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Previous task-related imaging studies in adults have demonstrated that there is a frontoparietal mirror neuron system (MNS) that preferentially engages in self-recognition. However, the development of the MNS during preschool (age 3–5 years) has not been thoroughly examined. In this study, we investigated the development of the MNS by examining the correlations in spontaneous fluctuations of the functional magnetic resonance imaging (fMRI) blood oxygen level-dependent (BOLD) signal in healthy, 3–5-year-old preschool children (n = 30, 15 in each group). Using a ROI-based (inferior frontal gyrus) functional connectivity analysis, we identified a right lateralized MNS during rest in both groups with a positive correlation between the inferior frontal gyrus and inferior parietal lobule. A significant increase in the functional connectivity of the MNS was observed in the older group. Our results suggest that the spontaneous functional connectivity of the MNS is shaped at as early as 3 years of age and undergoes age-related development within the preschool period.

Previous studies on brain functional connectivity networks in children have mainly focused on changes in function in specific brain regions, as opposed to whole brain connectivity in healthy children. By analyzing the independent components of activation and network connectivity between brain regions, we examined brain activity status and development trends in children aged 3 and 5 years. These data could provide a reference for brain function rehabilitation in children with illness or abnormal function. We acquired functional magnetic resonance images from 15 3-year-old children and 15 5-year-old children under natural sleep conditions. The participants were recruited from five kindergartens in the Nanshan District of Shenzhen City, China. The parents of the participants signed an informed consent form with the premise that they had been fully informed regarding the experimental protocol. We used masked independent component analysis and BrainNet Viewer software to explore the independent components of the brain and correlation connections between brain regions. We identified seven independent components in the two groups of children, including the executive control network, the dorsal attention network, the default mode network, the left frontoparietal network, the right frontoparietal network, the salience network, and the motor network. In the default mode network, the posterior cingulate cortex, medial frontal gyrus, and inferior parietal lobule were activated in both 3- and 5-year-old children, supporting the “three-brain region theory” of the default mode network. In the frontoparietal network, the frontal and parietal gyri were activated in the two groups of children, and functional connectivity was strengthened in 5-year-olds compared with 3-year-olds, although the nodes and network connections were not yet mature. The high-correlation network connections in the default mode networks and dorsal attention networks had been significantly strengthened in 5-year-olds vs. 3-year-olds. Further, the salience network in the 3-year-old children included an activated insula/inferior frontal gyrus-anterior cingulate cortex network circuit and an activated thalamus-parahippocampal-posterior cingulate cortex-subcortical regions network circuit. By the age of 5 years, nodes and high-correlation network connections (edges) were reduced in the salience network. Overall, activation of the dorsal attention network, default mode network, left frontoparietal network, and right frontoparietal network increased (the volume of activation increased, the signals strengthened, and the high-correlation connections increased and strengthened) in 5-year-olds compared with 3-year-olds, but activation in some brain nodes weakened or disappeared in the salience network, and the network connections (edges) were reduced. Between the ages of 3 and 5 years, we observed a tendency for function in some brain regions to be strengthened and for the generalization of activation to be reduced, indicating that specialization begins to develop at this time. The study protocol was approved by the local ethics committee of the Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences in China with approval No. SIAT-IRB-131115-H0075 on November 15, 2013.

Summary To examine the distribution of Trichodesmium relative to physicochemical factors during summer in the Changjiang (Yangtze River) Estuary and adjacent East China Sea shelf, three cruises were conducted separately in June 2009, July 2011, and August 2009. Trichodesmium species found were T. thiebautii , T. erythraeum , and T. hildebrandtii . The population was dominated by T. thiebautii , which accounted for >85% of the samples found. Most of them were free trichomes. Colonial forms were rarely observed (approximately 10% of our samples), occurring only in offshore waters. The depth integrated abundances of Trichodesmium were 308 × 10 3 , 1709 × 10 3 , and 3448 × 10 3 trichomes m −2 in June, July, and August, respectively. Trichodesmium was distributed abundantly in the southern or southeastern part of our study area, where nutrients were low and light penetration, temperature, and salinity were high, which were influenced by the Taiwan Warm Current (TWC) and Kuroshio. Trichodesmium was found in low abundance in inshore, eutrophic, low-salinity waters, which were mainly controlled by the Changjiang Diluted Water (CDW) and coastal current. These results suggest that spatiotemporal changes in the summer Trichodesmium distribution correlate highly with the variations in physicochemical properties that are primarily controlled by the TWC, Kuroshio, and CDW. The summer N 2 fixation rate of Trichodesmium was estimated at 12.3 μmol N m −2 d −1 in our study area, contributing >50% of biological N 2 fixation.

