Tipburn of Chinese cabbage in relation to calcium nutrition and distribution

Heading Chinese cabbage (Brassica campestris ssp. pekinensis Rupr.) grown with low Ca or B developed dark tan lesions near the leaf margins. A synergistic effect of low Ca and low B accompanied the development of this symptom. Plants grown under humid conditions were free of tipburn. Plants grown under less humidity developed tipburn. Total chemical analysis revealed a steady decrease in total Ca from the outer to the inner leaves. Fractional chemical analysis showed 7 times more water-soluble Ca in the outer than in the inner leaves, and 2 times more 1 N NaCl-soluble Ca in the outer than in inner leaves. Threshold concentration of water-soluble forms of Ca for tipburn was around 3.0 mg/g dry weight. Data suggest that root pressure flow is required to move adequate amounts of water-soluble Ca to the wrapper leaves to prevent tipburn of Chinese cabbage.     

The embryonic vertebrate heart tube is a dynamic suction pump

The embryonic vertebrate heart begins pumping blood long before the development of discernable chambers and valves. At these early stages, the heart tube has been described as a peristaltic pump. Recent advances in confocal laser scanning microscopy and four-dimensional visualization have warranted another look at early cardiac structure and function. We examined the movement of cells in the embryonic zebrafish heart tube and the flow of blood through the heart and obtained results that contradict peristalsis as a pumping mechanism in the embryonic heart. We propose a more likely explanation of early cardiac dynamics in which the pumping action results from suction due to elastic wave propagation in the heart tube.     

Phenotypic and molecular characterization of isolates of Ornithobacterium rhinotracheale from chickens and pigeons in Taiwan

Forty Ornithobacterium rhinotracheale (ORT) strains were isolated from 28 chickens and 12 pigeons for the first time in Taiwan. All isolates reacted positively in the p-nitrophenyl-beta-D-galactopyranoside (PNPG) and oxidase tests, showing an API 20NE identification system biocode 0-0-2-0-0-0-4. All the pigeon isolates and 85.7% (24 of 28) of the chicken isolates belonged to serotype A. Compared to the ORT ATCC 51464 strain, 14.3% (4 of 28) of chicken isolates and 58.3% (7 of 12) of pigeon isolates showed smaller colonies after 72 hr incubation. Most of the chicken isolates (22 of 28), but none of the pigeon isolates, could agglutinate chicken and pigeon red blood cells. There appears to be a correlation that ORT isolates with a larger colony size tend to be more able to agglutinate red blood cells than the ORT isolates with a smaller colony size. A majority of isolates was sensitive to amoxicillin, ampicillin, ceftiofur, penicillin, and oxytetracycline. The 16S ribosomal RNA (rRNA) sequences of 23 Taiwanese ORT isolates showed high identity (98%-100%) to sequences in GenBank. Phylogenetic analysis of these sequences showed that pigeon isolates formed a distinctive cluster, while chicken isolates and all other 16S rRNA sequences obtained from GenBank belonged to another two clusters. The results indicate that pigeon ORT isolates are different from most chicken isolates in regard to a number of phenotypic and molecular traits.     

Earthquake in a maze: compressional rupture branching during the 2012 M(w) 8.6 Sumatra earthquake

Seismological observations of the 2012 moment magnitude 8.6 Sumatra earthquake reveal unprecedented complexity of dynamic rupture. The surprisingly large magnitude results from the combination of deep extent, high stress drop, and rupture of multiple faults. Back-projection source imaging indicates that the rupture occurred on distinct planes in an orthogonal conjugate fault system, with relatively slow rupture speed. The east-southeast-west-northwest ruptures add a new dimension to the seismotectonics of the Wharton Basin, which was previously thought to be controlled by north-south strike-slip faulting. The rupture turned twice into the compressive quadrant, against the preferred branching direction predicted by dynamic Coulomb stress calculations. Orthogonal faulting and compressional branching indicate that rupture was controlled by a pressure-insensitive strength of the deep oceanic lithosphere.     

Characterization of turkey coronavirus from turkey poults with acute enteritis.

