Litchi and longan are tropic/subtropic fruits harboring recalcitrant seeds that are covered with sugar-rich arils as the edible part. A rapid sugar content decline, called sugar receding, in the arils after the fruit maturation largely reduces the fruit quality, however, the mechanism is unclear. Litchi and longan fruits grow and mature in a hot and rainy season with dry spells between rainfalls. Here, we found that the seed maturation was around 2 weeks earlier than the fruit maturation, after which the sugar contents of the arils significantly decreased, while the fruits could stay on the tree for 1–2 months with high seed vigor. A continuously low-level fruit drop after the seed maturation resulted in continuous seed germination and seedling establishment in around 2–3 months. Blocking assimilate supply by storage of detached fruits or on-tree girdling-plus-defoliation for 7 days, the aril sugar contents of the treated fruits significantly decreased, while the sugar levels and vigor of the seeds increased, implying that the arils are sugar sources to maintain or even enhance the seed vigor and suggesting that sugar receding in arils benefits the recalcitrant seeds of litchi and longan to cope with dry spells after maturation.

Adopting highly sensitive multivariate electroencephalography (EEG) and alpha-band decoding analyses, the present study investigated proactive and reactive language control during bilingual language production. In a language-switching task, Chinese-English bilinguals were asked to name pictures based on visually presented cues. EEG and alpha-band decoding accuracy associated with switch and non-switch trials were used as indicators for inhibition over the non-target language. Multivariate EEG decoding analyses showed that the decoding accuracy in L1 but not in L2, was above chance level shortly after cue onset. In addition, alpha-band decoding results showed that the decoding accuracy in L1 rose above chance level in an early time window and a late time window locked to the stimulus. Together, these asymmetric patterns of decoding accuracy indicate that both proactive and reactive attentional control over the dominant L1 are exerted during bilingual word production, with a possibility of overlap between two control mechanisms. We addressed theoretical implications based on these findings for bilingual language control models.

How speaking two languages affects executive functions has been a long-standing debate and the mechanisms underlying the observed cognitive advantages of bilingualism remain unspecified. Here, using multivariate pattern classification methods, we decoded spatial patterns of neural signals associated with Flanker task performance in mono-dialectal and bi-dialectal speakers of Chinese. While univariate approach to even-related potentials (ERPs) showed no between-group difference, decoding accuracy of ERPs was reduced in bi-dialectal as compared to mono-dialectal speakers in both congruent-neutral and incongruent-neutral classifications. There was no effect of bidialectalism, however, on decoding accuracy of alpha-band oscillations, an electrophysiological index implicated in inhibition. Behavioural data analysed using the Drift Diffusion Model (DDM) showed facilitating effects of bidialectalism on non-decision times but no effect on drift rates. These findings demonstrate that using two dialects on a daily basis enhances general attentional deployment rather than affecting specific component of executive functions such as inhibitory control. Given that the two dialects of Chinese differed almost exclusively in phonology, the bidialectalism effect was most likely motivated by resolving phonological competition at lexical processing level.

Numerous functional magnetic resonance imaging (fMRI) studies have examined the neural mechanisms of negative emotional words, but scarce evidence is available for the interactions among related brain regions from the functional brain connectivity perspective. Moreover, few studies have addressed the neural networks for negative word processing in bilinguals. To fill this gap, the current study examined the brain networks for processing negative words in the first language (L1) and the second language (L2) with Chinese-English bilinguals. To identify objective indicators associated with negative word processing, we first conducted a coordinate-based meta-analysis on contrasts between negative and neutral words (including 32 contrasts from 1589 participants) using the activation likelihood estimation method. Results showed that the left medial prefrontal cortex (mPFC), the left inferior frontal gyrus (IFG), the left posterior cingulate cortex (PCC), the left amygdala, the left inferior temporal gyrus (ITG), and the left thalamus were involved in processing negative words. Next, these six clusters were used as regions of interest in effective connectivity analyses using extended unified structural equation modeling to pinpoint the brain networks for bilingual negative word processing. Brain network results revealed two pathways for negative word processing in L1: a dorsal pathway consisting of the left IFG, the left mPFC, and the left PCC, and a ventral pathway involving the left amygdala, the left ITG, and the left thalamus. We further investigated the similarity and difference between brain networks for negative word processing in L1 and L2. The findings revealed similarities in the dorsal pathway, as well as differences primarily in the ventral pathway, indicating both neural assimilation and accommodation across processing negative emotion in two languages of bilinguals.

