sports performance. We tested this hypothesis in adults. Three experimental treatments were completed using a randomised, cross-over design; (i) cycle sprints plus an aggressive video (S+V), (ii) aggressive video plus cycle sprints (V+S), and (iii) a control session. 24 healthy adults (12 men and 12 women). Salivary T, oestradiol (E2) and cortisol (C) levels were measured on six occasions across each session and pooled for analysis. The S+V treatment was associated with a rise in T and C levels, and Dr-l was significantly and negatively correlated with T and E2 with these effects confined to men. The right 2D:4D and Dr-l were also negatively correlated with the T/C ratio and Dr-l negatively related to the E2/C ratio in men during the S+V treatment. We suggest that the hormonal responses to a challenge are programmed by prenatal levels of T and E with possible links to sporting performance in adulthood. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Exploring the limit of accuracy for density functionals based on the generalized gradient approximation: Local, global hybrid, and range-separated hybrid functionals with and without dispersion corrections

DOE PAGES

Mardirossian, Narbe; Head-Gordon, Martin

2014-03-25

The limit of accuracy for semi-empirical generalized gradient approximation (GGA) density functionals is explored in this paper by parameterizing a variety of local, global hybrid, and range-separated hybrid functionals. The training methodology employed differs from conventional approaches in 2 main ways: (1) Instead of uniformly truncating the exchange, same-spin correlation, and opposite-spin correlation functional inhomogeneity correction factors, all possible fits up to fourth order are considered, and (2) Instead of selecting the optimal functionals based solely on their training set performance, the fits are validated on an independent test set and ranked based on their overall performance on the trainingmore » and test sets. The 3 different methods of accounting for exchange are trained both with and without dispersion corrections (DFT-D2 and VV10), resulting in a total of 491 508 candidate functionals. For each of the 9 functional classes considered, the results illustrate the trade-off between improved training set performance and diminished transferability. Since all 491 508 functionals are uniformly trained and tested, this methodology allows the relative strengths of each type of functional to be consistently compared and contrasted. Finally, the range-separated hybrid GGA functional paired with the VV10 nonlocal correlation functional emerges as the most accurate form for the present training and test sets, which span thermochemical energy differences, reaction barriers, and intermolecular interactions involving lighter main group elements.« less

New Sequences with Low Correlation and Large Family Size

NASA Astrophysics Data System (ADS)

Zeng, Fanxin

In direct-sequence code-division multiple-access (DS-CDMA) communication systems and direct-sequence ultra wideband (DS-UWB) radios, sequences with low correlation and large family size are important for reducing multiple access interference (MAI) and accepting more active users, respectively. In this paper, a new collection of families of sequences of length pn-1, which includes three constructions, is proposed. The maximum number of cyclically distinct families without GMW sequences in each construction is φ(pn-1)/n·φ(pm-1)/m, where p is a prime number, n is an even number, and n=2m, and these sequences can be binary or polyphase depending upon choice of the parameter p. In Construction I, there are pn distinct sequences within each family and the new sequences have at most d+2 nontrivial periodic correlation {-pm-1, -1, pm-1, 2pm-1,…,dpm-1}. In Construction II, the new sequences have large family size p2n and possibly take the nontrivial correlation values in {-pm-1, -1, pm-1, 2pm-1,…,(3d-4)pm-1}. In Construction III, the new sequences possess the largest family size p(d-1)n and have at most 2d correlation levels {-pm-1, -1,pm-1, 2pm-1,…,(2d-2)pm-1}. Three constructions are near-optimal with respect to the Welch bound because the values of their Welch-Ratios are moderate, WR_??_d, WR_??_3d-4 and WR_??_2d-2, respectively. Each family in Constructions I, II and III contains a GMW sequence. In addition, Helleseth sequences and Niho sequences are special cases in Constructions I and III, and their restriction conditions to the integers m and n, pm≠2 (mod 3) and n≅0 (mod 4), respectively, are removed in our sequences. Our sequences in Construction III include the sequences with Niho type decimation 3·2m-2, too. Finally, some open questions are pointed out and an example that illustrates the performance of these sequences is given.

Spatially-resolved studies on the role of defects and boundaries in electronic behavior of 2D materials

NASA Astrophysics Data System (ADS)

Hus, Saban M.; Li, An-Ping

2017-08-01

Two-dimensional (2D) materials are intrinsically heterogeneous. Both localized defects, such as vacancies and dopants, and mesoscopic boundaries, such as surfaces and interfaces, give rise to compositional or structural heterogeneities. The presence of defects and boundaries can break lattice symmetry, modify the energy landscape, and create quantum confinement, leading to fascinating electronic properties different from the ;ideal; 2D sheets. This review summarizes recent progress in understanding the roles of defects and boundaries in electronic, magnetic, thermoelectric, and transport properties of 2D layered materials. The focus is on the understanding of correlation of atomic-scale structural information with electronic functions by interrogating heterogeneities individually. The materials concerned are graphene, transition metal dichalcogenides (TMDs), hexagonal boron nitride (hBN), and topological insulators (TIs). The experimental investigations benefit from new methodologies and techniques in scanning tunneling microscopy (STM), including spin-polarized STM, scanning tunneling potentiometry (STP), scanning tunneling thermopower microscopy, and multi-probe STM. The experimental effort is complemented by the computational and theoretical approaches, capable of discriminating between closely competing states and achieving the length scales necessary to bridge across features such as local defects and complex heterostructures. The goal is to provide a general view of current understanding and challenges in studying the heterogeneities in 2D materials and to evaluate the potential of controlling and exploiting these heterogeneities for novel functionalities and electron devices.

A method to calculate fission-fragment yields Y(Z,N) versus proton and neutron number in the Brownian shape-motion model

DOE PAGES

Moller, Peter; Ichikawa, Takatoshi

2015-12-23

In this study, we propose a method to calculate the two-dimensional (2D) fission-fragment yield Y(Z,N) versus both proton and neutron number, with inclusion of odd-even staggering effects in both variables. The approach is to use the Brownian shape-motion on a macroscopic-microscopic potential-energy surface which, for a particular compound system is calculated versus four shape variables: elongation (quadrupole moment Q 2), neck d, left nascent fragment spheroidal deformation ϵ f1, right nascent fragment deformation ϵ f2 and two asymmetry variables, namely proton and neutron numbers in each of the two fragments. The extension of previous models 1) introduces a method tomore » calculate this generalized potential-energy function and 2) allows the correlated transfer of nucleon pairs in one step, in addition to sequential transfer. In the previous version the potential energy was calculated as a function of Z and N of the compound system and its shape, including the asymmetry of the shape. We outline here how to generalize the model from the “compound-system” model to a model where the emerging fragment proton and neutron numbers also enter, over and above the compound system composition.« less

Noninvasive deep Raman detection with 2D correlation analysis

NASA Astrophysics Data System (ADS)

Kim, Hyung Min; Park, Hyo Sun; Cho, Youngho; Jin, Seung Min; Lee, Kang Taek; Jung, Young Mee; Suh, Yung Doug

2014-07-01

The detection of poisonous chemicals enclosed in daily necessaries is prerequisite essential for homeland security with the increasing threat of terrorism. For the detection of toxic chemicals, we combined a sensitive deep Raman spectroscopic method with 2D correlation analysis. We obtained the Raman spectra from concealed chemicals employing spatially offset Raman spectroscopy in which incident line-shaped light experiences multiple scatterings before being delivered to inner component and yielding deep Raman signal. Furthermore, we restored the pure Raman spectrum of each component using 2D correlation spectroscopic analysis with chemical inspection. Using this method, we could elucidate subsurface component under thick powder and packed contents in a bottle.

Evidence for Weakly Correlated Oxygen Holes in the Highest-Tc Cuprate Superconductor HgBa2 Ca2 Cu3 O8 +δ

NASA Astrophysics Data System (ADS)

Chainani, A.; Sicot, M.; Fagot-Revurat, Y.; Vasseur, G.; Granet, J.; Kierren, B.; Moreau, L.; Oura, M.; Yamamoto, A.; Tokura, Y.; Malterre, D.

2017-08-01

We study the electronic structure of HgBa2 Ca2 Cu3 O8 +δ (Hg1223; Tc=134 K ) using photoemission spectroscopy (PES) and x -ray absorption spectroscopy (XAS). Resonant valence band PES across the O K edge and Cu L edge identifies correlation satellites originating in O 2 p and Cu 3 d two-hole final states, respectively. Analyses using the experimental O 2 p and Cu 3 d partial density of states show quantitatively different on-site Coulomb energy for the Cu site (Ud d=6.5 ±0.5 eV ) and O site (Up p=1.0 ±0.5 eV ). Cu2 O7 -cluster calculations with nonlocal screening explain the Cu 2 p core level PES and Cu L -edge XAS spectra, confirm the Ud d and Up p values, and provide evidence for the Zhang-Rice singlet state in Hg1223. In contrast to other hole-doped cuprates and 3 d -transition metal oxides, the present results indicate weakly correlated oxygen holes in Hg1223.

Relation between heat of vaporization, ion transport, molar volume, and cation-anion binding energy for ionic liquids.

PubMed

Borodin, Oleg

2009-09-10

A number of correlations between heat of vaporization (H(vap)), cation-anion binding energy (E(+/-)), molar volume (V(m)), self-diffusion coefficient (D), and ionic conductivity for 29 ionic liquids have been investigated using molecular dynamics (MD) simulations that employed accurate and validated many-body polarizable force fields. A significant correlation between D and H(vap) has been found, while the best correlation was found for -log(DV(m)) vs H(vap) + 0.28E(+/-). A combination of enthalpy of vaporization and a fraction of the cation-anion binding energy was suggested as a measure of the effective cohesive energy for ionic liquids. A deviation of some ILs from the reported master curve is explained based upon ion packing and proposed diffusion pathways. No general correlations were found between the ion diffusion coefficient and molecular volume or the diffusion coefficient and cation/anion binding energy.

Interaction of xenobiotics on the glucose-transport system and the Na+/K(+)-ATPase of human skin fibroblasts.

PubMed

Cascorbi, I; Forêt, M

1991-02-01

The effects of individual and combined xenobiotics on functional properties of the plasma membrane of human skin fibroblasts were investigated. Good correlations between toxic effects on the D-glucose transport system or the Na+/K(+)-ATPase and the lipophilicity of the substances could be observed. The linear regression coefficients plotting log EC20 values (doses, leading to 20% inhibition) versus log Pow (octanol/water partition coefficient) were r = 0.95 (P less than 0.05). The combination of lipophilic with less lipophilic xenobiotics, such as pentachlorophenol with 4-chloroaniline, leads to additional effects. However, when the detergent sodium dodecyl benzenesulfonate was combined with the herbicide 2,4-dichlorophenoxyacetate (2,4-D), the toxic effect of 2,4-D on the Na+/K(+)-ATPase decreased considerably. The results support in general the assumption that the inhibition of integral functional proteins is based on an accumulation of xenobiotics in the plasma membrane, probably due to the enhanced membrane fluidity. Thus, the basic toxicity of xenobiotics can be predicted by their physicochemical properties.

Java Radar Analysis Tool

NASA Technical Reports Server (NTRS)

Zaczek, Mariusz P.

2005-01-01

Java Radar Analysis Tool (JRAT) is a computer program for analyzing two-dimensional (2D) scatter plots derived from radar returns showing pieces of the disintegrating Space Shuttle Columbia. JRAT can also be applied to similar plots representing radar returns showing aviation accidents, and to scatter plots in general. The 2D scatter plots include overhead map views and side altitude views. The superposition of points in these views makes searching difficult. JRAT enables three-dimensional (3D) viewing: by use of a mouse and keyboard, the user can rotate to any desired viewing angle. The 3D view can include overlaid trajectories and search footprints to enhance situational awareness in searching for pieces. JRAT also enables playback: time-tagged radar-return data can be displayed in time order and an animated 3D model can be moved through the scene to show the locations of the Columbia (or other vehicle) at the times of the corresponding radar events. The combination of overlays and playback enables the user to correlate a radar return with a position of the vehicle to determine whether the return is valid. JRAT can optionally filter single radar returns, enabling the user to selectively hide or highlight a desired radar return.

Measurement and Simulation of First-Orbit Fast-Ion D-Alpha Emission and the Application to Fast-Ion Loss Detection in the DIII-D Tokamak

NASA Astrophysics Data System (ADS)

Bolte, Nathan; Heidbrink, W. W.; Pace, D. C.; van Zeeland, M. A.; Chen, X.

2015-11-01

A new fast-ion diagnostic method uses passive emission of D-alpha radiation to determine fast-ion losses quantitatively. The passive fast-ion D-alpha simulation (P-FIDAsim) forward models the Doppler-shifted spectra of first-orbit fast ions that charge exchange with edge neutrals. Simulated spectra are up to 80 % correlated with experimental spectra. Calibrated spectra are used to estimate the 2D neutral density profile by inverting simulated spectra. The inferred neutral density shows the expected increase toward each x-point and an average value of 8 × 10 9 cm-3 at the plasma boundary and 1 × 10 11 cm-3 near the wall. Measuring and simulating first-orbit spectra effectively ``calibrates'' the system, allowing for the quantification of more general fast-ion losses. Sawtooth crashes are estimated to eject 1.2 % of the fast-ion inventory, in good agreement with a 1.7 % loss estimate made by TRANSP. Sightlines sensitive to passing ions observe larger sawtooth losses than sightlines sensitive to trapped ions. Supported by US DOE under SC-G903402, DE-FC02-04ER54698.

Comparison of biochemical cartilage imaging techniques at 3 T MRI.

PubMed

Rehnitz, C; Kupfer, J; Streich, N A; Burkholder, I; Schmitt, B; Lauer, L; Kauczor, H-U; Weber, M-A

2014-10-01

To prospectively compare chemical-exchange saturation-transfer (CEST) with delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and T2 mapping to assess the biochemical cartilage properties of the knee. Sixty-nine subjects were prospectively included (median age, 42 years; male/female = 32/37) in three cohorts: 10 healthy volunteers, 40 patients with clinically suspected cartilage lesions, and 19 patients about 1 year after microfracture therapy. T2 mapping, dGEMRIC, and CEST were performed at a 3 T MRI unit using a 15-channel knee coil. Parameter maps were evaluated using region-of-interest analysis of healthy cartilage, areas of chondromalacia and repair tissue. Differentiation of damaged from healthy cartilage was assessed using receiver-operating characteristic (ROC) analysis. Chondromalacia grade 2-3 had significantly higher CEST values (P = 0.001), lower dGEMRIC (T1-) values (P < 0.001) and higher T2 values (P < 0.001) when compared to the normal appearing cartilage. dGEMRIC and T2 mapping correlated moderately negative (Spearman coefficient r = -0.56, P = 0.0018) and T2 mapping and CEST moderately positive (r = 0.5, P = 0.007), while dGEMRIC and CEST did not significantly correlate (r = -0.311, P = 0.07). The repair tissue revealed lower dGEMRIC values (P < 0.001) and higher CEST values (P < 0.001) with a significant negative correlation (r = -0.589, P = 0.01), whereas T2 values were not different (P = 0.54). In healthy volunteers' cartilage, CEST and dGEMRIC showed moderate positive correlation (r = 0.56), however not reaching significance (P = 0.09). ROC-analysis demonstrated non-significant differences of T2 mapping vs CEST (P = 0.14), CEST vs dGEMRIC (P = 0.89), and T2 mapping vs dGEMRIC (P = 0.12). CEST is able to detect normal and damaged cartilage and is non-inferior in distinguishing both when compared to dGEMRIC and T2 mapping. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

4D scattering amplitudes and asymptotic symmetries from 2D CFT

NASA Astrophysics Data System (ADS)

Cheung, Clifford; de la Fuente, Anton; Sundrum, Raman

2017-01-01

We reformulate the scattering amplitudes of 4D flat space gauge theory and gravity in the language of a 2D CFT on the celestial sphere. The resulting CFT structure exhibits an OPE constructed from 4D collinear singularities, as well as infinite-dimensional Kac-Moody and Virasoro algebras encoding the asymptotic symmetries of 4D flat space. We derive these results by recasting 4D dynamics in terms of a convenient foliation of flat space into 3D Euclidean AdS and Lorentzian dS geometries. Tree-level scattering amplitudes take the form of Witten diagrams for a continuum of (A)dS modes, which are in turn equivalent to CFT correlators via the (A)dS/CFT dictionary. The Ward identities for the 2D conserved currents are dual to 4D soft theorems, while the bulk-boundary propagators of massless (A)dS modes are superpositions of the leading and subleading Weinberg soft factors of gauge theory and gravity. In general, the massless (A)dS modes are 3D Chern-Simons gauge fields describing the soft, single helicity sectors of 4D gauge theory and gravity. Consistent with the topological nature of Chern-Simons theory, Aharonov-Bohm effects record the "tracks" of hard particles in the soft radiation, leading to a simple characterization of gauge and gravitational memories. Soft particle exchanges between hard processes define the Kac-Moody level and Virasoro central charge, which are thereby related to the 4D gauge coupling and gravitational strength in units of an infrared cutoff. Finally, we discuss a toy model for black hole horizons via a restriction to the Rindler region.

Measuring sexual dimorphism with a race-gender face space.

PubMed

Hopper, William J; Finklea, Kristin M; Winkielman, Piotr; Huber, David E

2014-10-01

Faces are complex visual objects, and faces chosen to vary in 1 regard may unintentionally vary in other ways, particularly if the correlation is a property of the population of faces. Here, we present an example of a correlation that arises from differences in the degree of sexual dimorphism. In Experiment 1, paired similarity ratings were collected for a set of 40 real face images chosen to vary in terms of gender and race (Asian vs. White). Multidimensional scaling (MDS) placed these stimuli in a "face space," with different attributes corresponding to different dimensions. Gender was found to vary more for White faces, resulting in a negative or positive correlation between gender and race when only considering male or only considering female faces. This increased sexual dimorphism for White faces may provide an alternative explanation for differences in face processing between White and Asian faces (e.g., the own-race bias, face attractiveness biases, etc.). Studies of face processing that are unconfounded by this difference in the degree of sexual dimorphism require stimuli that are decorrelated in terms of race and gender. Decorrelated faces were created using a morphing technique, spacing the morphs uniformly around a ring in the 2-dimensional (2D) race-gender plane. In Experiment 2, paired similarity ratings confirmed the 2D positions of the morph faces. In Experiment 3, race and gender category judgments varied uniformly for these decorrelated stimuli. Our results and stimuli should prove useful for studying sexual dimorphism and for the study of face processing more generally.

Cross-correlating 2D and 3D galaxy surveys

DOE PAGES

Passaglia, Samuel; Manzotti, Alessandro; Dodelson, Scott

2017-06-08

Galaxy surveys probe both structure formation and the expansion rate, making them promising avenues for understanding the dark universe. Photometric surveys accurately map the 2D distribution of galaxy positions and shapes in a given redshift range, while spectroscopic surveys provide sparser 3D maps of the galaxy distribution. We present a way to analyse overlapping 2D and 3D maps jointly and without loss of information. We represent 3D maps using spherical Fourier-Bessel (sFB) modes, which preserve radial coverage while accounting for the spherical sky geometry, and we decompose 2D maps in a spherical harmonic basis. In these bases, a simple expression exists for the cross-correlation of the two fields. One very powerful application is the ability to simultaneously constrain the redshift distribution of the photometric sample, the sample biases, and cosmological parameters. We use our framework to show that combined analysis of DESI and LSST can improve cosmological constraints by factors ofmore » $${\\sim}1.2$$ to $${\\sim}1.8$$ on the region where they overlap relative to identically sized disjoint regions. We also show that in the overlap of DES and SDSS-III in Stripe 82, cross-correlating improves photo-$z$ parameter constraints by factors of $${\\sim}2$$ to $${\\sim}12$$ over internal photo-$z$ reconstructions.« less

Cross-correlating 2D and 3D galaxy surveys

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

Passaglia, Samuel; Manzotti, Alessandro; Dodelson, Scott

Galaxy surveys probe both structure formation and the expansion rate, making them promising avenues for understanding the dark universe. Photometric surveys accurately map the 2D distribution of galaxy positions and shapes in a given redshift range, while spectroscopic surveys provide sparser 3D maps of the galaxy distribution. We present a way to analyse overlapping 2D and 3D maps jointly and without loss of information. We represent 3D maps using spherical Fourier-Bessel (sFB) modes, which preserve radial coverage while accounting for the spherical sky geometry, and we decompose 2D maps in a spherical harmonic basis. In these bases, a simple expression exists for the cross-correlation of the two fields. One very powerful application is the ability to simultaneously constrain the redshift distribution of the photometric sample, the sample biases, and cosmological parameters. We use our framework to show that combined analysis of DESI and LSST can improve cosmological constraints by factors ofmore » $${\\sim}1.2$$ to $${\\sim}1.8$$ on the region where they overlap relative to identically sized disjoint regions. We also show that in the overlap of DES and SDSS-III in Stripe 82, cross-correlating improves photo-$z$ parameter constraints by factors of $${\\sim}2$$ to $${\\sim}12$$ over internal photo-$z$ reconstructions.« less

Anthropometrics related to the performance of a sample of male swimmers.

PubMed

Perciavalle, Valentina; Di Corrado, Donatella; Scuto, Claudia; Perciavalle, Vincenzo; Coco, Marinella

2014-06-01

The main purpose of the present investigation of 21 elite male swimmers was to assess whether the Ape Index (the ratio between the individual's arm span and height) and/or the second-to-fourth digit length ratio (2D:4D), i.e., the ratio between the length of the second and the fourth fingers of the right hand, are associated with the performance of high-level swimmers, when mood and/or executive function are covaried. The results showed no statistically significant correlation between the Ape Index and 2D:4D ratio, performance, executive function, or mood. In contrast, statistically significant correlations were found between 2D:4D ratio and performance, executive function, and mood. Regressions indicated that 2D:4D ratio and not Ape Index is related to the performances of a sample of male swimmers.

Data-Driven Correlation Analysis Between Observed 3D Fatigue-Crack Path and Computed Fields from High-Fidelity, Crystal-Plasticity, Finite-Element Simulations

NASA Astrophysics Data System (ADS)

Pierson, Kyle D.; Hochhalter, Jacob D.; Spear, Ashley D.

2018-05-01

Systematic correlation analysis was performed between simulated micromechanical fields in an uncracked polycrystal and the known path of an eventual fatigue-crack surface based on experimental observation. Concurrent multiscale finite-element simulation of cyclic loading was performed using a high-fidelity representation of grain structure obtained from near-field high-energy x-ray diffraction microscopy measurements. An algorithm was developed to parameterize and systematically correlate the three-dimensional (3D) micromechanical fields from simulation with the 3D fatigue-failure surface from experiment. For comparison, correlation coefficients were also computed between the micromechanical fields and hypothetical, alternative surfaces. The correlation of the fields with hypothetical surfaces was found to be consistently weaker than that with the known crack surface, suggesting that the micromechanical fields of the cyclically loaded, uncracked microstructure might provide some degree of predictiveness for microstructurally small fatigue-crack paths, although the extent of such predictiveness remains to be tested. In general, gradients of the field variables exhibit stronger correlations with crack path than the field variables themselves. Results from the data-driven approach implemented here can be leveraged in future model development for prediction of fatigue-failure surfaces (for example, to facilitate univariate feature selection required by convolution-based models).

N =1 Lagrangians for generalized Argyres-Douglas theories

NASA Astrophysics Data System (ADS)

Agarwal, Prarit; Sciarappa, Antonio; Song, Jaewon

2017-10-01

We find N = 1 Lagrangian gauge theories that flow to generalized ArgyresDouglas theories with N = 2 supersymmetry. We find that certain SU quiver gauge theories flow to generalized Argyres-Douglas theories of type ( A k-1 , A mk-1) and ( I m,km , S). We also find quiver gauge theories of SO/Sp gauge groups flowing to the ( A 2 m-1 , D 2 mk+1), ( A 2 m , D 2 m( k-1)+ k ) and D m(2 k + 2) m(2 k + 2) [ m] theories.

Correlative 3D imaging of Whole Mammalian Cells with Light and Electron Microscopy

PubMed Central

Murphy, Gavin E.; Narayan, Kedar; Lowekamp, Bradley C.; Hartnell, Lisa M.; Heymann, Jurgen A. W.; Fu, Jing; Subramaniam, Sriram

2011-01-01

We report methodological advances that extend the current capabilities of ion-abrasion scanning electron microscopy (IA–SEM), also known as focused ion beam scanning electron microscopy, a newly emerging technology for high resolution imaging of large biological specimens in 3D. We establish protocols that enable the routine generation of 3D image stacks of entire plastic-embedded mammalian cells by IA-SEM at resolutions of ~10 to 20 nm at high contrast and with minimal artifacts from the focused ion beam. We build on these advances by describing a detailed approach for carrying out correlative live confocal microscopy and IA–SEM on the same cells. Finally, we demonstrate that by combining correlative imaging with newly developed tools for automated image processing, small 100 nm-sized entities such as HIV-1 or gold beads can be localized in SEM image stacks of whole mammalian cells. We anticipate that these methods will add to the arsenal of tools available for investigating mechanisms underlying host-pathogen interactions, and more generally, the 3D subcellular architecture of mammalian cells and tissues. PMID:21907806

[Fractal dimension--a new EEG-based method of assessing the depth of anaesthesia].

PubMed

Willand, Monika; Rudner, Robert; Olejarczyk, Elzbieta; Wartak, Magdalena; Marciniak, Radosław; Stasiowski, Michał; Byrczek, Tomasz; Jałowiecki, Przemysław

2008-01-01

It has been suggested that analysis of the EEG signal using the fractal dimension method may be useful for assessment of depth of anaesthesia. Thirty ASA I and II patients, scheduled for elective surgery under general anaesthesia were induced with midazolam, fentanyl and propofol and paralyzed with rocuronium or cis-atracurium. Clinical signs of the depth of anaesthesia were classified to one of five OAA/S levels. Standard vital parameters were observed and brain electrical activity was measured using the bispectral index (BIS) and burst suppression ratio (BSR). The EEG signal was recorded and processed postoperatively to calculate Higuchi's fractal dimension (FD). The latter was presented as a derivative: (D(F)-1) x 100. Mean correlation coefficients between OAA/S scale levels, and BIS and (D(F)-1) x 100 values, were respectively: 0.749+/-0.172 and 0.753+/-0.220. In 28 (93.3%) patients, BIS correlated well with FD (r=0.63+/-0.33). In twenty cases, burst suppression occurred and the correlation coefficient between BIS and DF was much lower (r=0.5860+/-3650), when compared to the group of 10 patients in which no burst suppression was detected (r=0.711+/-0.251). Appropriate correction was made using the following formula: D(FK)=D(F)-(D(F) x BSR). The mean correlation coefficient between BIS values and D(FK) in the BS group was r=0.629+/-0.331. In all cases, the mean correlation coefficient between (D(F)-1) x 100 and BIS was r=0.661+/-0.307 (p<0.001). The fractal dimension method can be regarded as equal to BIS for assessment of depth of anaesthesia.

Spectral functions of strongly correlated extended systems via an exact quantum embedding

NASA Astrophysics Data System (ADS)

Booth, George H.; Chan, Garnet Kin-Lic

2015-04-01

Density matrix embedding theory (DMET) [Phys. Rev. Lett. 109, 186404 (2012), 10.1103/PhysRevLett.109.186404], introduced an approach to quantum cluster embedding methods whereby the mapping of strongly correlated bulk problems to an impurity with finite set of bath states was rigorously formulated to exactly reproduce the entanglement of the ground state. The formalism provided similar physics to dynamical mean-field theory at a tiny fraction of the cost but was inherently limited by the construction of a bath designed to reproduce ground-state, static properties. Here, we generalize the concept of quantum embedding to dynamic properties and demonstrate accurate bulk spectral functions at similarly small computational cost. The proposed spectral DMET utilizes the Schmidt decomposition of a response vector, mapping the bulk dynamic correlation functions to that of a quantum impurity cluster coupled to a set of frequency-dependent bath states. The resultant spectral functions are obtained on the real-frequency axis, without bath discretization error, and allows for the construction of arbitrary dynamic correlation functions. We demonstrate the method on the one- (1D) and two-dimensional (2D) Hubbard model, where we obtain zero temperature and thermodynamic limit spectral functions, and show the trivial extension to two-particle Green's functions. This advance therefore extends the scope and applicability of DMET in condensed-matter problems as a computationally tractable route to correlated spectral functions of extended systems and provides a competitive alternative to dynamical mean-field theory for dynamic quantities.