The present study was to characterize turkey coronavirus associated with turkey poult enteritis and mortality. Intestinal contents or intestines from affected turkey poults and inoculated turkey embryos contained coronaviruses as revealed by electron microscopy or were positive for turkey coronavirus by immunofluorescent antibody assay. Sucrose density gradient ultracentrifugation of the virus-containing intestinal homogenate yielded two opalescent bands corresponding to the buoyant densities of 1.14-1.15 and 1.18-1.20 g/ml, respectively. Coronaviral particles from intestinal contents or the sucrose density gradient preparation were mainly spherical in shape and had envelope and central depression. They were surrounded by a fringe of regularly spaced petal-shaped projections attached to the particles by a short stalk. Purified viruses hemagglutinated rabbit erythrocytes with a titer of 16. Major protein bands of purified viruses analyzed by SDS-PAGE were located at 200, 100-110, 50-60, and 30-35 kDa. The patterns of protein bands were consistent with those of Minnesota or Quebec turkey coronavirus isolates. A 568 bp nucleotide fragment of turkey coronavirus spike protein gene was amplified from RNA of inoculated turkey embryo intestine or purified virus. Sequence analysis of the 568 bp PCR product revealed high degree of identity with the corresponding spike protein gene sequence of human and bovine coronaviruses. The results indicated that turkey coronavirus was associated with turkey poults with acute enteritis.     

Mapping of QTLs in tomato line FLA456 associated with resistance to a virus causing tomato yellow leaf curl disease

Tomato (yellow) leaf curl disease (TYLCD) is a serious threat to tomato production in the tropics and subtropics. The genetics of resistance to Tomato yellow leaf curl Thailand virus Taiwan strain (TYLCTHV-[TW]) in a highly resistant tomato line FLA456 was studied through quantitative trait loci (QTL) analysis. Four QTLs named qTy4.1, qTy6.1, qTy10.1 and qTy11.1 were detected on chromosomes 4, 6, 10, and 11, respectively, through evaluation of an F₆ recombinant inbred line (RIL) population derived from a cross between FLA456 (resistant) and CLN1621L (susceptible). Gene action of all QTLs was recessive based on disease reaction of the F₁. The markers SINAC1 and SLM4-34 flanked qTy4.1 on chromosome 4, and SLM11-12 and SLM11-17 defined qTy11.1, which co-located with the previously identified Ty-5 and Ty-2 loci, respectively. qTy6.1 was flanked by the markers SLM6-55 and TES-0014, and qTy10.1 by the markers SLM10-80-SLM10-46 on chromosomes 6 and 10. The LOD values of the putative QTLs ranged from 2.79 to 13.76. The phenotypic variance explained by each QTL ranged from 7.1 to 31.9 %. The four QTLs collectively contributed about 60.5 % of the phenotypic variation in resistance against TYLCTHV-[TW]. Group mean severity scores of those RILs possessing three or four qTy were generally lower than RIL groups with only one or no qTy. Given the diversity of begomoviruses that cause TYLCD across the regions, the new QTLs from FLA456 would be valuable in tomato breeding for developing varieties with durable resistance. Two QTL intervals (qTy4.1 and qTy10.1) contained virus resistance candidate genes such as CTV.22 and eukaryotic translation initiation factor 4E.     

High processing tolerances of immunomodulatory proteins in Enoki and Reishi mushrooms

This study investigated the processing tolerances of two mushroom proteins with immunomodulatory activities, including FVE from Enoki ( Flammulia velutipes ) and LZ8 from Reishi ( Ganoderma lucidum ) mushrooms, under food processing treatments such as heating, sterilization, frozen storage, extraction in acid/alkaline conditions, and dehydration. Results showed that the capability of these two proteins to induce IFN-gamma secretion by murine splenocytes remained after 100 degrees C heating for 30 min, 121 degrees C autoclaving for 15 min, and -80 degrees C freezing. The retained activities of both proteins on cell proliferation and IFN-gamma production did not decrease at 0.6 M hydrochloric acid (at pH 2) but strikingly dropped at 5 M sodium hydrate (at pH 13). After vacuum dehydration, FVE and LZ8 retained most of their activities on cell proliferation; nevertheless, the IFN-gamma secretion decreased to about half of the initial values. These findings suggest that these two mushroom proteins have a good thermal/freezing resistance, acid tolerance, and dehydration stability and are candidates for processing in food and nutraceutical utilization.     

