Language control in the bilingual brain

How does the bilingual brain distinguish and control which language is in use? Previous functional imaging experiments have not been able to answer this question because proficient bilinguals activate the same brain regions irrespective of the language being tested. Here, we reveal that neuronal responses within the left caudate are sensitive to changes in the language or the meaning of words. By demonstrating this effect in populations of German-English and Japanese-English bilinguals, we suggest that the left caudate plays a universal role in monitoring and controlling the language in use.     

Suppression of MyoD induces spontaneous adipogenesis in skeletal muscle progenitor cell culture

The degree of intramuscular adipose tissue accumulation is one of the factors affecting meat quality. Accumulation of adipocytes is also observed under the pathological condition of skeletal muscle such as muscular dystrophy and sarcopenia. The origin of adipocytes seen in skeletal muscle is mesenchymal progenitor cells that can give rise to both adipocytes and fibroblasts. In the present study, we demonstrated that siRNA-mediated suppression of MyoD expression in rat skeletal muscle progenitor cell culture, which comprises both myogenic satellite cells and mesenchymal progenitor cells, resulted in diminished myotube formation and an unexpected spontaneous appearance of white adipocytes. Suppressing myomaker expression also resulted in complete absence of myotube formation without reducing MyoD expression, but no adipogenesis was seen in this scenario, indicating that decline in MyoD expression rather than decreased myotube formation is necessary to induce adipogenesis. In addition, spontaneous adipogenesis induced by suppressing MyoD expression in culture was inhibited by the conditioned medium from control culture, indicating that anti-adipogenic factor(s) are secreted from MyoD-positive myogenic cells. These results indicate the presence of regulatory mechanism on adipogenesis by myogenic cells.     

Neutrophilic nodules in the intestinal walls of Japanese monkeys associated with the neutrophil chemotactic activity of larval extracts and secretions of Oesophagostomum aculeatum

High neutrophil chemotactic activity was detected in the culture medium from Oesophagostomum aculeatum larvae in vitro using blind-well chambers with Millipore filters, and guinea pig leucocytes as indicator cells. Neutrophil chemotactic activity was also detected in the extract from larval worms in a dose dependent fashion. This activity was detected in the low molecular weight fractions adjacent to a sodium chloride marker by gel filtration on Sephadex G200. These results were further confirmed with monkey neutrophils. The possible role of this activity in the formation of granulomatous lesions rich in neutrophils found in O aculeatum infections in the Japanese monkey is discussed.     

Insect glutathione S-transferase: Separation of transferases from fat bodies of American cockroaches active on organophosphorus triesters

Several glutathione S-transferases which catalyze the conjugation of reduced glutathione with organophosphorus triesters were separated from fat bodies of adult female American cockroaches, Periplaneta americana (L.). Two transferases (I, V) were active on diazinon and three transferases (II, III, IV) were active on methyl parathion. The transferase (I) active on the pyrimidinyl moiety of diazinon was distinguishable from the other transferases on the O-methyl portion of methyl parathion, as shown by chromatographic properties, and additionally it was almost inactive or less active on 3,4-dichloronitrobenzene, methyl iodide, p-nitrobenzyl chloride, trans-cinnamaldehyde, and 1,2-epoxy-3-(p-nitrophenoxy)propane. Transferase II had high activities with “aryl” and “aralkyl” compounds, transferase III with “epoxide” and “alkene,” and transferase IV with “alkyl,” “aryl,” and “aralkyl” compounds. This indicated that the transferases had overlapping substrate specificities. The molecular weight was 35,000–37,000 for both of the enzymes active on methyl parathion and diazinon. The pH optima with methyl parathion and diazinon were about 8.5 and 6.5, respectively. At a glutathione concentration of 5 mM, Michaelis constants were 0.28 and 0.13 mM for methyl parathion and diazinon, respectively.     

Food habits of fishes in a freshwater reed belt in Lake Kitaura,eastern Japan,in summer

The diets and feeding guild structure of a freshwater reed belt fish assemblage (30 species) were examined in Lake Kitaura, part of the Lake Kasumigaura system, eastern Japan, from June to September in 2009 and 2010. Ontogenetic dietary shifts were recognized in 14 species, including several species (e.g., Cyprinus carpio, Tridentiger brevispinis and Hyporhamphus intermedius) targeted by local fisheries. Juveniles of these species generally fed on zooplankton, later switching to other prey items (e.g., benthic chironomid larvae, gammaridean amphipods, shrimps, juvenile fishes, diatoms and decomposing reeds) with growth. A cluster analysis based on dietary overlaps showed that the reed belt fish assemblage comprised five feeding guilds (plant, zooplankton, benthic invertebrate, terrestrial insect and fish feeders). Of these, zooplankton feeders were the most abundantly represented in terms of species numbers, suggesting that the main food items for the fish assemblage were zooplankton (e.g., cladocerans, and calanoid and cyclopoid copepods). Fish feeders included five species, of which one was an alien species introduced from another region in Japan (Opsariichthys uncirostris) and three were from foreign countries (Micropterus salmoides, Lepomis macrochirus macrochirus and Ictalurus punctatus).     

Radiocesium transfer from Andosols to brown rice in the northern and northwest areas of Tochigi Prefecture,in the first 3 years following the 2011 Fukushima Daiichi nuclear power plant accident

ABSTRACT

Following the Fukushima Daiichi Nuclear Power Plant accident of 2011, the potential for radiocesium transfer from contaminated soils, such as Andosols, to agricultural crops became a significant concern. Andosols account for up to 70％ of paddy soils in the northern and northwest areas of Tochigi Prefecture, where the radiocesium concentration is 1000 Bq kg^?1 or greater in the soil of some fields. The present study was carried out in order to determine the phytoavailability of radiocesium in Andosols by comparing it with that of gray lowland soils in the first 3 years following the accident. The transfer factor (TF) tended to be higher in Andosols than in gray lowland soils, leading to higher radiocesium concentrations in brown rice grown in Andosols. The exchangeable potassium (Ex-K₂O) in Andosols was highly and negatively correlated with TF, followed by clay. The Ex-K₂O value was positively correlated with the clay/total carbon (T-C) value, suggesting that a high T–C ratio could weaken K₂O adsorption on clay mineral sites; hence, the low clay/T-C values can partially explain the relatively large TF values of Andosols. Samples with Ex-K₂O contents less than 200 mg kg^?1 and with low clay/T-C values showed striking decreases in TF values from 2011 to 2012. However, the decrease from 2012 to 2013 was quite small; radiocesium in these samples was potentially available for rice uptake for a long time, likely due to the reversible adsorption and fixation characteristics of allophane. Most gray lowland soil samples showed very low TF values over the 3 years of the study, except for those with TF values greater than 0.1 due to low Ex-K₂O and clay contents; the geometric mean (GM) value of TF was below 0.01 in 2012. The extraction of exchangeable radiocesium (Ex-Cs) with a 1 mol L^?1 ammonium acetate solution may not be an appropriate method for explaining the variability in radiocesium TF in Andosols. This is because the Ex-Cs value was significantly correlated with Ex-K₂O in Andosols, but not in gray lowland soils, indicating that Ex-K₂O explained this variability in relation to Ex-Cs.