Mean Tilt Angle Research Articles

Can Surface Flux Transport Account for the Weak Polar Field in Cycle 23?

To reproduce the weak magnetic field on the polar caps of the Sun observed during the declining phase of cycle 23 poses a challenge to surface flux transport models since this cycle has not been particularly weak. We use a well-calibrated model to evaluate the parameter changes required to obtain simulated polar fields and open flux that are consistent with the observations. We find that the low polar field of cycle 23 could be reproduced by an increase of the meridional flow by 55% in the last cycle. Alternatively, a decrease of the mean tilt angle of sunspot groups by 28% would also lead to a similarly low polar field, but cause a delay of the polar field reversals by 1.5 years in comparison to the observations.

Orientation and morphology of chloroaluminum phthalocyanine films grown by vapor deposition: Electrical field-induced molecular alignment

The electric field influence on the molecular orientation and the surface morphology of the chloroaluminum(III) phthalocyanine (AlClPc) films has been studied using polarization dependent Raman spectroscopy and atomic force microscopy. The experimental studies were supported by DFT quantum chemical computations of the AlClPc vibrational spectra and 15N isotopic shifts. The electric field of 1.4 kV mm −1 applied parallel to the substrate plane during the physical vapour deposition modified the film structure noticeable. The AlClPc molecules were aligned nearly perpendicular to the substrate surface (the mean tilt angle increased to ∼80° from ∼20° in the films grown without the electric field). The AFM images of the AlClPc films grown in the absence of electric field revealed a predominant amount of crystallites of polyhedron shape, whereas in the case of the applied electric field the surface was more ordered and consisted of the crystallites of a smoother shape.

THE ORIENTATION OF THE NUCLEAR OBSCURER OF THE ACTIVE GALACTIC NUCLEI

We examine the distribution of axis ratios of a large sample of disk galaxies hosting type 2 AGNs selected from the Sloan Digital Sky Survey and compare it with a well-defined control sample of non-active galaxies. We find them significantly different, where the type 2 AGNs show both an excess of edge-on objects and deficit of round objects. This systematical bias can not be explained by a nuclear obscurer oriented randomly with respect to the stellar disk. However, a nuclear obscurer coplanar with the stellar disk also does not fit the data very well. By assuming that the nuclear obscurer having an opening angle of ~60 degree, we find the observed axis ratio distribution can be nicely reproduced by a mean tilt angle of ~30 degree between the nuclear obscurer and the stellar disk.

Measuring the levator hiatus with axial MRI sequences: Adjusting the angle of acquisition

We aimed to compare MRI measurements of the female levator hiatus and the most caudal "levator ani" muscles between image slices in a plane axial to the body (AxB) and an axial plane parallel to the direction of the puborectalis muscle (AxPRM). We performed high-resolution, T2-weighted axial magnetic resonance imaging (in two different planes) on 20 sequentially recruited asymptomatic nulliparous women. Levator hiatus measurements were compared between the two planes. The mean tilt angle of the AxPRM slices relative to the AxB slices was 18.9° (SD 8.5) and the area of the levator hiatus was 10% greater (P=0.04) in the AxPRM plane. By rotating the acquisition plane to be parallel to the puborectalis muscle (sometimes called the plane of minimal hiatal dimensions), some of the measurements of the distal and medial pelvic floor muscles (and the hiatus defined by them) are altered. This issue is important because both MRI and 3D ultrasound are increasingly being used to evaluate the pelvic floor hiatus, and its relationship to childbirth injury and pelvic floor disorders. To make meaningful comparisons, it is important that both modalities are measuring the same thing.

Surgical Versus Functional Treatment for Acute Ruptures of the Lateral Ligament Complex of the Ankle in Young Men

