Classification of Types of Stuttering Symptoms Based on Brain Activity

Among the non-fluencies seen in speech, some are more typical (MT) of stuttering speakers, whereas others are less typical (LT) and are common to both stuttering and fluent speakers. No neuroimaging work has evaluated the neural basis for grouping these symptom types. Another long-debated issue is which type (LT, MT) whole-word repetitions (WWR) should be placed in. In this study, a sentence completion task was performed by twenty stuttering patients who were scanned using an event-related design. This task elicited stuttering in these patients. Each stuttered trial from each patient was sorted into the MT or LT types with WWR put aside. Pattern classification was employed to train a patient-specific single trial model to automatically classify each trial as MT or LT using the corresponding fMRI data. This model was then validated by using test data that were independent of the training data. In a subsequent analysis, the classification model, just established, was used to determine which type the WWR should be placed in. The results showed that the LT and the MT could be separated with high accuracy based on their brain activity. The brain regions that made most contribution to the separation of the types were: the left inferior frontal cortex and bilateral precuneus, both of which showed higher activity in the MT than in the LT; and the left putamen and right cerebellum which showed the opposite activity pattern. The results also showed that the brain activity for WWR was more similar to that of the LT and fluent speech than to that of the MT. These findings provide a neurological basis for separating the MT and the LT types, and support the widely-used MT/LT symptom grouping scheme. In addition, WWR play a similar role as the LT, and thus should be placed in the LT type

CHEMICAL STATE ANALYSIS OF HYDROLYSIS PRODUCTS OF IRON (III) SALT SOLUTIONS BY MEANS OF MÖSSBAUER SPECTROMETRY

Des ions Fe(III) sont hydrolysés à pH = 1,2 ~ 1,8 et les composés α-FeOOH, β-FeOOH ou NaFe3 (SO4)2(OH)6 sont précipités en présence de Br- (NO3-), Cl- (F-) et SO4-- respectivement. Le rapport β-FeOO/α-FeOOH change de 0 à 1, quand Cl-/Fe(III) en solution varie de 0 à 1. Cl- est fortement lié à β-FeOOH (Cl/Fe = 0,147) alors que Br- est faiblement absorbé sur α-FeOOH (Br/Fe = 0.0125).Hydrolysis of iron (III) proceeds at pH 1,2 ~ l.8 and α-FeOOH, β-FeOOH or NaFe3(SO4)2(OH)6 are precipitated in the presence of Br- (NO3-), Cl- (F-) and SO42- respectively. Ratio of β-FeOOH/α-FeOOH changed from 0 to 1, as Cl-/Fe(III) in the solution varied from 0 to 1. Cl- is tightly bound into β-FeOOH (Cl/Fe = 0.147), whereas Br- is adsorbed loosely on the α-FeOOH (Br/Fe = 0.0125)

CHEMICAL STATE ANALYSIS OF CORROSION PRODUCTS ON STEEL SURFACE BY CONVERSION ELECTRON MÖSSBAUER SPECTROMETRY (CEMS).

The corrosion products of iron formed on steel surfaces by the immersion of steels in solutions containing chloride, sulfate, and nitrate ions, and in phosphating solutions were analyzed by CEMS and X-ray diffractometry. Positive identification of γ-FeOOH in 0.5M NaCl solutions, γ-FeOOH and Fe (OH)2 in 0.25M Na2SO4 solutions, and γ-FeOOH and Fe3O4 in 0.5M NaNO3 solutions was achieved. Amorphous paramagnetic Fe (III) compound, (Mn, Fe)5H2 (PO4)4 4H2O, and Zn2Fe(PO4)24H2O were mainly produced on the surfaces by the immersion in the iron phosphating, man ganese phosphating, and zinc phosphating solutions, respectively

CHEMICAL STATE ANALYSIS OF NITRIDED STEEL SURFACE BY MEANS OF CONVERSION ELECTRON MÖSSBAUER SPECTROMETRY

La spectroscopie Mössbauer d'électrons de conversion a été employée pour caractériser des surfaces d'acier nitruré ; l'état chimique des surfaces a été analysé couche par couche. La surface d'acier nitruré par réaction avec l'azote est composée de Fe2N-ε, Fe3-XN(0≤x≤1) distordu, de la martensite Fe4N-γ et d'une couche de fer-α légèrement déformé par l'azote introduit. La nitruration par attaque chimique conduit à une surface de Fe3N-ε, des couches intermédiaires de Fe3N-ε et Fe4N-γ' et du Fe-α distordu. La couche nitrurée par électrochimie a une épaisseur de 2 à 3 microns de Fe4N-γ'1, Fe4N-γ'2 et des couches de Fe-α distordu.CEMS was used to characterize the nitrided steel surfaces and chemical states of surfaces estimated layer by layer. Gas nitrided steel surface is composed of ε-Fe2N, distorted Fe3+xN (0≤x≤1), γ'-Fe4N martensite and α-Fe layer slightly disturbed by intruded nitrogen. Tufftrided steel surface consists of ε-Fe3N, intermediate ε-Fe3N and γ'-Fe4N, γ'-Fe4N and disturbed α-Fe layers. Ion nitrided steel surface has a 2~3 µm thickness of γ'2-Fe4N (magnetically randomly oriented), γ'2-Fe4N and distorted α-Fe layers

SENSITIVE AREA OF A BACK-SCATER-TYPE GAS FLOW DETECTOR FOR CONVERSION ELECTRON MÖSSBAUER SPECTROMETRY

Counting characteristics of a back-scatter-type detector for CEMS were studied in terms of a sample position, a distance from a sample to a source, a window diameter of a detector etc.. Useful information on a position sensitivity was obtained for the better sample setting in a detector

Free Volume Study on Three Types of Shape Memory Polymers by Positron Annihilation

Temperature dependence of nanoscopic environment of shape memory polymers such as polynorbornene (T$\text{}_{g}$≈313 K), polyurethane (T$\text{}_{g}$≈321 K=dynamic viscoelasticity, destruction of hydrogen bond ≈353 K) and styrene-butadiene copolymer (T$\text{}_{m}$=333 K) is observed in terms of free volume parameters - average size, numerical concentration and size distribution - estimated from positronium lifetime measurement, and mechanisms of their shape recoveries are discussed at a molecular level

Change of Free Volume in Polymer Gels As Studied by Positron Annihilation Lifetimes

Variations of a free volume size of a poly(N-isopropylacrylamide) gel and a polyacrylamide gel during a volume phase transition induced by a change of external environment - temperature, solvent composition, pH, and ion strength, are described. The free volume size is probed by positron annihilation lifetime technique. Variations of the free volume size suggest that a nanoscopic environment of the gels is affected by the free volume of the solvent phase and an interaction between the polymer chain and the solvent molecule in the swollen state, and by the aggregation of the polymer chain and a balance of the interaction among the polymer chain and the solvent molecules in the collapsed state. It is revealed that the free volume size reflects the essential change of the nanoscopic environment in the gels which could induce the macroscopic volume phase transition