Treatment with taurine attenuates hepatic apoptosis in NZB/W F1 mice fed with a high-cholesterol diet

Cholesterol-rich diets are known to cause hepatic apoptosis, which has been associated with the pathogenesis of systemic lupus erythematosus (SLE). However, the mechanisms and treatments for hepatic apoptosis in SLE are poorly understood. To clarify the effects of taurine on hepatic apoptosis in SLE, NZB/W F1 mice received control, cholesterol, and cholesterol/taurine diets. Significant reductions of caspase-3 activity, TUNEL-positive cells, and Fas- and mitochondrial- dependent apoptosis were detected in liver from the cholesterol/taurine group as compared to the cholesterol group. Moreover, significant increases of phosphorylated AKT, NF-kappaB (p65), and ERK1/2 proteins were detected in liver from the cholesterol/taurine group as compared to the cholesterol group. In contrast, a significant reduction of phosphorylated p38 protein was observed in the cholesterol/taurine group. These experimental results demonstrated positive effects of taurine against hepatic apoptosis in NZB/W F1 mice fed a high-cholesterol diet and suggested the therapeutic potential of taurine in SLE.     

A cell-based screening identifies compounds from the stem of Momordica charantia that overcome insulin resistance and activate AMP-activated protein kinase

Treatment of insulin resistance is a critical strategy in the prevention and management of type 2 diabetes. The crude extracts from all parts of Momordica charantia L. have been reported by many studies for the effective treatment of diabetes and related complications. However, the exact ingredients responsible for the hypoglycemic effect and the underlying mechanism of their actions have not been well characterized because of the lack of a proper assay and screening system. A new cell-based, nonradioactive, and nonfluorescent screening method was demonstrated in this study to screen for natural products from the stem of M. charantia, aiming to identify hypoglycemic components that can overcome cellular insulin resistance. The results suggest triterpenoids being potential hypoglycemic components of the plant and the mechanism underlying their action involving AMP-activated protein kinase.     

Characterization of porcine circovirus type 2 (PCV2) infection in swine lymphocytes using mitogen-stimulated peripheral blood lymphocytes from healthy PCV2-carrier pigs

Information regarding the susceptibility of swine lymphocytes to PCV2 is rather limited. To further explore and characterize the PCV2 infection in swine lymphocytes, an in vitro model using concanavalin A (Con A)-stimulated peripheral blood lymphocytes (PBLs) obtained from clinically healthy PCV2-carrier pigs was introduced. It was found that the PCV2 antigen-containing rate was below 2% in PBLs from healthy PCV2-free pigs following treated simultaneously with Con A and PCV2. However, significantly higher PCV2 antigen- and nucleic acid-containing rates could be seen in Con A-stimulated PBLs from clinically healthy PCV2-carrier pigs. Prior to Con A treatment, both of the PCV2 antigen- and nucleic acid-containing rates in PBLs from healthy PCV2-carrier pigs were less than 1%; however, they reached 22.1+/-5.7% by flow cytometry and 27.1+/-6.5% by in situ hybridization, respectively, at 4-day post-incubation with Con A. Phenotyping of PCV2 antigen-containing cells revealed that PCV2-positive cells could be detected in both T and B lymphocyte populations within which IgM-positive B lymphocytes appeared to have a relatively higher positive rate. The Con A-stimulated PBLs also displayed a significantly higher viral load by the measurement of either PCV2 DNA copy number or viral titer when compared with the non-treated PBLs from healthy PCV2-carrier pigs. The results indicate that PBLs, especially IgM-bearing B lymphocytes, are indeed susceptible to PCV2 infection and PCV2 is capable of replicating in dividing lymphocytes. This activation-induced replication may explain in part the pathogenesis of lymphoid depletion in PMWS-affected pigs.