Kyoko Tanaka

Placental Mesenchymal Dysplasia: Chronological Observation of Placental Images during Gestation and Review of the Literature

Placental mesenchymal dysplasia (PMD) is characterized by multiple hypoechoic vesicles which are similar to molar changes in the placenta; however, the process of such morphological changes of PMD during pregnancy has not been fully understood. We performed a review of all PMD cases published in English and identified 49 articles including 110 cases. With regard to the gestational age at which the multicystic pattern was seen, approximately 70% of cases were diagnosed at 13-20 weeks of gestation. Another characteristic feature of PMD is varicose dilation of fetal chorionic vessels. As many as 90% of cases were diagnosed as placenta with dilated fetal chorionic vessels in the third trimester. We also report a case of PMD which was found at 10 weeks of gestation according to ultrasonic molar patterns. Serial observations of the placenta using ultrasound and magnetic resonance imaging revealed that multicystic lesions became smaller after 23 weeks. In contrast, dilated placental vessels on the fetal side became apparent at 38 weeks. The present review highlights that placental vesicular lesions of PMD may precede dilation of fetal chorionic vessels during pregnancy. It also indicates the potential of a gradual reduction in size of PMDs placental vesicular lesions by serial study of placental images.

Detection of the fundamental frequency in noisy environment for speech enhancement of a hearing aid

This paper describes a method for noise-proof detection of the fundamental frequency of the voice in a noisy environment. Noise reduction techniques have been required in the development of a hearing aid, because noise makes intelligibility of hearing awfully inferior. In various methods of noise reduction, the fundamental frequency is often a significant parameter, but it is difficult to extract the frequency from the noisy voice. In order to utilize a comb filter method for noise reduction, a new method of detecting the fundamental frequency is developed by using the property of continuity in the fundamental frequency and the power spectrum envelope (PSE) of the human voice. The continuity of the PSE is utilized for determining the most reliable frequency. The gross pitch error (GPE) is reduced by the determination. Besides the frequency used for the comb filter is obtained from a linear predicting frequency and the latest fundamental frequency from the noisy voice, so as to suppress fluctuation of the frequency that degrades filtered voice. The procedure improves a fine pitch error (FPE) within 5%. The results of the evaluation showed that the present method proved to be superior to the traditional cepstrum method in the GPE and the FPE. We conclude that the proposed frequency detection method is available for noise reduction in the comb filter method.

Vector locus of an equivalent radius of the root in growing plants

Tree planting on arid land is taken up as one of the measures against global warming prevention. It is important for the tree planting to grasp growth state of the root after planting. To monitor the root advancement, a method measuring electric ground impedance of the root has been presented. By this method, we can know the growth state without digging the soil. To estimate the value of impedance, we introduce a concept of an equivalent radius. In this method, the value of ground impedance is converted to a radius of the disk electrode that has the same value as the object. Moreover, ground impedance of the root is indicated as complex number, which consists of resistance and capacity components of the root. The equivalent radius is also expressed by complex number. We propose the method indicating the change of equivalent radius as growing of the root by means of vector locus. It is demonstrated by the experiments on sunflower and kenaf during one summer that the present method is useful for estimating the growth state of the plant root.

An estimation method of ground resistance of trees growing in different lands

It is important to monitor the growing state of tree roots without digging the soil away from the bottom of the tree. Electrical ground resistance of tree roots indicates the grade of the growing state. The better roots advanced in the ground, the smaller the value of ground resistance becomes. However, ground resistance of the tree is modified by resistivity of the soil. If the growing state of roots is the same in trees growing in different lands, the value of ground resistance of each tree shows different values according to soil resistivity where trees are growing. This disables the comparison of the growth level between different lands, and complicates the estimation of results. In order to make comparison possible between the two without the effect of soil resistivity, the value of ground resistance of the tree is converted to that of a metal disk electrode. Here, if we know the soil resistivity, a radius of the disk becomes to be known. This disk radius is called equivalent radius that can indicate the growth level according to its value regardless of soil resistivity. Using the equivalent radius, we can estimate the growth level of plants growing in different lands evenly. Measured equivalent radii and the ratios to their butt radius of objective trees in West Australia, Hawaii Island, and Japan are summarized in figures.