Striatal D2/3 Binding Potential Values in Drug-Naïve First-Episode Schizophrenia Patients Correlate With Treatment Outcome

PubMed Central

Wulff, Sanne; Pinborg, Lars Hageman; Svarer, Claus; Jensen, Lars Thorbjørn; Nielsen, Mette Ødegaard; Allerup, Peter; Bak, Nikolaj; Rasmussen, Hans; Frandsen, Erik; Rostrup, Egill; Glenthøj, Birte Yding

2015-01-01

One of best validated findings in schizophrenia research is the association between blockade of dopamine D2 receptors and the effects of antipsychotics on positive psychotic symptoms. The aim of the present study was to examine correlations between baseline striatal D2/3 receptor binding potential (BPp) values and treatment outcome in a cohort of antipsychotic-naïve first-episode schizophrenia patients. Additionally, we wished to investigate associations between striatal dopamine D2/3 receptor blockade and alterations of negative symptoms as well as functioning and subjective well-being. Twenty-eight antipsychotic-naïve schizophrenia patients and 26 controls were included in the study. Single-photon emission computed tomography (SPECT) with [123I]iodobenzamide ([123I]-IBZM) was used to examine striatal D2/3 receptor BPp. Patients were examined before and after 6 weeks of treatment with the D2/3 receptor antagonist amisulpride. There was a significant negative correlation between striatal D2/3 receptor BPp at baseline and improvement of positive symptoms in the total group of patients. Comparing patients responding to treatment to nonresponders further showed significantly lower baseline BPp in the responders. At follow-up, the patients demonstrated a negative correlation between the blockade and functioning, whereas no associations between blockade and negative symptoms or subjective well-being were observed. The results show an association between striatal BPp of dopamine D2/3 receptors in antipsychotic-naïve first-episode patients with schizophrenia and treatment response. Patients with a low BPp have a better treatment response than patients with a high BPp. The results further suggest that functioning may decline at high levels of dopamine receptor blockade. PMID:25698711

Engineering correlation effects via artificially designed oxide superlattices.

PubMed

Chen, Hanghui; Millis, Andrew J; Marianetti, Chris A

2013-09-13

Ab initio calculations are used to predict that a superlattice composed of layers of LaTiO3 and LaNiO3 alternating along the [001] direction is a S=1 Mott insulator with large magnetic moments on the Ni sites, negligible moments on the Ti sites and a charge transfer gap set by the energy difference between Ni d and Ti d states, distinct from conventional Mott insulators. Correlation effects are enhanced on the Ni sites via filling the oxygen p states and reducing the Ni-O-Ni bond angle. Small hole (electron) doping of the superlattice leads to a two-dimensional single-band situation with holes (electrons) residing on the Ni d(x2-y2) (Ti d(xy)) orbital and coupled to antiferromagnetically correlated spins in the NiO2 layer.

Lipidomic profiling reveals distinct differences in plasma lipid composition in healthy, prediabetic, and type 2 diabetic individuals

PubMed Central

Zhong, Huanzi; Fang, Chao; Fan, Yanqun; Lu, Yan; Wen, Bo; Ren, Huahui; Hou, Guixue; Yang, Fangming; Xie, Hailiang; Jie, Zhuye; Peng, Ye; Ye, Zhiqiang; Wu, Jiegen; Zi, Jin; Zhao, Guoqing; Chen, Jiayu; Bao, Xiao; Hu, Yihe; Gao, Yan; Zhang, Jun; Yang, Huanming; Wang, Jian; Madsen, Lise; Kristiansen, Karsten

2017-01-01

Abstract The relationship between dyslipidemia and type 2 diabetes mellitus (T2D) has been extensively reported, but the global lipid profiles, especially in the East Asia population, associated with the development of T2D remain to be characterized. Liquid chromatography coupled to tandem mass spectrometry was applied to detect the global lipidome in the fasting plasma of 293 Chinese individuals, including 114 T2D patients, 81 prediabetic subjects, and 98 individuals with normal glucose tolerance (NGT). Both qualitative and quantitative analyses revealed a gradual change in plasma lipid features with T2D patients exhibiting characteristics close to those of prediabetic individuals, whereas they differed significantly from individuals with NGT. We constructed and validated a random forest classifier with 28 lipidomic features that effectively discriminated T2D from NGT or prediabetes. Most of the selected features significantly correlated with diabetic clinical indices. Hydroxybutyrylcarnitine was positively correlated with fasting plasma glucose, 2-hour postprandial glucose, glycated hemoglobin, and insulin resistance index (HOMA-IR). Lysophosphatidylcholines such as lysophosphatidylcholine (18:0), lysophosphatidylcholine (18:1), and lysophosphatidylcholine (18:2) were all negatively correlated with HOMA-IR. The altered plasma lipidome in Chinese T2D and prediabetic subjects suggests that lipid features may play a role in the pathogenesis of T2D and that such features may provide a basis for evaluating risk and monitoring disease development. PMID:28505362

Sodium ion effect on silk fibroin conformation characterized by solid-state NMR and generalized 2D NMR NMR correlation

NASA Astrophysics Data System (ADS)

Ruan, Qing-Xia; Zhou, Ping

2008-07-01

In the present work, we investigated Na + ion effect on the silk fibroin (SF) conformation. Samples are Na +-involved regenerated silk fibroin films. 13C CP-MAS NMR demonstrates that as added [Na +] increases, partial silk fibroin conformation transit from helix-form to β-form at certain Na + ion concentration which is much higher than that in Bombyx mori silkworm gland. The generalized two-dimensional NMR-NMR correlation analysis reveals that silk fibroin undergoes several intermediate states during its conformation transition process as [Na +] increase. The appearance order of the intermediates is followed as: helix and/or random coil → helix-like → β-sheet-like → β-sheet, which is the same as that produced by pH decrease from 6.8 to 4.8 in the resultant regenerated silk fibroin films. The binding sites of Na + to silk fibroin might involve the carbonyl oxygen atom of certain amino acids sequence which could promote the formation of β-sheet conformation. Since the Na +sbnd O bond is weak, the ability of Na + inducing the secondary structure transition is weaker than those of Ca 2+, Cu 2+ and even K +. It is maybe a reason why the sodium content is much lower than potassium in the silkworm gland.

Texture analysis on the fluence map to evaluate the degree of modulation for volumetric modulated arc therapy

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

Park, So-Yeon; Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744; Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744

Purpose: Texture analysis on fluence maps was performed to evaluate the degree of modulation for volumetric modulated arc therapy (VMAT) plans. Methods: A total of six textural features including angular second moment, inverse difference moment, contrast, variance, correlation, and entropy were calculated for fluence maps generated from 20 prostate and 20 head and neck VMAT plans. For each of the textural features, particular displacement distances (d) of 1, 5, and 10 were adopted. To investigate the deliverability of each VMAT plan, gamma passing rates of pretreatment quality assurance, and differences in modulating parameters such as multileaf collimator (MLC) positions, gantrymore » angles, and monitor units at each control point between VMAT plans and dynamic log files registered by the Linac control system during delivery were acquired. Furthermore, differences between the original VMAT plan and the plan reconstructed from the dynamic log files were also investigated. To test the performance of the textural features as indicators for the modulation degree of VMAT plans, Spearman’s rank correlation coefficients (r{sub s}) with the plan deliverability were calculated. For comparison purposes, conventional modulation indices for VMAT including the modulation complexity score for VMAT, leaf travel modulation complexity score, and modulation index supporting station parameter optimized radiation therapy (MI{sub SPORT}) were calculated, and their correlations were analyzed in the same way. Results: There was no particular textural feature which always showed superior correlations with every type of plan deliverability. Considering the results comprehensively, contrast (d = 1) and variance (d = 1) generally showed considerable correlations with every type of plan deliverability. These textural features always showed higher correlations to the plan deliverability than did the conventional modulation indices, except in the case of modulating parameter differences. The r{sub s} values of contrast to the global gamma passing rates with criteria of 2%/2 mm, 2%/1 mm, and 1%/2 mm were 0.536, 0.473, and 0.718, respectively. The respective values for variance were 0.551, 0.481, and 0.688. In the case of local gamma passing rates, the r{sub s} values of contrast were 0.547, 0.578, and 0.620, respectively, and those of variance were 0.519, 0.527, and 0.569. All of the r{sub s} values in those cases were statistically significant (p < 0.003). In the cases of global and local gamma passing rates, MI{sub SPORT} showed the highest correlations among the conventional modulation indices. For global passing rates, r{sub s} values of MI{sub SPORT} were −0.420, −0.330, and −0.632, respectively, and those for local passing rates were −0.455, −0.490 and −0.502. The values of r{sub s} of contrast, variance, and MI{sub SPORT} with the MLC errors were −0.863, −0.828, and 0.795, respectively, all with statistical significances (p < 0.001). The correlations with statistical significances between variance and dose-volumetric differences were observed more frequently than the others. Conclusions: The contrast (d = 1) and variance (d = 1) calculated from fluence maps of VMAT plans showed considerable correlations with the plan deliverability, indicating their potential use as indicators for assessing the degree of modulation of VMAT plans. Both contrast and variance consistently showed better performance than the conventional modulation indices for VMAT.« less

Further Progress Applying the Generalized Wigner Distribution to Analysis of Vicinal Surfaces

NASA Astrophysics Data System (ADS)

Einstein, T. L.; Richards, Howard L.; Cohen, S. D.

2001-03-01

Terrace width distributions (TWDs) can be well fit by the generalized Wigner distribution (GWD), generally better than by conventional Gaussians, and thus offers a convenient way to estimate the dimensionless elastic repulsion strength tildeA from σ^2, the TWD variance.(T.L. Einstein and O. Pierre-Louis, Surface Sci. 424), L299 (1999) The GWD σ^2 accurately reproduces values for the two exactly soluble cases at small tildeA and in the asymptotic limit. Taxing numerical simulations show that the GWD σ^2 interpolates well between these limits. Extensive applications have been made to experimental data, esp. on Cu.(M. Giesen and T.L. Einstein, Surface Sci. 449), 191 (2000) Recommended analysis procedures are catalogued.(H.L. Richards, S.D. Cohen, TLE, & M. Giesen, Surf Sci 453), 59 (2000) Extensions of the GWD for multistep distributions are tested, with good agreement for second-neighbor distributions, less good for third.(TLE, HLR, SDC, & OP-L, Proc ISSI-PDSC2000, cond-mat/0012xxxxx) Alternatively, step-step correlation functions, about which there is more theoretical information, should be measured.

Absence of long-range order in the frustrated magnet SrDy2O4 due to trapped defects from a dimensionality crossover

NASA Astrophysics Data System (ADS)

Gauthier, N.; Fennell, A.; Prévost, B.; Uldry, A.-C.; Delley, B.; Sibille, R.; Désilets-Benoit, A.; Dabkowska, H. A.; Nilsen, G. J.; Regnault, L.-P.; White, J. S.; Niedermayer, C.; Pomjakushin, V.; Bianchi, A. D.; Kenzelmann, M.

2017-04-01

Magnetic frustration and low dimensionality can prevent long-range magnetic order and lead to exotic correlated ground states. SrDy2O4 consists of magnetic Dy3 + ions forming magnetically frustrated zigzag chains along the c axis and shows no long-range order to temperatures as low as T =60 mK. We carried out neutron scattering and ac magnetic susceptibility measurements using powder and single crystals of SrDy2O4 . Diffuse neutron scattering indicates strong one-dimensional (1D) magnetic correlations along the chain direction that can be qualitatively accounted for by the axial next-nearest-neighbor Ising model with nearest-neighbor and next-nearest-neighbor exchange J1=0.3 meV and J2=0.2 meV, respectively. Three-dimensional (3D) correlations become important below T*≈0.7 K. At T =60 mK, the short-range correlations are characterized by a putative propagation vector k1 /2=(0 ,1/2 ,1/2 ) . We argue that the absence of long-range order arises from the presence of slowly decaying 1D domain walls that are trapped due to 3D correlations. This stabilizes a low-temperature phase without long-range magnetic order, but with well-ordered chain segments separated by slowly moving domain walls.

Performance of the PROMIS in Patients After Anterior Cruciate Ligament Reconstruction

PubMed Central

Scott, Elizabeth J.; Westermann, Robert; Glass, Nathalie A.; Hettrich, Carolyn; Wolf, Brian R.; Bollier, Matthew J.

2018-01-01

Background: The Patient-Reported Outcomes Measurement Information System (PROMIS) is designed to advance patient-reported outcome (PRO) instruments by utilizing question banks for major health domains. Purpose: To compare the responsiveness and construct validity of the PROMIS physical function computer adaptive test (PF CAT) with current PRO instruments for patients before and up to 2 years after anterior cruciate ligament (ACL) reconstruction. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Initially, 157 patients completed the PROMIS PF CAT, Short Form–36 Health Survey (SF-36 physical function [PF] and general health [GH]), Marx Activity Rating Scale (MARS), Knee injury and Osteoarthritis Outcome Score (KOOS activities of daily living [ADL], sport, and quality of life [QOL]), and EuroQol–5 dimensions questionnaire (EQ-5D) at 6 weeks, 6 months, and 2 years after ACL reconstruction. Correlations between instruments, ceiling and floor effects, effect sizes (Cohen d), and standardized response means to describe responsiveness were evaluated. Subgroup analyses compared participants with and without additional arthroscopic procedures using linear mixed models. Results: At baseline, 6 weeks, and 6 months, the PROMIS PF CAT showed excellent or excellent-good correlations with the SF-36 PF (r = 0.75-0.80, P < .01), KOOS-ADL (r = 0.63-0.70, P < .01), and KOOS-sport (r = 0.32-0.69, P < .01); excellent-good correlation with the EQ-5D (r = 0.60-0.71, P < .01); and good correlation with the KOOS-QOL (r = 0.52-0.58, P < .01). As expected, there were poor correlations with the MARS (r = 0.00-0.24, P < .01) and SF-36 GH (r = 0.16-0.34, P < .01 ). At 2 years, the PROMIS PF CAT showed good to excellent correlations with all PRO instruments (r = 0.42-0.72, P < .01), including the MARS (r = 0.42, P < .01), indicating frequent return to preinjury function. The PROMIS PF CAT had the fewest ceiling or floor effects of all instruments tested, and patients answered, on average, 4 questions. There was no significant difference in baseline physical function scores between subgroups; at follow-up, all groups showed improvements in scores that were not statistically different. Conclusion: The PROMIS PF CAT is a valid tool to assess outcomes after ACL reconstruction up to 2 years after surgery, demonstrating the highest responsiveness to change with the fewest ceiling and floor effects and a low time burden among all instruments tested. The PROMIS PF CAT is a beneficial alternative for assessing physical function in adults before and after ACL reconstruction. PMID:29854864

Performance of the PROMIS in Patients After Anterior Cruciate Ligament Reconstruction.

PubMed

Scott, Elizabeth J; Westermann, Robert; Glass, Nathalie A; Hettrich, Carolyn; Wolf, Brian R; Bollier, Matthew J

2018-05-01

The Patient-Reported Outcomes Measurement Information System (PROMIS) is designed to advance patient-reported outcome (PRO) instruments by utilizing question banks for major health domains. To compare the responsiveness and construct validity of the PROMIS physical function computer adaptive test (PF CAT) with current PRO instruments for patients before and up to 2 years after anterior cruciate ligament (ACL) reconstruction. Cohort study (diagnosis); Level of evidence, 2. Initially, 157 patients completed the PROMIS PF CAT, Short Form-36 Health Survey (SF-36 physical function [PF] and general health [GH]), Marx Activity Rating Scale (MARS), Knee injury and Osteoarthritis Outcome Score (KOOS activities of daily living [ADL], sport, and quality of life [QOL]), and EuroQol-5 dimensions questionnaire (EQ-5D) at 6 weeks, 6 months, and 2 years after ACL reconstruction. Correlations between instruments, ceiling and floor effects, effect sizes (Cohen d ), and standardized response means to describe responsiveness were evaluated. Subgroup analyses compared participants with and without additional arthroscopic procedures using linear mixed models. At baseline, 6 weeks, and 6 months, the PROMIS PF CAT showed excellent or excellent-good correlations with the SF-36 PF ( r = 0.75-0.80, P < .01), KOOS-ADL ( r = 0.63-0.70, P < .01), and KOOS-sport ( r = 0.32-0.69, P < .01); excellent-good correlation with the EQ-5D ( r = 0.60-0.71, P < .01); and good correlation with the KOOS-QOL ( r = 0.52-0.58, P < .01). As expected, there were poor correlations with the MARS ( r = 0.00-0.24, P < .01) and SF-36 GH ( r = 0.16-0.34, P < .01 ). At 2 years, the PROMIS PF CAT showed good to excellent correlations with all PRO instruments ( r = 0.42-0.72, P < .01), including the MARS ( r = 0.42, P < .01), indicating frequent return to preinjury function. The PROMIS PF CAT had the fewest ceiling or floor effects of all instruments tested, and patients answered, on average, 4 questions. There was no significant difference in baseline physical function scores between subgroups; at follow-up, all groups showed improvements in scores that were not statistically different. The PROMIS PF CAT is a valid tool to assess outcomes after ACL reconstruction up to 2 years after surgery, demonstrating the highest responsiveness to change with the fewest ceiling and floor effects and a low time burden among all instruments tested. The PROMIS PF CAT is a beneficial alternative for assessing physical function in adults before and after ACL reconstruction.

TBC1D24 genotype–phenotype correlation

PubMed Central

Balestrini, Simona; Milh, Mathieu; Castiglioni, Claudia; Lüthy, Kevin; Finelli, Mattea J.; Verstreken, Patrik; Cardon, Aaron; Stražišar, Barbara Gnidovec; Holder, J. Lloyd; Lesca, Gaetan; Mancardi, Maria M.; Poulat, Anne L.; Repetto, Gabriela M.; Banka, Siddharth; Bilo, Leonilda; Birkeland, Laura E.; Bosch, Friedrich; Brockmann, Knut; Cross, J. Helen; Doummar, Diane; Félix, Temis M.; Giuliano, Fabienne; Hori, Mutsuki; Hüning, Irina; Kayserili, Hulia; Kini, Usha; Lees, Melissa M.; Meenakshi, Girish; Mewasingh, Leena; Pagnamenta, Alistair T.; Peluso, Silvio; Mey, Antje; Rice, Gregory M.; Rosenfeld, Jill A.; Taylor, Jenny C.; Troester, Matthew M.; Stanley, Christine M.; Ville, Dorothee; Walkiewicz, Magdalena; Falace, Antonio; Fassio, Anna; Lemke, Johannes R.; Biskup, Saskia; Tardif, Jessica; Ajeawung, Norbert F.; Tolun, Aslihan; Corbett, Mark; Gecz, Jozef; Afawi, Zaid; Howell, Katherine B.; Oliver, Karen L.; Berkovic, Samuel F.; Scheffer, Ingrid E.; de Falco, Fabrizio A.; Oliver, Peter L.; Striano, Pasquale; Zara, Federico

2016-01-01

Objective: To evaluate the phenotypic spectrum associated with mutations in TBC1D24. Methods: We acquired new clinical, EEG, and neuroimaging data of 11 previously unreported and 37 published patients. TBC1D24 mutations, identified through various sequencing methods, can be found online (http://lovd.nl/TBC1D24). Results: Forty-eight patients were included (28 men, 20 women, average age 21 years) from 30 independent families. Eighteen patients (38%) had myoclonic epilepsies. The other patients carried diagnoses of focal (25%), multifocal (2%), generalized (4%), and unclassified epilepsy (6%), and early-onset epileptic encephalopathy (25%). Most patients had drug-resistant epilepsy. We detail EEG, neuroimaging, developmental, and cognitive features, treatment responsiveness, and physical examination. In silico evaluation revealed 7 different highly conserved motifs, with the most common pathogenic mutation located in the first. Neuronal outgrowth assays showed that some TBC1D24 mutations, associated with the most severe TBC1D24-associated disorders, are not necessarily the most disruptive to this gene function. Conclusions: TBC1D24-related epilepsy syndromes show marked phenotypic pleiotropy, with multisystem involvement and severity spectrum ranging from isolated deafness (not studied here), benign myoclonic epilepsy restricted to childhood with complete seizure control and normal intellect, to early-onset epileptic encephalopathy with severe developmental delay and early death. There is no distinct correlation with mutation type or location yet, but patterns are emerging. Given the phenotypic breadth observed, TBC1D24 mutation screening is indicated in a wide variety of epilepsies. A TBC1D24 consortium was formed to develop further research on this gene and its associated phenotypes. PMID:27281533

Multimessenger Predictions from 3D General-Relativistic Core-Collapse Supernovae Models

NASA Astrophysics Data System (ADS)

Kotake, Kei; Kuroda, Takami; Hayama, Kazuhiro

2017-02-01

In this contribution, we present results from fully general-relativistic three-dimensional (3D) simulations of a non-rotating 15M ⊙ star using different nuclear equations of state (EOSs). We show that the SASI (standing-accretion-shock-instability) activity occurs much more vigorously in models with softer EOS. By performing detailed analysis of the gravitational-wave (GW) emission, we find a new GW signature that is produced predominantly by the SASI-induced downflows to the proto-neutron star. We discuss the detectability of the GW signal by performing a coherent network analysis where multiple detectors including LIGO Hanford, LIGO Livingston, VIRGO, and KAGRA are considered. We point out that the GW signal, whose typical frequency is in the best sensitivity range of the laser-interferometers, could potentially provide the live broadcast that pictures how the supernova shock is dancing in the core. The detection horizon of the signal is estimated as 2~3 kpc for the current generation detectors, which can extend up to ~100 kpc for the third generation detectors like Cosmic Explorer. We furthermore perform a correlation analysis between the SASI-modulated GW and neutrino signals. Our results show that the time correlation of the two signals becomes highest when we take into account the travel timescale of adverting material from the (average) neutrino-sphere to the proto-neutron star surface.

Chaos analysis of viscoelastic chaotic flows of polymeric fluids in a micro-channel

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

Lim, C. P.; Lam, Y. C., E-mail: myclam@ntu.edu.sg; BioSystems and Micromechanics

2015-07-15

Many fluids, including biological fluids such as mucus and blood, are viscoelastic. Through the introduction of chaotic flows in a micro-channel and the construction of maps of characteristic chaos parameters, differences in viscoelastic properties of these fluids can be measured. This is demonstrated by creating viscoelastic chaotic flows induced in an H-shaped micro-channel through the steady infusion of a polymeric fluid of polyethylene oxide (PEO) and another immiscible fluid (silicone oil). A protocol for chaos analysis was established and demonstrated for the analysis of the chaotic flows generated by two polymeric fluids of different molecular weight but with similar relaxationmore » times. The flows were shown to be chaotic through the computation of their correlation dimension (D{sub 2}) and the largest Lyapunov exponent (λ{sub 1}), with D{sub 2} being fractional and λ{sub 1} being positive. Contour maps of D{sub 2} and λ{sub 1} of the respective fluids in the operating space, which is defined by the combination of polymeric fluids and silicone oil flow rates, were constructed to represent the characteristic of the chaotic flows generated. It was observed that, albeit being similar, the fluids have generally distinct characteristic maps with some similar trends. The differences in the D{sub 2} and λ{sub 1} maps are indicative of the difference in the molecular weight of the polymers in the fluids because the driving force of the viscoelastic chaotic flows is of molecular origin. This approach in constructing the characteristic maps of chaos parameters can be employed as a diagnostic tool for biological fluids and, more generally, chaotic signals.« less

Effects of vitamin D supplementation on strength, physical function, and health perception in older, community-dwelling men.

PubMed

Kenny, Anne M; Biskup, Bradley; Robbins, Bertha; Marcella, Glenn; Burleson, Joseph A

2003-12-01

To study the effects of vitamin D supplementation in healthier populations of men. : Randomized, controlled trial. General clinical research center. Sixty-five healthy, community-dwelling men (mean age+/-standard deviation=76+/-4, range 65-87). Cholecalciferol (1,000 IU/d) or placebo supplementation for 6 months; all received 500 mg supplemental calcium. Upper and lower extremity muscle strength and power, physical performance and activity, health perception, calcium and vitamin D intake, and biochemical assessment, including 25-hydroxyvitamin D (25OHD), parathyroid hormone (PTH), and ionized calcium levels. The levels of 25OHD increased and PTH decreased in the cholecalciferol group, whereas there were no significant changes in the control group (P<.001). Baseline 25OHD levels correlated with baseline single-leg stance time and physical activity score. Baseline PTH levels correlated with baseline 8-foot walk time and physical activity score. No significant difference in strength, power, physical performance, or health perception was found between groups. The 25OHD or PTH levels correlated with physical activity and physical performance in older, community-dwelling men with normal 25OHD status. Vitamin D supplementation increased 25OHD levels and decreased PTH levels but did not increase muscle strength or improve physical performance or health perception in this group of healthy, older men. Further investigations of the effects of vitamin D supplementation should focus on individuals with low levels of vitamin D.

Electro-acupuncture decreases 5-HT, CGRP and increases NPY in the brain-gut axis in two rat models of Diarrhea-predominant irritable bowel syndrome(D-IBS).

PubMed

Sun, Jianhua; Wu, Xiaoliang; Meng, Yunfang; Cheng, Jie; Ning, Houxu; Peng, Yongjun; Pei, Lixia; Zhang, Wei

2015-09-29

To examine whether electro-acupuncture (EA) could decrease 5-hydroxytryptamine (5-HT) and calcitonin gene-related peptide (CGRP), and increase neuro-peptide Y (NPY) in the brain-gut axis (BGA) in D-IBS using rat models. Rats were randomly exposed to unpredictable chronic stress for 3 weeks followed by 1-hour acute restraint stress (CAS) after 7 days of rest, or daily gavage of Senna decoction (6 g/kg) plus chronic restraint stress (for a duration of 2 h, starting from 1 h prior to the gavage) for 2 weeks (ISC). The content of 5-HT, CGRP and NPY in the distal colon, spinal cord, hypothalamus was examined at the end of the treatment. 1. The two rat models exhibited similar characteristics, e.g., increased number of fecal pellets expelled in 1 h, decreased sacchar-intake, decreased CRD, elevated 5-HT, CGRP content and decreased NPY in the distal colon, spinal cord, hypothalamus (P < 0.05 vs. that in healthy control rats). 2. A series of equations was developed based on correlation regression analysis. The analysis results demonstrated that 5-HT mediates the changes in hypothalamus, spinal cord and colon. 5-HT and CGRP in spinal cord was closely correlated with general behavior evaluation and other transmitters in BGA. 1. In comparison to 5-HT, CGRP and NPY (particularly in the spinal cord) had closer relationship with the D-IBS symptoms induced by either stress factors or Senna decotion. 2. EA treatment could restore the brain-gut axis to balanced levels.

Selection of the NIR region for a regression model of the ethanol concentration in fermentation process by an online NIR and mid-IR dual-region spectrometer and 2D heterospectral correlation spectroscopy.

PubMed

Nishii, Takashi; Genkawa, Takuma; Watari, Masahiro; Ozaki, Yukihiro

2012-01-01

A new selection procedure of an informative near-infrared (NIR) region for regression model building is proposed that uses an online NIR/mid-infrared (mid-IR) dual-region spectrometer in conjunction with two-dimensional (2D) NIR/mid-IR heterospectral correlation spectroscopy. In this procedure, both NIR and mid-IR spectra of a liquid sample are acquired sequentially during a reaction process using the NIR/mid-IR dual-region spectrometer; the 2D NIR/mid-IR heterospectral correlation spectrum is subsequently calculated from the obtained spectral data set. From the calculated 2D spectrum, a NIR region is selected that includes bands of high positive correlation intensity with mid-IR bands assigned to the analyte, and used for the construction of a regression model. To evaluate the performance of this procedure, a partial least-squares (PLS) regression model of the ethanol concentration in a fermentation process was constructed. During fermentation, NIR/mid-IR spectra in the 10000 - 1200 cm(-1) region were acquired every 3 min, and a 2D NIR/mid-IR heterospectral correlation spectrum was calculated to investigate the correlation intensity between the NIR and mid-IR bands. NIR regions that include bands at 4343, 4416, 5778, 5904, and 5955 cm(-1), which result from the combinations and overtones of the C-H group of ethanol, were selected for use in the PLS regression models, by taking the correlation intensity of a mid-IR band at 2985 cm(-1) arising from the CH(3) asymmetric stretching vibration mode of ethanol as a reference. The predicted results indicate that the ethanol concentrations calculated from the PLS regression models fit well to those obtained by high-performance liquid chromatography. Thus, it can be concluded that the selection procedure using the NIR/mid-IR dual-region spectrometer combined with 2D NIR/mid-IR heterospectral correlation spectroscopy is a powerful method for the construction of a reliable regression model.

Using 2D: 4D digit ratios to determine motor skills in children.

PubMed

Wang, Y; Wang, H-L; Li, Y-H; Zhu, F-L; Li, S-J; Ni, H

2016-03-01

In past few decades, there has an outburst of research surrounding second to fourth finger digit ratio (2D:4D) and its relation to prenatal sex steroids including both testosterone and estrogen. In utero, testosterone and estrogen are responsible for the differences in digit ratio between the genders. Recent research has tried to extend past the influence of steroids and look at the potential effect of digit ratios on fine and gross motor skills in children. We compiled the current understanding of the connection between sex hormones and the development of the 2D:4D ratio as well as the effect the ratio has on motor skills. There seems to be a significant positive correlation between 2D:4D digit ratio and precision of fine motor skill. In addition, there is a negative correlation between 2D:4D ratio and speed of fine motor activity. In this review, we will outline the use of 2D:4D ratio as a biomarker for prenatal sex steroids and through that, a proxy marker for fine and gross motor skills.

Temporal Lobe Toxicity Analysis After Proton Radiation Therapy for Skull Base Tumors

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

Pehlivan, Berrin; Ares, Carmen, E-mail: carmen.ares@psi.ch; Lomax, Antony J.