Domain-general cognitive control is closely related to language control during bilingual language production. Previous neural imaging studies have revealed a highly overlapped but rewired brain network for language control and nonverbal cognitive control. In the present study, we examined this issue from a training perspective. Two groups of participants performed the language switching task at pre-and post-tests during functional magnetic resonance imaging (fMRI) scanning. After the pre-test, the experimental group received 8-day training in a non-verbal switching task, while the control group performed an unrelated color judgement task. We found that only the experimental group but not the control group showed decreased strength of connectivity from the ventral lateral frontal cortex to the left caudate nucleus and from the medial surface of the frontal lobe to the left thalamus. These results indicate an increased efficiency after nonverbal training for the frontal cortex to implement domain-general suppression and monitoring in a domain-specific conflict context during bilingual language and lexical selections. This study is the first to investigate the transfer effects of nonverbal cognitive control on the brain network of bilingual language control and shed light on the mechanisms of how domain-general cognitive control may underpin bilingual language control.

Listeners regularly comprehend continuous speech despite noisy conditions. Previous studies show that neural tracking of speech degrades under noise, predicts comprehension, and increases for non-native listeners. We test the hypothesis that listeners similarly increase tracking for both L2 and noisy L1 speech, after adjusting for comprehension. Twenty-four Chinese-English bilinguals underwent EEG while listening to one hour of an audiobook, mixed with three levels of noise, in Mandarin and English and answered comprehension questions. We estimated tracking of the speech envelope in EEG for each one-minute segment using the multivariate temporal response function (mTRF). Contrary to our prediction, L2 tracking was significantly lower than L1, while L1 tracking significantly increased with noise maskers without reducing comprehension. However, greater L2 proficiency was positively associated with greater L2 tracking. We discuss how studies of speech envelope tracking using noise and bilingualism might be reconciled through a focus on exerted rather than demanded effort.

The cognitive function of the human cerebellum could be characterized as enigmatic. However, researchers have attempted to detail the comprehensive role of the cerebellum in several cognitive processes in recent years. Here, using functional magnetic resonance imaging (fMRI) and transcranial direct current stimulation (tDCS), we revealed different functions of bilateral cerebellar lobules in bilingual language production. Specifically, brain activation showed the bilateral posterolateral cerebellum was associated with bilingual language control, and an effective connectivity analysis built brain networks for the interaction between the cerebellum and the cerebral cortex. Furthermore, anodal tDCS over the right cerebellum significantly optimizes language control performance in bilinguals. Together, these results reveal a precise asymmetrical functional distribution of the cerebellum in bilingual language production, suggesting that the right cerebellum is more involved in language control. In contrast, its left counterpart undertakes a computational role in cognitive control function by connecting with more prefrontal, parietal, subcortical brain areas.

Superficial scald is a physiological storage disorder that significantly reduces the marketability of apple fruit. To gain fundamental knowledge about the biochemical pathways leading to the development of the disorder and mechanisms of treatments for prevention, an untargeted metabolomics experiment employing liquid chromatography and mass spectrometry with data independent acquisition was performed. Metabolomic changes of two apple cultivars ‘Cortland’ and ‘Red Delicious’ with scald development and scald control treatments, using diphenylamine and 1-MCP, at 0–1 °C for up to 7 months was investigated. In total, 833 features/compounds were analyzed, and among them 59 were found to change significantly in controls involved in scald development, and in response to DPA and 1-MCP treatments. Our results provide new evidence that metabolites in association with phenylpropanoid metabolism, antioxidant and redox systems, and amino acid metabolism are related closely to scald development and response to potential treatments.

Listeners regularly comprehend continuous speech despite noisy conditions. Previous studies show that cortical entrainment to speech degrades under noise, predicts comprehension, and increases for non-native listeners. We test the hypothesis that listeners similarly increase cortical entrainment for both L2 and noisy L1 speech, after controlling for comprehension. Twenty-four Chinese-English bilinguals underwent EEG while listening to one hour of an audiobook, mixed with three levels of noise, in Mandarin and English and answered comprehension questions. We estimated cortical entrainment for one-minute tracks using the multivariate temporal response function (mTRF). Contrary to our prediction, entrainment of the L2 was significantly lower than L1, while L1 entrainment significantly increased when speech was masked by noise without reducing comprehension. However, greater L2 proficiency was positively associated with greater entrainment. We discuss how studies of entrainment relating to noise and bilingualism might be reconciled with an approach focused on exerted rather than demanded effort.

