Flat Traces Research Articles

On the origin of deformation mechanisms in a heterostructured aluminum alloy via slip trace and lattice rotation analyses

In this study the micro-deformation mechanisms in an Al–Si cast alloy under stepwise compressive loading up to a cumulated plastic strain of 9.7% are examined via detailed EBSD and slip trace analyses. The presence of heterogeneous microstructural features in the alloy like eutectic structure and second-phase particles significantly affects slip trace characteristics. Four types of slip traces (namely, bowed, ‘C’-type curved, ‘S’-type curved, and flat slip traces) present in primary α-Al grains are identified, which unveil the nature of dislocation motion in the alloy and reflect the extent of deformation difficulty associated with α-Al grain orientations and eutectic Si particles. Crystallographic factors like lattice rotations, misorientation angles, active slip systems, and Schmid factors are jointly analyzed for the first time to understand the deformation behavior of the heterogeneous alloy.

Flat trace statistics of the transfer operator of a random partially expanding map

We consider the skew-product of an expanding map E on the circle with an almost surely random perturbation τ = τ0 + δτ of a deterministic function τ0:. The associated transfer operator can be decomposed with respect to frequency in the y variable into a family of operators acting on functions on the circle:. We show that the flat traces of behave as normal distributions in the semi classical limit n, ξ → ∞ up to the Ehrenfest time n ⩽ ck log ξ.

Whole Blood Impedance Aggregometry: A New Tool for Severe Inherited Platelet Disorder Diagnosis?

Abstract 5266Diagnosis and characterization of platelet function disorders may be challenging. It requires multiple laboratory data including the assessment of platelet functions. Platelet function analysis is most commonly performed using light transmission aggregometry (LTA). LTA is a time-consuming method requiring centrifugation steps and large blood volumes. It is difficult to perform in children and in cases of thrombocytopenia. In contrast, platelet aggregation in whole blood using impedancemetry (WBI) is a fast method, allows omission of centrifugation steps and performance of platelet function studies under more physiological conditions with small samples size. It is based on the change of resistance proportional to the amount of platelets sticking to two electrodes where an alternating current is applied. Multiplate® (for “multiple electrode aggregometry”, Dynabite Medical) is a new generation of WBI aggregometer using diluted blood and single-use test cells containing twin electrodes that reduce the variation of results. We have already showed the good Multiplate® performance concerning ristocetin-induced platelet aggregation in a population of 30 patients with characterized von Willebrand disease (Valarche et al, 2011). Our aim in this ongoing study was to assess the performance of WBI in patients with inherited platelet function disorders. We tested 8 patients including 2 unrelated patients with Glanzmann Thrombasthenia (GT), 2 unrelated patients with Bernard-Soulier Syndrome (BSS), 1 patient with Gray Platelet Syndrome (GPS) and 3 patients from the same family with a platelet type von Willebrand disease (PTVWD). GT, BSS, and PTVWD diagnosis were confirmed using genotyping. BSS and GPS patients had chronic thrombocytopenia. GT, BSS, GPS and 1/3 PTVWD had platelet function tests with LTA in parallel. WBI was performed on heparinized whole blood diluted at ½ in NaCl at 37°C and triggered using high (0.77 mg/mL, WBI RH) and low (0.5 mg/mL, WBI RL) final ristocetin concentrations, ADP (6.5 Âμ Mol, WBI ADP) and collagen (3.2 Âμg/mL, WBI Coll). Results were expressed in arbitrary unit (AU) corresponding to the area under the aggregation curve observed during 6 min. Normal ranges indicated in brackets were based on the mean +/− 2 SD of 30 healthy volunteers’ results. Results highlighted in grey are those out of the normal ranges (Table 1).Table 1:Results of the 8 patients with inherited platelet disorders.PatientsPlatelet count (109/L)WBI RH (AU) [>500]WBI RL (AU) [<150]WBI ADP (AU) [>550]WBI Coll (AU) [>500]GT 116923441443GT 224955417ND7BSS 134371119129BSS 230254733582GPS7916217ND42PTVWD22099493ND338PTVWD231116560ND1092PTVWD2341174168ND852All patients except those with PTVWD had decreased results with WBI. However, as expected, patients with GT had flat traces using WBI ADP and WBI Coll but normal or only decreased curves (234 – 554 AU) using WBI RH. On the opposite, BSS patients had flat traces using WBI RH but detectable curves using WBI ADP (191 – 335 AU) despite decreased platelet count. The thrombocytopenic GPS patient has a flat trace using WBI Coll and decreased WBI RH (162 AU). Members of the PTVWD family had normal results except a slightly increased result with WBI RH in 1/3 patients. Finally, LTA results performed in 6/8 patients were all in accordance with those of the WBI. In conclusion, in 8 patients with well characterized inherited platelet disorders, WBI was able to detect all abnormalities except PTVWD. In such cases, different ristocetin concentrations use might be critical to increase sensitivity. In our hands, WBI was able to discriminate disorders involving platelet glycoprotein (GP) IIb-IIIa from GP Ib-IX-V: GT patients exhibited flat traces using WBI ADP and WBI Coll, whereas patients with BSS exhibited flat traces with ristocetin. These preliminary results need to be confirmed on a larger population of patients with various characterized platelet function disorders. They suggest that WBI using the Multiplate® analyzer, which is a fast, easy and blood-preserving test, could be a valuable extra step before or in addition to the classic LTA for the diagnosis of severe inherited platelet disorders. Disclosures:No relevant conflicts of interest to declare.