2012-08-01

Purpose: Temporal lobe (TL) parenchyma toxicity constitutes one of the most frequent late adverse event in high-dose proton therapy (PT) for tumors of the skull base. We analyzed clinical events with dosimetric parameters in our patients treated for skull base tumors with spot-scanning PT. Methods and Materials: Between 1998 and 2005, a total of 62 patients received PT to a median dose of 71.7 Gy (relative biologic effectiveness [RBE]) (range, 63-74 Gy). The dose-volume histogram of each TL and the entire brain parenchyma (BP) were analyzed according to maximum, mean, and minimum dose as well as doses to 0.5, 1,more » 2, and 3 cc of brain volume (D{sub 0.5}, D{sub 1}, D{sub 2}, D{sub 3}) and correlated with clinical events. Generalized equivalent uniform dose (gEUD) values were calculated. Results: At a mean follow-up of 38 months (range, 14-92 months), 2 patients had developed symptomatic Grade 3 and 5 patients asymptomatic Grade 1 TL toxicity. Mean doses to a 2-cc volume of BP increased from 71 {+-} 5 Gy (RBE) for no toxicity to 74 {+-} 5 Gy (RBE) for Grade 1 and to 76 {+-} 2 Gy (RBE) for Grade 3 toxicity. TL events occurred in 6 of 7 patients (86%) at or above dose levels of {>=}64 Gy (RBE) D{sub 3}, {>=}68 Gy (RBE) D{sub 2}, {>=}72 Gy (RBE) D{sub 1}, and {>=}73 Gy (RBE) D{sub 0.5}, respectively (p = NS). No statistically significant dose/volume threshold was detected between patients experiencing no toxicity vs. Grade 1 or Grade 3. A strong trend for Grade 1 and 3 events was observed, when the gEUD was 60 Gy. Conclusions: A statistically significant normal tissue threshold dose for BP has not been successfully defined. However, our data suggest that tolerance of TL and BP to fractionated radiotherapy appears to be correlated with tissue volume included in high-dose regions. Additional follow-up time and patient accrual is likely needed to achieve clinical significance for these dose-volume parameters investigated. Our findings support the importance of establishing an organ-at-risk maximally permissible dose for BP.« less

Relational time in anyonic systems

NASA Astrophysics Data System (ADS)

Nikolova, A.; Brennen, G. K.; Osborne, T. J.; Milburn, G. J.; Stace, T. M.

2018-03-01

In a seminal paper [Phys. Rev. D 27, 2885 (1983), 10.1103/PhysRevD.27.2885], Page and Wootters suggest that time evolution could be described solely in terms of correlations between systems and clocks, as a means of dealing with the "problem of time" stemming from vanishing Hamiltonian dynamics in many theories of quantum gravity. Their approach seeks to identify relational dynamics given a Hamiltonian constraint on the physical states. Here we present a "state-centric" reformulation of the Page and Wootters model better suited to cases where the Hamiltonian constraint is satisfied, such as anyons emerging in Chern-Simons theories. We describe relational time by encoding logical "clock" qubits into topologically protected anyonic degrees of freedom. The minimum temporal increment of such anyonic clocks is determined by the universality of the anyonic braid group, with nonuniversal models naturally exhibiting discrete time. We exemplify this approach by using SU (2) 2 anyons and discuss generalizations to other states and models.

The DCDC2/intron 2 deletion and white matter disorganization: focus on developmental dyslexia.

PubMed

Marino, Cecilia; Scifo, Paola; Della Rosa, Pasquale A; Mascheretti, Sara; Facoetti, Andrea; Lorusso, Maria L; Giorda, Roberto; Consonni, Monica; Falini, Andrea; Molteni, Massimo; Gruen, Jeffrey R; Perani, Daniela

2014-08-01

The DCDC2 gene is involved in neuronal migration. Heterotopias have been found within the white matter of DCDC2-knockdown rats. A deletion in DCDC2/intron 2 (DCDC2d), which encompasses a regulatory region named 'regulatory element associated with dyslexia 1' (READ1), increases the risk for dyslexia. We hypothesized that DCDC2d can be associated to alterations of the white matter structure in general and in dyslexic brains. Based on a full-factorial analysis of covariance (ANCOVA) model, we investigated voxel-based diffusion tensor imaging (VB-DTI) data of four groups of subjects: dyslexia with/without DCDC2d, and normal readers with/without DCDC2d. We also tested DCDC2d effects upon correlation patterns between fractional anisotropy (FA) and reading scores. We found that FA was reduced in the left arcuate fasciculus and splenium of the corpus callosum in subjects with versus without DCDC2d, irrespective of dyslexia. Subjects with dyslexia and DCDC2d showed reduced FA, mainly in the left hemisphere and in the corpus callosum; their counterpart without DCDC2d showed similar FA alterations. Noteworthy, a conjunction analysis in impaired readers revealed common regions with lower FA mainly in the left hemisphere. When we compared subjects with dyslexia with versus without DCDC2d, we found lower FA in the inferior longitudinal fasciculus and genu of the corpus callosum, bilaterally. Normal readers with versus without DCDC2d had FA increases and decreases in both the right and left hemisphere. The major contribution of our study was to provide evidence relating genes, brain and behaviour. Overall, our findings support the hypothesis that DCDC2d is associated with altered FA. In normal readers, DCDC2-related anatomical patterns may mark some developmental cognitive vulnerability to learning disabilities. In subjects with dyslexia, DCDC2d accounted for both common - mainly located in the left hemisphere - and unique - a more severe and extended pattern - alterations of white matter fibre tracts. Copyright © 2014 Elsevier Ltd. All rights reserved.

Quantification of the kV X-ray imaging dose during real-time tumor tracking and from three- and four-dimensional cone-beam computed tomography in lung cancer patients using a Monte Carlo simulation.

PubMed

Nakamura, Mitsuhiro; Ishihara, Yoshitomo; Matsuo, Yukinori; Iizuka, Yusuke; Ueki, Nami; Iramina, Hiraku; Hirashima, Hideaki; Mizowaki, Takashi

2018-03-01

Knowledge of the imaging doses delivered to patients and accurate dosimetry of the radiation to organs from various imaging procedures is becoming increasingly important for clinicians. The purposes of this study were to calculate imaging doses delivered to the organs of lung cancer patients during real-time tumor tracking (RTTT) with three-dimensional (3D), and four-dimensional (4D) cone-beam computed tomography (CBCT), using Monte Carlo techniques to simulate kV X-ray dose distributions delivered using the Vero4DRT. Imaging doses from RTTT, 3D-CBCT and 4D-CBCT were calculated with the planning CT images for nine lung cancer patients who underwent stereotactic body radiotherapy (SBRT) with RTTT. With RTTT, imaging doses from correlation modeling and from monitoring of imaging during beam delivery were calculated. With CBCT, doses from 3D-CBCT and 4D-CBCT were also simulated. The doses covering 2-cc volumes (D2cc) in correlation modeling were up to 9.3 cGy for soft tissues and 48.4 cGy for bone. The values from correlation modeling and monitoring were up to 11.0 cGy for soft tissues and 59.8 cGy for bone. Imaging doses in correlation modeling were larger with RTTT. On a single 4D-CBCT, the skin and bone D2cc values were in the ranges of 7.4-10.5 cGy and 33.5-58.1 cGy, respectively. The D2cc from 4D-CBCT was approximately double that from 3D-CBCT. Clinicians should Figure that the imaging dose increases the cumulative doses to organs.

Quantification of the kV X-ray imaging dose during real-time tumor tracking and from three- and four-dimensional cone-beam computed tomography in lung cancer patients using a Monte Carlo simulation

PubMed Central

Nakamura, Mitsuhiro; Ishihara, Yoshitomo; Matsuo, Yukinori; Iizuka, Yusuke; Ueki, Nami; Iramina, Hiraku; Hirashima, Hideaki; Mizowaki, Takashi

2018-01-01

Abstract Knowledge of the imaging doses delivered to patients and accurate dosimetry of the radiation to organs from various imaging procedures is becoming increasingly important for clinicians. The purposes of this study were to calculate imaging doses delivered to the organs of lung cancer patients during real-time tumor tracking (RTTT) with three-dimensional (3D), and four-dimensional (4D) cone-beam computed tomography (CBCT), using Monte Carlo techniques to simulate kV X-ray dose distributions delivered using the Vero4DRT. Imaging doses from RTTT, 3D-CBCT and 4D-CBCT were calculated with the planning CT images for nine lung cancer patients who underwent stereotactic body radiotherapy (SBRT) with RTTT. With RTTT, imaging doses from correlation modeling and from monitoring of imaging during beam delivery were calculated. With CBCT, doses from 3D-CBCT and 4D-CBCT were also simulated. The doses covering 2-cc volumes (D2cc) in correlation modeling were up to 9.3 cGy for soft tissues and 48.4 cGy for bone. The values from correlation modeling and monitoring were up to 11.0 cGy for soft tissues and 59.8 cGy for bone. Imaging doses in correlation modeling were larger with RTTT. On a single 4D-CBCT, the skin and bone D2cc values were in the ranges of 7.4–10.5 cGy and 33.5–58.1 cGy, respectively. The D2cc from 4D-CBCT was approximately double that from 3D-CBCT. Clinicians should Figure that the imaging dose increases the cumulative doses to organs. PMID:29385514

Comparison between the disease-specific Airways Questionnaire 20 and the generic 15D instruments in COPD.

PubMed

Mazur, Witold; Kupiainen, Henna; Pitkäniemi, Janne; Kilpeläinen, Maritta; Sintonen, Harri; Lindqvist, Ari; Kinnula, Vuokko L; Laitinen, Tarja

2011-01-16

Given that the assessment of health-related quality of life (HRQoL) is an essential outcome measure to optimize chronic obstructive pulmonary disease (COPD) patient management, there is a need for a short and fast, reliable and valid instrument for routine use in clinical practice. The objective of this study was to analyse the relationship between the disease-specific Airways questionnaire (AQ20) and the generic 15D health-related quality of life (HRQoL) instrument simultaneously in a large cohort of patients with COPD. We also compare the HRQoL of COPD patients with that of the general population. The AQ20 and 15D were administered to 739 COPD patients representing an unselected hospital-based COPD population. The completion rates and validity of, and correlations among the questions and dimension scores were examined. A factor analysis with varimax rotation was performed in order to find subsets of highly correlating items of the questionnaires. The summary scores of AQ20 and 15D were highly correlated (r = - 0.71, p < 0.01). In AQ20 over 50% of patients reported frequent cough, breathlessness during domestic work, and chest problem limiting their full enjoyment of life. 15D results showed a noteworthy decrease of HRQoL in breathing, mobility, sleeping, usual activities, discomfort and symptoms, vitality, and sexual activity (scores ≤ 0.75). Compared to the age- and gender-standardized Finnish general population, the COPD patients were statistically significantly worse off on 13 of 15 dimensions. The AQ20 and 15D summary scores are comparable in terms of measuring HRQoL in COPD patients. The data support the validity of 15D to measure the quality of life in COPD. COPD compromises the HRQoL broadly, as reflected by the generic instrument. Both questionnaires are simple and short, and could easily be used in clinical practice with high completion rates.

Multiparticle collision simulations of two-dimensional one-component plasmas: Anomalous transport and dimensional crossovers

NASA Astrophysics Data System (ADS)

Di Cintio, Pierfrancesco; Livi, Roberto; Lepri, Stefano; Ciraolo, Guido

2017-04-01

By means of hybrid multiparticle collsion-particle-in-cell (MPC-PIC) simulations we study the dynamical scaling of energy and density correlations at equilibrium in moderately coupled two-dimensional (2D) and quasi-one-dimensional (1D) plasmas. We find that the predictions of nonlinear fluctuating hydrodynamics for the structure factors of density and energy fluctuations in 1D systems with three global conservation laws hold true also for 2D systems that are more extended along one of the two spatial dimensions. Moreover, from the analysis of the equilibrium energy correlators and density structure factors of both 1D and 2D neutral plasmas, we find that neglecting the contribution of the fluctuations of the vanishing self-consistent electrostatic fields overestimates the interval of frequencies over which the anomalous transport is observed. Such violations of the expected scaling in the currents correlation are found in different regimes, hindering the observation of the asymptotic scaling predicted by the theory.

WE-AB-207B-12: Prospective Study of the Relationship Between Dose-Volume Clinical Toxicity and Patient Reported Outcomes in Lung Cancer Patients Treated with SBRT

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

Mayyas, E; Vance, S; Brown, S

Purpose: To determine in a prospective study, the correlation between radiation dose/volume, clinical toxicities and patient-reported, quality of life (QOL) resulting from lung SBRT. Methods: For 106 non-small cell lung cancer (NSCLC) patients receiving SBRT (12 Gy × 4), symptoms including cough, dyspnea, fatigue and pneumonitis were measured at baseline (before treatment), after treatment and 3, 6, and 12 months post-treatment. Toxicity was graded from zero to five. Dosimetric parameters such as the MLD, D10%, D20%, and lung subvolumes (V10 and V20) were obtained from the treatment plan. Dosimetric parameters and number of patients demonstrating toxicity ≥ grade 2 weremore » tabulated. Linear regression analysis was used to calculate correlations between MLD and D10, D20, V10 and V20. Results: The percentages of patients with > grade 2 pneumonitis, fatigue, cough, and dyspnea over 3 to 12 months increased from 0.0% to 3.5%, 3.2% to 10.5%, 4.3% to 8.3%, and 10.8% to 18.8%, respectively. Computed dose indices D10%, D20% were 7.9±4.8 Gy and 3.0±2.3 Gy, respectively. MLD ranged from 0.34 Gy up to 9.9 Gy with overall average 3.0±1.7 Gy. The averages of the subvolumes V10 and V20 were respectively 8.9±5.3% and 3.0±2.4%. The linear regression analysis showed that V10 and D10 demonstrated the strongest correlation to MLD; R2= 0.92 and 0.87, respectively. V20, and D20 were also strongly correlated with MLD; R2 = 0.81 and 0.84 respectively. A correlation was also found to exist between MLD > 2 Gy and ≥ grade 2 cough and dyspnea. Subvolume values for 2Gy MLD were 5.3% for V10 and 2% for V20. Conclusion: Dosimetric indices: MLD ≥ 2Gy, D10 ≥ 5Gy and V10 ≥ 5% of the total lung volume were predictive of > grade 2 cough and dyspnea QOL data. The QOL results are a novel component of this work. acknowledgement of the Varian grant support.« less

Low 25-OH vitamin D serum levels correlate with severe fibrosis in HIV-HCV co-infected patients with chronic hepatitis.

PubMed

Terrier, Benjamin; Carrat, Fabrice; Geri, Guillaume; Pol, Stanislas; Piroth, Lionel; Halfon, Philippe; Poynard, Thierry; Souberbielle, Jean-Claude; Cacoub, Patrice

2011-10-01

Recent findings in hepatitis C virus (HCV)-monoinfected patients have shown a correlation between low serum levels of 25-OH vitamin D3 [25(OH)D3] and severe liver fibrosis and low sustained virologic response to therapy. Data are lacking in HIV-HCV coinfected patients. One hundred and eighty nine HIV-HCV coinfected patients, who received ≥80% of interferon (IFN) plus ribavirin therapy, were analyzed for baseline serum 25(OH)D3 levels. Correlations between serum 25(OH)D3 levels, chronic hepatitis C features, HCV virologic response to antiviral therapy, and HIV infection characteristics were analyzed. Mean serum 25(OH)D3 level was 18.5 ± 9.8 ng/ml, including 162 (85%) patients with level ≤30 ng/ml. Serum 25(OH)D3 levels were significantly correlated with the histological Metavir fibrosis score (r = -0.16; p = 0.027). Patients with severe fibrosis (Metavir F3/F4) had lower serum 25(OH)D3 levels compared to F2 and F1 patients (16.2 ± 10.0 vs. 18.9 ± 8.5 and 20.9 ± 11.1 ng/ml, respectively; p = 0.06). In multivariate analysis, low serum 25(OH)D levels were independently associated with severe liver fibrosis (p = 0.04) and cold season (p = 0.0002). Serum levels of 25(OH)D3 were also significantly correlated with liver fibrosis as assessed by FibroTest® (r = -0.22; p = 0.008) and serum α2-macroglobulin levels (r = -0.23; p = 0.006). In contrast, no correlation was found between 25(OH)D3 levels and HCV sustained virologic response to IFN-based therapy [OR 0.98 (0.95-1.01); p = 0.22]. No association was found between 25(OH)D3 levels and markers of HIV-related immunodeficiency. In HIV-HCV coinfected patients, low serum 25(OH)D3 levels correlate with severe liver fibrosis. In contrast, serum 25(OH)D3 levels are not linked to HCV virologic response to therapy or severity of immunodeficiency. Copyright © 2011 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

[Auditory evoked potential and personality traits in chronic primary insomniacs].

PubMed

Shen, Jian; Shui, Ren-de; Feng, Lei; Liu, Yu-Hong; He, Wei; Huang, Jing-Yi; Wang, Wei

2009-05-01

To investigate the personality traits and intensity dependence of auditory evoked potentials (AEPs) in chronic primary insomnia. Thirty-seven patients with chronic primary insomnia (insomnia group) and 44 healthy subjects (control group) were enrolled in the study. The AEPs were examined in insomnia and control groups; the personality traits were studied by Zuckerman's Sensation Seeking Scales (SSS) and Zuckerman-Kuhlman's Personality Questionnaire (ZKPQ); and the mood states by Plutchik-van Praag's Depression Inventory (PVP). The scores of neuroticism-anxiety and depression in insomnia group were significantly higher than those in control group (P<0.01); and the scores of impulsivity and aggression-hostility were also higher than those in control group (P<0.05); N1-P2 amplitude of AEP increased with stimulus intensity, which were significantly different in 70, 80, 90,100 dB (P<0.01). There were significant correlations between activity and N1 latency at 80 dB, activity and P2 latency at 100 dB (r=0.270, r=0.276, P<0.05); and between total scores of sensation seeking scale and N1-P2 amplitude (r=0.3746, r=0.35329, P<0.01) at 70 and 90 dB stimulus intensity in insomnia group. There were significant correlations among experience seeking and N1-P2 amplitude, experience seeking and slope rate (P<0.01) at 70, 80, 90, 100 dB stimulus intensity in insomnia group (r=0.539, r=0.3439, r=0.439, r=0.3278). There were significant correlations between sensation seeking of boredom susceptibility and slope rate (r=-0.282998, P<0.05) in insomnia group. There were significant correlations between thrill and adventure seeking and N1-P2 amplitude(r=0.2789, P<0.05) at 90 dB stimulus intensity in insomnia group; there were significant correlations between PVP and N1-P2 amplitude (r=-0.3434, r=-0.3158, P<0.05) at 70 dB and N1 latency at 80 dB in insomnia group. Chronic primary insomnia sufferers have higher levels of neuroticism-anxiety, depression, aggression-hostility and impulsivity, and some are correlated with stimulus intensity dependence in AEP.

A Parallel Approach in Computing Correlation Immunity up to Six Variables

DTIC Science & Technology

2015-03-10

their nonlinearity is divisible by 4. Let CI(n, k) (respectively, BCI (n, k)) be the number of exact order k correlation im- mune, (respectively...further balanced) n-variable Boolean functions. The notations CI(n, k, d), BCI (n, k, d) restricts the previous count to degree d Boolean functions...Theorem 3. The following are true: (i) BCI (n, n, 0) = 0, CI(n, n, 0) = 2, CI(n, k, 1) = BCI (n, k, 1) = 2 ( n k+1 ) , 0 ≤ k ≤ n− 1. (ii) BCI (n, n− 2) = 2

Spatially resolved D-T(2) correlation NMR of porous media.

PubMed

Zhang, Yan; Blümich, Bernhard

2014-05-01

Within the past decade, 2D Laplace nuclear magnetic resonance (NMR) has been developed to analyze pore geometry and diffusion of fluids in porous media on the micrometer scale. Many objects like rocks and concrete are heterogeneous on the macroscopic scale, and an integral analysis of microscopic properties provides volume-averaged information. Magnetic resonance imaging (MRI) resolves this spatial average on the contrast scale set by the particular MRI technique. Desirable contrast parameters for studies of fluid transport in porous media derive from the pore-size distribution and the pore connectivity. These microscopic parameters are accessed by 1D and 2D Laplace NMR techniques. It is therefore desirable to combine MRI and 2D Laplace NMR to image functional information on fluid transport in porous media. Because 2D Laplace resolved MRI demands excessive measuring time, this study investigates the possibility to restrict the 2D Laplace analysis to the sum signals from low-resolution pixels, which correspond to pixels of similar amplitude in high-resolution images. In this exploratory study spatially resolved D-T2 correlation maps from glass beads and mortar are analyzed. Regions of similar contrast are first identified in high-resolution images to locate corresponding pixels in low-resolution images generated with D-T2 resolved MRI for subsequent pixel summation to improve the signal-to-noise ratio of contrast-specific D-T2 maps. This method is expected to contribute valuable information on correlated sample heterogeneity from the macroscopic and the microscopic scales in various types of porous materials including building materials and rock. Copyright © 2014 Elsevier Inc. All rights reserved.

Point shear wave ultrasound elastography with Esaote compared to real-time 2D shear wave elastography with supersonic imagine for the quantification of liver stiffness.

PubMed

Mulazzani, L; Salvatore, V; Ravaioli, F; Allegretti, G; Matassoni, F; Granata, R; Ferrarini, A; Stefanescu, H; Piscaglia, Fabio

2017-09-01

Different shear wave elastography (SWE) machines able to quantify liver stiffness (LS) have been recently introduced by various companies. The aim of this study was to investigate the agreement between point SWE with Esaote MyLab Twice (pSWE.ESA) and 2D SWE with Aixplorer SuperSonic (2D SWE.SSI). Moreover, we assessed the correlation of these machines with Fibroscan in a subgroup of patients. A total of 81 liver disease patients and 27 subjects without liver disease accessing the ultrasound lab were considered. Exclusion criteria were liver nodules, BMI >35, and severe comorbidities. LS was sampled from the same intercostal space with both pSWE.ESA and 2D SWE.SSI and values were tested with Lin's analysis and Bland-Altman analysis (B&A). Agreement between each SWE machine and Fibroscan was assessed in 26 liver disease patients with Spearman correlation. Precision and accuracy between pSWE.ESA and 2D SWE.SSI were, respectively, 0.839 and 0.999. B&A showed a mean of only -0.2 kPa, with no systematic deviation between the techniques and limits of agreement at -11.6 and 11.3 kPa. Spearman's rho correlation versus Fibroscan was 0.849 for pSWE.ESA and 0.878 for 2D SWE.SSI. The relationship became less strict in the higher range of LS (≥15.2 kPa), corresponding to cirrhosis. The overall degree of concordance of pSWE.ESA and 2D SWE.SSI in measuring LS resulted remarkable, also when compared with Fibroscan. The less strict correlation for patients with LS in the higher range would not affect the staging of disease as such patients are anyhow classified as cirrhotic.

Adsorption of polar organic molecules on sediments: Case-study on Callovian-Oxfordian claystone.

PubMed

Rasamimanana, S; Lefèvre, G; Dagnelie, R V H

2017-08-01

The release and transport of anthropogenic organic matter through the geosphere is often an environmental criterion of safety. Sedimentary rocks are widely studied in this context as geological barriers for waste management. It is the case of Callovian-Oxfordian claystone (COx), for which several studies report adsorption of anthropogenic organic molecules. In this study, we evaluated and reviewed adsorption data of polar organic molecules on COx claystone. Experiments were performed on raw claystone, decarbonated and clay fractions. Adsorption isotherms were measured with adsorbates of various polarities: adipate, benzoate, ortho-phthalate, succinate, gluconate, oxalate, EDTA, citrate. A significant adsorption was observed for multidentate polycarboxylic acids as evidenced with phthalate, succinate, oxalate, gluconate, EDTA and citrate (R d  = 1.53, 3.52, 8.4, 8.8, 12.4, 54.7 L kg -1 respectively). Multiple linear regression were performed as a statistical analysis to determine the predictors from these adsorption data. A linear correlation between adsorption data (R d ) and dipole moment (μ) of adsorbates was evidenced (R 2  = 0.91). Molecules with a high dipole moment, μ(D) > 2.5, displayed a significant adsorption, R d ≫1 L kg -1 . A qualitative correlation can be easily estimated using the water/octanol partition coefficient, P ow , of adsorbates (R 2  = 0.77). In this case, two opposite trends were distinguished for polar and apolar molecules. The use of organic carbon content in sediments is relevant for predicting adsorption of apolar compounds, log (P ow )>+1. The oxides/clays contents may be relevant regarding polar molecules, log ( apparent P ow )<-1. The proposed scheme offers a general methodology for investigation of geo-barriers towards heterogeneous organic plumes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Vitamin D deficiency and its relationship with cardiac iron and function in patients with transfusion-dependent thalassemia at Chiang Mai University Hospital.

PubMed

Dejkhamron, Prapai; Wejaphikul, Karn; Mahatumarat, Tuanjit; Silvilairat, Suchaya; Charoenkwan, Pimlak; Saekho, Suwit; Unachak, Kevalee

2018-02-01

Vitamin D deficiency is common in patients with thalassemia. Vitamin D deficiency could be related to cardiac dysfunction. Increased parathyroid hormone (PTH) is also known to be associated with heart failure. To determine the prevalence of Vitamin D deficiency and to explore the impact of Vitamin D deficiency on cardiac iron and function in patients with transfusion-dependent thalassemia. A cross-sectional study in patients with Transfusion-dependent thalassemia was conducted. Patients with liver disease, renal disease, type 1 diabetes, malabsorption, hypercortisolism, malignancy, and contraindication for MRI were excluded. Calcium, phosphate, PTH, vitamin D-25OH were measured. CardiacT2 * and liver iron concentration (LIC) and left ventricular ejection fraction (LVEF) were determined. Results Sixty-one (33M/28F) patients with Transfusion-dependent thalassemia were enrolled. The prevalence of Vitamin D deficiency was 50.8%. Patients with cardiac siderosis had tendency for lower D-25OH than those without siderosis (15.9 (11.7-20.0) vs. 20.2 (15.85-22.3) ng/mL); p = 0.06). Serum calcium, phosphate, PTH, LIC, cardiac T2 * , and LVEF were not different between the groups with or without Vitamin D deficiency. Patients with Vitamin D deficiency had significantly lower hemoglobin levels compared to those without Vitamin D deficiency (7.5 (6.93-8.33) vs. 8.1 (7.30-8.50) g/dL; p = 0.04). The median hemoglobin in the last 12 months was significantly correlated with D-25OH. Cardiac T2 * had significant correlation with PTH. Vitamin D deficiency is prevalent in patients with Transfusion-dependent thalassemia. Vitamin D level is correlated with hemoglobin level. Vitamin D status should be routinely assessed in these patients. Low PTH is correlated with increased cardiac iron. This study did not demonstrate an association between Vitamin D deficiency and cardiac iron or function in patients with Transfusion-dependent thalassemia.

Vitamin D, Hypercalciuria and Kidney Stones

PubMed Central

Letavernier, Emmanuel; Daudon, Michel

2018-01-01

The estimated lifetime risk of nephrolithiasis is growing nowadays, and the formation of kidney stones is frequently promoted by hypercalciuria. Vitamin D, and especially its active metabolite calcitriol, increase digestive calcium absorption—as urinary calcium excretion is directly correlated with digestive calcium absorption, vitamin D metabolites could theoretically increase calciuria and promote urinary stone formation. Nevertheless, there was, until recently, low evidence that 25-hydroxyvitamin D serum levels would be correlated with kidney stone formation, even if high calcitriol concentrations are frequently observed in hypercalciuric stone formers. Low 25-hydroxyvitamin D serum levels have been associated with a broad spectrum of diseases, leading to a huge increase in vitamin D prescription in the general population. In parallel, an increased frequency of kidney stone episodes has been observed in prospective studies evaluating vitamin D alone or in association with calcium supplements, and epidemiological studies have identified an association between high 25-hydroxyvitamin D serum levels and kidney stone formation in some groups of patients. Moreover, urinary calcium excretion has been shown to increase in response to vitamin D supplements, at least in some groups of kidney stone formers. It seems likely that predisposed individuals may develop hypercalciuria and kidney stones in response to vitamin D supplements. PMID:29562593

Leaf Area Index Estimation in Vineyards from Uav Hyperspectral Data, 2d Image Mosaics and 3d Canopy Surface Models

NASA Astrophysics Data System (ADS)

Kalisperakis, I.; Stentoumis, Ch.; Grammatikopoulos, L.; Karantzalos, K.

2015-08-01

The indirect estimation of leaf area index (LAI) in large spatial scales is crucial for several environmental and agricultural applications. To this end, in this paper, we compare and evaluate LAI estimation in vineyards from different UAV imaging datasets. In particular, canopy levels were estimated from i.e., (i) hyperspectral data, (ii) 2D RGB orthophotomosaics and (iii) 3D crop surface models. The computed canopy levels have been used to establish relationships with the measured LAI (ground truth) from several vines in Nemea, Greece. The overall evaluation indicated that the estimated canopy levels were correlated (r2 > 73%) with the in-situ, ground truth LAI measurements. As expected the lowest correlations were derived from the calculated greenness levels from the 2D RGB orthomosaics. The highest correlation rates were established with the hyperspectral canopy greenness and the 3D canopy surface models. For the later the accurate detection of canopy, soil and other materials in between the vine rows is required. All approaches tend to overestimate LAI in cases with sparse, weak, unhealthy plants and canopy.

Proteasome modulator 9 gene SNPs, responsible for anti-depressant response, are in linkage with generalized anxiety disorder.

