Behavioral ecology of Japanese paper wasps,Polistes spp. IV. Comparison of ethograms between queens and workers ofP. chinensis antennalis in the ergonomic stage

Behavioral catalogues, transition matrices between 2 consecutive behavioral acts, and the frequency distribution of time spent in each behavioral act were described for queens and workers of a Japanese paper wasp,Polistes chinensis antennalis in the ergonomic stage (the period from the emergence of the first worker to the emergenece of the first reproductive). The results were; (1) The whole behavior repertoire of queens was completely included in that of workers. Workers oviposited frequently in queen-right colonies. (2) The proportion of off-nest activities to the number of total acts for workers was higher than that for queens. The proportion of time spent off the nest in workers was 5 times as high as that in queens. (3) There was no significant difference in the proportion of number of oviposition to the total number of acts between queens and workers. The oviposition rate was 0.06 eggs/h for workers and 0.37 eggs/h for queens. Queens made more dominance behavior and workers more subordinated behavior. Queens made abdomen wagging more frequently than workers. (4) For behavioral acts common in both queens and workers, the mean duration of a specific act was approximately equal for both. The mean duration of unsuccessful flesh collection for workers was 3.4 times as longs as that for queens. Workers did not search for flesh in 10.1% of duration of flesh collections in the field. (5) The pattern of transitions between 2 consecutive behavioral acts in workers was similar to that in queens. (6) Alien workers approaching a nest with a load were more often accepted by the nest occupants than alien workers with no load. Alien workers with no load were not accepted as often as a legitimate nestmates with no load. The reproductive division of labor between queens and workers inP. chinesis antennalis was incomplete. This suggests worker-queen conflict in different reproductive strategies among colony members. Several behaviors were consistent with the view that they are the behavioral expression of this conflict.     

Selection and reproductive success in males of the dragonfly,Orthetrum japonicum (Odonata: Libellulidae)

Reproductive success, copulation success, and mating success were measured for a population of male dragonflies,Orthetrum japonicum. Copulation success explained the greatest variation in reproductive success. The proportion of copulations followed by oviposition was positively correlated with the number of oviposited eggs per mating. Directional selection on four morphological characters was estimated. The effect of selection on correlated traits was comparable to that of direct selection. Directional selection varied between traits and between episodes in a single trait. The probability that the observed directional selection on the four morphological traits was expected under the condition of the selective neutrality of traits was not smaller than 5%.     

Changes in sensitivity to anoxia of the cardiac action potential plateau during chick embryonic development.

The effects of anoxia on cardiac action potentials were studied at different stages of development of embryonic chick heart. The plateau phase of the action potential was markedly depressed by anoxia in old (15–16 days old) embryonic hearts without any significant change in other configurations of the action potential. Raising the concentration of glucose in the external fluid prevented the shortening of the action potential plateau by anoxia, and, conversely, a further reduction was observed in glucose-free media. In young (3–4 days old) embryonic hearts, the shortening of the action potential plateau was not produced by anoxia, but was produced by a combination of anoxia and glucose deprivation. When the action potential was shortened by anoxia in old hearts and by anoxia plus glucose deprivation in young hearts, isoproterenol (10^?5M), dibutyryl cyclic 3′,5′-adenosine monophosphate (dBcAMP: 1 mM) plus aminophylline (1 mM), and calcium ion (3–6 mM), partially reversed the shortened action potential in old hearts, but did not produce any prolongation in the young hearts. Therefore, the cation channels responsible for the action potential plateau in young hearts may be pharmacologically different from those in old hearts. The differences in action potential plateau between young and old hearts were discussed in relation to dependence upon energy.     

Effects of the Consumption of Male Spermatophylax on the Oviposition Schedule of Females in the Decorated Cricket, Gryllodes sigillatus

The effects of the consumption of the spermatophylax produced by males on female fitness were studied in the decorated cricket, Gryllodes sigillatus. An increase in the number of spermatophylaces presented to females did not increase the total number of eggs made by females, the number of eggs laid, or the hatchability of eggs laid by females, but increased the number of eggs laid in the early stage of adult life of females. The duration of the egg stage decreased with the number of spermatophylaces presented to females. The implication of the results on the sham hypothesis that the spermatophylax does not have nutritional value is discussed.     