A measurement method of grounding impedance of a tree

This paper describes a method for measuring the grounding impedance of a tree. Electrode impedance of an electrode using for connection between the measurement circuit and the tree, brings serious error in the measurement. To avoid the effect of the electrode impedance, the four-electrode method known in the impedance measurement methodology, is newly introduced. The hybrid method of the four-electrode method and usual grounding impedance measurement method makes it possible to measure grounding impedance of the tree directly. The experiments of the measurement were conveyed for three materials, zelkova tree, cherry tree, and silk-tree with the girth of 1.7-2.0 meters. Obtained values of impedance were 60-100 O in absolute one, and they showed slight capacitive reactance. It is concluded that the presented method is available for the measurement of grounding impedance of the tree.

Prenatal sonographic diagnosis of fetal valproate syndrome: a case report

BackgroundPrenatal exposure of mother to valproate (VPA) causes teratogenic effects in the fetus, namely fetal valproate syndrome (FVS). We report a case of fetal valproate syndrome rarely diagnosed by prenatal sonographic examination.Case presentationOur patient was a female infant who was born to a 27-year-old nulliparous Japanese woman with epilepsy. The mother was diagnosed with infantile epilepsy at 1 year of age and had been using three antiepileptic drugs, including valproate, but preconceptional counseling was not performed. At 25 weeks of gestation, contracture of the fetal right wrist joint suggestive of a radial ray defect was observed by transabdominal ultrasonography. The fetus demonstrated growth retardation starting from 32 weeks of gestation. In addition, saddle nose as a facial anomaly was detected by three-dimensional ultrasound at 37 weeks of gestation. Accordingly, we suspected that the fetus had fetal valproate syndrome. At 39 weeks of gestation, the mother delivered an infant weighing 2056 g. The neonate had characteristic features of fetal valproate syndrome, such as facial configuration, slight muscular hypotonia of the whole body, breathing problems, right-hand articular contracture accompanied by radial ray defect, and cardiovascular malformation.ConclusionsWhen obstetricians manage epileptic pregnant women without enough preconceptional counseling or adjustment for antiepileptic drugs, careful sonographic observation of the fetus is mandatory.

Contents Vol. 75, 2013

M.A. Belfort, Provo, Utah J. Bornstein, Nahariya H.L. Brown, Durham, N.C. C. Chapron, Paris J. de Haan, Maastricht G.A. Dekker, Adelaide, S.A. J.A. Deprest, Leuven K. Hecher, Hamburg S. Kahhale, São Paulo H. Kliman, New Haven, Conn. T.F. Kruger, Tygerberg J.A. Kuller, Raleigh, N.C. M.J. Kupferminc, Tel Aviv H. Minkoff , Brooklyn, N.Y. J. Moodley, Congella J.M. Mwenda, Nairobi H. Odendaal, Tygerberg J.T. Repke, Hershey, Pa. G.R. Saade, Galveston, Tex. B.M. Sibai, Cincinnati, Ohio Founded 1895 as ‘Monatsschrift für Geburtshilfe und Gynäkologie’, continued 1946–1969 as ‘Gynaecologia’ and 1970–1977 as ‘Gynecologic Investigation’

An Evaluation Method of Ground Resistance of a Tree.

It is important to monitor the growing state of tree roots without digging the soil away from the bottom of the tree. Ground resistance of tree roots indicates the grade of the growing state. However, ground resistance of the tree is modified by resistivity of the soil. This disables the comparison of the growth level of trees in different places. In order to make the comparison possible among them without influence of soil resistivity, the value of ground resistance of the tree is converted to that of a metal disk electrode. If we know the soil resistivity, a radius of the disk becomes to be known. This disk radius is called the equivalent radius. Using the equivalent radius, we can estimate the growth level of trees growing in different places evenly. The results of field studies on some trees are shown.

Simultaneous measurement of the botanical tissue impedance and the electrode impedance by the multi-electrode method

We provide a multi-electrode method for measuring the bulk impedance of botanical tissues and electrode impedance used in the measurement, simultaneously. By stabbing many electrodes in the object along the circumference of the columnar body, the bulk impedance and impedance of electrodes can be measured. The impedance of the botanical body can be estimated when the number of electrodes is infinite. The experimental results applied to Japanese radish showed the usefulness of the proposed method.