PubMed

Gragnoli, Claudia

2014-09-01

Proteasome modulator 9 (PSMD9) gene single nucleotide polymorphism (SNP) rs1043307/rs2514259 (E197G) is associated with significant clinical response to the anti-depressant desipramine. PSMD9 SNP rs74421874 [intervening sequence (IVS) 3 + nt460 G>A], rs3825172 (IVS3 + nt437 C>T) and rs1043307/rs2514259 (E197G A>G) are all linked to type 2 diabetes (T2D), maturity-onset-diabetes-of the young 3 (MODY3), obesity and waist circumference, hypertension, hypercholesterolemia, T2D-macrovascular and T2D-microvascular disease, T2D-neuropathy, T2D-carpal tunnel syndrome, T2D-nephropathy, T2D-retinopathy, non-diabetic retinopathy and depression. PSMD9 rs149556654 rare SNP (N166S A>G) and the variant S143G A>G also contribute to T2D. PSMD9 is located in the chromosome 12q24 locus, which per se is in linkage with depression, bipolar disorder and anxiety. In the present study, we wanted to determine whether PSMD9 is linked to general anxiety disorder in Italian T2D families. Two-hundred Italian T2D families were phenotyped for generalized anxiety disorder, using the diagnostic criteria of DSM-IV. When the diagnosis was unavailable or unclear, the trait was reported as unknown. The 200 Italians families were tested for the PSMD9 T2D risk SNPs rs74421874 (IVS3 + nt460 G>A), rs3825172 (IVS3 +nt437 T>C) and for the T2D risk and anti-depressant response SNP rs1043307/rs2514259 (E197G A>G) for evidence of linkage with generalized anxiety disorder. Non-parametric linkage analysis was executed via Merlin software. One-thousand simulation tests were performed to exclude results due to random chance. In our study, the PSMD9 gene SNPs rs74421874, rs3825172, and rs1043307/rs2514259 result in linkage to generalized anxiety disorder. This is the first report describing PSMD9 gene SNPs in linkage to generalized anxiety disorder in T2D families. © 2014 Wiley Periodicals, Inc.

The Relationship between the Second-to-Fourth Digit Ratio and Behavioral Sexual Dimorphism in School-Aged Children.

PubMed

Mitsui, Takahiko; Araki, Atsuko; Miyashita, Chihiro; Ito, Sachiko; Ikeno, Tamiko; Sasaki, Seiko; Kitta, Takeya; Moriya, Kimihiko; Cho, Kazutoshi; Morioka, Keita; Kishi, Reiko; Shinohara, Nobuo; Takeda, Masayuki; Nonomura, Katsuya

2016-01-01

Sexually dimorphic brain development and behavior are known to be influenced by sex hormones exposure in prenatal periods. On the other hand, second-to forth digit ratio (2D/4D) has been used as an indirect method to investigate the putative effects of prenatal exposure to androgen. In the present study, we herein investigated the relationship between gender-role play behavior and the second-to-fourth digit ratio (2D/4D), which has been used as an indirect method to investigate the putative effects of prenatal exposure to androgens, in school-aged children. Among 4981 children who became 8 years old by November 2014 and were contactable for this survey by The Hokkaido Study of Environment and Children's Health, 1631 (32.7%), who had data for 2D/4D and Pre-school Activities Inventory (PSAI) as well as data for the survey at baseline, were available for analysis. Parents sent reports of PSAI on the sex-typical characteristics, preferred toys, and play activities of children, and black and white photocopies of the left and right hand palms via mail. PSAI consisted of 12 masculine items and 12 feminine items, and a composite score was created by subtracting the feminine score from the masculine score, with higher scores representing masculine-typical behavior. While composite scores in PSAI were significantly higher in boys than in girls, 2D/4D was significantly lower in boys than in girls. Although the presence or absence of brothers or sisters affected the composite, masculine, and feminine scored of PSAI, a multivariate regression model revealed that 2D/4D negatively correlated with the composite scores of PSAI in boys, whereas no correlation was found in girls. Although 2D/4D negatively correlated with the masculine score in boys and girls, no correlation was observed between 2D/4D and the feminine score. In conclusion, although social factors, such as the existence of brother or sisters, affect dimorphic brain development and behavior in childhood, the present study revealed that the prenatal hormonal environment was an important factor influencing masculine-typical dimorphic brain development and behavior in school-aged children.

Validation of the Polish version of Diabetes Quality of Life - Brief Clinical Inventory (DQL-BCI) among patients with type 2 diabetes.

PubMed

Dudzińska, Marta; Tarach, Jerzy S; Burroughs, Thomas E; Zwolak, Agnieszka; Matuszek, Beata; Smoleń, Agata; Nowakowski, Andrzej

2014-10-27

The aim of the study was to develop a Polish version of the Diabetes Quality of Life Brief Clinical Inventory (DQL-BCI) and to perform validating evaluation of selected psychometric aspects. The translation process was performed in accordance with generally accepted international principles of translation and cultural adaptation of measurement tools. Two hundred and seventy-four subjects with type 2 diabetes completed the Polish version of DQL-BCI, the generic EQ-5D questionnaire and the diabetes-specific DSC-R. The examination provides information about the reliability (internal consistency, test-retest) and the construct validity of the studied tool (the relationship between the DQL-BCI score and EQ-5D and DSC-R scales, as well as selected clinical patient characteristics). Cronbach's α (internal consistency) for the translated version of DQL-BCI was 0.76. Test-retest Pearson correlation coefficient was 0.96. Spearman's coefficient correlation between DQL-BCI score and EQ-5D index and EQ-VAS were 0.6 (p = 0.0000001) and 0.61 (p = 0.0000001) respectively. The correlation between scores of the examined tool and DSC-R total score was -0.6 (p = 0.0000001). Quality of life was lower among patients with microvascular as well as macrovascular complications and with occurring hypoglycemic episodes. The result of this study is the Polish scale used to test the quality of life of patients with diabetes, which includes the range of problems faced by patients while maintaining a patient-friendly form. High reliability of the scale and good construct validity qualify the Polish version of DQL-BCI as a reliable tool in both research and individual diagnostics.

Validation of the Polish version of Diabetes Quality of Life – Brief Clinical Inventory (DQL-BCI) among patients with type 2 diabetes

PubMed Central

Tarach, Jerzy S.; Burroughs, Thomas E.; Zwolak, Agnieszka; Matuszek, Beata; Smoleń, Agata; Nowakowski, Andrzej

2014-01-01

Introduction The aim of the study was to develop a Polish version of the Diabetes Quality of Life Brief Clinical Inventory (DQL-BCI) and to perform validating evaluation of selected psychometric aspects. Material and methods The translation process was performed in accordance with generally accepted international principles of translation and cultural adaptation of measurement tools. Two hundred and seventy-four subjects with type 2 diabetes completed the Polish version of DQL-BCI, the generic EQ-5D questionnaire and the diabetes-specific DSC-R. The examination provides information about the reliability (internal consistency, test-retest) and the construct validity of the studied tool (the relationship between the DQL-BCI score and EQ-5D and DSC-R scales, as well as selected clinical patient characteristics). Results Cronbach's α (internal consistency) for the translated version of DQL-BCI was 0.76. Test-retest Pearson correlation coefficient was 0.96. Spearman's coefficient correlation between DQL-BCI score and EQ-5D index and EQ-VAS were 0.6 (p = 0.0000001) and 0.61 (p = 0.0000001) respectively. The correlation between scores of the examined tool and DSC-R total score was –0.6 (p = 0.0000001). Quality of life was lower among patients with microvascular as well as macrovascular complications and with occurring hypoglycemic episodes. Conclusions The result of this study is the Polish scale used to test the quality of life of patients with diabetes, which includes the range of problems faced by patients while maintaining a patient-friendly form. High reliability of the scale and good construct validity qualify the Polish version of DQL-BCI as a reliable tool in both research and individual diagnostics. PMID:25395940

Lifetime of inner-shell hole states of Ar (2p) and Kr (3d) using equation-of-motion coupled cluster method

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

Ghosh, Aryya; Vaval, Nayana, E-mail: np.vaval@ncl.res.in; Pal, Sourav

2015-07-14

Auger decay is an efficient ultrafast relaxation process of core-shell or inner-shell excited atom or molecule. Generally, it occurs in femto-second or even atto-second time domain. Direct measurement of lifetimes of Auger process of single ionized and double ionized inner-shell state of an atom or molecule is an extremely difficult task. In this paper, we have applied the highly correlated complex absorbing potential-equation-of-motion coupled cluster (CAP-EOMCC) approach which is a combination of CAP and EOMCC approach to calculate the lifetime of the states arising from 2p inner-shell ionization of an Ar atom and 3d inner-shell ionization of Kr atom. Wemore » have also calculated the lifetime of Ar{sup 2+}(2p{sup −1}3p{sup −1}) {sup 1}D, Ar{sup 2+}(2p{sup −1}3p{sup −1}) {sup 1}S, and Ar{sup 2+}(2p{sup −1}3s{sup −1}) {sup 1}P double ionized states. The predicted results are compared with the other theoretical results as well as experimental results available in the literature.« less

Surprising loss of three-dimensionality in low-energy spin correlations on approaching superconductivity in Fe1 +yTe1 -xSex

NASA Astrophysics Data System (ADS)

Xu, Zhijun; Schneeloch, J. A.; Wen, Jinsheng; Winn, B. L.; Granroth, G. E.; Zhao, Yang; Gu, Genda; Zaliznyak, Igor; Tranquada, J. M.; Birgeneau, R. J.; Xu, Guangyong

2017-10-01

We report inelastic neutron scattering measurements of low-energy (ℏ ω ≲10 meV) magnetic excitations in the "11" system Fe1 +yTe1 -xSex . The spin correlations are two-dimensional (2D) in the superconducting samples at low temperature, but appear much more three-dimensional (3D) when the temperature rises well above Tc˜15 K, with a clear increase of the (dynamic) spin correlation length perpendicular to the Fe planes. This behavior is extremely unusual; typically, the suppression of thermal fluctuations at low temperature would favor the enhancement of 3D correlations, or even ordering, and the reversion to 2D cannot be naturally explained when only the spin degree of freedom is considered. Our results suggest that the low temperature physics in the 11 system, in particular the evolution of low-energy spin excitations towards superconducting pairing, intrinsically involves changes in orbital correlations.

Two Keggin-type heteropolytungstates with transition metal as a central atom: Crystal structure and magnetic study with 2D-IR correlation spectroscopy

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

Chai, Feng; Chen, YiPing, E-mail: ypchen007@sina.com; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002

2013-06-01

Two Keggin-type heteropolytungstates, [Co(phen)₃]₃[CoW₁₂O₄₀]·9H₂O 1 (phen=1,10-phenanthroline) and [Fe(phen)₃]₂[FeW₁₂O₄₀]·H₃O·H₂O 2, have been synthesized via the hydrothermal technique and characterized by single crystal X-ray diffraction analyses, IR, XPS, TG analysis, UV–DRS, XRD, thermal-dependent and magnetic-dependent 2D-COS IR (two-dimensional infrared correlation spectroscopy). Crystal structure analysis reveals that the polyanions in compound 1 are linked into 3D supramolecule through hydrogen bonding interactions between lattice water molecules and terminal oxygen atoms of polyanion units, and [Co(phen)₃]²⁺ cations distributed in the polyanion framework with many hydrogen bonding interactions. The XPS spectra indicate that all the Co atoms in 1 are +2 oxidation state, the Fe atomsmore » in 2 existing with +2 and +3 mixed oxidation states. - Graphical abstract: The magnetic-dependent synchronous 2D correlation IR spectra of 1 (a), 2 (b) over 0–50 mT in the range of 600–1000 cm⁻¹, the obvious response indicate two Keggin polyanions skeleton susceptible to applied magnetic field. Highlights: • Two Keggin-type heteropolytungstates with transition metal as a central atom has been obtained. • Compound 1 forms into 3D supramolecular architecture through hydrogen bonding between water molecules and polyanions. • Magnetic-dependent 2D-IR correlation spectroscopy was introduced to discuss the magnetism of polyoxometalate.« less

In vivo 1D and 2D correlation MR spectroscopy of the soleus muscle at 7T

PubMed Central

Ramadan, Saadallah; Ratai, Eva-Maria; Wald, Lawrence L.; Mountford, Carolyn E.

2013-01-01

Aim This study aims to (1) undertake and analyse 1D and 2D MR correlation spectroscopy from human soleus muscle in vivo at 7T, and (2) determine T1 and T2 relaxation time constants at 7T field strength due to their importance in sequence design and spectral quantitation. Method Six healthy, male volunteers were consented and scanned on a 7T whole-body scanner (Siemens AG, Erlangen, Germany). Experiments were undertaken using a 28 cm diameter detunable birdcage coil for signal excitation and an 8.5 cm diameter surface coil for signal reception. The relaxation time constants, T1 and T2 were recorded using a STEAM sequence, using the ‘progressive saturation’ method for the T1 and multiple echo times for T2. The 2D L-Correlated SpectroscopY (L-COSY) method was employed with 64 increments (0.4 ms increment size) and eight averages per scan, with a total time of 17 min. Results T1 and T2 values for the metabolites of interest were determined. The L-COSY spectra obtained from the soleus muscle provided information on lipid content and chemical structure not available, in vivo, at lower field strengths. All molecular fragments within multiple lipid compartments were chemically shifted by 0.20–0.26 ppm at this field strength. 1D and 2D L-COSY spectra were assigned and proton connectivities were confirmed with the 2D method. Conclusion In vivo 1D and 2D spectroscopic examination of muscle can be successfully recorded at 7T and is now available to assess lipid alterations as well as other metabolites present with disease. T1 and T2 values were also determined in soleus muscle of male healthy volunteers. PMID:20206561

Gallium Compounds: A Possible Problem for the G2 Approaches

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Melius, Carl F.; Allendorf, Mark D.; Arnold, James (Technical Monitor)

1998-01-01

The G2 atomization energies of fluorine and oxygen containing Ga compounds are greatly in error. This arises from an inversion of the Ga 3d core orbital and the F 2s or O 2s valence orbitals. Adding the Ga 3d orbital to the correlation treatment or removing the F 2s orbitals from the correlation treatment are shown to eliminate the problem. Removing the O 2s orbital from the correlation treatment reduces the error, but it can still be more than 6 kcal/mol. It is concluded that the experimental atomization energy of GaF2 is too large.

An empirical model for prediction of geomagnetic storms using initially observed CME parameters at the Sun

NASA Astrophysics Data System (ADS)

Kim, R.-S.; Cho, K.-S.; Moon, Y.-J.; Dryer, M.; Lee, J.; Yi, Y.; Kim, K.-H.; Wang, H.; Park, Y.-D.; Kim, Yong Ha

2010-12-01

In this study, we discuss the general behaviors of geomagnetic storm strength associated with observed parameters of coronal mass ejection (CME) such as speed (V) and earthward direction (D) of CMEs as well as the longitude (L) and magnetic field orientation (M) of overlaying potential fields of the CME source region, and we develop an empirical model to predict geomagnetic storm occurrence with its strength (gauged by the Dst index) in terms of these CME parameters. For this we select 66 halo or partial halo CMEs associated with M-class and X-class solar flares, which have clearly identifiable source regions, from 1997 to 2003. After examining how each of these CME parameters correlates with the geoeffectiveness of the CMEs, we find several properties as follows: (1) Parameter D best correlates with storm strength Dst; (2) the majority of geoeffective CMEs have been originated from solar longitude 15°W, and CMEs originated away from this longitude tend to produce weaker storms; (3) correlations between Dst and the CME parameters improve if CMEs are separated into two groups depending on whether their magnetic fields are oriented southward or northward in their source regions. Based on these observations, we present two empirical expressions for Dst in terms of L, V, and D for two groups of CMEs, respectively. This is a new attempt to predict not only the occurrence of geomagnetic storms, but also the storm strength (Dst) solely based on the CME parameters.

Lower vitamin-D production from solar ultraviolet-B irradiance may explain some differences in cancer survival rates.

PubMed Central

Grant, William B.

2006-01-01

Black Americans diagnosed with cancer generally have lower survival rates than white Americans, even after adjustment for stage of cancer at time of discovery and level of treatment received. The hypothesis developed in this work is that these lower cancer survival rates may be due to lower serum 25-hydroxyvitamin D [25(OH)DI for black Americans attributed to lower production rates of vitamin D from solar ultraviolet-B (UVB) irradiance due to darker skin. Black Americans generally have 50-75% as much serum 25(OH)D as white Americans, and vitamin D is now thought to reduce the risk of incidence and mortality for 18 types of cancer. To explore this hypothesis, data for mortality rates for various types of cancer for the period 1970-1994 for black Americans were used with indices for solar UVB levels for July, smoking, alcohol consumption, urban residence and poverty level, all averaged by state, in multiple linear regression analyses using the ecologic approach. Solar UVB was found significantly inversely correlated with mortality rates for breast, colon, esophageal, gastric and rectal cancers for black Americans, albeit with lower associations than for white Americans. Smoking and alcohol consumption were also significantly correlated with several cancers. Based on these results, it seems worthwhile to conduct observational, prevention and intervention studies to further test the hypothesis that vitamin D can reduce the risk of cancer incidence and death. PMID:16573299

Estimating unconsolidated sediment cover thickness by using the horizontal distance to a bedrock outcrop as secondary information

NASA Astrophysics Data System (ADS)

Kitterød, Nils-Otto

2017-08-01

Unconsolidated sediment cover thickness (D) above bedrock was estimated by using a publicly available well database from Norway, GRANADA. General challenges associated with such databases typically involve clustering and bias. However, if information about the horizontal distance to the nearest bedrock outcrop (L) is included, does the spatial estimation of D improve? This idea was tested by comparing two cross-validation results: ordinary kriging (OK) where L was disregarded; and co-kriging (CK) where cross-covariance between D and L was included. The analysis showed only minor differences between OK and CK with respect to differences between estimation and true values. However, the CK results gave in general less estimation variance compared to the OK results. All observations were declustered and transformed to standard normal probability density functions before estimation and back-transformed for the cross-validation analysis. The semivariogram analysis gave correlation lengths for D and L of approx. 10 and 6 km. These correlations reduce the estimation variance in the cross-validation analysis because more than 50 % of the data material had two or more observations within a radius of 5 km. The small-scale variance of D, however, was about 50 % of the total variance, which gave an accuracy of less than 60 % for most of the cross-validation cases. Despite the noisy character of the observations, the analysis demonstrated that L can be used as secondary information to reduce the estimation variance of D.

The s-Ordered Fock Space Projectors Gained by the General Ordering Theorem

NASA Astrophysics Data System (ADS)

Farid, Shähandeh; Mohammad, Reza Bazrafkan; Mahmoud, Ashrafi

2012-09-01

Employing the general ordering theorem (GOT), operational methods and incomplete 2-D Hermite polynomials, we derive the t-ordered expansion of Fock space projectors. Using the result, the general ordered form of the coherent state projectors is obtained. This indeed gives a new integration formula regarding incomplete 2-D Hermite polynomials. In addition, the orthogonality relation of the incomplete 2-D Hermite polynomials is derived to resolve Dattoli's failure.

FT-Raman study of quinine aqueous solutions with varying pH: 2D correlation study

NASA Astrophysics Data System (ADS)

Wesełucha-Birczyńska, Aleksandra

2007-01-01

Quinine (C 20H 24N 2O 2) is one of the best known, for its antimalarial activity, Cinchona alkaloid. In the current study 2D correlation method was applied to analyze FT-Raman spectra of quinine aqueous solutions with varying pH, which was regarded as an external perturbation. Protonation appears to be the main cause leading to the emergence of cross peaks in the synchronous and asynchronous correlation maps. One should know that protonation process is an important step associated with quinine antimalarial activity. Methoxy group manifests its presence by creation of the respective correlation peaks and seems to be significant for quinine mode of action.

Family dynamics and psychosocial functioning in children with SCI/D from Colombia, South America

PubMed Central

Nicolais, Christina J.; Perrin, Paul B.; Panyavin, Ivan; Nicholls, Elizabeth G.; Olivera Plaza, Silvia Leonor; Quintero, Lorena Medina; Arango-Lasprilla, Juan Carlos

2016-01-01

Objective The purpose of this study was to examine the connections between family dynamics and the psychosocial functioning of children with spinal cord injuries and disorders (SCI/D). Design Cross-sectional. Setting Participants were recruited from communities in Neiva, Colombia. Participants Thirty children with SCI/D and their primary caregiver participated. Children were between 8 and 17 years of age, and had sustained their injury at least six months prior to data collection. Interventions NA. Outcome measures Participating children completed measures assessing their own psychosocial functioning (Children's Depression Inventory, Revised Children's Manifest Anxiety Scale-2, Pediatric Quality of Life Inventory), and their primary caregiver completed measures of family dynamics (Family Adaptability and Cohesion Evaluation Scale- Fourth Edition, Family Communication Scale, Family Assessment Device- General Functioning, Family Satisfaction Scale, Relationship-Focused Coping Scale). Results A correlation matrix showed a number of significant bivariate correlations between child and family variables, and three multiple regressions showed that family satisfaction, empathy, and flexibility significantly explained 27% of the variance in child worry; family satisfaction and communication explained 18% of the variance in child social anxiety; and family cohesion and communication explained 23% of the variance in child emotional functioning. Conclusions These findings highlight the importance of rehabilitation professionals considering the association between family dynamics and the psychosocial functioning of children with SCI/D when working with this population. PMID:25582185

Genetically determined measures of striatal D2 signaling predict prefrontal activity during working memory performance.

PubMed

Bertolino, Alessandro; Taurisano, Paolo; Pisciotta, Nicola Marco; Blasi, Giuseppe; Fazio, Leonardo; Romano, Raffaella; Gelao, Barbara; Lo Bianco, Luciana; Lozupone, Madia; Di Giorgio, Annabella; Caforio, Grazia; Sambataro, Fabio; Niccoli-Asabella, Artor; Papp, Audrey; Ursini, Gianluca; Sinibaldi, Lorenzo; Popolizio, Teresa; Sadee, Wolfgang; Rubini, Giuseppe

2010-02-22

Variation of the gene coding for D2 receptors (DRD2) has been associated with risk for schizophrenia and with working memory deficits. A functional intronic SNP (rs1076560) predicts relative expression of the two D2 receptors isoforms, D2S (mainly pre-synaptic) and D2L (mainly post-synaptic). However, the effect of functional genetic variation of DRD2 on striatal dopamine D2 signaling and on its correlation with prefrontal activity during working memory in humans is not known. Thirty-seven healthy subjects were genotyped for rs1076560 (G>T) and underwent SPECT with [123I]IBZM (which binds primarily to post-synaptic D2 receptors) and with [123I]FP-CIT (which binds to pre-synaptic dopamine transporters, whose activity and density is also regulated by pre-synaptic D2 receptors), as well as BOLD fMRI during N-Back working memory. Subjects carrying the T allele (previously associated with reduced D2S expression) had striatal reductions of [123I]IBZM and of [123I]FP-CIT binding. DRD2 genotype also differentially predicted the correlation between striatal dopamine D2 signaling (as identified with factor analysis of the two radiotracers) and activity of the prefrontal cortex during working memory as measured with BOLD fMRI, which was positive in GG subjects and negative in GT. Our results demonstrate that this functional SNP within DRD2 predicts striatal binding of the two radiotracers to dopamine transporters and D2 receptors as well as the correlation between striatal D2 signaling with prefrontal cortex activity during performance of a working memory task. These data are consistent with the possibility that the balance of excitatory/inhibitory modulation of striatal neurons may also affect striatal outputs in relationship with prefrontal activity during working memory performance within the cortico-striatal-thalamic-cortical pathway.

Genetically Determined Measures of Striatal D2 Signaling Predict Prefrontal Activity during Working Memory Performance

PubMed Central

Bertolino, Alessandro; Taurisano, Paolo; Pisciotta, Nicola Marco; Blasi, Giuseppe; Fazio, Leonardo; Romano, Raffaella; Gelao, Barbara; Bianco, Luciana Lo; Lozupone, Madia; Di Giorgio, Annabella; Caforio, Grazia; Sambataro, Fabio; Niccoli-Asabella, Artor; Papp, Audrey; Ursini, Gianluca; Sinibaldi, Lorenzo; Popolizio, Teresa; Sadee, Wolfgang; Rubini, Giuseppe

2010-01-01

Background Variation of the gene coding for D2 receptors (DRD2) has been associated with risk for schizophrenia and with working memory deficits. A functional intronic SNP (rs1076560) predicts relative expression of the two D2 receptors isoforms, D2S (mainly pre-synaptic) and D2L (mainly post-synaptic). However, the effect of functional genetic variation of DRD2 on striatal dopamine D2 signaling and on its correlation with prefrontal activity during working memory in humans is not known. Methods Thirty-seven healthy subjects were genotyped for rs1076560 (G>T) and underwent SPECT with [123I]IBZM (which binds primarily to post-synaptic D2 receptors) and with [123I]FP-CIT (which binds to pre-synaptic dopamine transporters, whose activity and density is also regulated by pre-synaptic D2 receptors), as well as BOLD fMRI during N-Back working memory. Results Subjects carrying the T allele (previously associated with reduced D2S expression) had striatal reductions of [123I]IBZM and of [123I]FP-CIT binding. DRD2 genotype also differentially predicted the correlation between striatal dopamine D2 signaling (as identified with factor analysis of the two radiotracers) and activity of the prefrontal cortex during working memory as measured with BOLD fMRI, which was positive in GG subjects and negative in GT. Conclusions Our results demonstrate that this functional SNP within DRD2 predicts striatal binding of the two radiotracers to dopamine transporters and D2 receptors as well as the correlation between striatal D2 signaling with prefrontal cortex activity during performance of a working memory task. These data are consistent with the possibility that the balance of excitatory/inhibitory modulation of striatal neurons may also affect striatal outputs in relationship with prefrontal activity during working memory performance within the cortico-striatal-thalamic-cortical pathway. PMID:20179754

Assessment of tolerant sunfish populations (Lepomis sp.) inhabiting selenium-laden coal ash effluents. 2. Tissue biochemistry evaluation.

PubMed

Lohner, T W; Reash, R J; Williams, M

2001-11-01

Sunfish were collected from a fly ash pond-receiving stream and an Ohio River reference site to assess biochemical responses to coal ash effluent exposure. Selenium levels in sunfish from the receiving stream were higher than toxic thresholds associated with adverse population effects and reproductive impairment. Tissue biochemistry was found to be indicative of metal exposure and effect, but varied widely. Liver glycogen was positively correlated with increased liver metal levels, indicating no adverse effect upon stored carbohydrate levels. Lipid levels decreased with increasing metals, indicating possible nutritional stress. Protein levels increased with increasing metal levels, possibly due to the synthesis of proteins to sequester the metals. ATPase, dUTPase, and alkaline phosphatase activity generally decreased with exposure to ash pond metals, but remained within normal physiological ranges. Fish condition factors and liver somatic indices were correlated with liver lipid levels, dUTPase activity, and gill ATPase and alkaline phosphatase activity. Exposure to coal ash effluents produced biochemical markers of exposure that were associated with fish condition indicators; however, the indices themselves were not significantly affected by effluent exposure.

Comparison of 2-D and 3-D estimates of placental volume in early pregnancy.

PubMed

Aye, Christina Y L; Stevenson, Gordon N; Impey, Lawrence; Collins, Sally L

2015-03-01

Ultrasound estimation of placental volume (PlaV) between 11 and 13 wk has been proposed as part of a screening test for small-for-gestational-age babies. A semi-automated 3-D technique, validated against the gold standard of manual delineation, has been found at this stage of gestation to predict small-for-gestational-age at term. Recently, when used in the third trimester, an estimate obtained using a 2-D technique was found to correlate with placental weight at delivery. Given its greater simplicity, the 2-D technique might be more useful as part of an early screening test. We investigated if the two techniques produced similar results when used in the first trimester. The correlation between PlaV values calculated by the two different techniques was assessed in 139 first-trimester placentas. The agreement on PlaV and derived "standardized placental volume," a dimensionless index correcting for gestational age, was explored with the Mann-Whitney test and Bland-Altman plots. Placentas were categorized into five different shape subtypes, and a subgroup analysis was performed. Agreement was poor for both PlaV and standardized PlaV (p < 0.001 and p < 0.001), with the 2-D technique yielding larger estimates for both indices compared with the 3-D method. The mean difference in standardized PlaV values between the two methods was 0.007 (95% confidence interval: 0.006-0.009). The best agreement was found for regular rectangle-shaped placentas (p = 0.438 and p = 0.408). The poor correlation between the 2-D and 3-D techniques may result from the heterogeneity of placental morphology at this stage of gestation. In early gestation, the simpler 2-D estimates of PlaV do not correlate strongly with those obtained with the validated 3-D technique. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Determination of melamine of milk based on two-dimensional correlation infrared spectroscopy

NASA Astrophysics Data System (ADS)

Yang, Ren-jie; Liu, Rong; Xu, Kexin

2012-03-01

The adulteration of milk with harmful substances is a threat to public health and beyond question a serious crime. In order to develop a rapid, cost-effective, high-throughput analysis method for detecting of adulterants in milk, the discriminative analysis of melamine is established in milk based on the two-dimensional (2D) correlation infrared spectroscopy in present paper. Pure milk samples and adulterated milk samples with different content of melamine were prepared. Then the Fourier Transform Infrared spectra of all samples were measured at room temperature. The characteristics of pure milk and adulterated milk were studied by one-dimensional spectra. The 2D NIR and 2D IR correlation spectroscopy were calculated under the perturbation of adulteration concentration. In the range from 1400 to 1800 cm-1, two strong autopeaks were aroused by melamine in milk at 1464 cm-1 and 1560 cm-1 in synchronous spectrum. At the same time, the 1560 cm-1 band does not share cross peak with the 1464 cm-1 band, which further confirm that the two bands have the same origin. Also in the range from 4200 to 4800 cm-1, the autopeak was shown at 4648 cm-1 in synchronous spectrum of melamine in milk. 2D NIR-IR hetero-spectral correlation analysis confirmed that the bands at 1464, 1560 and 4648 cm-1 had the same origin. The results demonstrated that the adulterant can be discriminated correctly by 2D correlation infrared spectroscopy.