Some have recommended surgical treatment of Grade-III lateral ligament injuries in very active individuals with high functional demands on the ankle. The purpose of this study was to establish whether surgery provides better long-term results than functional treatment for acute ruptures of the lateral ligaments of the ankle. Physically active Finnish men (mean age, 20.4 years) with an acute Grade-III lateral ligament rupture of the ankle were randomly allocated to surgical (n = 25) or functional (n = 26) treatment. Ligament injury was confirmed with stress radiographs. Surgical treatment comprised suture repair of the injured ligament(s) within the first week after injury. A below-the-knee plaster cast was worn for six weeks with full weight-bearing. Functional treatment consisted of the use of an Aircast ankle brace for three weeks. The main outcome measures included final follow-up examinations, calculation of an ankle score, stress radiographs, and magnetic resonance imaging scans. Fifteen (60%) of twenty-five surgically treated patients and eighteen (69%) of twenty-six functionally treated patients returned for long-term follow-up (mean duration, fourteen years). All patients in both groups had recovered their preinjury activity level and reported that they could walk and run normally. The prevalence of reinjury was one of fifteen in the surgical group and seven of eighteen in the functional treatment group (risk difference: 32%; 95% confidence interval: 6% to 58%). The mean ankle score did not differ significantly between the groups (mean difference: 8.3 points; 95% confidence interval: -0.03 to 16.6 points). Stress radiographs revealed no difference between groups with regard to the mean anterior drawer (-1 mm in the surgical group and 0 mm in the functional treatment group; mean difference: 0.7 mm; 95% confidence interval: -1.4 to 2.7 mm) or mean tilt angle (0° in both groups; mean difference: 0.1°; 95% confidence interval: -3.2° to 3.5°). Grade-II osteoarthritis was observed on magnetic resonance images of four of the fifteen surgically treated patients and in none of the eighteen functionally treated patients (risk difference: 27%; 95% confidence interval: 4% to 49%). These findings indicate that, in terms of recovery of the preinjury activity level, the long-term results of surgical treatment of acute lateral ligament rupture of the ankle correspond with those of functional treatment. Although surgery appeared to decrease the prevalence of reinjury of the lateral ligaments, there may be an increased risk for the subsequent development of osteoarthritis.

Anatomical transverse patella double tunnel reconstruction of medial patellofemoral ligament with a hamstring tendon autograft for recurrent patellar dislocation

The purpose of this study was to describe our transverse patella double tunnel technique to reconstruct the medial patellofemoral ligament (MPFL) with a hamstring tendon autograft in patients who suffered recurrent dislocation of the patella, and to evaluate the intermediate-term outcomes of reconstruction treatment. Fifty-nine consecutive knees (52 patients) with recurrent dislocation of the patella without marked predisposing anatomic abnormalities and radiographically documented moderate/severe osteochondral lesions were included in the study. Outcomes were assessed with physical and radiographic examination, the Kujala and the modified Cincinnati scores preoperatively and postoperatively at 3, 6, 12, 36, 60 and 84months. There were 19 male and 33 female patients with up to 7.1-year follow-up (mean 5.7years). The mean age was 24.3years. A comparison of preoperative scores with those obtained at most recent follow-up revealed a significant improvement for all outcomes measured: range of motion (30±2° vs. 125±5°, P<0.01), the mean Kujala scores (41.4 vs. 82.6, P<0.001), the mean modified Cincinnati scores (50.6 vs. 88.7, P<0.01), the mean congruence angle (12.2° vs. -2.4°, P<0.01) and the mean tilt angle (11.4° vs. 8.4°, P<0.05). No recurrent episodes of dislocation or subluxation were postoperatively reported, although there were seven knees with an occasional unstable feeling without redislocation. MPFL reconstruction with the double-transverse tunnels technique is safe and effective in patients of all ages, without marked predisposing anatomic abnormalities and moderate/severe osteochondral lesions, who suffered recurrent dislocation of the patella.

Gadolinium (III) ion in liquid water: Structure, dynamics, and magnetic interactions from first principles

We applied first principles molecular dynamics (MD) technique to study structure, dynamics, and magnetic interactions of the Gd(3+) aqua ion dissolved in liquid water, a prototypical system for Gd-based complexes used as contrast agents for magnetic resonance imaging. The first coordination sphere contains eight water molecules with an average Gd-O distance of 2.37 A and an average geometric arrangement close to a square antiprism. The mean tilt angle of the electric dipole vector of these water molecules is theta=145 degrees . In our picosecond time scale simulation we observe no exchange event from the first coordination sphere but only fast "wagging" motions. The second coordination sphere is well pronounced though water molecules in this sphere are subjected to large amplitude dynamic motions. The isotropic hyperfine coupling constants for the inner sphere water molecules [A(iso)((17)O(I))=0.65+/-0.03 MHz, A(iso)((1)H(I))=0.085+/-0.005 MHz] are in good agreement with experimental data and with an earlier study using classical MD. Second sphere Fermi contact hyperfine coupling constants calculated are more than one order of magnitude smaller and of opposite sign as those of the first coordination sphere. The effect of spin polarization induced by the paramagnetic Gd(3+) ion on the dipolar hyperfine interaction was found to be sizable only for the (17)O nuclei of inner sphere water molecules and has a screening character.

