Optimization of freezing point regulator and its penetration dynamics on large yellow croaker

Different kinds of freezing-point regulators were evaluated to expand the freezing point zone of large yellow croaker, and several treatment methods such as ordinary atmospheric pressure, vacuum environment and injection during the process of penetration were compared to reveal the relationship of diffusion velocities, diffusion time and freezing point of the large yellow croaker. Results obtained for ideal freezing-point regulators were as follows: Sodium chloride 2.5% (w/w), trehalose 2.5% (w/w) and edible alcohol 2.0% (w/w), which could decrease the freezing point from -1.5℃ to -4.2℃. Comparing with atmospheric pressure or vacuum degrees treatment, using injection method to deal with the freezing-point regulators could decrease the freezing point in a short time and benefit the meat quality

Effects of dimers on cooperation in the spatial prisoner's dilemma game

We investigate the evolutionary prisoner's dilemma game in structured populations by introducing dimers, which are defined as that two players in each dimer always hold a same strategy. We find that influences of dimers on cooperation depend on the type of dimers and the population structure. For those dimers in which players interact with each other, the cooperation level increases with the number of dimers though the cooperation improvement level depends on the type of network structures. On the other hand, the dimers, in which there are not mutual interactions, will not do any good to the cooperation level in a single community, but interestingly, will improve the cooperation level in a population with two communities. We explore the relationship between dimers and self-interactions and find that the effects of dimers are similar to that of self-interactions. Also, we find that the dimers, which are established over two communities in a multi-community network, act as one type of interaction through which information between communities is communicated by the requirement that two players in a dimer hold a same strategy.Comment: 12 pages and 3 figure

A Gemini/GMOS Study of Intermediate Luminosity Early-Type Virgo Cluster Galaxies. I. Globular Cluster and Stellar Kinematics

We present a kinematic analysis of the globular cluster systems and diffuse stellar light of four intermediate luminosity (sub-$L^{\ast}$) early-type galaxies in the Virgo cluster based on Gemini/GMOS data. Our galaxy sample is fainter ($-23.8<M_K<-22.7$) than most previous studies, nearly doubling the number of galaxies in this magnitude range that now have GC kinematics. The data for the diffuse light extends to $4R_e$, and the data for the globular clusters reaches 8--$12R_e$. We find that the kinematics in these outer regions are all different despite the fact that these four galaxies have similar photometric properties, and are uniformly classified as "fast rotators" from their stellar kinematics within $1R_e$. The globular cluster systems exhibit a wide range of kinematic morphology. The rotation axis and amplitude can change between the inner and outer regions, including a case of counter-rotation. This difference shows the importance of wide-field kinematic studies, and shows that stellar and GC kinematics can change significantly as one moves beyond the inner regions of galaxies. Moreover, the kinematics of the globular cluster systems can differ from that of the stars, suggesting that the formation of the two populations are also distinct.Comment: 24 pages, 21 figures, 9 table, ApJ in pres

Oxyphyllones A and B, novel sesquiterpenes with an unusual 4,5-secoeudesmane skeleton from Alpinia oxyphylla

Two novel 4,5-secoeudesmane sesquiterpenoids, oxyphyllones A (1) and B (2) were isolated from the fruits of Alpinia oxyphylla. Their structures were established by spectroscopic methods including 1D and 2D NMR spectra. These two compounds are the first example of naturally occurring sesquiterpenoids with a 4,5-secoeudesmane skeleton in the family of Zingiberaceae and oxyphyllone A (1) is the first 4,5-secoeudesmane type of 13-norsesquiterpenoid. Compounds 1 and 2 exhibited no cytotoxicities against three cancer cell lines at 10 mg/mL

