Specific heat and thermal conductivity of ferromagnetic magnons in Yttrium Iron Garnet

The specific heat and thermal conductivity of the insulating ferrimagnet Y$_3$Fe$_5$O$_{12}$ (Yttrium Iron Garnet, YIG) single crystal were measured down to 50 mK. The ferromagnetic magnon specific heat $C$$_m$ shows a characteristic $T^{1.5}$ dependence down to 0.77 K. Below 0.77 K, a downward deviation is observed, which is attributed to the magnetic dipole-dipole interaction with typical magnitude of 10$^{-4}$ eV. The ferromagnetic magnon thermal conductivity $\kappa_m$ does not show the characteristic $T^2$ dependence below 0.8 K. To fit the $\kappa_m$ data, both magnetic defect scattering effect and dipole-dipole interaction are taken into account. These results complete our understanding of the thermodynamic and thermal transport properties of the low-lying ferromagnetic magnons.Comment: 5 pages, 5 figure

Nodeless superconductivity in Ir1−x_{1-x}Ptx_xTe2_2 with strong spin-orbital coupling

The thermal conductivity $\kappa$ of superconductor Ir$_{1-x}$Pt$_{x}$Te$_2$ ($x$ = 0.05) single crystal with strong spin-orbital coupling was measured down to 50 mK. The residual linear term $\kappa_0/T$ is negligible in zero magnetic field. In low magnetic field, $\kappa_0/T$ shows a slow field dependence. These results demonstrate that the superconducting gap of Ir$_{1-x}$Pt$_{x}$Te$_2$ is nodeless, and the pairing symmetry is likely conventional s-wave, despite the existence of strong spin-orbital coupling and a quantum critical point.Comment: 5 pages, 4 figure

Screening and verification of late embryogenesis abundant protein interacting with anthocyanidin reductase in grape berries

Anthocyanidin reductase (ANR, EC 1.3.1.77) catalyzes the conversion of anthocyanidins to 2R, 3R-flavan-3-ols in Vitis vinifera grapes. These are basic structural units of proanthocyanidins (PAs). The regulation of PA biosynthesis at protein level is not yet clear. Here, we find a VvANR interaction partner called late embryogenesis abundant protein (LEA), which can interact with VvANR in the yeast two-hybrid (Y2H) system. We verified the interaction between VvANR and Vv-LEA by Y2H and co-immunoprecipitation (CoIP) in yeast in vitro, and using the firefly luciferase complementation imaging (LCI) system in vivo. Additionally, the co-localization of VvANR and VvLEA in Arabidopsis thaliana protoplasts also provids the essential conditions for their interaction. The different expressions of VvANR and VvLEA depended both on the age of the grape berries and on the duration of cold treatment. These findings provide primary evidence for proteinregulation and the potential formation of multi-enzyme complex of VvANR, as well as of the PA biosynthesis.

Giant panda BAC library construction and assembly of a 650-kb contig spanning major histocompatibility complex class II region

<p>Abstract</p> <p>Background</p> <p>Giant panda is rare and endangered species endemic to China. The low rates of reproductive success and infectious disease resistance have severely hampered the development of captive and wild populations of the giant panda. The major histocompatibility complex (MHC) plays important roles in immune response and reproductive system such as mate choice and mother-fetus bio-compatibility. It is thus essential to understand genetic details of the giant panda MHC. Construction of a bacterial artificial chromosome (BAC) library will provide a new tool for panda genome physical mapping and thus facilitate understanding of panda MHC genes.</p> <p>Results</p> <p>A giant panda BAC library consisting of 205,800 clones has been constructed. The average insert size was calculated to be 97 kb based on the examination of 174 randomly selected clones, indicating that the giant panda library contained 6.8-fold genome equivalents. Screening of the library with 16 giant panda PCR primer pairs revealed 6.4 positive clones per locus, in good agreement with an expected 6.8-fold genomic coverage of the library. Based on this BAC library, we constructed a contig map of the giant panda MHC class II region from <it>BTNL2 </it>to <it>DAXX </it>spanning about 650 kb by a three-step method: (1) PCR-based screening of the BAC library with primers from homologous MHC class II gene loci, end sequences and BAC clone shotgun sequences, (2) DNA sequencing validation of positive clones, and (3) restriction digest fingerprinting verification of inter-clone overlapping.</p> <p>Conclusion</p> <p>The identifications of genes and genomic regions of interest are greatly favored by the availability of this giant panda BAC library. The giant panda BAC library thus provides a useful platform for physical mapping, genome sequencing or complex analysis of targeted genomic regions. The 650 kb sequence-ready BAC contig map of the giant panda MHC class II region from <it>BTNL2 </it>to <it>DAXX</it>, verified by the three-step method, offers a powerful tool for further studies on the giant panda MHC class II genes.</p