Writing sequences play an important role in handwriting of Chinese characters. However, little is known regarding the integral brain patterns and network mechanisms of processing Chinese character writing sequences. The present study decoded brain patterns during observing Chinese characters in motion by using multi-voxel pattern analysis, meta-analytic decoding analysis, and extended unified structural equation model. We found that perception of Chinese character writing sequence recruited brain regions not only for general motor schema processing, i.e., the right inferior frontal gyrus, shifting, and inhibition functions, i.e., the right postcentral gyrus and bilateral pre-SMA/dACC, but also for sensorimotor functions specific for writing sequences. More importantly, these brain regions formed a cooperatively top-down brain network where information was transmitted from brain regions for general motor schema processing to those specific for writing sequences. These findings not only shed light on the neural mechanisms of Chinese character writing sequences, but also extend the hierarchical control model on motor schema processing.

Bilingual language experience, such as switching between languages, has been shown to shape both cognitive and neural mechanisms of non-linguistic cognitive control. However, the neural adaptations induced by language switching remain unclear. Using fMRI, the current study examined the impact of short-term language switching training on the neural network of domain-general cognitive control for unbalanced Chinese-English bilinguals. Effective connectivity maps were constructed by using the extended unified structural equation models (euSEM) within 10 common brain regions involved in both language control and domain-general cognitive control. Results showed that, the dorsal anterior cingulate cortex/pre-supplementary motor area (dACC/pre-SMA) lost connection from the right thalamus after training, suggesting that less neural connectivity was required to complete the same domain-general cognitive control task. These findings not only provide direct evidence for the modulation of language switching training on the neural interaction of domain-general cognitive control, but also have important implications for revealing the potential neurocognitive adaptation effects of specific bilingual language experiences.

It has been documented that conflict adaptation (conflict resolution in a task enhanced by that in a previous task) exists not only in the same domain but also across different domains with shared cognitive control mechanisms. For the first time, the present study adopted a cross-task adaptive blocked design to examine the relationship between bilingual language control and cognitive control from the perspective of the immediately adjacent, mutual influence on the neural connectivity level. The results showed that the conflict setting induced by previous tasks changed the nodal degrees of the anterior cingulate cortex/presupplementary motor area and the right thalamus, and connectivity strength of shared links between adjacent language and cognitive control tasks. In addition, pre-activation of the cognitive control network affected the transitivity of the successive use of the language control network. These findings not only indicate a cross-task adaptation effect on the neural connectivity level, but also provide evidence for similarities in conflict detection and inhibition control between language-specific control and domain-general cognitive control. In addition, our results also suggest that there is only partial overlap between bilingual language control and domain-general cognitive control.

目的 概述果皮蜡质的成分、性质、形态结构,以及调控与转运途径等,以探讨果皮蜡质与果实耐藏性的关系及其作用机理,展望如何延长果实的贮藏期.方法 通过分析文献,理清果皮蜡质与果实耐藏性关系的研究范畴和热点,从果皮天然蜡质的成分、性质、形态结构,果皮蜡质与果实耐藏性的关系及其作用机理,果皮蜡质的合成、调控与转运途径等方面入手,对相关研究成果进行整理与综述,并对蜡质研究在果实采后贮藏中的应用前景进行展望.结论 果实表面的蜡质层是保护果实的天然屏障,具有防止果实水分散失、维持表面清洁、避免病菌侵害等作用,对果实耐藏性具有重要的影响.

The present study investigated the effect of language-switching training on the neural correlates of both reactive and proactive control in bilingual language production, as well as the modulating role of the proficiency level of the second language (L2). During the pre-test, Chinese-English bilinguals performed a picture-naming task while being scanned with functional magnetic resonance imaging (fMRI). Participants then took part in an 8-day training on language switching and performed the same task again in the post-test. The results suggest that language switch training facilitates the neural correlates for reactive control, resulting in reduced activation in some brain areas. Such effect also transfers to proactive control, especially for lower-proficiency bilinguals. The present study not only provides evidence for the plasticity of the neural mechanism of bilingual language control, but also highlights the role of the L2 proficiency in bilingual word production.