Multifocal Visual Evoked Potential Is Dependent on Electrode Position

Purpose: To investigate whether the multifocal visual evoked potential (mVEP) is dependent on the electrode position, and to confirm the reproducibility of the mVEP. Methods: The mVEPs were recorded using the Veris III system with two different bipolar electrode settings. In Position 1, electrodes were placed at equal distances in vertical alignment 2 cm above and below the inion. In Position 2, the electrodes were placed in horizontal alignment at equal distances 2 cm to the left and right of the inion. Dartboard pattern stimulation was conducted. The mVEPs were repeatedly recorded from 4 volunteers, and mainly the second-order kernel response components were analyzed. Results: Although the reproducibility of mVEP was good in both Position 1 and Position 2, each waveform of the mVEP was drastically different between the two positions. This difference in the waveforms was clearly shown in the center and at the horizontal meridian. We also investigated the first-order kernel response components of the mVEPs. Several traces of the first-order kernel response components did not reveal flat traces. This point is also worthy of consideration. Conclusion: Responses from mVEPs are clearly dependent on the electrode position.

Long-term middle-ear effects of middle-ear/eustachian tube packing after translabyrinthine surgery.

The purpose of this study was to evaluate the long-term effect on middle ear and eustachian tube function following the packing of the middle-ear space to prevent cerebrospinal fluid rhinorrhoea at the termination of translabyrinthine vestibular schwannoma removal. This was an observational study of a sample of 14 patients examined between two and five years post-operatively. Photo-otoscopy and tympanometry were performed bilaterally to evaluate appearance and function. All operated middle ears were air-containing although eight out of 14 showed scarring as evidence of operative intervention. There were no drum retractions. Ten out of 14 middle-ear compliance peaks were lower in the operated ear with four flat traces. Two out of 14 were the same and two out of 14 showed high compliance. The middle-ear pressure was always within the normal range when determinable. This technique appears to have no detrimental effects on the middle ear and does not permanently obliterate the eustachian tube. The reduced compliance in the majority of cases is probably a result of scarring and fibrosis. When drum hypermobility is seen this is accounted for by incus removal.

Математичне моделювання та розрахунок взаємодії примежового шару зі слідами тіл різної форми

Given are the results of mathematical modeling of interaction of boundary layer on flat surface and traces of bodies of various form (streamlined and badly streamlined). Calculations are made in accordance with proposed and worked out residual difference method. The design parameters are compared to the well-known experimental data of E.G. Tylapyrkara, V. Ramzhy, R. Radzhasekara

Antepartum fetal heart rate monitoring. II. Deceleration patterns.

Fetal heart rate was studied during the antepartum period in 246 patients, yielding a total of 1964 recordings. The following parameters were evaluated and correlated: --the semi-quantitative assessment of fetal heart rate instability (as expressed by the percentage of duration of flat traces); --the presence of decelerations and their relationship to the presence or absence of uterine contractions; --the neonatal condition. Overall, 50% of the patients exhibited uterine contractions while 30% contained decelerations patterns either occurring spontaneously or in association with uterine contractions. A definite relationship was observed between the presence of severe decelerations (irrespective of the time relationship with any uterine contraction) and poor neonatal outcome. A relationship does exist between the presence of severe decelerations and flattening in the recording, which, as demonstrated in the previous part of the paper also exhibited a strong positive relationship with the neonatal outcome. When one considers the different degrees of flattening, it appears that a further correlation between decelerations and neonatal state is demonstrable only in the case of a 10--50% flat recording. Here the probability of a distressed baby is 20% in the absence of decelerations, but 43.4% in the presence of decelerations. In other cases (i.e., less than a 10% or more than a 50% flat recording) the pronostic significance of the instability of the record is not significantly modified by he presence or absence of decelerations. These results indicate that consideration of decelerations is only advisable in these cases where instability is moderately affected (flattening in 10-50% of the record) and that the use of the oxytocin challenge test OCT may be reserved for such cases, when these are neither spontaneous contractions nor decelerations and not contraindications present.

Nodal and leaf anatomy of Xanthophyllum (Polygalaceae)

The nodal anatomy of Xanthophyllum is unilacunar with a single broad trace departing the cauline stele. The “stipular glands” or extra floral nectaries of some species are vascularized by bundles originating from the base of the leaf trace. Considerable variation exists among species in petiole vasculature with siphonosteles, steles with medullary bundles and simple, flat traces present. The lamina also shows variation in the presence or absence of a hypodermis, nature of vein sheathing, presence or absence of abaxial epidermal papillae, amount of intercellular spaces, and mature stomatal patterns which range from anisocytic and paracytic to those in which no subsidiary cells are discernible. Of nearly uniform occurrence throughout the genus are extraordinary tracheoid foliar idioblasts, which are confined to the veins in terminal or subterminal positions. The large amount of variation in leaf anatomy is shown to be taxonomically significant within the genus.