Acute effects of bisphenol (BPA), an environmental chemical, on estradiol (17α or β-E2)-dependent recognition memory and dendritic spines in the medial prefrontal cortex and hippocampus were ...investigated in adult female rats. Ovariectomized rats received BPA 30 min before or immediately after a sample trial (viewing objects), and retention trials were performed 4 h later. Retention trials tested discrimination between old and new objects (visual memory) or locations (place memory). When given immediately after the sample trial, BPA, 1–400 μg/kg, did not alter recognition memory, but 1 and 40 μg/kg BPA, respectively, blocked 17β-E2-dependent increases in place and visual memory. When ovariectomized rats were tested with 17α-E2, 1 μg/kg BPA blocked place memory, but up to 40 μg did not block visual memory. BPA, given to cycling rats at 40 μg/kg, blocked visual, but not place, memory during proestrus when 2 h intertrial delays were given. Spine density was assessed at times of memory consolidation (30 min) and retention (4 h) after 17β-E2 or BPA + 17β-E2. In prefrontal cortex, BPA did not alter E2-dependent increases. In the hippocampus, BPA blocked E2 increases in basal spines at 4 h and was additive with E2 at 30 min. Thus, these novel data show that doses of BPA, below the current Environmental Protection Agency safe limit of 50 μg/kg, rapidly alter neural functions dependent on E2 in adult female rats.
We study the regularization dependence on meson properties and the phase diagram of quark matter by using the two flavor Nambu–Jona-Lasinio model. The model also has the parameter dependence in each ...regularization, so we explicitly give the model parameters for some sets of the input observables, then investigate its effect on the phase diagram. We find that the location or the existence of the critical end point highly depends on the regularization methods and the model parameters. Then we think that regularization and parameters are carefully considered when one investigates the QCD critical end point in the effective model studies.
The symbiosis between lower termites and their intestinal microorganisms, essential for wood digestion, is well characterized. Termites exhibit a reproductive division of labor—kings and queens ...specialize in reproduction, and workers are responsible for foraging and feeding the colony members. Therefore, the gut microbial community in royals is expected to be down-regulated because it is less important than that in workers. Indeed, we recently reported that, in the termite species
Reticulitermes speratus
, workers have symbiotic protists; kings, and neotenic queens in mature field colonies completely lose protists in their guts. However, the dynamics of the protist community during caste differentiation remain unclear. In this study, we investigated the relationship between the abundance of intestinal protists and the neotenic differentiation of
R. speratus
. First, we confirmed that both sexes of late instar nymphs possessed intestinal protist communities like those of workers. Nevertheless, after molting for neotenic differentiation, they lost most of their intestinal protists and did not regain them. Based on our behavioral observation, workers, nymphs, and neotenics received proctodeal food from surrounding workers. This suggests protists can enter neotenics’ guts, while they cannot establish after the neotenic differentiation. Our study highlights that the interaction between termites and gut microbes changes dynamically during caste differentiation.
We study the three-flavor Nambu–Jona-Lasinio model with various regularization procedures. We perform parameter fitting in each regularization and apply the obtained parameter sets to evaluate ...various physical quantities, several light meson masses, decay constant and the topological susceptibility. The model parameters are adopted even at very high cutoff scale compare to the hadronic scale to study the asymptotic behavior of the model. It is found that all the regularization methods except for the dimensional one actually lead reliable physical predictions for the kaon decay constant, sigma meson mass and topological susceptibility without restricting the ultra-violet cutoff below the hadronic scale.
Acute effects of estrogens on mnemonic processes were examined at the behavioral and neurochemical levels. 17β-estradiol and 17α-estradiol influences on memory consolidation were assessed using ...object placement (OP) and object recognition (OR) tasks. Subjects received treatment immediately after a sample trial (exploring two novel objects), and memory of objects (OR memory) or location of objects (OP memory) was tested 4
h later. Both isomers of estradiol enhanced memory. For spatial memory, 15 and 20
µg/kg of 17β-estradiol facilitated OP, while lower and higher doses were ineffective. 17α-estradiol had a similar pattern, but a lower dose was effective. When treatment was delayed until 45
min after a sample trial, memory was not enhanced. For non-spatial memory, OR was facilitated at 5
µg/kg of 17β-estradiol and at 1 and 2
µg/kg of 17α-estradiol and, similar to OP, lower and higher doses were ineffective. These data demonstrate that beneficial effects of estrogens are dose, time and task dependent, and the dose–response pattern is an inverted U. Because monoamines are known to have contributions to memory, brains were removed 30
min after treatment for measurements of dopamine (DA), norepinephrine (NE), serotonin (5-HT), and metabolites. Estrogen elevated 5HT, NE metabolite MHPG, turnover ratio of NE to MHPG, and DA metabolite DOPAC levels in the prefrontal cortex, while NE and MHPG were decreased in the hippocampus. Thus, acute estrogens exert rapid effects on memory consolidation and neural function, which suggests that its mnemonic effects may involve activation of membrane associated estrogen receptors and subsequent signaling cascades, and that monoamines may contribute to this process.