Synthesis of textured thin piezoelectric AlN films with a nonzero C-axis mean tilt for the fabrication of shear mode resonators

A method for the deposition of thin piezoelectric aluminum nitride (AlN) films with a nonzero c-axis mean tilt has been developed. The deposition is done in a standard reactive magnetron sputter deposition system without any hardware modifications. In essence, the method consists of a two-stage deposition process. The resulting film has a distinct tilted texture with the mean tilt of the c-axis varying roughly in the interval 28 to 32 degrees over the radius of the wafer excluding a small exclusion zone at the center of the latter. The mean tilt angle distribution over the wafer has a circular symmetry. A membrane-type shear mode thickness-excited thin film bulk acoustic resonator together with a micro-fluidic transport system has been subsequently fabricated using the two stage AlN deposition as well as standard bulk micro machining of Si. The resonator consisted of a 2-microm-thick AlN film with 200nm-thick Al top and bottom electrodes. The resonator was characterized with a network analyzer when operating in both air and water. The shear mode resonance frequency was about 1.6 GHz, the extracted device Q around 350, and the electromechanical coupling kt2 2% when the resonator was operated in air, whereas the latter two dropped down to 150 and 1.8%, respectively, when the resonator was operated in pure water.

Mosaic Structure Evolution in GaN Films with Annealing TimeGrown by Metalorganic Chemical Vapour Deposition

We investigate mosaic structure evolution of GaN filmsannealed for a long time at 800°C grown on sapphire substrates bymetalorganic chemical vapour deposition by high-resolution x-raydiffraction. The result show that residual stress in GaN films isrelaxed by generating edge-type threading dislocations (TDs) instead ofscrew-type TDs. Compared to as-grown GaN films, the annealed ones havelarger mean twist angles corresponding to higher density of edge-typeTDs but smaller mean tilt angles corresponding to lower density ofscrew-type TDs films. Due to the increased edge-type TD density, thelateral coherence lengths of the annealed GaN films also decrease. Theresults obtained from chemical etching experiment and grazing-incidencex-ray diffraction (GIXRD) also support the proposed structureevolution.

Investigation of Solid Surfaces Modified by Langmuir−Blodgett Monolayers Using Sum-Frequency Vibrational Spectroscopy and X-ray Photoelectron Spectroscopy

Langmuir-Blodgett (LB) monomolecular layers of alkylhydroxamic acids and alkylphosphonic acids on copper and iron substrates have been studied by X-ray photoelectron spectroscopy (XPS) and sum-frequency vibrational spectroscopy. According to the XPS results, the structures of the hydroxamic acid and phosphonic acid Langmuir-Blodgett films are very similar: the thickness of the layer of the hydrocarbon tails is typically 1.9-2.1 nm, while the layer of headgroups is about 0.3-0.35 nm thick. The tilt angle of the carbon chains is estimated to be 20-30 degrees with respect to the sample surface normal, and the molecules are connected to the substrate via their headgroups. Analysis of the P 2p and N 1s lines indicates the presence of deprotonated headgroups. The substrate Cu 2p line includes a component which can be assigned to Cu(2+) ions in a thin Cu(OH)(2) layer. The deposition of LB layers led to significant decrease of the hydroxide-related signal, which indicates that binding of the headgroups to the surface is accompanied by the elimination of water molecules. The sum-frequency spectra also clearly indicate that well-ordered monolayers can be formed by the Langmuir-Blodgett technique. Since the non-resonant background from the metal substrates renders the analysis of the spectra more difficult, model system samples on glass were prepared. It was found that the alkyl chains of the adsorbed acids predominantly adopt the all-trans conformation and form an ordered structure. Upper limits for the mean tilt angle of the terminal methyl groups are approximately 10-20 degrees.

