Physiological effects of Shinrin-yoku (taking in the atmosphere of the forest)--using salivary cortisol and cerebral activity as indicators

The purpose of this study is to examine the physiological effects of Shinrin-yoku (taking in the atmosphere of the forest). The subjects were 12 male students (22.8+/-1.4 yr). On the first day of the experiments, one group of 6 subjects was sent to a forest area, and the other group of 6 subjects was sent to a city area. On the second day, each group was sent to the opposite area for a cross check. In the forenoon, the subjects were asked to walk around their given area for 20 minutes. In the afternoon, they were asked to sit on chairs and watch the landscapes of their given area for 20 minutes. Cerebral activity in the prefrontal area and salivary cortisol were measured as physiological indices in the morning at the place of accommodation, before and after walking in the forest or city areas during the forenoon, and before and after watching the landscapes in the afternoon in the forest and city areas, and in the evening at the place of accommodation. The results indicated that cerebral activity in the prefrontal area of the forest area group was significantly lower than that of the group in the city area after walking; the concentration of salivary cortisol in the forest area group was significantly lower than that of the group in the city area before and after watching each landscape. The results of the physiological measurements show that Shinrin-yoku can effectively relax both people's body and spirit.     

Mice lacking alpha1,3-fucosyltransferase IX demonstrate disappearance of Lewis x structure in brain and increased anxiety-like behaviors

The 3-fucosyl-N-acetyllactosamine [Lewis x (Le(x)), CD15, SSEA-1] carbohydrate structure is expressed on several glycolipids, glycoproteins, and proteoglycans of the nervous system and has been implicated in cell-cell recognition, neurite outgrowth, and neuronal migration during development. To characterize the functional role of Le(x) carbohydrate structure in vivo, we have generated mutant mice that lack alpha1,3-fucosyltransferase IX (Fut9(-/-)). Fut9(-/-) mice were unable to synthesize the Le(x) structure carried on glycoproteins and glycolipids in embryonic and adult brain. However, no obvious pathological differences between wild-type and Fut9(-/-) mice were found in brain. In behavioral tests, Fut9(-/-) mice exhibited increased anxiety-like responses in dark-light preference and in elevated plus maze tests. Immunohistochemical analysis showed that the number of calbindin-positive neurons was decreased in the basolateral amygdala in Fut9(-/-) mice. These observations indicated that the carbohydrates synthesized by Fut9 play critical roles in functional regulations of interneurons in the amygdalar subdivisions and suggested a role for the Le(x) structure in some aspects of emotional behavior in mice.     

Remarkably stereoselective photoinduced electron-transfer reaction between zinc myoglobin and optically active binaphthyl bisviologen

We have designed and synthesized new optically active bisviologens ([BNMV](4+)) containing a binaphthyl moiety to examine the stereoselective photoinduced electron-transfer (ET) reactions with zinc-substituted myoglobin (ZnMb) by flash photolysis. The photoexcited triplet state of ZnMb, (3)(ZnMb)*, was successfully quenched by [BNMV](4+) ions to form the radical pair of a ZnMb cation (ZnMb(.+)) and a reduced viologen ([BNMV](.3+)), followed by a thermal ET reaction to the ground state. The rate constants ( k(q)) for the ET quenching at 25 degrees C were obtained as k(q)( R)=(2.9+/-0.2)x10(7) M(-1) s(-1) and k(q)( S)=(2.2+/-0.2)x10(7) M(-1) s(-1), respectively. The ratio of k(q)( R)/ k(q)( S)=1.3 indicates that the ( R)-isomer of the chiral viologen preferentially quenches (3)(ZnMb)*. On the other hand, the rate constants ( k) for the thermal ET reaction from [BNMV](.3+) to ZnMb(-+) at 25 degrees C were k( R)=(1.2+/-0.1)x10(8) M(-1) s(-1) and k( S)=(0.47+/-0.03)x10(8) M(-1) s(-1), respectively, and the ratio remarkably increased to k( R)/ k( S)=2.6. The activation parameters, Delta H(not equal) and Delta S(not equal), were determined from the kinetic measurements at various temperatures (10-30 degrees C) to understand the ET mechanisms. In the quenching reaction, the energy differences of Delta Delta H*(R- S) and T Delta Delta S*( R- S) at 25 degrees C were calculated to be -3.9+/-1.6 and -3.3+/-0.2 kJ mol(-1), respectively, whereas Delta Delta H*( R-S)=7.7+/-1.9 kJ mol(-1 )and T Delta Delta S*( R-S)=9.9+/-0.5 kJ mol(-1 )were found for the thermal ET reaction. Therefore, the thermal ET reaction to the ground state was proved to be dominated by the entropy term, and the large stereoselectivity may arise from the decrease in charge repulsion between donor and acceptor.     

