Interactions oftrans-cinnamic acid,its related phenolic allelochemicals,and abscisic acid in seedling growth and seed germination of lettuce

Phenolic compounds have been identified as the most common allelochemicals produced by higher plants. Inhibitions of cinnamic acid, its related phenolic derivatives, and abscisic acid (ABA) on seedling growth and seed germination of lettuce were studied.trans-Cinnamic acid, ando-,m-, andp-coumaric acids inhibited the growth of etiolated seedlings of lettuce at concentrations higher than 10^–4 M and seed germination above 10^–3 M. Coumarin inhibited seedling growth and seed germination at 10^–5 M or above. Chlorogenic acid inhibited seedling growth above 10^–4 M, but did not inhibit seed germination at 10^–5–5×10^–3 M. Low concentrations (below 10^–3 M) of caffeic and ferulic acids promoted the elongation of hypocotyls, but higher concentrations (over 10^–3 M) inhibited seedling growth and seed germination. These phenolic compounds and abscisic acid had additive inhibitory effects both on seedling growth and seed germination. The inhibition on lettuce was reversed by caffeic and ferulic acids at concentrations lower than 10^–3 M except for the inhibition of germination by coumarin. These results suggest that in naturetrans-cinnamic acid,o-, m-, p-coumaric acids, coumarin, and chlorogenic acid inhibit plant growth regardless of their concentration. However, caffeic and ferulic acids can either promote or inhibit plant growth according to their concentration.     

Thermal Expansion of Solid Solutions in the ZrTiO4—In2O3—M2O5 (M = Sb, Ta) System

Axial and dilatometric thermal expansions and phase transformations were studied for solid solutions having the α-PbO₂ structure in the ZrTiO₄—In₂O₃—M₂O₅ (M = Sb, Ta) system with nominal formulas of Zr _x Ti _y In _z Sb _z O₄ and Zr _x Ti _y In _z Ta _z O₄ where x + y + 2 z = 2. With increased substitution of z , the cell volume increased, the difference in the b parameters at room temperature between those quenched from 1400° and 1000°C decreased, and the thermal expansion decreased. The axial thermal expansion of ZrTi _y In _z · Ta _z O₄ with z = 0.3 was almost identical with that of HfTiO₄, and those with z = 0.4 and z = 0.45 were smaller than that of HfTiO₄. Unit-cell volumes of these compound were compared with those of single oxides to make it clear that the unit-cell volume of ZrTiO₄ was small anomalously and to distinguish the normal and abnormal substitution systems. These results were explained by the working hypothesis proposed for these compounds.     

Temperature measurements of polymer melts in the heating barrel during injection molding. Part I. Temperature distribution along the screw axis in the reservoir

A new procedure has been developed to measure the temperature distribution of the polymer melts along the screw axis during injection by using a small sheath thermocouple. At the same time, the effects of molding conditions on temperature distribution has been studied. The temperature distribution of the polymer melt along the screw axis during injection can be obtained from the difference between the standard temperature profile and the temperature profile of the polymer melt with unknown and non-uniform temperature measured under the same rate of injection. The temperature of a polymer melt within a shot is not uniform. The difference between the maximum and the minimum temperature within a shot may exceed 10°C in some cases. There are two major factors which govern the effects of molding conditions on the temperature distribution of the polymer melts during injection. The first is the amount of shear heating in the metering zone. The second is the amount of heat absorbed into the polymer in the compression and feed zones.     

Formation and transformation of cubic 3PbO·2Ta2O5 solid solution

The formation of lead tantalates in the PbO-rich region is studied using the powders prepared by the simultaneous hydrolysis of lead and tantalum alkoxides. Cubic 3PbO · 2Ta₂O₅ solid solutions crystallize at low temperatures from amorphous materials between 60 and 75 mol% PbO. The lattice parameter,a, increases linearly from 1.0545 to 1.0705 nm with increasing PbO. At higher temperatures the solid solutions above 66.67 mol% PbO are transformed into those of rhombohedral 2PbO · Ta₂O₅. Rhombohedral 5PbO · 2Ta₂O₅ is formed at 850 to 900 °C by transformation of 2PbO·Ta₂O₅ solid solution corresponding to 71.43 mol% PbO. The existence of previously reported 3PbO·Ta₂O₅ is not confirmed.     

Extrasynaptic-GABA-mediated neuromodulation in a sensory cortical neural network

Simulating a neural network model of an early sensory cortical area, we investigated how gamma-aminobutyric acid (GABA) accumulated in extracellular space (ambient GABA), which depends on the synaptic activity of GABAergic interneurons, acts on the GABAa-receptors located on extrasynaptic membrane regions of principal cells (P), feedback inhibitory cells (F) and lateral inhibitory cells (L). The ambient GABA enhanced the selective responsiveness of P-cells to a target feature stimulus, if it acted on the extrasynaptic GABAa-receptors of P-cells. The ambient GABA led to depolarizing P-cells during ongoing (spontaneous) neuronal-activity periods, if it acted on the extrasynaptic GABAa-receptors of F or L cells. This membrane depolarization contributed to establishing an ongoing subthreshold neuronal state, by which the P-cells could respond quickly to the target stimulus. We suggest that the combinatorial inhibition of P, F, and L cells, meditated by extrasynaptic GABAa-receptors recognizing ambient GABA, is crucial for processing the information of relevant sensory features and for establishing an ongoing subthreshold cortical state that prepares as a ready state for subsequent sensory input. A failure in neuronal-activity-dependent regulation of ambient GABA, stemming largely from the depletion of GABA in extracellular space during senescence, may cause the degeneration of intracortical inhibition that leads to cognitive dysfunction in old animals.     