When bilinguals intend to speak in their first (L1) or second language (L2) according to the environment, a brain network involving cortical-subcortical regions is recruited to resolve cross-language interference. Research has found that the activation of these brain regions varies with language contexts. However, previous studies have not yet examined adaptive changes in the interactions of brain regions for different language contexts. To address this gap, we adopted extended unified structural equation modeling (euSEM) to identify the connectivity patterns of the bilingual control network. Twenty-one unbalanced Chinese-English bilinguals were instructed to name pictures in L1-single, L2-single, and dual-language contexts while undergoing functional magnetic resonance imaging (fMRI). We found that unbalanced bilinguals relied on a more functional integrated brain network, which was reflected by clearer core-periphery structures and increased global efficiency, in dual-language and L2-single contexts compared to L1-single context. Furthermore, the pattern of brain connectivity in the dual-language context was more similar to that in the L1-single context than the L2-single context. More importantly, we found more similarities between the connectivity patterns of dual-language and L1-single contexts in bilinguals with lower inhibitory control abilities. These findings provide the first connectivity evidence for the effect of language context on the bilingual language control network, which inhibits the base language and underpins bilinguals' change along the monolingual-bilingual mode continuum.

Brunfelsia calycina flowers lose anthocyanins rapidly and are therefore well suited for the study of anthocyanin degradation mechanisms, which are unclear in planta. Here, we isolated an anthocyanin-β-glycosidase from B. calycina petals. The MS/MS (Mass Spectrometry) peptide sequencing showed that the enzyme (72 kDa) was a β-xylosidase (BcXyl). The enzyme showed high activity to p-Nitrophenyl-β-d-galactopyranoside (pNPGa) and p-Nitrophenyl-β-d-xylopyranoside (pNPX), while no activity to p-Nitrophenyl-β-d-glucopyranoside (pNPG) or p-Nitrophenyl-β-D-mannopyranoside (pNPM) was seen. The optimum temperature of BcXyl was 40 °C and the optimum pH was 5.0. The enzyme was strongly inhibited by 1 mM D-gluconate and Ag+. HPLC (High Performance Liquid Chromatography) analysis showed that BcXyl catalyzed the degradation of an anthocyanin component of B. calycina, and the release of xylose and galactose due to hydrolysis of glycosidic bonds by BcXyl was detected by GC (Gas Chromatography) /MS. A full-length mRNA sequence (2358 bp) of BcXyl (NCBI No. MK411219) was obtained and the deduced protein sequence shared conserved domains with two anthocyanin-β-glycosidases (Bgln and BadGluc, characterized in fungi). BcXyl, Bgln and BadGluc belong to AB subfamily of Glycoside hydrolase family 3. Similar to BcPrx01, an anthocyanin-degradation-related Peroxidase (POD), BcXyl was dramatically activated at the stage at which the rapid anthocyanin degradation occurred. Taken together, we suggest that BcXyl may be the first anthocyanin-β-glycosidase identified in higher plants.

目的:探索新型黑血动态增强磁共振成像(MRI)技术对早期动脉粥样斑块炎性反应成像的可行性研究.方法:制备五指山小型猪(n=20)动脉粥样硬化模型.动物模型制备前、后分别行MRI黑血动态增强序列扫描(TR=750 ms;TE=12 ms;TI1=325 ms;TI2=125 ms,ETL=8).对比剂采用Gd-DTPA(0.05 mmol/kg),高压注射器的流速为0.1 mL/s.对模型制备前、后MR图像数据进行定量分析,测量血管壁容积传输常数(Ktrans),血浆容积(Vp),血管外细胞外容积(Ve),曲线下面积(AUC).通过与病理结果对照,分析MR图像数据参数与微血管及巨噬细胞的相关性.并比较模型制备前、后的差异.结果:成功建立五指山小型猪动脉粥样硬化模型15只.与病理结果相对照,Ktrans与微血管数目具有较好的相关性(r=0.913,P=0.000).与巨噬细胞数目比较发现,Ktrans亦有具有较好的相关性(r=0.781,P＜0.000).与模型制备前比较,MR图像数据参数Ktrans、Vp、Ve及AUC数值均显著性升高(P≤0.000).结论:黑血动态增强MRI成像方法可以反映早期动脉粥样硬化斑块炎症特征.并可以作为定量测量炎性反应的影像指标,为早期动脉粥样硬化提供了一种新型无创的影像学监测手段.

