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Neurochemical lateralization has been demonstrated in the rat brain suggesting that such lateralization might contribute to behavior. Thus, the aim of the present study was to examine neurochemical asymmetry in the hippocampus, molecular basis of neurochemical lateralization and its impact on spatial learning and memory. Changes in noradrenaline content, tyrosine hydroxylase (TH) were studied in the right and left hippocampus of naive control and chronically isolated rats, by applying TaqMan RT-PCR and Western blot analysis. Hippocampal-based spatial learning and memory were evaluated using the Barnes maze. In control rats an asymmetrical right-left distribution of noradrenaline content and gene expression of catecholamine synthesizing enzyme was found. Chronic psychosocial stress further emphasized asymmetry. Isolation stress reduced noradrenaline content only in the right hippocampus. No changes were observed in gene expression and protein levels of TH in the right hippocampus, whereas expression of catecholamine synthesizing enzyme was elevated in the left hippocampus. Reduced noradrenaline content in the right hippocampus did not cause impairment in spatial learning and memory. Our findings suggest that chronic psychosocial stress reduces noradrenaline stores in the right hippocampus which may be caused by molecular asymmetry, but it does not affect spatial learning and memory.
hand ( 27 , 33 , 44 ). This behavioral asymmetry is known as “right-handedness.” Proprioception is an essential element of motor control. Activation of muscle, skin, and joint receptors allows sensing the orientation of body and body parts
References Adamski , P. and Z.J. Witowski . 2002 . Increase in fluctuating asymmetry during a population extinction: the case of the apollo butterfly Parnassius apollo
. , G.L. Lövei and M. Bátki . 2014 . Fluctuating asymmetry in ground beetles (Carabidae) as an indication of the impact of urbanisation in Denmark . Community Ecol. 15 : 131 – 138
affect the inflation rate? Does this effect differ in the short- and long-terms? Is this effect linear? Is there an asymmetry or nonlinearity, as pointed out in Mork (1989) , Hooker (2002) , Balke et al. (2002) , Hamilton (2011) , Bala – Chin (2018
Abstract
The quality of measurement of heat capacity by differential scanning calorimetry (DSC) is based on strict symmetry of the twin calorimeter. This symmetry is of particular importance for temperature-modulated DSC (TMDSC) since positive and negative deviations from symmetry cannot be distinguished in the most popular analysis methods. The heat capacities for sapphire-filled and empty aluminum calorimeters (pans) under designed cell imbalance caused by different pan-masses were measured. In addition, the positive and negative signs of asymmetry have been explored by analyzing the phase-shift between temperature and heat flow for sapphire and empty runs. The phase shifts change by more than 180° depending on the sign of the asymmetry. Once the sign of asymmetry is determined, the asymmetry correction for temperature-modulated DSC can be made.
Abstract
The quality of measurement of heat capacity by differential scanning calorimetry (DSC) is based on the symmetry of the twin calorimeters. This symmetry is of particular importance for the temperature-modulated DSC (TMDSC) since positive and negative deviations from symmetry cannot be distinguished in the most popular analysis methods. Three different DSC instruments capable of modulation have been calibrated for asymmetry using standard non-modulated measurements and a simple method is described that avoids potentially large errors when using the reversing heat capacity as the measured quantity. It consists of overcompensating the temperature-dependent asymmetry by increasing the mass of the sample pan.
This study focuses on the notions of explicitation and implicitation in translation and aims to provide empirical evidence for operational asymmetry (Klaudy 2001). Bi-directional (SL=L1→TL=L2 and SL=L2→TL=L1) comparisons show that when explicitation takes place in the L1→L2 direction, implicitation can be observed in the L2→L1 direction. This phenomenon is referred to as symmetric explicitation. It may also happen, however, that when explicitation is carried out in the L1→L2 direction, no implicitation occurs in the L2→L1 direction. This phenomenon is referred to as asymmetric explicitation. It would be logical to suppose that all cases of language-specific explicitation in the L1→L2 direction are symmetrical (i.e., matched by implicitation in the L2→L1 direction), but this does not seem to be the case. The present paper reports on the findings of an empirical study designed to investigate the validity of the asymmetry hypothesis in the translation of reporting verbs in literary texts translated from English into Hungarian and from Hungarian into English. Using the method of two-way qualitative translation analysis, the study demonstrates that translators tend to prefer the more explicit forms to the more implicit ones in both directions and often fail to perform implicitation. The study may thus provide further evidence for the assumption that semantic explicitation is in fact a universal translation strategy.
Environmental stress can lead to a reduction in developmental homeostasis, which could be reflected in increased variability of morphological traits. Fluctuating asymmetry (FA) is one possible manifestation of such a stress, and is often taken as a proxy for individual fitness. To test the usefulness of FA in morphological traits as an indicator of environmental quality, we studied the effect of urbanisation on FA in ground beetles (Carabidae) near a Danish city. First, we performed a critical examination whether morphological character traits suggested in the literature displayed true fluctuating asymmetry in three common predatory ground beetles, Carabus nemoralis, Nebria brevicollis and Pterostichus melanarius. Eight metrical (length of the second and third antennal segments, elytral length, length of the first tarsus segment, length of the first and second tibiae, length of the proximal and distal spines on the first femurs) and one meristic (the number of spines on the second tibiae) traits were examined. Most of them showed FA but not consistently. Females generally displayed a higher level of FA than males. Finally, we examined the changes in the level of FA in bilateral morphological traits along an urbanisation gradient (forest - suburban forest - forest fragments in urban park) to test whether environmental stress created by urbanisation is reflected in FA. Ground beetles common along a Danish urbanisation gradient did not seem to indicate differences in habitat quality by their level of FA.
Mars Orbiter Laser Altimeter (MOLA) team discovered “the striking difference” in elevation between northern and southern hemispheres: “on Mars, the South Pole lying about six km higher than the North Pole, … the planet’s center of mass (is) 3 km north of its geometric center” (Physics Today, Oct 1999, p. 34). The same topography we have for solid Earth: low Arctic and high Antarctic with the same difference 5–7 km. No sound explanation of NS asymmetry was proposed: impact, planetary evolution, mantle convection … are rather artificial and vague. Meanwhile, NS asymmetry is inherent property of any freely rotating flexible celestial body as it follows from Kozyrev’s Causal or asymmetrical mechanics. Relations of Causal mechanics are supported by experimental study of vertical component of causal force by weight change measurement of rotated gyroscope and the study of its horizontal component by pendulum deflection measurement. Kozyrev made measurements at latitudes φ from 45° to 84° and proved that causal force is directed along Earth rotation axis: to the North for φ < 73° and to South for φ > 73°. The magnitude of causal force has order (1–5) × 10−5 of gravity force.