Equation of state of wet granular matter.

PubMed

Fingerle, A; Herminghaus, S

2008-01-01

An expression for the near-contact pair correlation function of D -dimensional weakly polydisperse hard spheres is presented, which arises from elementary free-volume arguments. Its derivative at contact agrees very well with our simulations for D=2 . For jammed states, the expression predicts that the number of exact contacts is equal to 2D, in agreement with established simulations. When the particles are wetted, they interact by the formation and rupture of liquid capillary bridges. Since formation and rupture events of capillary bonds are well separated in configuration space, the interaction is hysteretic with a characteristic energy loss Ecb. The pair correlation is strongly affected by this capillary interaction depending on the liquid-bond status of neighboring particles. A theory is derived for the nonequilibrium probability currents of the capillary interaction which determines the pair correlation function near contact. This finally yields an analytic expression for the equation of state, P=P(N/V,T), of wet granular matter for D=2, valid in the complete density range from gas to jamming. Driven wet granular matter exhibits a van der Waals-like unstable branch at granular temperatures TT, is of relevance for aggregation in general, simulations have been performed which show very good agreement with the theoretically predicted coordination K of capillary bonds as a function of the bond length scrit. This result implies that particles that stick at the surface, scrit=0, form isostatic clusters. An extension of the theory in which the bridge coordination number K plays the role of a self-consistent mean-field is proposed.

Equation of state of wet granular matter

NASA Astrophysics Data System (ADS)

Fingerle, A.; Herminghaus, S.

2008-01-01

An expression for the near-contact pair correlation function of D -dimensional weakly polydisperse hard spheres is presented, which arises from elementary free-volume arguments. Its derivative at contact agrees very well with our simulations for D=2 . For jammed states, the expression predicts that the number of exact contacts is equal to 2D, in agreement with established simulations. When the particles are wetted, they interact by the formation and rupture of liquid capillary bridges. Since formation and rupture events of capillary bonds are well separated in configuration space, the interaction is hysteretic with a characteristic energy loss Ecb . The pair correlation is strongly affected by this capillary interaction depending on the liquid-bond status of neighboring particles. A theory is derived for the nonequilibrium probability currents of the capillary interaction which determines the pair correlation function near contact. This finally yields an analytic expression for the equation of state, P=P(N/V,T) , of wet granular matter for D=2 , valid in the complete density range from gas to jamming. Driven wet granular matter exhibits a van der Waals-like unstable branch at granular temperatures T

Numerical investigation of unsteady cavitation around a NACA 66 hydrofoil using OpenFOAM

NASA Astrophysics Data System (ADS)

Hidalgo, V. H.; Luo, X. W.; Escaler, X.; Ji, J.; Aguinaga, A.

2014-03-01

The prediction and control of cavitation damage in pumps, propellers, hydro turbines and fluid machinery in general is necessary during the design stage. The present paper deals with a numerical investigation of unsteady cloud cavitation around a NACA 66 hydrofoil. The current study is focused on understanding the dynamic pressures generated during the cavity collapses as a fundamental characteristic in cavitation erosion. A 2D and 3D unsteady flow simulation has been carried out using OpenFOAM. Then, Paraview and Python programming language have been used to characterize dynamic pressure field. Adapted Large Eddy Simulation (LES) and Zwart cavitation model have been implemented to improve the analysis of cloud motion and to visualize the bubble expansions. Additional results also confirm the correlation between cavity formation and generated pressures.

Cross-sectional investigation of correlation between hepatic steatosis and IVIM perfusion on MR imaging.

PubMed

Lee, James T; Liau, Joy; Murphy, Paul; Schroeder, Michael E; Sirlin, Claude B; Bydder, Mark

2012-05-01

The purpose of this study was to investigate the relationship between liver fat fraction (FF) and diffusion parameters derived from the intravoxel incoherent motion (IVIM) model. Thirty-six subjects with suspected nonalcoholic fatty liver disease underwent diffusion-weighted magnetic resonance imaging with 10 b-values and spoiled gradient recalled echo imaging with six echoes for fat quantification. Correlations were measured between FF, transverse relaxivity (R2), diffusivity (D) and perfusion fraction (f). The primary finding was that no significant correlation was obtained for D vs. FF or f vs. FF. Significant correlations were obtained for D vs. R2 (r=-0.490, P=.002) and f vs. D (r=-0.458, P=.005). The conclusion is that hepatic steatosis does not affect measurement of perfusion or diffusion and therefore is unlikely to confound the use of apparent diffusivity to evaluate hepatic fibrosis. Copyright © 2012 Elsevier Inc. All rights reserved.

Regional oxygen saturation index (rSO2) in brachioradialis and deltoid muscle. Correlation and prognosis in patients with respiratory sepsis.

PubMed

Rodríguez, A; Claverias, L; Marín, J; Magret, M; Rosich, S; Bodí, M; Trefler, S; Pascual, S; Gea, J

2015-03-01

To compare oxygen saturation index (rSO2) obtained simultaneously in two different brachial muscles. Prospective and observational study. Intensive care unit. Critically ill patients with community-acquired pneumonia. Two probes of NIRS device (INVOS 5100) were simultaneously placed on the brachioradialis (BR) and deltoid (D) muscles. rSO2 measurements were recorded at baseline (ICU admission) and at 24h. Demographic and clinical variables were registered. Pearson's correlation coefficient was used to assess the association between continuous variables. The consistency of the correlation was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman plot. The predictive value of the rSO2 for mortality was calculated by ROC curve. Nineteen patients were included with an ICU mortality of 21.1%. The rSO2 values at baseline and at 24h were significantly higher in D than in BR muscle. Values obtained simultaneously in both limbs showed a strong correlation and adequate consistency: BR (r=0.95; p<0.001; ICC=0.94; 95% CI: 0.90-0.96; p<0.001), D (r=0.88; p=0.01; ICC=0.88; 95% CI: 0.80-0.90; p>0.001) but a wide limit of agreement. Non-survivors had rSO2 values significantly lower than survivors at all times of the study. No patient with rSO2 >60% in BR died, and only 17.6% died with an rSO2 value >60% in D. Both muscles showed consistent discriminatory power for mortality. Both BR and D muscles were appropriate for measuring rSO2. Copyright © 2013 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

Accurate potential energy surface for the 1(2)A' state of NH(2): scaling of external correlation versus extrapolation to the complete basis set limit.

PubMed

Li, Y Q; Varandas, A J C

2010-09-16

An accurate single-sheeted double many-body expansion potential energy surface is reported for the title system which is suitable for dynamics and kinetics studies of the reactions of N(2D) + H2(X1Sigmag+) NH(a1Delta) + H(2S) and their isotopomeric variants. It is obtained by fitting ab initio energies calculated at the multireference configuration interaction level with the aug-cc-pVQZ basis set, after slightly correcting semiempirically the dynamical correlation using the double many-body expansion-scaled external correlation method. The function so obtained is compared in detail with a potential energy surface of the same family obtained by extrapolating the calculated raw energies to the complete basis set limit. The topographical features of the novel global potential energy surface are examined in detail and found to be in general good agreement with those calculated directly from the raw ab initio energies, as well as previous calculations available in the literature. The novel function has been built so as to become degenerate at linear geometries with the ground-state potential energy surface of A'' symmetry reported by our group, where both form a Renner-Teller pair.

Comparison of Pore Fractal Characteristics Between Marine and Continental Shales

NASA Astrophysics Data System (ADS)

Liu, Jun; Yao, Yanbin; Liu, Dameng; Cai, Yidong; Cai, Jianchao

Fractal characterization offers a quantitative evaluation on the heterogeneity of pore structure which greatly affects gas adsorption and transportation in shales. To compare the fractal characteristics between marine and continental shales, nine samples from the Lower Silurian Longmaxi formation in the Sichuan basin and nine from the Middle Jurassic Dameigou formation in the Qaidam basin were collected. Reservoir properties and fractal dimensions were characterized for all the collected samples. In this study, fractal dimensions were originated from the Frenkel-Halsey-Hill (FHH) model with N2 adsorption data. Compared to continental shale, marine shale has greater values of quartz content, porosity, specific surface area and total pore volume but lower level of clay minerals content, permeability, average pore diameter and methane adsorption capacity. The quartz in marine shale is mostly associated with biogenic origin, while that in continental shale is mainly due to terrigenous debris. The N2 adsorption-desorption isotherms exhibit that marine shale has fewer inkbottle-shaped pores but more plate-like and slit-shaped pores than continental shale. Two fractal dimensions (D1 and D2) were obtained at P/Po of 0-0.5 and 0.5-1. The dimension D2 is commonly greater than D1, suggesting that larger pores (diameter >˜ 4nm) have more complex structures than small pores (diameter <˜ 4nm). The fractal dimensions (both D1 and D2) positively correlate to clay minerals content, specific surface area and methane adsorption capacity, but have negative relationships with porosity, permeability and average pore diameter. The fractal dimensions increase proportionally with the increasing quartz content in marine shale but have no obvious correlation with that in continental shale. The dimension D1 is correlative to the TOC content and permeability of marine shale at a similar degree with dimension D2, while the dimension D1 is more sensitive to those of continental shale than dimension D2. Compared with dimension D2, for two shales, dimension D1 is better associated with the content of clay minerals but has worse correlations with the specific surface area and average pore diameter.

Digit Ratio (2D:4D): A Biomarker for Prenatal Sex Steroids and Adult Sex Steroids in Challenge Situations.

PubMed

Manning, John; Kilduff, Liam; Cook, Christian; Crewther, Blair; Fink, Bernhard

2014-01-01

Digit ratio (2D:4D) denotes the relative length of the second and fourth digits. This ratio is considered to be a biomarker of the balance between fetal testosterone (T) and estrogen (E) in a narrow window of early ontogeny. Evidence for this assertion is derived from direct and indirect measures of prenatal hormonal exposure (in experimental animals, via amniotic fluid samples and in the study of sex-typical traits) in relation to 2D:4D. In contrast, the relationships between 2D:4D and levels of sex steroids in adults are less clear, as many correlational studies of 2D:4D and adult sex steroids have concluded that this association is statistically non-significant. Here, we suggest that in order to understand the link between 2D:4D and sex hormones, one must consider both fetal organizing and adult activating effects of T and E. In particular, we hypothesize that 2D:4D correlates with organizing effects on the endocrine system that moderate activating effects in adulthood. We argue that this is particularly evident in "challenging" conditions such as aggressive and sexual encounters, in which individuals show increased levels of T. We discuss this refinement of the 2D:4D paradigm in relation to the links between 2D:4D and sports performance, and aggression.

Digit Ratio (2D:4D): A Biomarker for Prenatal Sex Steroids and Adult Sex Steroids in Challenge Situations

PubMed Central

Manning, John; Kilduff, Liam; Cook, Christian; Crewther, Blair; Fink, Bernhard

2013-01-01

Digit ratio (2D:4D) denotes the relative length of the second and fourth digits. This ratio is considered to be a biomarker of the balance between fetal testosterone (T) and estrogen (E) in a narrow window of early ontogeny. Evidence for this assertion is derived from direct and indirect measures of prenatal hormonal exposure (in experimental animals, via amniotic fluid samples and in the study of sex-typical traits) in relation to 2D:4D. In contrast, the relationships between 2D:4D and levels of sex steroids in adults are less clear, as many correlational studies of 2D:4D and adult sex steroids have concluded that this association is statistically non-significant. Here, we suggest that in order to understand the link between 2D:4D and sex hormones, one must consider both fetal organizing and adult activating effects of T and E. In particular, we hypothesize that 2D:4D correlates with organizing effects on the endocrine system that moderate activating effects in adulthood. We argue that this is particularly evident in “challenging” conditions such as aggressive and sexual encounters, in which individuals show increased levels of T. We discuss this refinement of the 2D:4D paradigm in relation to the links between 2D:4D and sports performance, and aggression. PMID:24523714

Genetic co-variance functions for live weight, feed intake, and efficiency measures in growing pigs.

PubMed

Coyne, J M; Berry, D P; Matilainen, K; Sevon-Aimonen, M-L; Mantysaari, E A; Juga, J; Serenius, T; McHugh, N

2017-09-01

The objective of the present study was to estimate genetic co-variance parameters pertaining to live weight, feed intake, and 2 efficiency traits (i.e., residual feed intake and residual daily gain) in a population of pigs over a defined growing phase using Legendre polynomial equations. The data set used consisted of 51,893 live weight records and 903,436 feed intake, residual feed intake (defined as the difference between an animal's actual feed intake and its expected feed intake), and residual daily gain (defined as the difference between an animal's actual growth rate and its expected growth rate) records from 10,201 growing pigs. Genetic co-variance parameters for all traits were estimated using random regression Legendre polynomials. Daily heritability estimates for live weight ranged from 0.25 ± 0.04 (d 73) to 0.50 ± 0.03 (d 122). Low to moderate heritability estimates were evident for feed intake, ranging from 0.07 ± 0.03 (d 66) to 0.25 ± 0.02 (d 170). The estimated heritability for residual feed intake was generally lower than those of both live weight and feed intake and ranged from 0.04 ± 0.01 (d 96) to 0.17 ± 0.02 (d 159). The heritability for feed intake and residual feed intake increased in the early stages of the test period and subsequently sharply declined, coinciding with older ages. Heritability estimates for residual daily gain ranged from 0.26 ± 0.03 (d 188) to 0.42 ± 0.03 (d 101). Genetic correlations within trait were strongest between adjacent ages but weakened as the interval between ages increased; however, the genetic correlations within all traits tended to strengthen between the extremes of the trajectory. Moderate to strong genetic correlations were evident among live weight, feed intake, and the efficiency traits, particularly in the early stage of the trial period (d 66 to 86), but weakened with age. Results from this study could be implemented into the national genetic evaluation for pigs, providing comprehensive information on the profile of growth and efficiency throughout the growing period of the animal's life, thus helping producers identify genetically superior animals.

Simulation study of 2D spectrum of molecular aggregates coupled to correlated vibrations

NASA Astrophysics Data System (ADS)

Abramavicius, Darius; Butkus, Vytautas; Valkunas, Leonas; Mukamel, Shaul

2011-03-01

Oscillatory dynamics of two-dimensional (2D) spectra of photosynthetic pigment-protein complexes raise the questions of how to disentangle various origins of these oscillations, which may include quantum beats, quantum transport, or molecular vibrations. We study the effects of correlated overdamped fluctuations and under-damped vibrations on the 2D spectra of Fenna-Matthews-Olson (FMO) aggregate, which has well-resolved exciton resonances, and a circular porphyrin aggregate (P6), whose absorption shows vibrational progression. We use a generic exciton Hamiltonian coupled to a bath, characterized by a spectral density. Fluctuations have smooth, while vibtations have δ -type spectral densities. We show how various scenarios of correlated molecular fluctuations lead to some highly oscillatory crosspeaks. Molecular vibrations cause progression of diagonal peaks in the 2D spectrum and make their corresponding cross-peaks highly oscillatory. We, thus, demonstrate that bath fluctuations and molecular vibrations of realistic molecular aggregates are highly entangled in 2D spectroscopy. DA acknowledges grant VP1-3.1-SMM-07-V, SM - the grants CHE0745892 (NSF), DRPA BAA-10-40 QUBE.

Striatal dopamine D2/3 receptor regulation by stress inoculation in squirrel monkeys.

PubMed

Lee, Alex G; Nechvatal, Jordan M; Shen, Bin; Buckmaster, Christine L; Levy, Michael J; Chin, Frederick T; Schatzberg, Alan F; Lyons, David M

2016-06-01

Intermittent mildly stressful situations provide opportunities to learn, practice, and improve coping in a process called stress inoculation. Stress inoculation also enhances cognitive control and response inhibition of impulsive motivated behavior. Cognitive control and motivation have been linked to striatal dopamine D2 and/or D3 receptors (DRD2/3) in rodents, monkeys, and humans. Here, we study squirrel monkeys randomized early in life to stress inoculation with or without maternal companionship and a no-stress control treatment condition. Striatal DRD2/3 availability in adulthood was measured in vivo by [ 11 C]raclopride binding using positron emission tomography (PET). DRD2/3 availability was greater in caudate and putamen compared to ventral striatum as reported in PET studies of humans and other non-human primates. DRD2/3 availability in ventral striatum was also consistently greater in stress inoculated squirrel monkeys compared to no-stress controls. Squirrel monkeys exposed to stress inoculation in the presence of their mother did not differ from squirrel monkeys exposed to stress inoculation without maternal companionship. Similar effects in different social contexts extend the generality of our findings and together suggest that stress inoculation increases striatal DRD2/3 availability as a correlate of cognitive control in squirrel monkeys.

New sesquiterpenes from Euonymus europaeus (Celastraceae).

PubMed

Descoins, Charles; Bazzocchi, Isabel López; Ravelo, Angel Gutiérrez

2002-02-01

A new sesquiterpene evoninate alkaloid (1), and two sesquiterpenes (2, 3) with a dihydro-beta-agarofuran skeleton, along with three known sesquiterpenes (4-6), were isolated from the seeds of Euonymus europaeus. Their structures were elucidated by high resolution mass analysis, and one- and two-dimensional (1D and 2D) NMR spectroscopy, including homonuclear and heteronuclear correlation [correlation spectroscopy (COSY), rotating frame Overhauser enhancement spectroscopy (ROESY), heteronuclear single quantum coherence (HSQC), and heteronuclear multiple bond correlation (HMBC)] experiments.

Formulation of D-brane Dynamics

NASA Astrophysics Data System (ADS)

Evans, Thomas

2012-03-01

It is the purpose of this paper (within the context of STS rules & guidelines ``research report'') to formulate a statistical-mechanical form of D-brane dynamics. We consider first the path integral formulation of quantum mechanics, and extend this to a path-integral formulation of D-brane mechanics, summing over all the possible path integral sectors of R-R, NS charged states. We then investigate this generalization utilizing a path-integral formulation summing over all the possible path integral sectors of R-R charged states, calculated from the mean probability tree-level amplitude of type I, IIA, and IIB strings, serving as a generalization of all strings described by D-branes. We utilize this generalization to study black holes in regimes where the initial D-brane system is legitimate, and further this generalization to look at information loss near regions of nonlocality on a non-ordinary event horizon. We see here that in these specific regimes, we can calculate a path integral formulation, as describing D0-brane mechanics, tracing the dissipation of entropy throughout the event horizon. This is used to study the information paradox, and to propose a resolution between the phenomena and the correct and expected quantum mechanical description. This is done as our path integral throughout entropy entering the event horizon effectively and correctly encodes the initial state in subtle correlations in the Hawking radiation.

Scale Effects in the Flow of a Shear-Thinning Fluid in Geological Fractures

NASA Astrophysics Data System (ADS)

Meheust, Y.; Roques, C.; Le Borgne, T.; Selker, J. S.

2017-12-01

Subsurface flow processes involving non-Newtonian fluids play a major role in many engineering applications, from in-situ remediation to enhanced oil recovery. The fluids of interest in such applications (f.e., polymers in remediation) often present shear-thinning properties, i.e., their viscosity decreases as a function of the local shear rate. We investigate how fracture wall roughness impacts the flow of a shear-thinning fluid. Numerical simulations of flow in 3D geological fractures are carried out by solving a modified Navier-Stokes equation incorporating the Carreau viscous-shear model. The numerical fractures consist of two isotropic self-affine surfaces which are correlated with each other above a characteristic scale (thecorrelation length of Méheust et al. PAGEOPH 2003). Perfect plastic closing is assumed when the surfaces are in contact. The statistical parameters describing a fracture are the standard deviation of the wall roughness, the mean aperture, the correlation length, and the fracture length, the Hurst exponent being fixed (equal to 0.8). The objective is to investigate how varying the correlation length impacts the flow behavior, for different degrees of closure, and how this behavior diverges from what is known for Newtonian fluids. The results from the 3D simulations are also compared to 2D simulations based on the lubrication theory, which we have developed as an extension of the Reynolds equation for Newtonian fluids. These 2D simulations run orders of magnitude faster, which allows considering a significant statistics of fractures of identical statistical parameters, and therefore draw general conclusions despite the large stochasticity of the media. We also discuss the implications of our results for solute transport by such flows. References:Méheust, Y., & Schmittbuhl, J. (2003). Scale effects related to flow in rough fractures. Pure and Applied Geophysics, 160(5-6), 1023-1050.

Non-Gaussian lineshapes and dynamics of time-resolved linear and nonlinear (correlation) spectra.

PubMed

Dinpajooh, Mohammadhasan; Matyushov, Dmitry V

2014-07-17

Signatures of nonlinear and non-Gaussian dynamics in time-resolved linear and nonlinear (correlation) 2D spectra are analyzed in a model considering a linear plus quadratic dependence of the spectroscopic transition frequency on a Gaussian nuclear coordinate of the thermal bath (quadratic coupling). This new model is contrasted to the commonly assumed linear dependence of the transition frequency on the medium nuclear coordinates (linear coupling). The linear coupling model predicts equality between the Stokes shift and equilibrium correlation functions of the transition frequency and time-independent spectral width. Both predictions are often violated, and we are asking here the question of whether a nonlinear solvent response and/or non-Gaussian dynamics are required to explain these observations. We find that correlation functions of spectroscopic observables calculated in the quadratic coupling model depend on the chromophore's electronic state and the spectral width gains time dependence, all in violation of the predictions of the linear coupling models. Lineshape functions of 2D spectra are derived assuming Ornstein-Uhlenbeck dynamics of the bath nuclear modes. The model predicts asymmetry of 2D correlation plots and bending of the center line. The latter is often used to extract two-point correlation functions from 2D spectra. The dynamics of the transition frequency are non-Gaussian. However, the effect of non-Gaussian dynamics is limited to the third-order (skewness) time correlation function, without affecting the time correlation functions of higher order. The theory is tested against molecular dynamics simulations of a model polar-polarizable chromophore dissolved in a force field water.

Three-dimensional photography for the evaluation of facial profiles in obstructive sleep apnoea.

PubMed

Lin, Shih-Wei; Sutherland, Kate; Liao, Yu-Fang; Cistulli, Peter A; Chuang, Li-Pang; Chou, Yu-Ting; Chang, Chih-Hao; Lee, Chung-Shu; Li, Li-Fu; Chen, Ning-Hung

2018-06-01

Craniofacial structure is an important determinant of obstructive sleep apnoea (OSA) syndrome risk. Three-dimensional stereo-photogrammetry (3dMD) is a novel technique which allows quantification of the craniofacial profile. This study compares the facial images of OSA patients captured by 3dMD to three-dimensional computed tomography (3-D CT) and two-dimensional (2-D) digital photogrammetry. Measurements were correlated with indices of OSA severity. Thirty-eight patients diagnosed with OSA were included, and digital photogrammetry, 3dMD and 3-D CT were performed. Distances, areas, angles and volumes from the images captured by three methods were analysed. Almost all measurements captured by 3dMD showed strong agreement with 3-D CT measurements. Results from 2-D digital photogrammetry showed poor agreement with 3-D CT. Mandibular width, neck perimeter size and maxillary volume measurements correlated well with the severity of OSA using all three imaging methods. Mandibular length, facial width, binocular width, neck width, cranial base triangle area, cranial base area 1 and middle cranial fossa volume correlated well with OSA severity using 3dMD and 3-D CT, but not with 2-D digital photogrammetry. 3dMD provided accurate craniofacial measurements of OSA patients, which were highly concordant with those obtained by CT, while avoiding the radiation associated with CT. © 2018 Asian Pacific Society of Respirology.

Synthesis and First Principles Investigation of HMX/NMP Cocrystal Explosive

NASA Astrophysics Data System (ADS)

Lin, He; Zhu, Shun-Guan; Zhang, Lin; Peng, Xin-Hua; LI, Hong-Zhen

2013-10-01

1,3,5,7-Tetranitro-l,3,5,7-tetrazocine (HMX)/N-methyl-2-pyrrolidone (NMP) cocrystal explosive was prepared by a solution evaporation method. This cocrystal explosive crystallized in the trigonal system (space group ? ), with cell parameters a = 16.605(8) Å and c = 31.496(4) Å. Theoretical investigations of the formation mechanism of HMX/NMP cocrystal were carried out in Cambridge serial total energy package (CASTEP) based on dispersion-corrected density functional theory (DFT-D) with a plane wave scheme. The exchange-correlation potential was treated with the Perdew-Burke-Ernzerhof function of generalized gradient approximation, and dispersion force was correlated using Grimme's method. The band structure, density of states, projected density of states, and Mulliken populations were calculated at the generalized gradient approximation level. The results showed that the main host-guest interactions in HMX/NMP cocrystal were hydrogen bonds and stacking interactions, which were the same as those analyzed using X-ray diffraction. Theoretical investigations of HMX/NMP cocrystal explosive may provide the basis for the preparation of cocrystal explosive composed of HMX and energetic materials.

Melting behavior of poly(3-hydroxybutyrate) investigated by two-dimensional infrared correlation spectroscopy

NASA Astrophysics Data System (ADS)

Padermshoke, Adchara; Katsumoto, Yukiteru; Sato, Harumi; Ekgasit, Sanong; Noda, Isao; Ozaki, Yukihiro

2005-02-01

The melting behavior of a bacterially synthesized biodegradable polymer, poly(3-hydroxybutyrate) (PHB), was investigated by using generalized two-dimensional infrared (2D IR) correlation spectroscopy. Temperature-dependent spectral variations in the regions of the CH stretching (3100-2850 cm -1), CO stretching (1800-1680 cm -1), and COC stretching (1320-1120 cm -1) bands were monitored during the melting process. The asynchronous 2D correlation spectrum for the CO stretching band region resolved two crystalline bands at 1731 and 1723 cm -1. The intense band at 1723 cm -1 may be due to the highly ordered crystalline part of PHB, and the weak band at 1731 cm -1 possibly arises from the crystalline part with a less ordered structure. These crystalline bands at 1731 and 1723 cm -1 share asynchronous cross peaks with a band at around 1740 cm -1 assignable to the CO band due to the amorphous component. This observation indicates that the decreases in the crystalline components do not proceed simultaneously with the increase in the amorphous component. In the 3020-2915 cm -1 region where bands due to the asymmetric CH 3 stretching and antisymmetric CH 2 stretching modes are expected to appear, eight bands are identified at 3007, 2995, 2985, 2975, 2967, 2938, 2934, and 2929 cm -1. The bands at 2985 and 2938 cm -1 are ascribed to the amorphous part while the rest come from crystal field splitting, which is a characteristic of polymers with a helical structure.

Dopamine D1 receptor density in the mPFC responds to cognitive demands and receptor turnover contributes to general cognitive ability in mice.

PubMed

Wass, Christopher; Sauce, Bruno; Pizzo, Alessandro; Matzel, Louis D

2018-03-14

In both humans and mice, performance on tests of intelligence or general cognitive ability (GCA) is related to dopamine D1 receptor-mediated activity in the prelimbic cortex, and levels of DRD1 mRNA predict the GCA of mice. Here we assessed the turnover rate of D1 receptors as well as the expression level of the D1 chaperone protein (DRiP78) in the medial PPC (mPFC) of mice to determine whether rate of receptor turnover was associated with variations in the GCA of genetically heterogeneous mice. Following assessment of GCA (aggregate performance on four diverse learning tests) mice were administered an irreversible dopamine receptor antagonist (EEDQ), after which the density of new D1 receptors were quantified. GCA was positively correlated with both the rate of D1 receptor recovery and levels of DRiP78. Additionally, the density of D1 receptors was observed to increase within 60 min (or less) in response to intense demands on working memory, suggesting that a pool of immature receptors was available to accommodate high cognitive loads. These results provide evidence that innate general cognitive abilities are related to D1 receptor turnover rates in the prefrontal cortex, and that an intracellular pool of immature D1 receptors are available to accommodate cognitive demands.

Implications of vitamin D deficiency in lithiasic patient and in general population.