Review of Abnormal Self-Knowledge in Major Depressive Disorder

Background: Major depressive disorder (MDD) is an affective disorder that is harmful to both physical and mental health. Abnormal self-knowledge, which refers to abnormal judgments about oneself, is a core symptom of depression. However, little research has summarized how and why patients with MDD differ from healthy individuals in terms of self-knowledge.Objective: To gain a better understanding of MDD, we reviewed previous studies that focused on the behavioral and neurological changes of self-knowledge in this illness.Main Findings: On the behavioral level, depressed individuals exhibited negative self-knowledge in an explicit way, while more heterogeneous patterns were reported in implicit results. On the neurological level, depressed individuals, as compared with non-depressed controls, showed abnormal self-referential processing in both early perception and higher cognitive processing phases during the Self-Referential Encoding Task. Furthermore, fMRI studies have reported aberrant activity in the medial prefrontal cortex area for negative self-related items in depression. These results revealed several behavioral features and brain mechanisms underlying abnormal self-knowledge in depression.Future Studies: The neural mechanism of implicit self-knowledge in MDD remains unclear. Future research should examine the importance of others' attitudes on the self-concept of individuals with MDD, and whether abnormal self-views may be modified through cognitive or pharmacological approaches. In addition, differences in abnormal self-knowledge due to genetic variation between depressed and non-depressed populations remain unconfirmed. Importantly, it remains unknown whether abnormal self-knowledge could be used as a specific marker to distinguish healthy individuals from those with MDD.Conclusion: This review extends our understanding of the relationship between self-knowledge and depression by indicating several abnormalities among individuals with MDD and those who are at risk for this illness

Structural diversity and electronic properties in potassium silicides

Stable potassium silicides in the complete compositional landscape were systematically explored up to 30 GPa using the variable-composition evolutionary structure prediction method. The results show that K4Si, K3Si, K5Si2, K2Si, K3Si2, KSi, KSi2, KSi3, and K8Si46 have their stability fields in the phase diagram. The spatial dimensional diversity of polymerized silicon atoms (0D “isolated” anion, dimer, Si4 group, 1D zigzag chain, 2D layer, and 3D network) under the potassium sublattice was uncovered as silicon content increases. Especially, the 2D layered silicon presents interestingly a variety of shapes, such as the “4 + 6” ring, “4 + 8”ring, and 8-membered ring. K-Si bonding exhibits a mixed covalency and ionicity, while Si-Si bonding is always of covalent character. Semiconductivity or metallicity mainly depends on the form of sublattices and K:Si ratio, which allows us to find more semiconductors in the Si-rich side when closed-shell K cations are encompassed by polymerized Si. The semiconducting silicides present strong absorption in the infrared and visible light range. These findings open up the avenue for experimental synthesis of alkali metal-IVA compounds and potential applications as battery electrode materials or photoelectric materials

De novo design of a transmembrane Zn²⁺-transporting four-helix bundle.

The design of functional membrane proteins from first principles represents a grand challenge in chemistry and structural biology. Here, we report the design of a membrane-spanning, four-helical bundle that transports first-row transition metal ions Zn(2+) and Co(2+), but not Ca(2+), across membranes. The conduction path was designed to contain two di-metal binding sites that bind with negative cooperativity. X-ray crystallography and solid-state and solution nuclear magnetic resonance indicate that the overall helical bundle is formed from two tightly interacting pairs of helices, which form individual domains that interact weakly along a more dynamic interface. Vesicle flux experiments show that as Zn(2+) ions diffuse down their concentration gradients, protons are antiported. These experiments illustrate the feasibility of designing membrane proteins with predefined structural and dynamic properties

The Next Generation Virgo Cluster Survey. X. Properties of Ultra-Compact Dwarfs in the M87, M49 and M60 Regions

We use imaging from the Next Generation Virgo cluster Survey (NGVS) to present a comparative study of ultra-compact dwarf (UCD) galaxies associated with three prominent Virgo sub-clusters: those centered on the massive, red-sequence galaxies M87, M49 and M60. We show how UCDs can be selected with high completeness using a combination of half-light radius and location in color-color diagrams ($u^*iK_s$ or $u^*gz$). Although the central galaxies in each of these sub-clusters have nearly identical luminosities and stellar masses, we find large differences in the sizes of their UCD populations, with M87 containing ~3.5 and 7.8 times more UCDs than M49 and M60, respectively. The relative abundance of UCDs in the three regions scales in proportion to sub-cluster mass, as traced by X-ray gas mass, total gravitating mass, number of globular clusters, and number of nearby galaxies. We find that the UCDs are predominantly blue in color, with ~85% of the UCDs having colors similar to blue GCs and stellar nuclei of dwarf galaxies. We present evidence that UCDs surrounding M87 and M49 may follow a morphological sequence ordered by the prominence of their outer, low surface brightness envelope, ultimately merging with the sequence of nucleated low-mass galaxies, and that envelope prominence correlates with distance from either galaxy. Our analysis provides evidence that tidal stripping of nucleated galaxies is an important process in the formation of UCDs.Comment: 37 pages, 40 figures. To appear in The Astrophysical Journa