The picoplankton distribution in the East China Sea was investigated during bloom events occurred in spring (June) and summer (August) 2011. In spring, there was no significant difference in picoplankton abundances between areas where bloom conditions were or were not established. In the bloom area, Synechococcus, picoeukaryotes and heterotrophic prokaryotes exhibited at only some stations that abundances were higher than those within the non-bloom area. In summer, the abundances of Synechococcus and picoeukaryotes were significantly higher inside the bloom area than outside. Among the picoplankton components, heterotrophic prokaryotes represented the highest carbon biomass. Factors that most influenced picoplankton distribution under bloom conditions in the East China Sea varied with season. In spring, ciliates and salinity tended to be the main factors, whereas in summer, this role was played by temperature and chlorophyll a concentration. (C) 2015 Elsevier Ltd. All rights reserved.

In recent years, research on human functional brain imaging using resting-state fMRI techniques has been increasingly prevalent. The term "default mode" was proposed to describe a baseline or default state of the brain during rest. Recent studies suggested that the default mode network (DMN) is comprised of two functionally distinct subsystems: a dorsal-medial prefrontal cortex (DMPFC) subsystem involved in self-oriented cognition (i.e., theory of mind) and a medial temporal lobe (MTL) subsystem engaged in memory and scene construction; both subsystems interact with the anterior medial prefrontal cortex (aMPFC) and posterior cingulate (PCC) as the core regions of DMN. The present study explored the development of DMN core regions and these two subsystems in both hemispheres from 3- to 5-year-old children. The analysis of the intrinsic activity showed strong developmental changes in both subsystems, and significant changes were specifically found in MTL subsystem, but not in DMPFC subsystem, implying distinct developmental trajectories for DMN subsystems. We found stronger interactions between the DMPFC and MTL subsystems in 5-year-olds, particularly in the left subsystems that support the development of environmental adaptation and relatively complex mental activities. These results also indicate that there is stronger right hemispheric lateralization at age 3, which then changes as bilateral development gradually increases through to age 5, suggesting in turn the hemispheric dominance in DMN subsystems changing with age. The present results provide primary evidence for the development of DMN subsystems in early life, which might be closely related to the development of social cognition in childhood.

Fluorescence-based maximal photochemical efficiency, F v/F m, is widely used as an indicator to photosynthetic competence in marine systems. It has been considered a useful parameter diagnosing the nutrient stress on phytoplankton photosynthesis, but many studies argue its usefulness. In the present study, we try to find a temporal relationship between F v/F m and nitrogen concentration, and provide a possible explanation on the controversy. We continuously measured F v/F m and nitrogen concentration once every 10 days from September 2003 to March 2004 at two stations in Jiaozhou Bay, northern China. It was found that F v/F m did not significantly correlate to synchronous nitrogen concentration, but the variation (i.e. the change between two adjacent cruises) of nitrogen concentration of the previous cruise and the variation of F v/F m of the current cruise were strongly correlated. This result indicates that a time lag exists between the variation of nutrient status and the subsequent F v/F m response. Length of the time lag seems just matched the interval of our measurements (10 days). In the field, direct dependence of F v/F m on nitrogen concentration may not be found because of the lagged response of F v/F m to nitrogen concentration variations or physiological acclimation. Our results provide a possible way to explain the previously reported conflicting results on the relationship between F v/F m and nutrient status. To give a more-accurate estimate about the length of the time lag, an investigation that includes more frequent measurements is needed.