PubMed

Millán-Rodríguez, F; Gavrilov, P; Gracia-García, S; Angerri-Feu, O; Sánchez-Martín, F M; Villavicencio-Mavrich, H

2015-05-01

Vitamin D deficiency causes problems in mineral metabolism but also overall health. In first place a review of the topic was carried out. Then, in order to contextualize it in lithiasic patient, a study on Vitamin D deficiency and its possible relationship with impaired PTH levels is performed. A review of topics such as metabolism, epidemiology and the relationship of vitamin D deficiency with several pathologies was performed. Besides a multivariate analysis and a correlation study between vitamin D and PTH levels was conducted in 100 lithiasic patients. We present a review of Vitamin D metabolism, receptors and functions, as well as about its valuation methodology and the treatment of its deficiency. Lithiasic patients show a higher vitamin D deficiency than general population. Vitamin D deficiency has been significantly associated with increased PTH levels. In addition, there is enough literature showing a relationship between vitamin D deficiency not only with bone disease, but also with multiple diseases. vitamin D levels should be measured in all lithiasic patients, and those with vitamin D deficiency should be treated. Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Quantum Algorithms to Simulate Many-Body Physics of Correlated Fermions

NASA Astrophysics Data System (ADS)

Jiang, Zhang; Sung, Kevin J.; Kechedzhi, Kostyantyn; Smelyanskiy, Vadim N.; Boixo, Sergio

2018-04-01

Simulating strongly correlated fermionic systems is notoriously hard on classical computers. An alternative approach, as proposed by Feynman, is to use a quantum computer. We discuss simulating strongly correlated fermionic systems using near-term quantum devices. We focus specifically on two-dimensional (2D) or linear geometry with nearest-neighbor qubit-qubit couplings, typical for superconducting transmon qubit arrays. We improve an existing algorithm to prepare an arbitrary Slater determinant by exploiting a unitary symmetry. We also present a quantum algorithm to prepare an arbitrary fermionic Gaussian state with O (N2) gates and O (N ) circuit depth. Both algorithms are optimal in the sense that the numbers of parameters in the quantum circuits are equal to those describing the quantum states. Furthermore, we propose an algorithm to implement the 2D fermionic Fourier transformation on a 2D qubit array with only O (N1.5) gates and O (√{N }) circuit depth, which is the minimum depth required for quantum information to travel across the qubit array. We also present methods to simulate each time step in the evolution of the 2D Fermi-Hubbard model—again on a 2D qubit array—with O (N ) gates and O (√{N }) circuit depth. Finally, we discuss how these algorithms can be used to determine the ground-state properties and phase diagrams of strongly correlated quantum systems using the Hubbard model as an example.

Volume estimation of tonsil phantoms using an oral camera with 3D imaging

PubMed Central

Das, Anshuman J.; Valdez, Tulio A.; Vargas, Jose Arbouin; Saksupapchon, Punyapat; Rachapudi, Pushyami; Ge, Zhifei; Estrada, Julio C.; Raskar, Ramesh

2016-01-01

Three-dimensional (3D) visualization of oral cavity and oropharyngeal anatomy may play an important role in the evaluation for obstructive sleep apnea (OSA). Although computed tomography (CT) and magnetic resonance (MRI) imaging are capable of providing 3D anatomical descriptions, this type of technology is not readily available in a clinic setting. Current imaging of the oropharynx is performed using a light source and tongue depressors. For better assessment of the inferior pole of the tonsils and tongue base flexible laryngoscopes are required which only provide a two dimensional (2D) rendering. As a result, clinical diagnosis is generally subjective in tonsillar hypertrophy where current physical examination has limitations. In this report, we designed a hand held portable oral camera with 3D imaging capability to reconstruct the anatomy of the oropharynx in tonsillar hypertrophy where the tonsils get enlarged and can lead to increased airway resistance. We were able to precisely reconstruct the 3D shape of the tonsils and from that estimate airway obstruction percentage and volume of the tonsils in 3D printed realistic models. Our results correlate well with Brodsky’s classification of tonsillar hypertrophy as well as intraoperative volume estimations. PMID:27446667

Impact of Aircraft Emissions on Reactive Nitrogen over the North Atlantic Flight Corridor Region

NASA Technical Reports Server (NTRS)

Koike, M.; Kondo, Y.; Ikeda, H.; Gregory, G. L.; Anderson, B. E.; Sachse, G. W.; Blake, D.; Liu, S. C.; Singh, H. B.; Thompson, A.

1999-01-01

The impact of aircraft emissions on reactive nitrogen in the upper troposphere (UT) and lowermost stratosphere (LS) was estimated using the NO(y)-O3 correlation obtained during the SASS Ozone and NO(x) Experiment (SONEX) carried out over the US continent and North Atlantic Flight Corridor (NAFC) region in October and November 1997. To evaluate the large scale impact, we made a reference NO(y)-O3 relationship in air masses, upon which aircraft emissions were considered to have little impact. For this purpose, the integrated input of NO(x) from aircraft into an air mass along a 10-d back trajectory (DELTA-NO(y)) was calculated based on the ANCAT/EC2 emission inventory. The excess NO(y) (dNO(y)) was calculated from the observed NO(y) and the reference NO(y)-O3 relationship. As a result, a weak positive correlation was found between the dNO(y) and DELTA-NO(y), and dNO(y) and NO(x)/NO(y) values, while no positive correlation between the dNO(y) and CO values was found, suggesting that dNO(y) values can be used as a measure of the NO(x) input from aircraft emissions. The excess NO(y) values calculated from another NO(y)-O3 reference relationship made using in-situ CN data also agreed with these dNO(y) values, within the uncertainties. At the NAFC region (45 N - 60 N), the median value of dNO(y) in the troposphere increased with altitude above 9 km and reached 70 pptv (20% of NO(y)) at 11 km. The excess NO(x) was estimated to be about half of the dNO(y) values, corresponding to 30% of the observed NO(x) level. Higher dNO(y) values were generally found in air masses where O3 = 75 - 125 ppbv, suggesting a more pronounced effect around the tropopause. The median value of dNO(y) in the stratosphere at the NAFC region at 8.5 - 11.5 km was about 120 pptv. The higher dNO(y) values in the LS were probably due to the accumulated effect of aircraft emissions, given the long residence time of affected air in the LS. Similar dNO(y) values were also obtained in air masses sampled over the US continent.

Cluster and propensity based approximation of a network

PubMed Central

2013-01-01

Background The models in this article generalize current models for both correlation networks and multigraph networks. Correlation networks are widely applied in genomics research. In contrast to general networks, it is straightforward to test the statistical significance of an edge in a correlation network. It is also easy to decompose the underlying correlation matrix and generate informative network statistics such as the module eigenvector. However, correlation networks only capture the connections between numeric variables. An open question is whether one can find suitable decompositions of the similarity measures employed in constructing general networks. Multigraph networks are attractive because they support likelihood based inference. Unfortunately, it is unclear how to adjust current statistical methods to detect the clusters inherent in many data sets. Results Here we present an intuitive and parsimonious parametrization of a general similarity measure such as a network adjacency matrix. The cluster and propensity based approximation (CPBA) of a network not only generalizes correlation network methods but also multigraph methods. In particular, it gives rise to a novel and more realistic multigraph model that accounts for clustering and provides likelihood based tests for assessing the significance of an edge after controlling for clustering. We present a novel Majorization-Minimization (MM) algorithm for estimating the parameters of the CPBA. To illustrate the practical utility of the CPBA of a network, we apply it to gene expression data and to a bi-partite network model for diseases and disease genes from the Online Mendelian Inheritance in Man (OMIM). Conclusions The CPBA of a network is theoretically appealing since a) it generalizes correlation and multigraph network methods, b) it improves likelihood based significance tests for edge counts, c) it directly models higher-order relationships between clusters, and d) it suggests novel clustering algorithms. The CPBA of a network is implemented in Fortran 95 and bundled in the freely available R package PropClust. PMID:23497424

Evaluation of a 3D local multiresolution algorithm for the correction of partial volume effects in positron emission tomography.

PubMed

Le Pogam, Adrien; Hatt, Mathieu; Descourt, Patrice; Boussion, Nicolas; Tsoumpas, Charalampos; Turkheimer, Federico E; Prunier-Aesch, Caroline; Baulieu, Jean-Louis; Guilloteau, Denis; Visvikis, Dimitris

2011-09-01

Partial volume effects (PVEs) are consequences of the limited spatial resolution in emission tomography leading to underestimation of uptake in tissues of size similar to the point spread function (PSF) of the scanner as well as activity spillover between adjacent structures. Among PVE correction methodologies, a voxel-wise mutual multiresolution analysis (MMA) was recently introduced. MMA is based on the extraction and transformation of high resolution details from an anatomical image (MR/CT) and their subsequent incorporation into a low-resolution PET image using wavelet decompositions. Although this method allows creating PVE corrected images, it is based on a 2D global correlation model, which may introduce artifacts in regions where no significant correlation exists between anatomical and functional details. A new model was designed to overcome these two issues (2D only and global correlation) using a 3D wavelet decomposition process combined with a local analysis. The algorithm was evaluated on synthetic, simulated and patient images, and its performance was compared to the original approach as well as the geometric transfer matrix (GTM) method. Quantitative performance was similar to the 2D global model and GTM in correlated cases. In cases where mismatches between anatomical and functional information were present, the new model outperformed the 2D global approach, avoiding artifacts and significantly improving quality of the corrected images and their quantitative accuracy. A new 3D local model was proposed for a voxel-wise PVE correction based on the original mutual multiresolution analysis approach. Its evaluation demonstrated an improved and more robust qualitative and quantitative accuracy compared to the original MMA methodology, particularly in the absence of full correlation between anatomical and functional information.

Evaluation of a 3D local multiresolution algorithm for the correction of partial volume effects in positron emission tomography

PubMed Central

Le Pogam, Adrien; Hatt, Mathieu; Descourt, Patrice; Boussion, Nicolas; Tsoumpas, Charalampos; Turkheimer, Federico E.; Prunier-Aesch, Caroline; Baulieu, Jean-Louis; Guilloteau, Denis; Visvikis, Dimitris

2011-01-01

Purpose Partial volume effects (PVE) are consequences of the limited spatial resolution in emission tomography leading to under-estimation of uptake in tissues of size similar to the point spread function (PSF) of the scanner as well as activity spillover between adjacent structures. Among PVE correction methodologies, a voxel-wise mutual multi-resolution analysis (MMA) was recently introduced. MMA is based on the extraction and transformation of high resolution details from an anatomical image (MR/CT) and their subsequent incorporation into a low resolution PET image using wavelet decompositions. Although this method allows creating PVE corrected images, it is based on a 2D global correlation model which may introduce artefacts in regions where no significant correlation exists between anatomical and functional details. Methods A new model was designed to overcome these two issues (2D only and global correlation) using a 3D wavelet decomposition process combined with a local analysis. The algorithm was evaluated on synthetic, simulated and patient images, and its performance was compared to the original approach as well as the geometric transfer matrix (GTM) method. Results Quantitative performance was similar to the 2D global model and GTM in correlated cases. In cases where mismatches between anatomical and functional information were present the new model outperformed the 2D global approach, avoiding artefacts and significantly improving quality of the corrected images and their quantitative accuracy. Conclusions A new 3D local model was proposed for a voxel-wise PVE correction based on the original mutual multi-resolution analysis approach. Its evaluation demonstrated an improved and more robust qualitative and quantitative accuracy compared to the original MMA methodology, particularly in the absence of full correlation between anatomical and functional information. PMID:21978037

Estimates of genetic parameters, genetic trends, and inbreeding in a crossbred dairy sheep research flock in the United States.

PubMed

Murphy, T W; Berger, Y M; Holman, P W; Baldin, M; Burgett, R L; Thomas, D L

2017-10-01

For the past 2 decades, the Spooner Agriculture Research Station (ARS) of the University of Wisconsin-Madison operated the only dairy sheep research flock in North America. The objectives of the present study were to 1) obtain estimates of genetic parameters for lactation and reproductive traits in dairy ewes, 2) estimate the amount of genetic change in these traits over time, and 3) quantify the level of inbreeding in this flock over the last 20 yr. Multiple-trait repeatability models (MTRM) were used to analyze ewe traits through their first 6 parities. The first MTRM jointly analyzed milk (180-d-adjusted milk yield [180d MY]), fat (180-d-adjusted fat yield [180d FY]), and protein (180-d-adjusted protein yield [180d PY]) yields adjusted to 180 d of lactation; number of lambs born per ewe lambing (NLB); and lactation average test-day somatic cell score (LSCS). A second MTRM analyzed 180d MY, NLB, LSCS, and percentage milk fat (%F) and percentage milk protein (%P). The 3 yield traits were moderately heritable (0.26 to 0.32) and strongly genetically correlated (0.91 to 0.96). Percentage milk fat and %P were highly heritable (0.53 and 0.61, respectively) and moderately genetically correlated (0.61). Milk yield adjusted to 180 d was negatively genetically correlated with %F and %P (-0.31 and -0.34, respectively). Ewe prolificacy was not significantly ( > 0.67) genetically correlated with yield traits, %P, or LSCS but lowly negatively correlated with %F (-0.26). Lactation somatic cell score was unfavorably genetically correlated with yield traits (0.28 to 0.39) but not significantly ( > 0.09) correlated with %F, %P, and NLB. Within-trait multiple-trait models through the first 4 parities revealed that 180d MY, 180d FY, 180d PY, %F, and %P were strongly genetically correlated across parity (0.67 to 1.00). However, the genetic correlations across parity for NLB and LSCS were somewhat lower (0.51 to 0.96). Regressing predicted breeding values for 180d MY, without and with the addition of breed effects, on ewe year of birth revealed a positive genetic gain of 2.30 and 6.24 kg/yr, respectively, over the past 20 yr in this flock. Inbreeding coefficients of ewes with an extended pedigree ranged from 0.0 to 0.29, with an average of 0.07. To optimize genetic gains and avoid excessive inbreeding, the development of a national genetic improvement program should be a top priority for the growing dairy sheep industry.

The Relationship Between Digit Ratio (2D:4D) and Sexual Orientation in Men from China.

PubMed

Xu, Yin; Zheng, Yong

2016-04-01

We examined the relationship between 2D:4D digit ratio and sexual orientation in men from China and analyzed the influences of the components used to assess sexual orientation and the criteria used to classify individuals as homosexual on this relationship. A total of 309 male and 110 female participants took part in a web-based survey. Our results showed that heterosexual men had a significantly lower 2D:4D than heterosexual women and exclusively homosexual men had a significantly higher left 2D:4D than heterosexual men whereas only exclusively homosexual men had a significantly higher right 2D:4D than heterosexual men when sexual orientation was assessed via sexual attraction. The left 2D:4D showed a significant positive correlation with sexual identity, sexual attraction, and sexual behavior, and the right 2D:4D showed a significant positive correlation with sexual attraction. The effect sizes for differences in 2D:4D between homosexual and heterosexual men varied according to criteria used to classify individuals as homosexual and sexual orientation components; the more stringent the criteria (scores closer to the homosexual category), the larger the effect sizes; further, sexual attraction yielded the largest effect size. There were no significant effects of age and latitude on Chinese 2D:4D. This study contributes to the current understanding of the relationship between 2D:4D and male sexual orientation.

Accelerating and focusing protein-protein docking correlations using multi-dimensional rotational FFT generating functions.

PubMed

Ritchie, David W; Kozakov, Dima; Vajda, Sandor

2008-09-01

Predicting how proteins interact at the molecular level is a computationally intensive task. Many protein docking algorithms begin by using fast Fourier transform (FFT) correlation techniques to find putative rigid body docking orientations. Most such approaches use 3D Cartesian grids and are therefore limited to computing three dimensional (3D) translational correlations. However, translational FFTs can speed up the calculation in only three of the six rigid body degrees of freedom, and they cannot easily incorporate prior knowledge about a complex to focus and hence further accelerate the calculation. Furthemore, several groups have developed multi-term interaction potentials and others use multi-copy approaches to simulate protein flexibility, which both add to the computational cost of FFT-based docking algorithms. Hence there is a need to develop more powerful and more versatile FFT docking techniques. This article presents a closed-form 6D spherical polar Fourier correlation expression from which arbitrary multi-dimensional multi-property multi-resolution FFT correlations may be generated. The approach is demonstrated by calculating 1D, 3D and 5D rotational correlations of 3D shape and electrostatic expansions up to polynomial order L=30 on a 2 GB personal computer. As expected, 3D correlations are found to be considerably faster than 1D correlations but, surprisingly, 5D correlations are often slower than 3D correlations. Nonetheless, we show that 5D correlations will be advantageous when calculating multi-term knowledge-based interaction potentials. When docking the 84 complexes of the Protein Docking Benchmark, blind 3D shape plus electrostatic correlations take around 30 minutes on a contemporary personal computer and find acceptable solutions within the top 20 in 16 cases. Applying a simple angular constraint to focus the calculation around the receptor binding site produces acceptable solutions within the top 20 in 28 cases. Further constraining the search to the ligand binding site gives up to 48 solutions within the top 20, with calculation times of just a few minutes per complex. Hence the approach described provides a practical and fast tool for rigid body protein-protein docking, especially when prior knowledge about one or both binding sites is available.

Integration of a 3D perspective view in the navigation display: featuring pilot's mental model

NASA Astrophysics Data System (ADS)

Ebrecht, L.; Schmerwitz, S.

2015-05-01

Synthetic vision systems (SVS) appear as spreading technology in the avionic domain. Several studies prove enhanced situational awareness when using synthetic vision. Since the introduction of synthetic vision a steady change and evolution started concerning the primary flight display (PFD) and the navigation display (ND). The main improvements of the ND comprise the representation of colored ground proximity warning systems (EGPWS), weather radar, and TCAS information. Synthetic vision seems to offer high potential to further enhance cockpit display systems. Especially, concerning the current trend having a 3D perspective view in a SVS-PFD while leaving the navigational content as well as methods of interaction unchanged the question arouses if and how the gap between both displays might evolve to a serious problem. This issue becomes important in relation to the transition and combination of strategic and tactical flight guidance. Hence, pros and cons of 2D and 3D views generally as well as the gap between the egocentric perspective 3D view of the PFD and the exocentric 2D top and side view of the ND will be discussed. Further a concept for the integration of a 3D perspective view, i.e., bird's eye view, in synthetic vision ND will be presented. The combination of 2D and 3D views in the ND enables a better correlation of the ND and the PFD. Additionally, this supports the building of pilot's mental model. The authors believe it will improve the situational and spatial awareness. It might prove to further raise the safety margin when operating in mountainous areas.

Naval Research Logistics Quarterly. Volume 28. Number 3,

DTIC Science & Technology

1981-09-01

denotes component-wise maximum. f has antone (isotone) differences on C x D if for cl < c2 and d, < d2, NAVAL RESEARCH LOGISTICS QUARTERLY VOL. 28...or negative correlations and linear or nonlinear regressions. Given are the mo- ments to order two and, for special cases, (he regression function and...data sets. We designate this bnb distribution as G - B - N(a, 0, v). The distribution admits only of positive correlation and linear regressions

Spin-polarized structural, elastic, electronic and magnetic properties of half-metallic ferromagnetism in V-doped ZnSe

NASA Astrophysics Data System (ADS)

Monir, M. El Amine.; Baltache, H.; Murtaza, G.; Khenata, R.; Ahmed, Waleed K.; Bouhemadou, A.; Omran, S. Bin; Seddik, T.

2015-01-01

Based on first principles spin-polarized density functional theory, the structural, elastic electronic and magnetic properties of Zn1-xVxSe (for x=0.25, 0.50, 0.75) in zinc blende structure have been studied. The investigation was done using the full-potential augmented plane wave method as implemented in WIEN2k code. The exchange-correlation potential was treated with the generalized gradient approximation PBE-GGA for the structural and elastic properties. Moreover, the PBE-GGA+U approximation (where U is the Hubbard correlation terms) is employed to treat the "d" electrons properly. A comparative study between the band structures, electronic structures, total and partial densities of states and local moments calculated within both GGA and GGA+U schemes is presented. The analysis of spin-polarized band structure and density of states shows the half-metallic ferromagnetic character and are also used to determine s(p)-d exchange constants N0α (conduction band) and N0β (valence band) due to Se(4p)-V(3d) hybridization. It has been clearly evidence that the magnetic moment of V is reduced from its free space change value of 3 μB and the minor atomic magnetic moment on Zn and Se are generated.

Simultaneous acquisition of 2D and 3D solid-state NMR experiments for sequential assignment of oriented membrane protein samples.

PubMed

Gopinath, T; Mote, Kaustubh R; Veglia, Gianluigi

2015-05-01

We present a new method called DAISY (Dual Acquisition orIented ssNMR spectroScopY) for the simultaneous acquisition of 2D and 3D oriented solid-state NMR experiments for membrane proteins reconstituted in mechanically or magnetically aligned lipid bilayers. DAISY utilizes dual acquisition of sine and cosine dipolar or chemical shift coherences and long living (15)N longitudinal polarization to obtain two multi-dimensional spectra, simultaneously. In these new experiments, the first acquisition gives the polarization inversion spin exchange at the magic angle (PISEMA) or heteronuclear correlation (HETCOR) spectra, the second acquisition gives PISEMA-mixing or HETCOR-mixing spectra, where the mixing element enables inter-residue correlations through (15)N-(15)N homonuclear polarization transfer. The analysis of the two 2D spectra (first and second acquisitions) enables one to distinguish (15)N-(15)N inter-residue correlations for sequential assignment of membrane proteins. DAISY can be implemented in 3D experiments that include the polarization inversion spin exchange at magic angle via I spin coherence (PISEMAI) sequence, as we show for the simultaneous acquisition of 3D PISEMAI-HETCOR and 3D PISEMAI-HETCOR-mixing experiments.

Transverse spin correlations of the random transverse-field Ising model

NASA Astrophysics Data System (ADS)

Iglói, Ferenc; Kovács, István A.

2018-03-01

The critical behavior of the random transverse-field Ising model in finite-dimensional lattices is governed by infinite disorder fixed points, several properties of which have already been calculated by the use of the strong disorder renormalization-group (SDRG) method. Here we extend these studies and calculate the connected transverse-spin correlation function by a numerical implementation of the SDRG method in d =1 ,2 , and 3 dimensions. At the critical point an algebraic decay of the form ˜r-ηt is found, with a decay exponent being approximately ηt≈2 +2 d . In d =1 the results are related to dimer-dimer correlations in the random antiferromagnetic X X chain and have been tested by numerical calculations using free-fermionic techniques.

Two-particle microrheology of quasi-2D viscous systems.

PubMed

Prasad, V; Koehler, S A; Weeks, Eric R

2006-10-27

We study the spatially correlated motions of colloidal particles in a quasi-2D system (human serum albumin protein molecules at an air-water interface) for different surface viscosities eta s. We observe a transition in the behavior of the correlated motion, from 2D interface dominated at high eta s to bulk fluid dependent at low eta s. The correlated motions can be scaled onto a master curve which captures the features of this transition. This master curve also characterizes the spatial dependence of the flow field of a viscous interface in response to a force. The scale factors used for the master curve allow for the calculation of the surface viscosity eta s that can be compared to one-particle measurements.

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

Liang, X; Li, Z; Zheng, D

Purpose: In the context of evaluating dosimetric impacts of a variety of uncertainties involved in HDR Tandem-and-Ovoid treatment, to study the correlations between conventional point doses and 3D volumetric doses. Methods: For 5 cervical cancer patients treated with HDR T&O, 150 plans were retrospectively created to study dosimetric impacts of the following uncertainties: (1) inter-fractional applicator displacement between two treatment fractions within a single insertion by applying Fraction#1 plan to Fraction#2 CT; (2) positional dwell error simulated from −5mm to 5mm in 1mm steps; (3) simulated temporal dwell error of 0.05s, 0.1s, 0.5s, and 1s. The original plans were basedmore » on point dose prescription, from which the volume covered by the prescription dose was generated as the pseudo target volume to study the 3D target dose effect. OARs were contoured. The point and volumetric dose errors were calculated by taking the differences between original and simulated plans. The correlations between the point and volumetric dose errors were analyzed. Results: For the most clinically relevant positional dwell uncertainty of 1mm, temporal uncertainty of 0.05s, and inter-fractional applicator displacement within the same insertion, the mean target D90 and V100 deviation were within 1%. Among these uncertainties, the applicator displacement showed the largest potential target coverage impact (2.6% on D90) as well as the OAR dose impact (2.5% and 3.4% on bladder D2cc and rectum D2cc). The Spearman correlation analysis shows a correlation coefficient of 0.43 with a p-value of 0.11 between target D90 coverage and H point dose. Conclusion: With the most clinically relevant positional and temporal dwell uncertainties and patient interfractional applicator displacement within the same insertion, the dose error is within clinical acceptable range. The lack of correlation between H point and 3D volumetric dose errors is a motivator for the use of 3D treatment planning in cervical HDR brachytherapy.« less

Fe-H/D stretching and bending modes in nuclear resonant vibrational, Raman and infrared spectroscopies: Comparisons of density functional theory and experiment

PubMed Central

Pelmenschikov, Vladimir; Guo, Yisong; Wang, Hongxin; Cramer, Stephen P.; Case, David A.

2010-01-01

Infrared, Raman, and nuclear resonant vibrational (NRVS) spectroscopies have been used to address the Fe-H bonding in trans-Fe(H)(CO) iron hydride compound, Fe(H)(CO)(dppe)2, dppe = 1,2-bis(diphenylphosphino)ethane. H and D isotopomers of the compound, with the selective substitution at the metal-coordinated hydrogen, have been considered in order to address the Fe-H/D stretching and bending modes. Experimental results are compared to the normal mode analysis by the density functional theory (DFT). The results are that (i) the IR spectrum does not clearly show Fe–H stretching or bending modes; (ii) Fe–H stretching modes are clear but weak in the Raman spectrum, and Fe–H bending modes are weak; (iii) NRVS 57Fe spectroscopy resolves Fe-H bending clearly, but Fe–H or Fe–D stretching is above its experimentally resolved frequency range. DFT caclulations (with no scaling of frequencies) show intensities and peak locations that allow unambigous correlations between observed and calculated features, with frequency errors generally less than 15 cm−1. Prospects for using these techniques to unravel vibrational modes of protein active sites are discussed. PMID:21322496

Nonequilibrium dynamical mean-field theory

NASA Astrophysics Data System (ADS)

Freericks, James

2007-03-01

Dynamical mean-field theory (DMFT) is establishing itself as one of the most powerful approaches to the quantum many-body problem in strongly correlated electron materials. Recently, the formalism has been generalized to study nonequilibrium problems [1,2], such as the evolution of Bloch oscillations in a material that changes from a diffusive metal to a Mott insulator [2,3]. Using a real-time formalism on the Kadanoff-Baym-Keldysh contour, the DMFT algorithm can be generalized to the case of systems that are not time-translation invariant. The computational algorithm has a parallel implementation with essentially a linear scale up when running on thousands of processors. Results on the decay of Bloch oscillations, their change of character within the Mott insulator, and movies on how electrons redistribute themselves due to their response to an external electrical field will be presented. In addition to solid-state applications, this work also applies to the behavior of mixtures of light and heavy cold atoms in optical lattices. [1] V. M. Turkowski and J. K. Freericks, Spectral moment sum rules for strongly correlated electrons in time-dependent electric fields, Phys. Rev. B 075108 (2006); Erratum, Phys. Rev. B 73, 209902(E) (2006). [2] J. K. Freericks, V. M. Turkowski , and V. Zlati'c, Nonlinear response of strongly correlated materials to large electric fields, in Proceedings of the HPCMP Users Group Conference 2006, Denver, CO, June 26--29, 2006 edited by D. E. Post (IEEE Computer Society, Los Alamitos, CA, 2006), to appear. [3] J. K. Freericks, V. M. Turkowski, and V. Zlati'c, Nonequilibrium dynamical mean-field theory, submitted to Phys. Rev. Lett. cond-mat//0607053.

Variational model for one-dimensional quantum magnets

NASA Astrophysics Data System (ADS)

Kudasov, Yu. B.; Kozabaranov, R. V.

2018-04-01

A new variational technique for investigation of the ground state and correlation functions in 1D quantum magnets is proposed. A spin Hamiltonian is reduced to a fermionic representation by the Jordan-Wigner transformation. The ground state is described by a new non-local trial wave function, and the total energy is calculated in an analytic form as a function of two variational parameters. This approach is demonstrated with an example of the XXZ-chain of spin-1/2 under a staggered magnetic field. Generalizations and applications of the variational technique for low-dimensional magnetic systems are discussed.

3D reconstruction of a carotid bifurcation from 2D transversal ultrasound images.

PubMed

Yeom, Eunseop; Nam, Kweon-Ho; Jin, Changzhu; Paeng, Dong-Guk; Lee, Sang-Joon

2014-12-01

Visualizing and analyzing the morphological structure of carotid bifurcations are important for understanding the etiology of carotid atherosclerosis, which is a major cause of stroke and transient ischemic attack. For delineation of vasculatures in the carotid artery, ultrasound examinations have been widely employed because of a noninvasive procedure without ionizing radiation. However, conventional 2D ultrasound imaging has technical limitations in observing the complicated 3D shapes and asymmetric vasodilation of bifurcations. This study aims to propose image-processing techniques for better 3D reconstruction of a carotid bifurcation in a rat by using 2D cross-sectional ultrasound images. A high-resolution ultrasound imaging system with a probe centered at 40MHz was employed to obtain 2D transversal images. The lumen boundaries in each transverse ultrasound image were detected by using three different techniques; an ellipse-fitting, a correlation mapping to visualize the decorrelation of blood flow, and the ellipse-fitting on the correlation map. When the results are compared, the third technique provides relatively good boundary extraction. The incomplete boundaries of arterial lumen caused by acoustic artifacts are somewhat resolved by adopting the correlation mapping and the distortion in the boundary detection near the bifurcation apex was largely reduced by using the ellipse-fitting technique. The 3D lumen geometry of a carotid artery was obtained by volumetric rendering of several 2D slices. For the 3D vasodilatation of the carotid bifurcation, lumen geometries at the contraction and expansion states were simultaneously depicted at various view angles. The present 3D reconstruction methods would be useful for efficient extraction and construction of the 3D lumen geometries of carotid bifurcations from 2D ultrasound images. Copyright © 2014 Elsevier B.V. All rights reserved.