Social insects live in closely related family groups but face risks of intrusion and infection by pathogenic and parasitic microbes. To cope with the microbes invading their nests and feeding sites, ...social insects produce various types of antimicrobial substances. Subterranean termites occupy microbe-rich decaying wood and soil at high density, expanding their nest area by exploring and feeding on wood outward from the royal chamber (room for kings and queens). Although antimicrobial agents have been identified in many termite species, few studies have investigated those used by foraging workers in decaying wood under development, which is richer in microbes than the well-sterilized royal chamber and its surroundings. Here, we report that phenylacetic acid, an antifungal aromatic compound, is secreted by foraging workers of the Japanese subterranean termite
Reticulitermes speratus
. The compound was detected by gas chromatography–mass spectrometry analysis of ethyl acetate extracts of shelter papers infested with the workers, and antimicrobial tests demonstrated that it inhibits the germination and/or mycelial growth of the entomopathogenic fungi (
Metarhizium anisopliae
and
Beauveria bassiana
) and the termite egg-mimicking fungus
Athelia termitophila
. Our study provides new insights into the antimicrobial defense mechanisms of termites, including by combining different types of antimicrobial substances secreted by different castes, and thus the survival strategy of entomopathogenic and parasitic fungi in termite nests.
We present an experimental scheme of implementing multiple spins in a classical XY model using a non-degenerate optical parametric oscillator (NOPO) network. We built an NOPO network to simulate a ...one-dimensional XY Hamiltonian with 5000 spins and externally controllable effective temperatures. The XY spin variables in our scheme are mapped onto the phases of multiple NOPO pulses in a single ring cavity and interactions between XY spins are implemented by mutual injections between NOPOs. We show the steady-state distribution of optical phases of such NOPO pulses is equivalent to the Boltzmann distribution of the corresponding XY model. Estimated effective temperatures converged to the setting values, and the estimated temperatures and the mean energy exhibited good agreement with the numerical simulations of the Langevin dynamics of NOPO phases.
Accumulating evidence indicates that chronic low dose exposure to Bisphenol A (BPA), an endocrine disruptor, may disrupt normal brain development and behavior mediated by the gonadotropin-releasing ...hormone (GnRH) pathways. While it is known that GnRH neurons in the hypothalamus regulate reproductive physiology and behavior, functional roles of extra-hypothalamic GnRH neurons remain unclear. Furthermore, little is known whether BPA interacts with extra-hypothalamic GnRH3 neural systems in vulnerable developing brains. Here we examined the impact of low dose BPA exposure on the developing GnRH3 neural system, eye and brain growth, and locomotor activity in transgenic medaka embryos and larvae with GnRH3 neurons tagged with GFP. Fertilized eggs were collected daily and embryos/larvae were chronically exposed to 200ng/ml of BPA, starting at 1 day post fertilization (dpf). BPA significantly increased fluorescence intensity of the GnRH3-GFP neural population in the terminal nerve (TN) of the forebrain at 3dpf, but decreased the intensity at 5dpf, compared with controls. BPA advanced eye pigmentation without affecting eye and brain size development, and accelerated times to hatch. Following chronic BPA exposure, 20dpf larvae showed suppression of locomotion, both in distance covered and speed of movement (47% and 43% reduction, respectively). BPA-induced hypoactivity was accompanied by decreased cell body sizes of individual TN-GnRH3 neurons (14% smaller than those of controls), but not of non-GnRH3 neurons. These novel data demonstrate complex neurobehavioral effects of BPA on the development of extra-hypothalamic GnRH3 neurons in teleost fish.
Gauged Nambu-Jona-Lasinio inflation Inagaki, T.; Odintsov, S. D.; Sakamoto, H.
Astrophysics and space science,
12/2015, Letnik:
360, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We investigate the gauged Nambu-Jona-Lasinio model in curved space-time at the large
N
c
limit and in slow-roll approximation. The model can be described by the renormalization group corrected ...gauge-Higgs-Yukawa theory with the corresponding compositeness conditions. Evaluating the renormalization group (RG) improved effective action, we show that such model can produce CMB fluctuations and find inflationary parameters: spectral index, tensor-to-scalar-ratio and running of the spectral index. We demonstrate that the model can naturally satisfy the Planck 2015 data and maybe considered as an alternative candidate for Higgs inflation.
Division of labor is fundamental to the ecological success of social insects. In termites, both sexes engage in social tasks, and the sexual division of labor is common in many taxa. Each caste ...consisting of both sexes is supplied from the population of newly hatched larvae. To understand their social system, it is necessary to investigate the influence of larval sex composition on their developmental fate. However, no method currently exists for sexing young larvae non-invasively, which is essential for experimental manipulation of the sex composition in a society. Here, we report on sex-specific characteristics of the first and second instar larvae of the subterranean termite
Reticulitermes speratus
. Male larvae possess bristles near the center of the posterior margin of the eighth abdominal sternite that are absent in females. The bristles are detectable under a stereomicroscope without damaging the young instar larvae. The validity of morphological sexing was confirmed by a known sex-specific genetic marker. The sex-specific bristles were also useful to identify the sex of first and second instar larvae of the damp-wood termite
Zootermopsis nevadensis
, suggesting that morphological sexing is possible for a wide range of termite species. The morphological sexing presented here has broad applicability in studies addressing sex differences in development, caste differentiation, and behavior. These approaches will contribute to understanding why both sexes co-exist in a termite society and allocate tasks, and which tasks are completely compensable by the other sex, thereby deepening our understanding of social systems where both sexes engage in tasks.
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