Structural studies of [2',6'-dimethyl-L-tyrosine1]endomorphin-2 analogues: enhanced activity and cis orientation of the Dmt-Pro amide bond

Analogues of endomorphin-2 (EM-2: Tyr-Pro-Phe-Phe-NH(2)) (1) were designed to examine the importance of each residue on mu-opioid receptor interaction. Replacement of Tyr(1) by 2',6'-dimethyl-L-tyrosine (Dmt) (9-12) exerted profound effects: [Dmt(1)]EM-2 (9) elevated mu-opioid affinity 4.6-fold (K(i mu=0.15 nM) yet selectivity fell 330-fold as delta-affinity rose (K(i)delta=28.2 nM). This simultaneous increased mu- and delta-receptor bioactivities resulted in dual agonism (IC(50)=0.07 and 1.87 nM, respectively). While substitution of Phe(4) by a phenethyl group (4) decreased mu affinity (K(i)mu=13.3 nM), the same derivative containing Dmt (12) was comparable to EM-2 but also acquired weak delta antagonism (pA(2)=7.05). 1H NMR spectroscopy revealed a trans configuration (1:2 to 1:3, cis/trans) in the Tyr-Pro amide bond, but a cis configuration (5:3 to 13:7, cis/trans) with Dmt-Pro analogues.     

Urocystis tranzscheliana,a newly recorded smut fungus onPrimula sieboldii from Japan

A smut fungus onPrimula sieboldii was newly found in Japan and identified asUrocystis tranzscheliana by comparative morphology. This species causes systemic infection ofP. sieboldii and produces sori in its ovaries.Contribution No. 121, Laboratories of Plant Pathology and Mycology, Institute of Agriculture and Forestry, University of Tsukuba.     

Lattice population dynamics for plants with dispersing seeds and Vegetative propagation

The population dynamics of plants in a lattice structured habitat are studied theoretically. Plants are assumed to propagate both by producing seeds that scatter over the population and by vegetative reproduction by extending runners, rhizomes, or roots, to neighboring vacant sites. In addtion, the seed production rate may be dependent on the local density in the neighborhood, indicating beneficial or harmful crowding effects. Two sets of population dynamical equation(s) are derived: one based onmean-field approximation and the other based onpair approximation (tracing both global and local densities simultaneously). We examine the accuracy of these approximate dynamics by comparing them with direct computer simulation of the stochastic lattice model. Pair approximation is much more accurate than mean-field approximation. Mean-field approximation overestimates the parameter range for persistence if crowding effects on seed production are harmful or weakly beneficial, but underestimates it if crowding effects are highly beneficial. Dynamics may show bistability (both population persistence and extinction) if the effect of crowding is strongly beneficial. If there is a linear trade-off between seed production and vegetative reproduction, the equilibrium abundance of the population may be maximised by a mixture of seed production and vegetative reproduction, rather than by pure seed production or by pure vegetative reproduction. This result is correctly predicted by pair approximation but not by mean-field approximation.     

ATP-induced shrinkage of DNA with MukB protein and the MukBEF complex of Escherichia coli

Fluorescence microscopic observation of individual T4 DNA molecules revealed that the MukBEF complex (bacterial condensin) and its subunit, the MukB (a member of the SMC [structural maintenance of chromosomes] superfamily) homodimer, of Escherichia coli markedly shrunk large DNA molecules in the presence of hydrolyzable ATP. In contrast, in the presence of ADP or ATP-gammaS, the conformation of DNA was almost not changed. This suggests that the ATPase activity of subunit MukB is essential for shrinking large DNA molecules. Stretching experiments on the shrunken DNA molecules in the presence of ATP and MukBEF indicated a cross-bridging interaction between DNA molecules.     

Oral lipase activities and fat-taste receptors for fat-taste sensing in chickens

It has been reported that a functional fat-taste receptor, GPR120, is present in chicken oral tissues, and that chickens can detect fat taste in a behavioral test. However, although triglycerides need to be digested to free fatty acids to be recognized by fat-taste receptors such as GPR120, it remains unknown whether lipase activities exist in chicken oral tissues. To examine this question, we first cloned another fat-taste receptor candidate gene, CD36, from the chicken palate. Then, using RT-PCR, we determined that GPR120 and CD36 were broadly expressed in chicken oral and gastrointestinal tissues. Also by RT-PCR, we confirmed that several lipase genes were expressed in both oral and gastrointestinal tissues. Finally, we analyzed the lipase activities of oral tissues by using a fluorogenic triglyceride analog as a lipase substrate. We found there are functional lipases in oral tissues as well as in the stomach and pancreas. These results suggested that chickens have a basic fat-taste reception system that incorporates a triglycerides/oral-lipases/free fatty acids/GPR120 axis and CD36 axis.