目的 探讨高分辨MRI颈动脉狭窄程度与易损斑块的相关性,判断其识别易损斑块的能力.资料与方法66例患者行双侧颈动脉MRI检查,包括常规增强血管造影和高分辨斑块MRI.测量管腔狭窄程度,定性分析斑块成分,判断斑块的稳定性.结果 血管狭窄程度与易损斑块内出血、纤维帽破裂呈正相关(r=0.25,P=0.007;r=0.36,P=0.001).受试者工作特征(ROC)曲线分析显示,管腔狭窄程度预测斑块内出血及纤维帽破裂的准确性均较低(斑块内出血ROC曲线下面积0.74,95％ CI0.52～0.96,P=0.10;纤维帽破裂ROC曲线下面积0.65,95％ CI0.43～0.88,P=-0.20).即使在颈动脉管腔无狭窄的血管壁上,仍有8.7％出现斑块内出血,4.3％出现纤维帽破裂.结论 单纯评判血管狭窄程度不足以判断斑块的稳定性,需结合血管狭窄程度及斑块的易损成分综合评估患者的危险性.

AIM: To explore the relationship between computed tomography (CT) angiography (CTA)-derived collateral status and CT perfusion (CTP)-derived tissue viability. MATERIALS AND METHODS: Patients having middle cerebral artery (MCA) M1/M2 segment and/or internal carotid artery (ICA) occlusion and within 12 hours of onset were included. Collateral was graded from 0 to 3 on maximum intensity projection (MIP) images of CTA. The area with relative cerebral blood flow (rCBF) <30% or time-to-maximum (Tmax) >10 or >12 or >14 seconds was defined as the infarct core, and Tmax >6 seconds as the penumbra. Kruskal-Wallis and Spearman's correlation tests were performed to assess the correlation between collateral grade and infarct size or mismatch ratio. RESULTS: Eighty-three patients were enrolled and 52 of them met the inclusion criteria. Infarct size defined by rCBF <30% or Tmax >10 or >12 or > 14 seconds and mismatch ratios were significantly different among the four groups. The correlation between collateral grades and infarct core using rCBF <30% (rho=-0.814, p<0.01) was better than that defined by Tmax >10s, >12s or >14s. Mismatch ratio for the infarct core defined by rCBF <30% (rho=0.945, p<0.01) had the best correlation with collateral grades. CONCLUSION: Patients with good collaterals show a smaller infarct core and higher mismatch ratio. Infarct size defined by rCBF <30% and mismatch ratio defined by rCBF <30% and Tmax >6 seconds appear to be more correlated with collaterals in AIS patients. (C) 2019 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Cavendish banana (Musa AAA) shows green-ripening at high temperatures above 24 degrees C, while Bluggoe fruit (Musa ABB) turns completely yellow. To understand the genomic constitution of the fruit de-greening trait, we compared fruit ripening and chlorophyll (Chl) degradation in 4 banana cultivars, belonging to the Cavendish (AAA), Mysore (AAB), Pisang Awak (ABB) and Bluggoe (ABB) subgroups, at 30 degrees C and 20 degrees C. Compared with fruit at 20 degrees C, ripening progress of the 4 cultivars at 30 degrees C, as represented by the change in fruit firmness and expression of fruit ripening-related genes, ACS ACO and PG, was accelerated, while the de-greening of fruits was repressed in the AAA cultivar but enhanced in the 3 hybrids (AAB/ABB). The expression of Stay-Green 1 (SGR1), a key Chl degradation gene, was reduced in the AAA cultivar but induced in the hybrids, correlating to the fruit de-greening patterns. The A- and B-SGR1 alleles, from the A- and B-genome, respectively, and a recombinant of the two alleles (H-SGR1) were identified in the AAB/ABB cultivars. A highly conserved polymorphism code was found to differentiate the A/B/H-SGR1 alleles. Allele-specific expression analysis showed that the Bluggoe fruit transcribed only B-SGR1, while Pisang Awak and Mysore expressed B/H- and A/B-SGR1, respectively, and higher B-SGR1 transcription levels were detected at 30 degrees C than at 20 degrees C. Transient expression of A/B/H-SGRI in tobacco leaves demonstrated that SGRls were all targeted to chloroplasts, and A-SGR1 showed a weaker Chl degradation capacity than B/H-SGR1. The allelic imbalanced expression (AIE) of SGR1 was demonstrated to confer the different fruit de-greening traits to the AAA and AAB/ABB cultivars at high temperatures.