Aspects of Scale Invariance in Physics and Biology

NASA Astrophysics Data System (ADS)

Alba, Vasyl

We study three systems that have scale invariance. The first system is a conformal field theory in d > 3 dimensions. We prove that if there is a unique stress-energy tensor and at least one higher-spin conserved current in the theory, then the correlation functions of the stress-energy tensors and the conserved currents of higher-spin must coincide with one of the following possibilities: a) a theory of n free bosons, b) a theory of n free fermions or c) a theory of n (d-2)/2-forms. The second system is the primordial gravitational wave background in a theory with inflation. We show that the scale invariant spectrum of primordial gravitational waves is isotropic only in the zero-order approximation, and it gets a small correction due to the primordial scalar fluctuations. When anisotropy is measured experimentally, our result will allow us to distinguish between different inflationary models. The third system is a biological system. The question we are asking is whether there is some simplicity or universality underlying the complexities of natural animal behavior. We use the walking fruit fly (Drosophila melanogaster) as a model system. Based on the result that unsupervised flies' behaviors can be categorized into one hundred twenty-two discrete states (stereotyped movements), which all individuals from a single species visit repeatedly, we demonstrated that the sequences of states are strongly non-Markovian. In particular, correlations persist for an order of magnitude longer than expected from a model of random state-to-state transitions. The correlation function has a power-law decay, which is a hint of some kind of criticality in the system. We develop a generalization of the information bottleneck method that allows us to cluster these states into a small number of clusters. This more compact description preserves a lot of temporal correlation. We found that it is enough to use a two-cluster representation of the data to capture long-range correlations, which opens a way for a more quantitative description of the system. Usage of the maximal entropy method allowed us to find a description that closely resembles a famous inverse-square Ising model in 1d in a small magnetic field.

Inhomogeneity induced and appropriately parameterized semilocal exchange and correlation energy functionals in two-dimensions.

PubMed

Patra, Abhilash; Jana, Subrata; Samal, Prasanjit

2018-04-07

The construction of meta generalized gradient approximations based on the density matrix expansion (DME) is considered as one of the most accurate techniques to design semilocal exchange energy functionals in two-dimensional density functional formalism. The exchange holes modeled using DME possess unique features that make it a superior entity. Parameterized semilocal exchange energy functionals based on the DME are proposed. The use of different forms of the momentum and flexible parameters is to subsume the non-uniform effects of the density in the newly constructed semilocal functionals. In addition to the exchange functionals, a suitable correlation functional is also constructed by working upon the local correlation functional developed for 2D homogeneous electron gas. The non-local effects are induced into the correlation functional by a parametric form of one of the newly constructed exchange energy functionals. The proposed functionals are applied to the parabolic quantum dots with a varying number of confined electrons and the confinement strength. The results obtained with the aforementioned functionals are quite satisfactory, which indicates why these are suitable for two-dimensional quantum systems.

Inhomogeneity induced and appropriately parameterized semilocal exchange and correlation energy functionals in two-dimensions

NASA Astrophysics Data System (ADS)

Patra, Abhilash; Jana, Subrata; Samal, Prasanjit

2018-04-01

The construction of meta generalized gradient approximations based on the density matrix expansion (DME) is considered as one of the most accurate techniques to design semilocal exchange energy functionals in two-dimensional density functional formalism. The exchange holes modeled using DME possess unique features that make it a superior entity. Parameterized semilocal exchange energy functionals based on the DME are proposed. The use of different forms of the momentum and flexible parameters is to subsume the non-uniform effects of the density in the newly constructed semilocal functionals. In addition to the exchange functionals, a suitable correlation functional is also constructed by working upon the local correlation functional developed for 2D homogeneous electron gas. The non-local effects are induced into the correlation functional by a parametric form of one of the newly constructed exchange energy functionals. The proposed functionals are applied to the parabolic quantum dots with a varying number of confined electrons and the confinement strength. The results obtained with the aforementioned functionals are quite satisfactory, which indicates why these are suitable for two-dimensional quantum systems.

Two-point correlation function in systems with van der Waals type interaction

NASA Astrophysics Data System (ADS)

Dantchev, D.

2001-09-01

The behavior of the bulk two-point correlation function G( r; T| d ) in d-dimensional system with van der Waals type interactions is investigated and its consequences on the finite-size scaling properties of the susceptibility in such finite systems with periodic boundary conditions is discussed within mean-spherical model which is an example of Ornstein and Zernike type theory. The interaction is supposed to decay at large distances r as r - (d + σ), with 2 < d < 4, 2 < σ < 4 and d + σ≤6. It is shown that G( r; T| d ) decays as r - (d - 2) for 1 ≪ r≪ξ, exponentially for ξ≪ r≪ r *, where r * = (σ - 2)ξlnξ, and again in a power law as r - (d + σ) for r≫ r *. The analytical form of the leading-order scaling function of G( r; T| d ) in any of these regimes is derived.

Comparison of 3-D Multi-Lag Cross-Correlation and Speckle Brightness Aberration Correction Algorithms on Static and Moving Targets

PubMed Central

Ivancevich, Nikolas M.; Dahl, Jeremy J.; Smith, Stephen W.

2010-01-01

Phase correction has the potential to increase the image quality of 3-D ultrasound, especially transcranial ultrasound. We implemented and compared 2 algorithms for aberration correction, multi-lag cross-correlation and speckle brightness, using static and moving targets. We corrected three 75-ns rms electronic aberrators with full-width at half-maximum (FWHM) auto-correlation lengths of 1.35, 2.7, and 5.4 mm. Cross-correlation proved the better algorithm at 2.7 and 5.4 mm correlation lengths (P < 0.05). Static cross-correlation performed better than moving-target cross-correlation at the 2.7 mm correlation length (P < 0.05). Finally, we compared the static and moving-target cross-correlation on a flow phantom with a skull casting aberrator. Using signal from static targets, the correction resulted in an average contrast increase of 22.2%, compared with 13.2% using signal from moving targets. The contrast-to-noise ratio (CNR) increased by 20.5% and 12.8% using static and moving targets, respectively. Doppler signal strength increased by 5.6% and 4.9% for the static and moving-targets methods, respectively. PMID:19942503

Comparison of 3-D multi-lag cross- correlation and speckle brightness aberration correction algorithms on static and moving targets.

PubMed

Ivancevich, Nikolas M; Dahl, Jeremy J; Smith, Stephen W

2009-10-01

Phase correction has the potential to increase the image quality of 3-D ultrasound, especially transcranial ultrasound. We implemented and compared 2 algorithms for aberration correction, multi-lag cross-correlation and speckle brightness, using static and moving targets. We corrected three 75-ns rms electronic aberrators with full-width at half-maximum (FWHM) auto-correlation lengths of 1.35, 2.7, and 5.4 mm. Cross-correlation proved the better algorithm at 2.7 and 5.4 mm correlation lengths (P < 0.05). Static cross-correlation performed better than moving-target cross-correlation at the 2.7 mm correlation length (P < 0.05). Finally, we compared the static and moving-target cross-correlation on a flow phantom with a skull casting aberrator. Using signal from static targets, the correction resulted in an average contrast increase of 22.2%, compared with 13.2% using signal from moving targets. The contrast-to-noise ratio (CNR) increased by 20.5% and 12.8% using static and moving targets, respectively. Doppler signal strength increased by 5.6% and 4.9% for the static and moving-targets methods, respectively.

SU-E-QI-17: Dependence of 3D/4D PET Quantitative Image Features On Noise

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

Oliver, J; Budzevich, M; Zhang, G

2014-06-15

Purpose: Quantitative imaging is a fast evolving discipline where a large number of features are extracted from images; i.e., radiomics. Some features have been shown to have diagnostic, prognostic and predictive value. However, they are sensitive to acquisition and processing factors; e.g., noise. In this study noise was added to positron emission tomography (PET) images to determine how features were affected by noise. Methods: Three levels of Gaussian noise were added to 8 lung cancer patients PET images acquired in 3D mode (static) and using respiratory tracking (4D); for the latter images from one of 10 phases were used. Amore » total of 62 features: 14 shape, 19 intensity (1stO), 18 GLCM textures (2ndO; from grey level co-occurrence matrices) and 11 RLM textures (2ndO; from run-length matrices) features were extracted from segmented tumors. Dimensions of GLCM were 256×256, calculated using 3D images with a step size of 1 voxel in 13 directions. Grey levels were binned into 256 levels for RLM and features were calculated in all 13 directions. Results: Feature variation generally increased with noise. Shape features were the most stable while RLM were the most unstable. Intensity and GLCM features performed well; the latter being more robust. The most stable 1stO features were compactness, maximum and minimum length, standard deviation, root-mean-squared, I30, V10-V90, and entropy. The most stable 2ndO features were entropy, sum-average, sum-entropy, difference-average, difference-variance, difference-entropy, information-correlation-2, short-run-emphasis, long-run-emphasis, and run-percentage. In general, features computed from images from one of the phases of 4D scans were more stable than from 3D scans. Conclusion: This study shows the need to characterize image features carefully before they are used in research and medical applications. It also shows that the performance of features, and thereby feature selection, may be assessed in part by noise analysis.« less

A Novel Approach to Estimating Nitrous Oxide Emissions during Wetting Events from Single-Timepoint Flux Measurements.

PubMed

Davis, Brian W; Needelman, Brian A; Cavigelli, Michel A; Yarwood, Stephanie A; Maul, Jude E; Bagley, Gwendolyn A; Mirsky, Steven B

2017-03-01

Precipitation and irrigation induce pulses of NO emissions in agricultural soils, but the magnitude, duration, and timing of these pulses remain uncertain. This uncertainty makes it difficult to accurately extrapolate emissions from unmeasured time periods between chamber sampling events. Therefore, we developed a modeling protocol to predict NO emissions from data collected daily for 7 d after wetting events. Within a cover crop-based corn ( L.) production system in Beltsville, MD, we conducted the 7-d time series during four time periods representing a range of corn growth stages in 2013 and 2014. Treatments included mixtures and monocultures of grass and legume cover crops that were fertilized with pelletized poultry litter or urea-ammonium nitrate solution (9-276 kg N ha). Most fluxes did not exhibit the expected exponential decay over time (82%); therefore, cumulative emissions were calculated using trapezoidal integration over 7 d after the wetting event. Cumulative 7-d emissions were well correlated with single point gas fluxes on the second day after a wetting event using a generalized linear mixed model (ln[emissions] = 0.809∙ln[flux] + 2.47). Soil chemical covariates before or after a wetting event were weakly associated with cumulative emissions. The ratio of dissolved organic C to total inorganic N was negatively correlated with cumulative emissions ( = 0.23-0.29), whereas nitrate was positively correlated with cumulative emissions ( = 0.23-0.33). Our model is an innovative approach that is calibrated using site-specific time series data, which may then be used to estimate short-term NO emissions after wetting events using only a single flux measurement. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Health-related quality of life associated with bullying and aggression: a cross-sectional study in English secondary schools.

PubMed

Fantaguzzi, Catherine; Allen, Elizabeth; Miners, Alec; Christie, Deborah; Opondo, Charles; Sadique, Zia; Fletcher, Adam; Grieve, Richard; Bonell, Chris; Viner, Russell M; Legood, Rosa

2018-06-01

Associations between adolescent health-related quality of life (HRQoL), bullying, and aggression are not well understood. We used baseline data from a large-cluster randomized school trial to study the relationship between HRQoL, bullying experience, and other demographic factors. Cross-sectional self-reported questionnaires collected pre-randomization from the on-going INCLUSIVE trial. The questionnaires were completed in the classroom. The Gatehouse Bullying Scale measured bullying victimization and the Edinburgh Study of Youth Transitions and Crime school misbehavior subscale (ESYTC) measured aggressive behaviors. HRQoL was assessed using the Child Health Utility 9 Dimensions (CHU-9D) and general quality of life using the Pediatric Quality of Life Inventory (PedsQL). Participants were a cohort of year 7 students (age 11-12 years) from 40 state secondary schools in England. Descriptive statistics for the CHU-9D and PedsQL were calculated using standard methods with tests for differences in median scores by sex assessed using quantile regression. Correlation between HRQoL measures was conducted using Spearman's rank correlation coefficients. Predictors of HRQoL were identified using univariate and multiple regressions. A total of 6667 students filled out the questionnaire. The CHU-9D was correlated with the PedsQL (0.63, p < 0.001). The multivariable regression results suggest that if students were bullied frequently and upset it resulted in a decrement in CHU-9D scores of (-0.108) and fall in PedsQL score of (-16.2). The impact of the antisocial/aggressive behavior on the ESYTC scale resulted in a utility decrement of -0.004 and fall of -.5 on the PedsQL. Adolescents' involvement in bullying and aggression is a strong correlate of HRQoL. These data have important implications for the potential cost-effectiveness of reducing bullying and aggression in schools.

Measuring the Sensitivity and Construct Validity of 6 Utility Instruments in 7 Disease Areas.

PubMed

Richardson, Jeff; Iezzi, Angelo; Khan, Munir A; Chen, Gang; Maxwell, Aimee

2016-02-01

Health services that affect quality of life (QoL) are increasingly evaluated using cost utility analyses (CUA). These commonly employ one of a small number of multiattribute utility instruments (MAUI) to assess the effects of the health service on utility. However, the MAUI differ significantly, and the choice of instrument may alter the outcome of an evaluation. The present article has 2 objectives: 1) to compare the results of 3 measures of the sensitivity of 6 MAUI and the results of 6 tests of construct validity in 7 disease areas and 2) to rank the MAUI by each of the test results in each disease area and by an overall composite index constructed from the tests. Patients and the general public were administered a battery of instruments, which included the 6 MAUI, disease-specific QoL instruments (DSI), and 6 other comparator instruments. In each disease area, instrument sensitivity was measured 3 ways: by the unadjusted mean difference in utility between public and patient groups, by the value of the effect size, and by the correlation between MAUI and DSI scores. Content and convergent validity were tested by comparison of MAUI utilities and scores from the 6 comparator instruments. These included 2 measures of health state preferences, measures of subjective well-being and capabilities, and generic measures of physical and mental QoL derived from the SF-36. The apparent sensitivity of instruments varied significantly with the measurement method and by disease area. Validation test results varied with the comparator instruments. Notwithstanding this variability, the 15D, AQoL-8D, and the SF-6D generally achieved better test results than the QWB and EQ-5D-5L. © The Author(s) 2015.

Validity and reliability of three commonly used quality of life measures in a large European population of coronary heart disease patients.

PubMed

De Smedt, Delphine; Clays, Els; Doyle, Frank; Kotseva, Kornelia; Prugger, Christof; Pająk, Andrzej; Jennings, Catriona; Wood, David; De Bacquer, Dirk

2013-09-01

To investigate the validity and reliability of the EuroQol-5D (EQ-5D), the 12-item Short-Form Health Survey (SF-12v2), and the Hospital Anxiety and Depression Scale (HADS) in a stable coronary population. Cross-sectional study EUROASPIRE III. Quality of life data (QoL) were available on 8745 patients hospitalized for coronary artery bypass graft (CABG), percutaneous coronary intervention (PCI), acute myocardial infarction (AMI), or myocardial ischemia. They were interviewed and examined at least 6 months after their hospital admission. Reliability and validity of the 3 instruments were tested. Internal consistency, and discriminative, convergent, criterion and construct validity were assessed. Cronbach's alpha indicated good internal consistency for all measures (0.73 to 0.87). Discriminative validity analyses confirmed significant QoL differences between known groups: age, gender, educational level. In addition, all hypothesized correlations between QoL constructs (convergent validity) and items (criterion validity) were confirmed with significant correlations. Confirmatory factor analyses indicated good construct validity for HADS and SF-12v2. On country-specific level, results were roughly similar. The EQ-5D as well as the SF-12v2 and the HADS are reliable and valid instruments for use in a stable coronary population, both on aggregate European level and on country-specific level. However, our results must be generalized with caution, because EUROASPIRE III patients might not be representative for all patients with stable coronary heart disease. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Converting Parkinson-Specific Scores into Health State Utilities to Assess Cost-Utility Analysis.

PubMed

Chen, Gang; Garcia-Gordillo, Miguel A; Collado-Mateo, Daniel; Del Pozo-Cruz, Borja; Adsuar, José C; Cordero-Ferrera, José Manuel; Abellán-Perpiñán, José María; Sánchez-Martínez, Fernando Ignacio

2018-06-07

The aim of this study was to compare the Parkinson's Disease Questionnaire-8 (PDQ-8) with three multi-attribute utility (MAU) instruments (EQ-5D-3L, EQ-5D-5L, and 15D) and to develop mapping algorithms that could be used to transform PDQ-8 scores into MAU scores. A cross-sectional study was conducted. A final sample of 228 evaluable patients was included in the analyses. Sociodemographic and clinical data were also collected. Two EQ-5D questionnaires were scored using Spanish tariffs. Two models and three statistical techniques were used to estimate each model in the direct mapping framework for all three MAU instruments, including the most widely used ordinary least squares (OLS), the robust MM-estimator, and the generalized linear model (GLM). For both EQ-5D-3L and EQ-5D-5L, indirect response mapping based on an ordered logit model was also conducted. Three goodness-of-fit tests were employed to compare the models: the mean absolute error (MAE), the root-mean-square error (RMSE), and the intra-class correlation coefficient (ICC) between the predicted and observed utilities. Health state utility scores ranged from 0.61 (EQ-5D-3L) to 0.74 (15D). The mean PDQ-8 score was 27.51. The correlation between overall PDQ-8 score and each MAU instrument ranged from - 0.729 (EQ-5D-5L) to - 0.752 (EQ-5D-3L). A mapping algorithm based on PDQ-8 items had better performance than using the overall score. For the two EQ-5D questionnaires, in general, the indirect mapping approach had comparable or even better performance than direct mapping based on MAE. Mapping algorithms developed in this study enable the estimation of utility values from the PDQ-8. The indirect mapping equations reported for two EQ-5D questionnaires will further facilitate the calculation of EQ-5D utility scores using other country-specific tariffs.

Hypovitaminosis D in obese children and adolescents: relationship with adiposity, insulin sensitivity, ethnicity, and season.

PubMed

Alemzadeh, Ramin; Kichler, Jessica; Babar, Ghufran; Calhoun, Mariaelena

2008-02-01

Low 25-hydroxyvitamin D (25[OH] D) results in hyperparathyroidism and is among the endocrine derangements of adult obesity. There are differing recommendations on defining low 25(OH) D: hypovitaminosis D (serum 25[OH] D concentration <75 nmol/L) and vitamin D deficiency (serum 25[OH] D concentration <50 nmol/L). We sought to evaluate the prevalence of low levels of 25(OH) D by examining hypovitaminosis D (<75 nmol/L), vitamin D sufficiency (> or =75 nmol/L), vitamin D insufficiency (50-74.9 nmol/L), and vitamin D deficiency (<50 nmol/L) in pediatric obesity and the relationship to other calciotropic hormones and adiposity. Serum 25(OH) D, intact parathyroid hormone (iPTH), ionized calcium, glucose, and insulin levels along with hemoglobin A(1c) (HbA(1c)) and quantitative insulin sensitivity check index (QUICKI) were determined in 127 subjects aged 13.0 +/- 3.0 years (49 Caucasian [C], 39 Hispanic [H], and 39 African American [AA]; 61.2% female; body mass index 36.4 +/- 8.1 kg/m(2)) during fall/winter (F/W) and spring/summer (S/S). Body composition was determined by bioelectrical impedance. Hypovitaminosis D was present in 74% of the cohort, but was more prevalent in the H (76.9%, P < .05) and AA (87.2%, P < .05) groups than in the C group (59.1%). Hypovitaminosis D corresponded to decreased vitamin D intake (P < .005) and was more prevalent in F/W than S/S (98.4% vs 49.2, P < .01). Vitamin D deficiency was identified in 32.3% of the entire cohort and was more prevalent in the H (43.6%, P < .0001) and AA (48.7%, P < .0001) groups than in the C group (10.2%) associated with decreased vitamin D intake (P < .0001). Vitamin D insufficiency was present in 41.7% of the cohort, with similar prevalence among C (48.9%), H (33.3%), and AA (38.5%). Vitamin D insufficiency corresponded to decreased vitamin D intake (P < .005), with similar prevalence in F/W and S/S (45.3% vs 38.1%), whereas vitamin D deficiency was not only accompanied by decreased vitamin D intake (P < .0001) but was more prevalent in F/W than S/S (53.1% vs 11.1%, P < .0001). Serum 25(OH) D and iPTH (r = -0.41, P < .0001) levels were negatively correlated without seasonal and ethnic/racial influences. Hypovitaminosis D and vitamin D-deficient groups had higher body mass index, fat mass (FM), and iPTH, but had lower QUICKI than vitamin D-sufficient group (P < .01). Whereas FM was negatively correlated with 25(OH) D (r = -0.40, P < .0001), it was positively correlated with iPTH (r = 0.46, P < .0001) without seasonal and racial/ethnic influences. Serum 25(OH) D was also positively correlated with QUICKI (r = 0.24, P < .01), but was inversely correlated with HbA(1c) (r = -0.23, P < .01). Hypovitaminosis D was identified in 74% of obese subjects, whereas vitamin D deficiency was observed in 32.3% of our cohort. Vitamin D status was influenced by vitamin D intake, season, ethnicity/race, and adiposity. Interrelationships between 25(OH) D, iPTH, and FM were not influenced by season and race/ethnicity. Furthermore, serum 25(OH) D was positively correlated with insulin sensitivity, which was FM mediated, but negatively correlated with HbA(1c), implying that obese children and adolescents with low vitamin D status may be at increased risk of developing impaired glucose metabolism independent of body adiposity. Additional studies are needed to evaluate the underlying mechanisms.

Spin-Polarized Scanning Tunneling Microscope for Atomic-Scale Studies of Spin Transport, Spin Relaxation, and Magnetism in Graphene

DTIC Science & Technology

2017-11-09

to correlate the atomic-scale magnetism and spin density with the macroscopic spin transport properties of 2D materials. This is a long-term effort...devices, our goal is to correlate the atomic-scale magnetism and spin density with the macroscopic spin transport properties of 2D materials. This is a... correlate the change in transport with the atomic structure of hydrogen-doped graphene, we subsequently use the STM to investigate the graphene

Metal Thio- and Selenophosphates as Multifunctional van der Waals Layered Materials.

PubMed

Susner, Michael A; Chyasnavichyus, Marius; McGuire, Michael A; Ganesh, Panchapakesan; Maksymovych, Petro

2017-10-01

Since the discovery of Dirac physics in graphene, research in 2D materials has exploded with the aim of finding new materials and harnessing their unique and tunable electronic and optical properties. The follow-on work on 2D dielectrics and semiconductors has led to the emergence and development of hexagonal boron nitride, black phosphorus, and transition metal disulfides. However, the spectrum of good insulating materials is still very narrow. Likewise, 2D materials exhibiting correlated phenomena such as superconductivity, magnetism, and ferroelectricity have yet to be developed or discovered. These properties will significantly enrich the spectrum of functional 2D materials, particularly in the case of high phase-transition temperatures. They will also advance a fascinating fundamental frontier of size and proximity effects on correlated ground states. Here, a broad family of layered metal thio(seleno)phosphate materials that are moderate- to wide-bandgap semiconductors with incipient ionic conductivity and a host of ferroic properties are reviewed. It is argued that this material class has the potential to merge the sought-after properties of complex oxides with electronic functions of 2D and quasi-2D electronic materials, as well as to create new avenues for both applied and fundamental materials research in structural and magnetic correlations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ovarian morphology in polycystic ovary syndrome: estimates from 2D and 3D ultrasound and magnetic resonance imaging and their correlation to anti-Müllerian hormone.

PubMed

Nylander, Malin; Frøssing, Signe; Bjerre, Anne H; Chabanova, Elizaveta; Clausen, Helle V; Faber, Jens; Skouby, Sven O

2017-08-01

Background Due to improved ultrasound scanners, new three-dimensional (3D) modalities, and novel Anti-Müllerian hormone (AMH)-assays, the ultrasound criteria for polycystic ovarian morphology are under debate and the appropriate thresholds are often requested. Purpose To quantify the differences in estimates of ovarian volume and antral follicle count (AFC) from two-dimensional (2D) and 3D transvaginal ultrasound (TVUS) and magnetic resonance imaging (MRI). Material and Methods A cross-sectional study on 66 overweight women with polycystic ovary syndrome (PCOS) according to Rotterdam criteria. Ovarian volume and AFC were estimated from MRI, 2D TVUS, and 3D TVUS, and serum AMH levels were assessed. Bland-Altman statistics were used for comparison. Results Participants had a median age of 29 years (age range, 19-44 years) with a mean BMI of 32.7 kg/m 2 (SD 4.5). Ovarian volume from 2D TVUS was 1.48 mL (95% confidence interval [CI], 0.94-2.03; P < 0.001) and 1.25 mL (95% CI, 0.62-1.87; P < 0.001) smaller than from 3D TVUS and MRI, respectively. AFC from 2D TVUS was 18% (95% CI, 13-23; P < 0.005) and 16% (95% CI, 6-25; P < 0.005) smaller than estimates from 3D TVUS and MRI, respectively. Correlations between AMH and AFC from 2D TVUS, 3D TVUS, and MRI were 0.67, 0.78, and 0.70, respectively ( P < 0.001 for all). Conclusion In an overweight PCOS population, 2D TVUS underestimated ovarian volume and AFC as compared with 3D TVUS and MRI. Serum AMH correlated best with AFC from 3D TVUS, followed by MRI and 2D TVUS. The advantage of 3D TVUS might be of minor clinical importance when diagnosing PCOS, but useful when the actual AFC are of interest, e.g. in fertility counseling and research.

Fermionic Approach to Weighted Hurwitz Numbers and Topological Recursion

NASA Astrophysics Data System (ADS)

Alexandrov, A.; Chapuy, G.; Eynard, B.; Harnad, J.

2017-12-01

A fermionic representation is given for all the quantities entering in the generating function approach to weighted Hurwitz numbers and topological recursion. This includes: KP and 2D Toda {τ} -functions of hypergeometric type, which serve as generating functions for weighted single and double Hurwitz numbers; the Baker function, which is expanded in an adapted basis obtained by applying the same dressing transformation to all vacuum basis elements; the multipair correlators and the multicurrent correlators. Multiplicative recursion relations and a linear differential system are deduced for the adapted bases and their duals, and a Christoffel-Darboux type formula is derived for the pair correlator. The quantum and classical spectral curves linking this theory with the topological recursion program are derived, as well as the generalized cut-and-join equations. The results are detailed for four special cases: the simple single and double Hurwitz numbers, the weakly monotone case, corresponding to signed enumeration of coverings, the strongly monotone case, corresponding to Belyi curves and the simplest version of quantum weighted Hurwitz numbers.

Fermionic Approach to Weighted Hurwitz Numbers and Topological Recursion

NASA Astrophysics Data System (ADS)

Alexandrov, A.; Chapuy, G.; Eynard, B.; Harnad, J.

2018-06-01

A fermionic representation is given for all the quantities entering in the generating function approach to weighted Hurwitz numbers and topological recursion. This includes: KP and 2 D Toda {τ} -functions of hypergeometric type, which serve as generating functions for weighted single and double Hurwitz numbers; the Baker function, which is expanded in an adapted basis obtained by applying the same dressing transformation to all vacuum basis elements; the multipair correlators and the multicurrent correlators. Multiplicative recursion relations and a linear differential system are deduced for the adapted bases and their duals, and a Christoffel-Darboux type formula is derived for the pair correlator. The quantum and classical spectral curves linking this theory with the topological recursion program are derived, as well as the generalized cut-and-join equations. The results are detailed for four special cases: the simple single and double Hurwitz numbers, the weakly monotone case, corresponding to signed enumeration of coverings, the strongly monotone case, corresponding to Belyi curves and the simplest version of quantum weighted Hurwitz numbers.

Impact of aircraft emissions on reactive nitrogen over the North Atlantic Flight Corridor region

NASA Astrophysics Data System (ADS)

Koike, M.; Kondo, Y.; Ikeda, H.; Gregory, G. L.; Anderson, B. E.; Sachse, G. W.; Blake, D. R.; Liu, S. C.; Singh, H. B.; Thompson, A. M.; Kita, K.; Zhao, Y.; Sugita, T.; Shetter, R. E.; Toriyama, N.