Robust control method for the inverted pendulum system with structured uncertainty caused by measurement error

In this article, we propose a design method for an inverted pendulum system with a structured uncertainty. We consider that such an uncertainty is caused by a measurement error in the rotation angle of the pendulum and effects on the system structure that cannot be included in the nominal elements. For the uncertain system obtained, we apply an integral tracking control and the guaranteed cost control to design a robust, stable, tracking control system. Finally, we show the effectiveness of our method through a numerical example.     

A new quadruple therapy for the eradication of Helicobacter pylori. Effect of pretreatment with omeprazole on the cure rate

The aim of the study was to assess the speech discrimination ability of postlingually deaf adults implanted with the Combi 40 cochlear implant and to compare the results with the postoperative data published for other devices. The postoperative open and closed set speech perception performance of 21 consecutive patients was tested using a standardized test battery comprising a number, monosyllable, sentence, consonant and vowel discrimination test as well as a rhyme test in the sound only condition. Mean values achieved for each test 1, 6 and 12 months after "switch on" were evaluated. The results demonstrate that all patients have a substantial benefit from their implant and show a continuous improvement in their speech perception abilities with increased device experience. The mean percentages of correct answers after 12 months were 93.4 for numbers, 44.6 for monosyllables, 78.5 for sentences, 67.6 for the rhyme test, 59.8 for vowel, and 67.3 for consonant discrimination. Preoperatively, the mean discrimination score for monosyllables was 0%. The speech discrimination scores of our patients were similar or higher than described for similar patient groups implanted with other devices. The high stimulation rate of the implant system using the continuous interleaved speech processing strategy as well as a deep atraumatic electrode insertion into the apicalmost regions of the scala tympani may be the reason for good performance.     

Analysis of right ventricular function during bypass of the left side of the heart by afterload alterations in both normal and failing hearts

This study investigated the mechanism of right ventricular failure during bypass of the left side of the heart by precisely assessing right ventricular function with use of a conductance catheter. Bypass of the left side of the heart was established with a centrifugal pump in 10 mongrel dogs weighing 11 to 19 kg. Right ventricular function during left heart bypass was evaluated by two parameters that were both derived from measurement of relative change in right ventricular volume by the conductance catheter technique. One parameter was the right ventricular end-systolic pressure-volume relationship as a load-independent index, and the other was the peak right ventricular pressure-right ventricular stroke volume relationship as a "force-velocity relationship." These parameters were measured in both normal and failing hearts while afterload was increased by bilateral intrapulmonary balloon inflation. Moreover, changes in these relationships were observed by varying assist ratios of left heart bypass from 0% to 100%. Failing heart models were induced by normothermic aortic clamping for 20 minutes. The right ventricular end-systolic pressure-volume relationship in normal hearts did not change, irrespective of the assist ratio of left heart bypass, whereas that in failing hearts decreased from 4.25 +/- 1.41 mm Hg/ml without bypass of the left side of the heart to 3.53 +/- 1.30 mm Hg/ml after 100% assist of left heart bypass (p < 0.05). In the peak right ventricular pressure-right ventricular stroke volume relationship, right ventricular stroke volume was almost constant in normal hearts when afterload was increased regardless of the assist ratio of left heart bypass. Moreover, right ventricular stroke volume was maintained at a higher level during bypass of the left side of the heart compared with that without left heart bypass. However, that slope of the relationship in failing hearts was inversely linear and became significantly steeper after 100% assist of bypass of the left side of the heart compared with that without left heart bypass (-0.131 +/- 0.042 versus -0.051 +/- 0.038, p < 0.005). Therefore ++these two slopes of the relationship intersected at a point that was considered the critical point of afterload during bypass of the left side of the heart. In other words, right ventricular stroke volume was decreased by 100% left heart bypass above the critical point of afterload. In conclusion, this study demonstrates not only that bypass of the left side of the heart results in an increase in right ventricular stroke volume in both normal and failing hearts at the physiologic range of afterload, but also that right ventricular function against higher afterload is impaired by 100% assist of bypass of the left side of the heart in failing hearts.     

Successful electroconvulsive therapy of Cotard syndrome with bitemporal hypoperfusion

A case study is presented to illustrate a rare condition described by Cotard as "délire de négation". The central symptom is a nihilistic delusion with denial of one's own existence of oneself and that of the external world. In the present case, the syndrome became manifest as an escalation of a recurrent depressive disorder late in life. After initial resistance to therapy, the syndrome was successfully treated with electroconvulsive therapy. For the first time, we report the regional cerebral blood flow measured by 99mTc-HMPAO-SPECT before and after therapy. Before treatment, significant bitemporal hypoperfusion relative to the cerebellum was found, which was no longer demonstrable on remission.     

Vehicle inductive signatures recognition using a Madaline neural network

In this paper, we report results obtained with a Madaline neural network trained to classify inductive signatures of two vehicles classes: trucks with one rear axle and trucks with double rear axle. In order to train the Madaline, the inductive signatures were pre-processed and both classes, named C2 and C3, were subdivided into four subclasses. Thus, the initial classification task was split into four smaller tasks (theoretically) easier to be performed. The heuristic adopted in the training attempts to minimize the effects of the input space non-linearity on the classifier performance by uncoupling the learning of the classes and, for this, we induce output Adalines to specialize in learning one of the classes. The percentages of correct classifications presented concern patterns which were not submitted to the neural network in the training process, and, therefore, they indicate the neural network generalization ability. The results are good and stimulate the maintenance of this research on the use of Madaline networks in vehicle classification tasks using not linearly separable inductive signatures.