Human C4b-binding Protein, Structural Basis for Interaction with Streptococcal M Protein, a Major Bacterial Virulence Factor

Human C4b-binding protein (C4BP) protects host tissue, and those pathogens able to hijack this plasma glycoprotein, from complement-mediated destruction. We now show that the first two complement control protein (CCP) modules of the C4BP alpha-chain, plus the four residues connecting them, are necessary and sufficient for binding a bacterial virulence factor, the Streptococcus pyogenes M4 (Arp4) protein. Structure determination by NMR reveals two tightly coupled CCP modules in an elongated arrangement within this region of C4BP. Chemical shift perturbation studies demonstrate that the N-terminal, hypervariable region of M4 binds to a site including strand 1 of CCP module 2. This interaction is accompanied by an intermodular reorientation within C4BP. We thus provide a detailed picture of an interaction whereby a pathogen evades complement.

Local orientations of fluctuating fluid interfaces

Thermal fluctuations cause the local normal vectors of fluid interfaces to deviate from the vertical direction defined by the flat mean interface position. This leads to a nonzero mean value of the corresponding polar tilt angle which renders a characterization of the thermal state of an interface. Based on the concept of an effective interface Hamiltonian we determine the variances of the local interface position and of its lateral derivatives. This leads to the probability distribution functions for the metric of the interface and for the tilt angle which allows us to calculate its mean value and its mean-square deviation. We compare the temperature dependences of these quantities as predicted by the simple capillary-wave model, by an improved phenomenological model, and by the microscopic effective interface Hamiltonian derived from density-functional theory. The mean tilt angle discriminates clearly between these theoretical approaches and emphasizes the importance of the variation of the surface tension at small wavelengths. Also the tilt angle two-point correlation function is determined which renders an additional structural characterization of interfacial fluctuations. Various experimental accesses to measure the local orientational fluctuations are discussed.

Effect of ω-Hydrogenation on the Adsorption of Fluorononanols at the Hexane/Water Interface: Pressure Effect on the Adsorption of Fluorononanols

The interfacial tension gamma of the hexane solution of 1H,1H-perfluorononanol (FDFC(9)OH) and its omega-hydrogenated analogue, 1H,1H,9H-perfluorononanol (HDFC(9)OH), against water was measured as a function of pressure and concentration at 298.15 K in order to clarify the effect of omega-dipole on the orientation of fluorononanol molecules from the viewpoint of volume. The adsorbed films of both alcohols exhibit two kinds of phase transitions among three different states: the gaseous, expanded, and condensed states. The partial molar volume changes of adsorption - in the expanded and condensed states were evaluated and compared between the two systems. The - values of both alcohols are negative, and thus the alcohol molecules have smaller volume in the adsorbed film than in the bulk solution. Furthermore, the value was obtained through the evaluation of by the density measurement of the bulk hexane solution. It was found that the value of HDFC(9)OH is smaller than that of FDFC(9)OH in the condensed state. On the basis of three matters concerning the molecular structure of alcohols, the occupied area at the interface, and the orientation of FDFC(9)OH in the adsorbed film deduced from the earlier results of X-ray reflectivity measurement, the mean tilt angle of HDFC(9)OH from the interface normal in the condensed film was estimated to be 15 degrees . The thermodynamic estimation demonstrated here is highly valuable one to provide structure information on an adsorbed film.

プラントキャノピーアナライザによる植物面積指数の測定誤差とその葉群傾斜角への依存性

The Plant Area Index (PAI) of rice, measured indirectly using a Plant Canopy Analyzer (PCA), was compared with that measured directly using a leaf area meter to determine the primary factor that causes the PAI to be underestimated on vertically oriented canopies. Comparison measurements were conducted on several growth stages of the rice in three different cropping seasons; i.e., the usual season (from May to September), the early season (from March to July) and the late season (from June to October) in a warm temperate climate.The ratio of PAI measured using a PCA to directly (PAIPCA/PAID) showed a seasonal variation from 0.62 to 1.07. The lowest values of PAIPCA/PAID (0.62-0.65) were observed near the flowering time of the rice in all cropping seasons, due to the deviation from random distribution of the foliage as a result of vertically oriented leaves, tillers and panicles. A simple method was proposed to correct the PCA measurements by expressing PAIPCA/PAID as a function of the mean tilt angle of the foliage. The corrected values using this function showed good agreement with the directly measured values. The correction method was confirmed by additional comparison measurements conducted in the usual cropping season in the following year.