Cyclic nucleotide PDE-3

Type 3 cyclic nucleotide phosphodiesterase (PDE-3) isoforms exhibit a high affinity (“lowK _m”) for cAMP and are specifically inhibited by cGMP and a number of pharmacological agents, which increase myocardial contractility, inhibit platelet aggregation, and increase smooth muscle relaxation. The PDE-3 family consists of at least two isozymes, PDE-3A (cardiac type) and PDE-3B (adipocyte type), with distinct tissue-specific distributions. PDE-3A mRNA is highly expressed in the cardiovascular system, whereas PDE-3B mRNA is primarily expressed in adipocytes and hepatocytes. Toward understanding potential roles of PDE-3 in diabetes mellitus, we have established a specific and sensitive RNase protection assay (RPA) for quantitating PDE-3A and PDE-3B mRNA in rat diabetic models. In fatty Zucker diabetic (ZDF) rats, PDE-3A mRNA, but not PDE-3B mRNA, was expressed in heart, whereas liver and white and brown fat tissues predominantly expressed PDE-3B mRNA. Unexpectedly, PDE-3B mRNA expression was ≈2.5 times higher than PDE-3A mRNA in aorta from both ZDF and Sprague-Dawley (SD) rats. In contrast, expression levels of PDE-3A mRNA in heart were similar in both species. With this RPA, we were thus able to compare PDE-3A and-3B mRNA levels in different tissues as well as in different rat species.     

Action of endothelin-1 on rat astrocytes through the ETB receptor.

We investigated the effect of ET-1 on the state of rat cerebral astrocytes (AC) differentiation. AC ceased to proliferate and changed into its differentiated state by treatment with dibutyryl cyclic AMP (DBcAMP). The cell growth activity in DBcAMP-treated AC was stimulated by ET-1 in a dose-dependent manner. Over similar dose ranges, ET-1 suppressed the glutamine synthetase activity in DBcAMP-treated AC. The molar potency of ET-1 in this action was at least 3 orders of magnitude higher than that in mitogenic action in AC under the proliferative state previously reported. Northern blot analysis revealed that ETB receptor mRNA level in DBcAMP-treated AC was markedly higher than that in AC untreated with DBcAMP. Consistently, binding studies showed that the Bmax value for [125I]ET-1 in DBcAMP-treated AC was 16 times higher than that in AC untreated with DBcAMP. These results suggest that ET-1 potently induced a retraction of the differentiation state of AC from fully the specialized state and that the high responsiveness of differentiated AC to ET-1 was partly attributed to the high level expression of the ETB receptor.     

Structural and Immunological Effects of Skin Cryoablation in a Mouse Model

Cryoablation is therapeutically applied for various disorders in several organs, and skin diseases are typical targets as this cryotherapy has been widely used for viral warts, benign tumors, and actinic keratosis. The main mechanisms of cryoablation consist of direct freezing effect on skin constituents, thrombosis formation in microcirculation, and subsequent immunological responses. Among them, however, the immunological mechanism remains unelucidated, and it is an issue how the direct freezing injury induces immunological consequences. We established a mouse cryoablation model with liquid nitrogen applied to the shaved back skin, and used this system to study the immunological excitement. After application of liquid nitrogen, the thermal decrease ratio was -25°C/sec or less and the lowest temperature was less than -100°C, which was sufficient to induce ulceration. Destruction of cornified layer and necrosis of epidermal cells were observed in transmission electron microscopy image, and increased transepidermal water loss and skin permeability were detected by the functional measurements. By flow cytometry, antigen-presenting dendritic cells (DCs), including PDCA1⁺B220⁺CD19^- plasmacytoid DCs (pDCs) and CD11c⁺ myeloid DCs, as well as neutrophils and macrophages were increased in subcutaneous tissue. In parallel, the mRNA expressions of interferon α1 which are known as pDC-producing cytokines, was elevated. We also found marked degranulation of mast cells, providing a possibility that released histamine attracts pDCs. Finally, FITC migration assay revealed that pDCs and CD11c⁺ DCs emigrated from the cryoablated skin to the draining lymph nodes. Our study suggests that cryoablation induces destruction of the barrier/epidermis, accumulation of pDCs and CD11c⁺ DCs to the skin, and migration of DCs to regional lymph nodes. Viral elements or tumor cell lysates released from damaged keratinocytes may stimulate the DCs, thereby leading to antiviral or antitumor effect.     

The Structure of Mindful Brain

Mindfulness is currently attracting a great deal of attention as a psychotherapy technique. It is defined as bringing one''s complete attention to the experiences occurring in the present moment in a nonjudgmental or accepting way. The Five Facet Mindfulness Questionnaire (FFMQ) was developed to assess individual differences in mindfulness states. The FFMQ is composed of five facets representing elements of mindfulness: non-reactivity to inner experience, non-judging, acting with awareness, describing, and observing. In the present study, we applied voxel-based morphometry to investigate the relationship between the brain structure and each facet as measured by the FFMQ. The results showed a positive association between the describing facet of mindfulness on the FFMQ and gray matter volume in the right anterior insula and the right amygdala. In conclusion, mindfulness was related with development in parts of the somatic marker circuit of the brain.