2000-02-01

The impact of aircraft emissions on reactive nitrogen in the upper troposphere (UT) and lowermost stratosphere (LS) was estimated using the NOy-O3 correlation obtained during the Subsonic Assessment (SASS) Ozone and Nitrogen Oxide Experiment (SONEX) carried out over the U.S. continent and North Atlantic Flight Corridor (NAFC) region in October and November 1997. To evaluate the large-scale impact, we made a reference NOy-O3 relationship in air masses, upon which aircraft emissions were considered to have little impact. For this purpose, the integrated input of NOx from aircraft into an air mass along a 10-day back trajectory (ΔNOy) was calculated based on the Abatement of Nuisance Caused by Air Traffic/European Commission (ANCAT/EC2) emission inventory. The excess NOy (dNOy) was calculated from the observed NOy and the reference NOy-O3 relationship. As a result, a weak positive correlation was found between the dNOy and ΔNOy, and dNOy and NOx/NOy values, while no positive correlation between the dNOy and CO values was found, suggesting that dNOy values can be used as a measure of the NOx input from aircraft emissions. The excess NOy values calculated from another NOy-O3 reference relationship made using in situ condensation nuclei data also agreed with these dNOy values, within the uncertainties. At the NAFC region (45°N-60°N) the median value of dNOy in the troposphere increased with altitude above 9 km and reached 70 parts per trillion by volume (pptv) (20% of NOy) at 11 km. The excess NOx was estimated to be about half of the dNOy values, corresponding to 30% of the observed NOx level. Higher dNOy values were generally found in air masses where O3 = 75-125 ppbv, suggesting a more pronounced effect around the tropopause. The median value of dNOy in the stratosphere at the NAFC region at 8.5-11.5 km was about 120 pptv. The higher dNOy values in the LS were probably due to the accumulated effect of aircraft emissions, given the long residence time of affected air in the LS. Similar dNOy values were also obtained in air masses sampled over the U.S. continent.

Exploring the squeezed three-point galaxy correlation function with generalized halo occupation distribution models

NASA Astrophysics Data System (ADS)

Yuan, Sihan; Eisenstein, Daniel J.; Garrison, Lehman H.

2018-04-01

We present the GeneRalized ANd Differentiable Halo Occupation Distribution (GRAND-HOD) routine that generalizes the standard 5 parameter halo occupation distribution model (HOD) with various halo-scale physics and assembly bias. We describe the methodology of 4 different generalizations: satellite distribution generalization, velocity bias, closest approach distance generalization, and assembly bias. We showcase the signatures of these generalizations in the 2-point correlation function (2PCF) and the squeezed 3-point correlation function (squeezed 3PCF). We identify generalized HOD prescriptions that are nearly degenerate in the projected 2PCF and demonstrate that these degeneracies are broken in the redshift-space anisotropic 2PCF and the squeezed 3PCF. We also discuss the possibility of identifying degeneracies in the anisotropic 2PCF and further demonstrate the extra constraining power of the squeezed 3PCF on galaxy-halo connection models. We find that within our current HOD framework, the anisotropic 2PCF can predict the squeezed 3PCF better than its statistical error. This implies that a discordant squeezed 3PCF measurement could falsify the particular HOD model space. Alternatively, it is possible that further generalizations of the HOD model would open opportunities for the squeezed 3PCF to provide novel parameter measurements. The GRAND-HOD Python package is publicly available at https://github.com/SandyYuan/GRAND-HOD.

32 CFR Appendix D to Part 310 - Provisions of the Privacy Act From Which a General or Specific Exemption May Be Claimed

Code of Federal Regulations, 2010 CFR

2010-07-01

... General or Specific Exemption May Be Claimed D Appendix D to Part 310 National Defense Department of.... 310, App. D Appendix D to Part 310—Provisions of the Privacy Act From Which a General or Specific Exemption May Be Claimed (See paragraph (d) of § 310.26 ) Exemptions (j)(2) (k) (1-7) Section of the Privacy...

Three-dimensional power Doppler sonography in screening for carotid artery disease.

PubMed

Keberle, M; Jenett, M; Beissert, M; Jahns, R; Haerten, R; Hahn, D

2000-01-01

Color Doppler sonography has gained considerable recognition as a noninvasive method to detect carotid artery disease and to assess the degree of carotid artery stenosis. However, results are highly operator-dependent and cannot be presented as survey images. The purpose of this study was to evaluate real-time 3-dimensional (3D) power Doppler sonography as a method for screening for atherosclerosis in the carotid arteries. We prospectively screened 75 patients for carotid artery disease using both conventional color Doppler sonography and 3D power Doppler sonography, and the results from the 2 modalities were compared. A total of 150 common carotid arteries, 150 internal carotid arteries, and 150 external carotid arteries were examined utilizing a 7.5-MHz linear-array transducer combined with tissue harmonic imaging. Color Doppler sonography detected 297 normal or atherosclerotic arteries without stenosis, 57 arteries with mild (1-49%) stenosis, 41 with moderate (50-69%) stenosis, 32 with severe (70-99%) stenosis, and 9 with occlusions. The degree of stenosis determined by color Doppler sonography correlated with that determined by 3D power Doppler sonography (r = 0.982-0.998). Moreover, there was a good correlation between the measurements for both the length of the lesion and its distance from the bulb as determined by the 3D volume surveys and by color Doppler sonography (r = 0.986). The interobserver variability rate was 3.7% +/- 0.5%. Generally, the acquisition and reconstruction of the 3D data took less than 5 minutes. 3D power Doppler sonography is easy to perform and is an accurate method in screening for atherosclerotic lesions of the carotid arteries. Moreover, it provides excellent 3D volume surveys that may be helpful in the planning of surgical treatment. Copyright 2000 John Wiley & Sons, Inc.

X-ray-diffraction study of in-plane and interlayer correlations in layered compounds AgxTiS2

NASA Astrophysics Data System (ADS)

Kuroiwa, Yoshihiro; Ohshima, Ken-Ichi; Watanabe, Yousuke

1990-12-01

X-ray measurements have been performed on the development of in-plane and interplanar correlations of intercalated Ag atoms in stage-2 and -1 AgxTiS2 single crystals. The abrupt change of the c-axis parameter for stage-2 Ag0.15TiS2 at around 250 K, due to the structural transformation of the stacking sequence, was observed, although the a-axis parameter changes continuously. Rodlike diffuse scattering parallel to c* at 1/31/3.0, 2/32/3.0, and their equivalent positions is observed for stage-2 Ag0.15TiS2 above 250 K and shows the two-dimensional (2D) feature of the disordered state. Such a diffuse rod is modulated below 250 K, with maxima appearing at every half-integer. This reveals an enhancement of the three-dimensional nature and a stacking sequence αβαβ... . By analyzing rodlike diffuse scattering at 350, 300, 280, and 250 K for stage-2 Ag0.15TiS2, the 2D short-range-order parameters were determined. By comparing the 2D short-range-order parameters with the 2D Ornstein-Zernike correlation function, it was obtained that the correlation length varies from 4.1+/-0.6 Å at 350 K to 37.1+/-1.6 Å at 250 K. These results can be interpreted with the use of the Daumas-Hérold island model. On the other hand, for stage-1 AgxTiS2, the modulation of the diffuse rod parallel to the c* axis at 1/31/3.0, 2/32/3.0, and their equivalent positions was observed at room temperature, which shows the 3D nature.

Decrease in lean body mass in men with prostate cancer receiving androgen deprivation therapy: mechanism and biomarkers.

PubMed

Hara, Noboru; Ishizaki, Fumio; Saito, Toshihiro; Nishiyama, Tsutomu; Kawasaki, Takashi; Takahashi, Kota

2013-02-01

To elucidate the mechanism of the androgen deprivation therapy (ADT)-related decrease in lean body mass (LBM). The LBM and blood samples were studied before and after 6 months of ADT in 72 patients with localized prostate cancer. The LBM was assessed using a foot-to-foot bioelectrical impedance analyzer. Before ADT, the LBM correlated with none of the serum sex steroid levels; however, it correlated closely with serum 5α-androstane-3α,17β-diol glucuronide (Spearman's rank correlation coefficient = 0.409, P = .001) and insulin-like growth factor-1 (IGF-I, Spearman's rank correlation coefficient = 0.329, P = .005). After ADT, the LBM decreased by 0.9% (P = .036), and the serum testosterone and dihydrotestosterone had decreased by 96.8% and 94.3%, respectively (P <.001 for both), and the IGF-I had increased by 11.6% (from 19.9 to 22.2 nmol/L, P = .001). The serum 1,25-dihydroxyvitamin D3 [1,25(OH)2D] levels decreased after ADT by 9.8% (from 66.2 to 59.7 pg/mL, P = .008), and the post-treatment LBM correlated inversely with 1,25(OH)2D (Spearman's rank correlation coefficient = -0.343, P = .003). The post-treatment LBM was dissociated with 5α-androstane-3α,17β-diol glucuronide and IGF-I. The pretreatment and post-treatment LBMs both correlated inversely with serum sex hormone-binding globulin (P = .024 and P = .016, respectively). The deficiency in androgen levels was suggested to be a link to the ADT-related decrease in LBM; the androgen metabolite 5α-androstane-3α,17β-diol glucuronide has a potential value for assessing the LBM in untreated men. IGF-I also promotes muscle building and is positively regulated during ADT. Sex hormone-binding globulin possibly accelerates the ADT-related decrease in LBM. Although the mechanism for the decrease in 1,25(OH)2D and its inverse correlation with LBM during ADT is unclear, 1,25(OH)2D might be a biomarker reflecting the ADT-related decrease in LBM. Copyright © 2013 Elsevier Inc. All rights reserved.

Short-range order in the quantum XXZ honeycomb lattice material BaCo2(PO4)2

NASA Astrophysics Data System (ADS)

Nair, Harikrishnan S.; Brown, J. M.; Coldren, E.; Hester, G.; Gelfand, M. P.; Podlesnyak, A.; Huang, Q.; Ross, K. A.

2018-04-01

We present observations of highly frustrated quasi-two-dimensional (2D) magnetic correlations in the honeycomb lattice layers of the Seff =1 /2 compound γ -BaCo2(PO4)2 (γ -BCPO). Specific heat shows a broad peak comprised of two weak kink features at TN 1˜6 K and TN 2˜3.5 K, the relative weights of which can be modified by sample annealing. Neutron powder diffraction measurements reveal short range quasi-2D order that is established below TN 1 and TN 2, at which two separate, incompatible, short range magnetic orders onset: commensurate antiferromagnetic correlations with correlation length ξc=60 ±2 Å (TN 1) and in quasi-2D helical domains with ξh=350 ±11 Å (TN 2). The ac magnetic susceptibility response lacks frequency dependence, ruling out spin freezing. Inelastic neutron scattering data on γ -BCPO is compared with linear spin wave theory, and two separate parameter regions of the XXZ J1-J2-J3 model with ferromagnetic nearest-neighbor exchange J1 are favored, both near regions of high classical degeneracy. High energy coherent excitations (˜10 meV) persist up to at least 40 K, suggesting strong in-plane correlations persist above TN. These data show that γ -BCPO is a rare highly frustrated, quasi-2D Seff =1 /2 honeycomb lattice material which resists long range magnetic order and spin freezing.

A high-resolution (13)C 3D CSA-CSA-CSA correlation experiment by means of magic angle turning.

PubMed

Hu, J Z; Ye, C; Pugmire, R J; Grant, D M

2000-08-01

It is shown in this paper that a previously reported 90 degrees sample flipping (13)C 2D CSA-CSA correlation experiment may be carried out alternatively by employing constant slow sample rotation about the magic angle axis and by synchronizing the read pulse to 13 of the rotor cycle. A high-resolution 3D CSA-CSA-CSA correlation experiment based on the magic angle turning technique is reported in which the conventional 90 degrees 2D CSA-CSA powder pattern for each carbon in a system containing a number of inequivalent carbons may be separated according to the isotropic chemical shift value. The technique is demonstrated on 1,2,3-trimethoxybenzene in which all of the overlapping powder patterns that cannot be segregated by the 2D CSA-CSA experiment are resolved successfully by the 3D CSA-CSA-CSA experiment, including even the two methoxy groups (M(1) and M(3)) whose isotropic shifts, confirmed by high-speed MAS, are separated by only 1 ppm. A difference of 4 ppm in the principal value component (delta(33)) between M(1) and M(3) is readily obtained. Copyright 2000 Academic Press.

Quantumness and the role of locality on quantum correlations

NASA Astrophysics Data System (ADS)

Bellomo, G.; Plastino, A.; Plastino, A. R.

2016-06-01

Quantum correlations in a physical system are usually studied with respect to a unique and fixed decomposition of the system into subsystems, without fully exploiting the rich structure of the state space. Here, we show several examples in which the consideration of different ways to decompose a physical system enhances the quantum resources and accounts for a more flexible definition of quantumness measures. Furthermore, we give a different perspective regarding how to reassess the fact that local operations play a key role in general quantumness measures that go beyond entanglement—as discordlike ones. We propose a family of measures to quantify the maximum quantumness of a given state. For the discord-based case, we present some analytical results for 2 ×d -dimensional states. Applying our definition to low-dimensional bipartite states, we show that different behaviors can be reported for separable and entangled states vis-à-vis those corresponding to the usual measures of quantum correlations. We show that there is a close link between our proposal and the criterion to witness quantum correlations based on the rank of the correlation matrix, proposed by Dakić, Vedral, and Brukner [Phys. Rev. Lett. 105, 190502 (2010), 10.1103/PhysRevLett.105.190502].

[Bezafibrate in an infant with congenital generalized lipodystrophy and severe hypertriglyceridemia].

PubMed

Araújo, Rogério Santiago; Ramos, André de Paula Silva; Borges, Máriton de Araújo Sousa

2013-11-01

Congenital generalized lipodystrophy (CGL) with severe hypertriglyceridemia in a children less than 1 year of age is associated with worse metabolic risk. We used data from patient records, as well as extensive literature research to write the manuscript. We report the case of an infant with typical phenotype of CGL and hypertriglyceridemia of 1,360 mg/dL who was treated with bezafibrate at a dose of 30 to 60 mg/day from age 11 months to 5.5 years old, with a measurement of nadir of triglycerides of 55 mg/dL. Clinical evolution and clinical laboratory tests before and after bezafibrate were carried out over 5 years and 6 months. Phenotype was classified as CGL type 2. Despite the efficient control of hypertriglyceridemia and absence of development of diabetes mellitus, the use of bezafibrate did not prevent the onset of hepatic steatosis during evolution. Hypolipidemic therapy with bezafibrate proved effective in maintaining the levels of triglycerides, cholesterol and its fractions at normal levels, and its use was not correlated with severe side effects during the described period.

Age-related changes in vertebral and iliac crest 3D bone microstructure--differences and similarities.

PubMed

Thomsen, J S; Jensen, M V; Niklassen, A S; Ebbesen, E N; Brüel, A

2015-01-01

Age-related changes of vertebra and iliac crest 3D microstructure were investigated, and we showed that they were in general similar. The 95th percentile of vertebral trabecular thickness distribution increased with age for women. Surprisingly, vertebral and iliac crest bone microstructure was only weakly correlated (r = 0.38 to 0.75), despite the overall similar age-related changes. The purposes of the study were to determine the age-related changes in iliac and vertebral bone microstructure for women and men over a large age range and to investigate the relationship between the bone microstructure at these skeletal sites. Matched sets of transiliac crest bone biopsies and lumbar vertebral body (L2) specimens from 41 women (19-96 years) and 39 men (23-95 years) were micro-computed tomography (μCT) scanned, and the 3D microstructure was quantified. For both women and men, bone volume per total volume (BV/TV), connectivity density (CD), and trabecular number (Tb.N) decreased significantly, while structure model index (SMI) and trabecular separation (Tb.Sp) increased significantly with age at either skeletal site. Vertebral trabecular thickness (Tb.Th) was independent of age for both women and men, while iliac Tb.Th decreased significantly with age for men, but not for women. In general, the vertebral and iliac age-related changes were similar. The 95th percentile of the Tb.Th distribution increased significantly with age for women but was independent of age for men at the vertebral body, while it was independent of age for either sex at the iliac crest. The Tb.Th probability density functions at the two skeletal sites became significantly more similar with age for women, but not for men. The microstructural parameters at the iliac crest and the vertebral bodies were only moderately correlated from r = 0.38 for SMI in women to r = 0.75 for Tb.Sp in men. Age-related changes in vertebral and iliac bone microstructure were in general similar. The iliac and vertebral Tb.Th distributions became more similar with age for women. Despite the overall similar age-related changes in trabecular bone microstructure, the vertebral and iliac bone microstructural measures were only weakly correlated (r = 0.38 to 0.75).

The expression status of TRX, AR, and cyclin D1 correlates with clinicopathological characteristics and ER status in breast cancer.

PubMed

Huang, Weisun; Nie, Weiwei; Zhang, Wenwen; Wang, Yanru; Zhu, Aiyu; Guan, Xiaoxiang

2016-01-01

The ER signaling pathway plays a critical role in breast cancer. ER signaling pathway-related proteins, such as TRX, AR, and cyclin D1, may have an important function in breast cancer. However, the ways that they influence breast cancer development and progression are still unclear. A total of 101 Chinese female patients diagnosed with invasive ductal breast adenocarcinoma were retrospectively enrolled in the study. The expression levels of TRX, AR, and cyclin D1 were detected by immunohistochemistry and analyzed via correlation with clinicopathological characteristics and the expression status of ER, PR, and HER2. The expression status of TRX, AR, and cyclin D1 was not associated with the patient's age, menopausal status, tumor size, or histological differentiation (P>0.05), but was positively correlated with ER and PR (P<0.001, respectively). Most (66/76, 86.8) TRX-positive patients were also HER2-positive (P=0.003). Of AR- or cyclin D1-positive patients, most had relatively earlier I-II tumor stage (P=0.005 and P=0.047, respectively) and no metastatic lymph node involvement (P=0.008 and P=0.005, respectively). TRX was found to be positively correlated with ER and PR expression, whereas it was negatively correlated with HER2 expression. In addition, we found that the positive expression of AR and cyclin D1 was correlated with lower TNM stage and fewer metastatic lymph nodes, and it was more common in ER-positive breast cancer than in the basal-like subtype. This may indicate that AR and cyclin D1 are good predictive and prognostic factors and closely interact with ER signaling pathway. Further studies will be necessary to investigate the response and clinical outcomes of treatment targeting TRX, AR, and cyclin D1.

Scaled lattice fermion fields, stability bounds, and regularity

NASA Astrophysics Data System (ADS)

O'Carroll, Michael; Faria da Veiga, Paulo A.

2018-02-01

We consider locally gauge-invariant lattice quantum field theory models with locally scaled Wilson-Fermi fields in d = 1, 2, 3, 4 spacetime dimensions. The use of scaled fermions preserves Osterwalder-Seiler positivity and the spectral content of the models (the decay rates of correlations are unchanged in the infinite lattice). In addition, it also results in less singular, more regular behavior in the continuum limit. Precisely, we treat general fermionic gauge and purely fermionic lattice models in an imaginary-time functional integral formulation. Starting with a hypercubic finite lattice Λ ⊂(aZ ) d, a ∈ (0, 1], and considering the partition function of non-Abelian and Abelian gauge models (the free fermion case is included) neglecting the pure gauge interactions, we obtain stability bounds uniformly in the lattice spacing a ∈ (0, 1]. These bounds imply, at least in the subsequential sense, the existence of the thermodynamic (Λ ↗ (aZ ) d) and the continuum (a ↘ 0) limits. Specializing to the U(1) gauge group, the known non-intersecting loop expansion for the d = 2 partition function is extended to d = 3 and the thermodynamic limit of the free energy is shown to exist with a bound independent of a ∈ (0, 1]. In the case of scaled free Fermi fields (corresponding to a trivial gauge group with only the identity element), spectral representations are obtained for the partition function, free energy, and correlations. The thermodynamic and continuum limits of the free fermion free energy are shown to exist. The thermodynamic limit of n-point correlations also exist with bounds independent of the point locations and a ∈ (0, 1], and with no n! dependence. Also, a time-zero Hilbert-Fock space is constructed, as well as time-zero, spatially pointwise scaled fermion creation operators which are shown to be norm bounded uniformly in a ∈ (0, 1]. The use of our scaled fields since the beginning allows us to extract and isolate the singularities of the free energy when a ↘ 0.

Characterization of beta cell and incretin function in patients with MODY1 (HNF4A MODY) and MODY3 (HNF1A MODY) in a Swedish patient collection.

PubMed

Ekholm, E; Shaat, N; Holst, J J

2012-10-01

The aim of this study was to evaluate the beta cell and incretin function in patients with HNF4A and HNF1A MODY during a test meal. Clinical characteristics and biochemical data (glucose, proinsulin, insulin, C-peptide, GLP-1 and GIP) during a test meal were compared between MODY patients from eight different families. BMI-matched T2D and healthy subjects were used as two separate control groups. The early phase of insulin secretion was attenuated in HNF4A, HNF1A MODY and T2D (AUC0-30 controls: 558.2 ± 101.2, HNF4A MODY: 93.8 ± 57.0, HNF1A MODY: 170.2 ± 64.5, T2D: 211.2 ± 65.3, P < 0.01). Markedly reduced levels of proinsulin were found in HNF4A MODY compared to T2D and that tended to be so also in HNF1A MODY (HNF4A MODY: 3.7 ± 1.2, HNF1A MODY: 8.3 ± 3.8 vs. T2D: 26.6 ± 14.3). Patients with HNF4A MODY had similar total GLP-1 and GIP responses as controls (GLP-1 AUC: (control: 823.9 ± 703.8, T2D: 556.4 ± 698.2, HNF4A MODY: 1,257.0 ± 999.3, HNF1A MODY: 697.1 ± 818.4) but with a different secretion pattern. The AUC insulin during the test meal was strongly correlated with the GIP secretion (Correlation coefficient 1.0, P < 0.001). No such correlation was seen for insulin and GLP-1. Patients with HNF4A and HNF1A MODY showed an attenuated early phase of insulin secretion similar to T2Ds. AUC insulin during the test meal was strongly correlated with GIP secretion, whereas no such correlation was seen for insulin and GLP-1. Thus, GIP may be a more important factor for insulin secretion than GLP-1 in MODY patients.

Validation of the Physical Activity Scale for individuals with physical disabilities.

PubMed

van den Berg-Emons, Rita J; L'Ortye, Annemiek A; Buffart, Laurien M; Nieuwenhuijsen, Channah; Nooijen, Carla F; Bergen, Michael P; Stam, Henk J; Bussmann, Johannes B

2011-06-01

To determine the criterion validity of the Physical Activity Scale for Individuals With Physical Disabilities (PASIPD) by means of daily physical activity levels measured by using a validated accelerometry-based activity monitor in a large group of persons with a physical disability. Cross-sectional. Participants' home environment. Ambulatory and nonambulatory persons with cerebral palsy, meningomyelocele, or spinal cord injury (N=124). Not applicable. Self-reported physical activity level measured by using the PASIPD, a 2-day recall questionnaire, was correlated to objectively measured physical activity level measured by using a validated accelerometry-based activity monitor. Significant Spearman correlation coefficients between the PASIPD and activity monitor outcome measures ranged from .22 to .37. The PASIPD overestimated the duration of physical activity measured by using the activity monitor (mean ± SD, 3.9±2.9 vs 1.5±0.9h/d; P<.01). Significant correlation (ρ=-.74; P<.01) was found between average number of hours of physical activity per day measured by using the 2 methods and difference in hours between methods. This indicates larger overestimation for persons with higher activity levels. The PASIPD correlated poorly with objective measurements using an accelerometry-based activity monitor in people with a physical disability. However, similar low correlations between objective and subjective activity measurements have been found in the general population. Users of the PASIPD should be cautious about overestimating physical activity levels. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Vibrational correlation between conjugated carbonyl and diazo modes studied by single- and dual-frequency two-dimensional infrared spectroscopy

NASA Astrophysics Data System (ADS)

Maekawa, Hiroaki; Sul, Soohwan; Ge, Nien-Hui

2013-08-01

We have applied infrared three-pulse photon echo and single- and dual-frequency 2D IR spectroscopy to the ester Cdbnd O and diazo Ndbnd N stretching modes in ethyl diazoacetate (EDA), and investigated their vibrational frequency fluctuations and correlation. The two modes exhibit different vibrational dynamics and 2D lineshape, which are well simulated by frequency-frequency correlation functions (FFCFs) with two decaying components. Although the FT IR spectrum shows a single Cdbnd O band, absolute magnitude 2D IR nonrephasing spectrum displays spectral signatures supporting the presence of cis and trans conformations. The cross-peak inclined toward the anti-diagonal in the dual-frequency 2D IR spectrum, indicating that the frequency fluctuations of the two modes are anticorrelated. This behavior is attributed to anticorrelated change in the bond orders when solvent and structural fluctuations causes EDA to adopt a different mixture of the two dominant resonance structures. The effects of cross FFCF on the cross-peak line shape are discussed.

Proton-detected 3D {sup 1}H/{sup 13}C/{sup 1}H correlation experiment for structural analysis in rigid solids under ultrafast-MAS above 60 kHz

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

Zhang, Rongchun; Ramamoorthy, Ayyalusamy, E-mail: ramamoor@umich.edu; Nishiyama, Yusuke

2015-10-28

A proton-detected 3D {sup 1}H/{sup 13}C/{sup 1}H chemical shift correlation experiment is proposed for the assignment of chemical shift resonances, identification of {sup 13}C-{sup 1}H connectivities, and proximities of {sup 13}C-{sup 1}H and {sup 1}H-{sup 1}H nuclei under ultrafast magic-angle-spinning (ultrafast-MAS) conditions. Ultrafast-MAS is used to suppress all anisotropic interactions including {sup 1}H-{sup 1}H dipolar couplings, while the finite-pulse radio frequency driven dipolar recoupling (fp-RFDR) pulse sequence is used to recouple dipolar couplings among protons and the insensitive nuclei enhanced by polarization transfer technique is used to transfer magnetization between heteronuclear spins. The 3D experiment eliminates signals from non-carbon-bonded protonsmore » and non-proton-bonded carbons to enhance spectral resolution. The 2D (F1/F3) {sup 1}H/{sup 1}H and 2D {sup 13}C/{sup 1}H (F2/F3) chemical shift correlation spectra extracted from the 3D spectrum enable the identification of {sup 1}H-{sup 1}H proximity and {sup 13}C-{sup 1}H connectivity. In addition, the 2D (F1/F2) {sup 1}H/{sup 13}C chemical shift correlation spectrum, incorporated with proton magnetization exchange via the fp-RFDR recoupling of {sup 1}H-{sup 1}H dipolar couplings, enables the measurement of proximities between {sup 13}C and even the remote non-carbon-bonded protons. The 3D experiment also gives three-spin proximities of {sup 1}H-{sup 1}H-{sup 13}C chains. Experimental results obtained from powder samples of L-alanine and L-histidine ⋅ H{sub 2}O ⋅ HCl demonstrate the efficiency of the 3D experiment.« less

Correlated electron and nuclear dynamics in strong field photoionization of H(2)(+).

PubMed

Silva, R E F; Catoire, F; Rivière, P; Bachau, H; Martín, F

2013-03-15

We present a theoretical study of H(2)(+) ionization under strong IR femtosecond pulses by using a method designed to extract correlated (2D) photoelectron and proton kinetic energy spectra. The results show two distinct ionization mechanisms-tunnel and multiphoton ionization-in which electrons and nuclei do not share the energy from the field in the same way. Electrons produced in multiphoton ionization share part of their energy with the nuclei, an effect that shows up in the 2D spectra in the form of energy-conservation fringes similar to those observed in weak-field ionization of diatomic molecules. In contrast, tunneling electrons lead to fringes whose position does not depend on the proton kinetic energy. At high intensity, the two processes coexist and the 2D plots show a very rich behavior, suggesting that the correlation between electron and nuclear dynamics in strong field ionization is more complex than one would have anticipated.

MRI of the lumbar spine: comparison of 3D isotropic turbo spin-echo SPACE sequence versus conventional 2D sequences at 3.0 T.

PubMed

Lee, Sungwon; Jee, Won-Hee; Jung, Joon-Yong; Lee, So-Yeon; Ryu, Kyeung-Sik; Ha, Kee-Yong

2015-02-01

Three-dimensional (3D) fast spin-echo sequence with variable flip-angle refocusing pulse allows retrospective alignments of magnetic resonance imaging (MRI) in any desired plane. To compare isotropic 3D T2-weighted (T2W) turbo spin-echo sequence (TSE-SPACE) with standard two-dimensional (2D) T2W TSE imaging for evaluating lumbar spine pathology at 3.0 T MRI. Forty-two patients who had spine surgery for disk herniation and had 3.0 T spine MRI were included in this study. In addition to standard 2D T2W TSE imaging, sagittal 3D T2W TSE-SPACE was obtained to produce multiplanar (MPR) images. Each set of MR images from 3D T2W TSE and 2D TSE-SPACE were independently scored for the degree of lumbar neural foraminal stenosis, central spinal stenosis, and nerve compression by two reviewers. These scores were compared with operative findings and the sensitivities were evaluated by McNemar test. Inter-observer agreements and the correlation with symptoms laterality were assessed with kappa statistics. The 3D T2W TSE and 2D TSE-SPACE had similar sensitivity in detecting foraminal stenosis (78.9% versus 78.9% in 32 foramen levels), spinal stenosis (100% versus 100% in 42 spinal levels), and nerve compression (92.9% versus 81.8% in 59 spinal nerves). The inter-observer agreements (κ = 0.849 vs. 0.451 for foraminal stenosis, κ = 0.809 vs. 0.503 for spinal stenosis, and κ = 0.681 vs. 0.429 for nerve compression) and symptoms correlation (κ = 0.449 vs. κ = 0.242) were better in 3D TSE-SPACE compared to 2D TSE. 3D TSE-SPACE with oblique coronal MPR images demonstrated better inter-observer agreements compared to 3D TSE-SPACE without oblique coronal MPR images (κ = 0.930 vs. κ = 0.681). Isotropic 3D T2W TSE-SPACE at 3.0 T was comparable to 2D T2W TSE for detecting foraminal stenosis, central spinal stenosis, and nerve compression with better inter-observer agreements and symptom correlation. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.