Distance measurements between paramagnetic centers and a planar object by matrix Mims electron nuclear double resonance

Frequency-domain electron nuclear double resonance (ENDOR), two time-domain electron nuclear double resonance techniques, and electron spin echo envelope modulation spectroscopy are compared with respect to their merit in measurements of small hyperfine couplings to nuclei with intermediate gyromagnetic ratio such as 31P. The frequency-domain Mims ENDOR experiment is found to provide the most faithful line shapes. In the limit of long electron-nuclear distances of more than 0.5 nm, sensitivity of this experiment is optimized by matching the first interpulse delay to the transverse relaxation time of the electron spins. In the same limit, Mims ENDOR efficiency scales inversely with the sixth power of distance. Hyperfine splittings as small as 33 kHz can be detected, corresponding to an electron-31P distance of 1 nm. In systems, where a certain kind of nuclei is distributed in a plane, measurements of intermolecular hyperfine couplings can be analyzed in terms of a distance of closest approach of a paramagnetic center to that plane. By applying this technique to spin-labeled lipids in a fully hydrated lipid bilayer it is found that for a fraction of lipids, chain tilt angles can be 25 degrees larger than the mean tilt angle of the lipid chains. This model of all-trans hydrocarbon chains with a broad distribution of tilt angles is also consistent with orientation selection effects in high-field ENDOR spectra.

Acoustic remote sensing of swimbladder orientation and species mix in the oreo population on the Chatham Rise.

A method for combining in situ measurements and theoretical swimbladder-derived estimates of target strength of the deep-water fish, black and smooth oreos, is described. The technique uses Monte Carlo simulation and yields fish length-target strength relationships suitable for use in estimating biomass from echo integration acoustic surveys. The relationships are derived from estimates of the mean and standard deviation of the tilt angle distributions of the wild fish generated by the method. The relationships may also be used to estimate proportions of the two oreo species in the wild. The mean tilt angle of black oreos in the wild was about 10 degrees with a standard deviation of 8 degrees. For smooth oreos it was close to zero with a standard deviation of about 4 degrees. The target strength relationships derived for biomass estimation purposes were TSB= -78.05+25.3 log10(L)+1.62 sin(0.0815L+0.238) and TSS = -82.16+24.6 log10(L)+1.03 sin(0.1165L-1.765), where L is the fish length and TSB and TSS are the target strengths of black and smooth oreos respectively.

The Anatomy of the Aortic Root

Objective: Since the aortic root preserving methods are spreading in heart surgery, the importance of aortic root anatomy is increasing. The surgical and anatomical descriptions of the aortic root are not always congruent. Therefore, the present study focuses on the surgical aspects of the aortic root anatomy. Methods: We measured the distances between the three commissures, the distances between the basal point of the sinus and the sinotubular junction and the heights of the sinuses. The circumference of the sinotubular junction and the annuli fibrosi were also obtained. In addition, the volume of every sinus was directly measured. Finally both vertical and horizontal histological sections of annuli fibrosi were made. Results: All measured parameters were averaged and the standard deviation (SD) was calculated, except in the case of the tilt angle. The distance for the right sinus commissures was 18.82 mm (SD 1.93 mm), and that of the non- and left coronary sinus were 17.43 (SD 2.06) and 15.21 (SD 1.88) mm, respectively. The mean height of the right, non- and left coronary sinus were 19.45 (SD 1.91), 17.68 (SD 1.77) and 17.45 (SD 1.39) mm, respectively. These differences between the height of the sinuses determines a mean tilt angle of 5.47° for the sinotubular junction and aortic root base. The mean circumference of the aortic root base and of the sinotubular junction was 69.20 (SD 6.93), and 65.82 (SD 8.31) mm. respectively. Mean volumes of the right, non- and left coronary sinuses were 1.6 (SD 0.34). 1.33 (SD 0.27) and 1.04 (SD 0.23l) ml. According to the histological sections we can say that the histological border of the annuli fibrosi is positioned at the interleaflate triangles. Conclusion: According to the measured data we can state that all parameters follow the pattern in which the right sinus structures had the greatest dimensions followed by the non coronary sinus, and finally the left coronary sinus. The tilt angle for aortic root base and sinotubular junction, and the difference in the diameters could be of hemodynamic and of surgical relevance