Nodeless superconductivity in Ca3Ir4Sn13: evidence from quasiparticle heat transport

We report resistivity $\rho$ and thermal conductivity $\kappa$ measurements on Ca$_3$Ir$_4$Sn$_{13}$ single crystals, in which superconductivity with $T_c \approx 7$ K was claimed to coexist with ferromagnetic spin-fluctuations. Among three crystals, only one crystal shows a small hump in resistivity near 20 K, which was previously attributed to the ferromagnetic spin-fluctuations. Other two crystals show the $\rho \sim T^2$ Fermi-liquid behavior at low temperature. For both single crystals with and without the resistivity anomaly, the residual linear term $\kappa_0/T$ is negligible in zero magnetic field. In low fields, $\kappa_0(H)/T$ shows a slow field dependence. These results demonstrate that the superconducting gap of Ca$_3$Ir$_4$Sn$_{13}$ is nodeless, thus rule out nodal gap caused by ferromagnetic spin-fluctuations.Comment: 5 pages, 4 figure

Accumulation Pattern of Flavonoids in Cabernet Sauvignon Grapes Grown in a Low-Latitude and High-Altitude Region

Particular climate conditions in a low-latitude and high-altitude region endow grape berries with distinctivequality characteristics. So far, few reports have been concerned with the formation of berry flavour in such aregion. This study aimed to investigate the accumulation pattern of flavonoids in Vitis vinifera L. cv. CabernetSauvignon grape berries growing at different altitudes of the highland in southwest China in two consecutivevintages. In addition to the 3-O-monoglucosides and 3-O-acyl monoglucosides of the five main anthocyanidins(delphinidin, cyanidin, peonidin, petunidin and malvidin), some uncommon anthocyanins, such as threediglucosides of anthocyanidins and pelargonidin-3-O-glucoside, were detected in the grape berries. Higheraltitude cultivation greatly promoted the production of anthocyanins and flavonols, particularly cyanidintypeanthocyanins and quercetin-type flavonols from the F3’H branch of the flavonoid biosynthetic pathway.Flavan-3-ols from both branches were comparatively less influenced by vineyard altitude. Vintage in thishigh-altitude region also had a dramatic influence on the accumulation of flavonoids. Most of the anthocyaninand flavonol components were affected more by vineyard altitude than by vintage, whereas the accumulationof flavan-3-ols differed mainly between vintages. The present data will not only improve the understandingof flavonoid accumulation in grapes from a high-altitude region with different climates, but also providepractical guidance for the production of high-quality grapes and wine

Preparation and biological application of antibodies against leucoanthocyanidin reductase and anthocyanidin reductase from grape berry

Proanthocyanidins (PAs) endow wine with the flavor of bitterness and astringency. Both leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR) are two key enzymes of PA biosynthesis in grape berries, but the previous studies on these enzymes only focused on the transcriptional expression of these genes. Here, the full-length cDNAs of VvLAR1, VvLAR2 and VvANR, respectively, were cloned from wine grape berries and were then introduced into the pGEX-4T-1 expression vectors, which were highly expressed in Escherichia coli DH5α cells with the induction of the isopropyl-β-D-thiogalactoside (IPTG). The purified fusion proteins were used as the antigens to immunize rabbits, separately. The obtained antiserums were further purified to obtain the immunoglobulin G (Ig G) fractions, which were demonstrated to be capable of specifically immuno-recognizing the VvLAR1, VvLAR2 and VvANR from the crude protein extracts from grape berries with weight masses of approximately 43 kD. The analyses of translational expression of these enzyme genes during berry development and immunohistochemical localization of these proteins, by using the obtained antibodies, showed that a high amount of VvLAR1, VvLAR2 or VvANR was present at the pre-veraison stage and these enzyme proteins were all localized on the outer layer of the berry skin and the vascular bundle, as well as in the inner layer of the seed coat. This work provides an important basis for further studies on PA biosynthesis in grape berries.