The perception of the faces of parents is different from that of other faces. Mother's face perception is associated with childbearing and parenting and has specific cognitive processing properties. Yet, the underlying mechanism remains unknown. We investigated the neural network that is involved in the perception of parent's face based upon parental face selective tasks that were completed by 23 normal adults. Resting state functional magnetic resonance imaging (fMRI) and a task block design with fixation cross sign control fMRI were used. The faces activated the right inferior frontal gyrus, the left and right middle frontal gyri, and the left and right inferior parietal lobule. In addition, the parental faces task resulted in more activation than the control tasks in the left and right anterior cingulate, left middle (superior) temporal gyrus, right and left inferior frontal gyrus. The anterior cingulate cortex (ACC) and the inferior parietal lobe (IPL) are central nodes of the brain network, while the parental face perception network includes the anterior cingulate cortex and superior temporal gyrus (ACC-STG)/parahippocampal network as well as the inferior frontal and inferior parietal lobule (IFG-IPL) network. The network of father's face perception involves the left inferior parietal lobule and left middle frontal gyrus/right middle frontal gyrus/right inferior frontal gyrus, while mother's face perception involves the right inferior parietal lobe and frontal network (MFG.L/IFG.R). The experiments showed that the ACC-STG/parahippocampal network and IFG-IPL network are neural networks used in parental face perception, and the ACC and IPL are central nodes in the network. The neural pathway of parental face perception is similar to the perception of a stranger's face, as both include the STG, but is different in that the perception of the stranger's face involves a connected STG and IPL as a specific neural pathway.

Phytoplankton pigment patterns and community composition were investigated in the northern South China Sea using high-performance liquid chromatography and the CHEMTAX software from February 11 to 23, 2009. We recognized four different vertical distribution patterns of pigments: chlorophyll a (Chi a)-like type, divinyl chlorophyll a (DV Chi a) type, even distribution type, and surface type. The average value of ratios of accessory photo-protective pigments (APP) to accessory photo-synthetic pigments was 0.89±0.63 in the upper 50 m and 0.16±0.06 below 50 m depth. With increasing depth, APP decreased and photo-synthetically active radiation was attenuated. There was an obvious succession in the phytoplankton community from inshore to the open sea. Diatoms were dominant in the inshore region, while pelagophytes, Prochlorococcus, cyanobacteria and prymnesiophytes were dominant in the open sea. The vertical distribution of phytoplankton also differed greatly from inshore to the open sea. In the coastal and shelf region, diatoms were important components in the whole water column. Cyanobacteria also had a high abundance at the Subsurface Chlorophyll a Maxima (SCM) in the shelf region. In the slope and open sea, Prochlorococcus and cyanobacteria were important groups above the SCM, while pelagophytes dominated below the SCM.

Instinctively responding to maternal face is an evolutionary function of enhancing survival and development. However, because of the confounding nature of familiarity, little is known concerning the neural mechanism involved in maternal face recognition. We had a rare opportunity to examine Mosuo preschool children who were raised in a matrilineal society in which mothers and aunts represent equally familiar faces to the children. The participants were exposed to photographs of their mother's face, aunt's face, and an unfamiliar female's faces during electroencephalography (EEG) recording. The EEG results showed that the mother's face elicited a more negative N1 component, a larger left N170 component, and a larger P300 component; both the mother's and aunt's faces elicited a larger right N170 component. These results suggest that the emotional attachment between mother and child has neural ramifications across three successive face processing stages that are distinguished from the neural effects of facial familiarity. (C) 2014 Elsevier B.V. All rights reserved.

This study aims to explore the modulation effects of attachment relationships with parents on the neural correlates that are associated with parental faces. The event-related potentials elicited in 31 college students while viewing facial stimuli of their parents in two single oddball paradigms (father vs. unfamiliar male and mother vs. unfamiliar female) were measured. We found that enhanced P3a and P3b and attenuated N2b were elicited by parental faces; however, the N170 component failed to discriminate parental faces from unfamiliar faces. An experienced attachment relationship with the father was positively correlated to the P3a response associated with the father's face, whereas no correlation was found in the case of mothers. Further exploration in dipole source localization showed that, within the time window of the P300, distinctive brain regions were involved in the processing of parental faces; the father's face was located in the medial frontal gyrus, which might be involved in self effect, and the anterior cingulate gyrus was activated in response to the mother's face. This research is the first to demonstrate that neural mechanisms involved with parents can be modulated differentially by the qualities of the attachments to the parents. In addition, parental faces share a highly similar temporal pattern, but the origins of these neural responses are distinct, which could merit further investigation.