The anatomy of the aortic root

Objective: Since the aortic root preserving methods are spreading in heart surgery, the importance of aortic root anatomy is increasing. The surgical and anatomical descriptions of the aortic root are not always congruent. Therefore, the present study focuses on the surgical aspects of the aortic root anatomy. Methods: We measured the distances between the three commissures, the distances between the basal point of the sinus and the sinotubular junction and the heights of the sinuses. The circumference of the sinotubular junction and the annuli fibrosi were also obtained. In addition, the volume of every sinus was directly measured. Finally both vertical and horizontal histological sections of annuli fibrosi were made. Results: All measured parameters were averaged and the standard deviation (SD) was calculated, except in the case of the tilt angle. The distance for the right sinus commissures was 18.82 mm (SD 1.93 mm), and that of the non- and left coronary sinus were 17.43 (SD 2.06) and 15.21 (SD 1.88) mm, respectively. The mean height of the right, non- and left coronary sinus were 19.45 (SD 1.91), 17.68 (SD 1.77) and 17.45 (SD 1.39) mm, respectively. These differences between the height of the sinuses determines a mean tilt angle of 5.47° for the sinotubular junction and aortic root base. The mean circumference of the aortic root base and of the sinotubular junction was 69.20 (SD 6.93), and 65.82 (SD 8.31) mm, respectively. Mean volumes of the right, non- and left coronary sinuses were 1.6 (SD 0.34), 1.33 (SD 0.27) and 1.04 (SD 0.23l) ml. According to the histological sections we can say that the histological border of the annuli fibrosi is positioned at the interleaflate triangles. Conclusion: According to the measured data we can state that all parameters follow the pattern in which the right sinus structures had the greatest dimensions followed by the non coronary sinus, and finally the left coronary sinus. The tilt angle for aortic root base and sinotubular junction, and the difference in the diameters could be of hemodynamic and of surgical relevance

Orientation Distributions for Cytochrome c on Polar and Nonpolar Interfaces by Total Internal Reflection Fluorescence

The formation of chemisorbed monolayers of yeast cytochrome c on both uncharged polar and nonpolar soft surfaces of organic self-assembled monolayers (SAM) on solid inorganic substrates was followed in situ by polarized total internal reflection fluorescence. Two types of nonpolar surfaces and one type of uncharged polar surface were used. The first type of nonpolar surface contained only thiol endgroups, while the other was composed of a mixture of thiol and methyl endgroups. The uncharged polar surface was provided by the mixture of thiol and hydroxyl endgroups. The thiol endgroups were used to form a covalent disulfide bond with the unique surface-exposed cysteine residue 102 of the protein. The mean tilt angle of the protein’s zinc-substituted porphyrin was found to be 41° and 50° for the adsorption onto the nonpolar and uncharged polar surfaces, respectively. The distribution widths for the pure thiol and the thiol/methyl and thiol/hydroxyl mixtures were 9°, 1°, and 18°, respectively. The high degree of the orientational order and good stability achieved for the protein monolayer on the mixed thiol/methyl endgroup SAM makes this system very attractive for studies of both intramolecular and intermolecular electron transfer processes.

Variable Acquisition Angle Total Internal Reflection Fluorescence: A New Technique for Orientation Distribution Studies of Ultrathin Films

A new technique for the determination of the orientation distribution of a fluorophore within an ultrathin film, in terms of the mean tilt angle relative to the monolayer normal and the distribution width, is described. The technique utilizes the measurement of polarized fluorescence, excited by the evanescent field appearing upon total internal reflection. The main difference between this and existing techniques is that the fluorescence intensity is measured as a function of the acquisition angle with low aperture detection. The potential of the technique was investigated with the help of computer modeling and experimentally utilizing a Langmuir−Blodgett film of arachidic acid doped with a fluorophore DiI. Both computer modeling and the measurements show that the acquisition of the angular dependence of the fluorescence dramatically improves the technique, increasing manyfold the accuracy and resolution of the determined orientation distribution parameters.