We established a mastitis model using exogenous infection of the mammary gland of Chinese Holstein cows with Staphylococcus aureus and extracted total RNA from S. aureus-infected and healthy mammary quarters. Differential expression of genes due to mastitis was evaluated using Affymetrix technology and results revealed a total of 1230 differentially expressed mRNAs. A subset of affected genes was verified via Q-PCR and pathway analysis. In addition, Solexa high-throughput sequencing technology was used to analyze profiles of miRNA in infected and healthy quarters. These analyses revealed a total of 52 differentially expressed miRNAs. A subset of those results was verified via Q-PCR. Bioinformatics techniques were used to predict and analyze the correlations among differentially expressed miRNA and mRNA. Results revealed a total of 329 pairs of negatively associated miRNA/mRNA, with 31 upregulated pairs of mRNA and 298 downregulated pairs of mRNA. Differential expression of miR-15a and interleukin-1 receptor-associated kinase-like 2 (IRAK2), were evaluated by western blot and luciferase reporter assays. We conclude that miR-15a and miR-15a target genes (IRAK2) constitute potential miRNA–mRNA regulatory pairs for use as biomarkers to predict a mastitis response.

The dispersal unit of many species of Brassicaceae is an indehiscent fruit, but relatively few studies have tested the effect of the pericarp on seed germination in this family. Our aim was to determine the effect of the pericarp on seed dormancy in six species of Brassicaceae native to the cold desert of north-west China. Intact dispersal units and isolated seeds of Chorispora sibirica, Euclidium syriacum, Goldbachia laevigata, Spirorrhynchus sabulosus, Sterigmostemum fuhaiense and Tauscheria lasiocarpa were stored dry at ambient laboratory conditions for 0–12 months and tested for germination in light and in dark at 5/2, 15/2 and 30/15°C. The amount of water absorbed by fruits and by seeds within the fruits was determined. For four species, intact fruits, isolated seeds and isolated seeds plus the removed pericarps were used to test for the mechanical versus possible chemical role of the pericarp in seed dormancy. Fresh isolated seeds, which have a fully developed embryo, germinated to lower percentages and rates than afterripened seeds. Thus, seeds have non-deep physiological dormancy. The pericarp significantly reduced germination, but inhibition was not due to lack of water uptake by seeds or to chemical inhibitors. Afterripened seeds of the six species germinated to 0–50% inside the fruits. We conclude that the pericarp plays a dominant role in seed dormancy of the six study species, and it does so by mechanically restricting embryo growth. Thus, the pericarp has the potential to spread germination over an extended period of time.

Although Asteraceae species are important in the cold deserts of Central Asia, little is known about their seed dormancy and germination. We determined dormancy breaking and germination requirements of three annual Asteraceae, Echinops gmelinii, Epilasia acrolasia and Koelpinia linearis. Achenes (seeds) were tested for germination in light and in darkness over a range of alternating temperatures after various periods of burial outdoors and of dry storage. Germination phenology was monitored for seeds sown in irrigated and non-irrigated sand, and temperature requirements for dormancy break were determined under wet and dry conditions. Effects of pericarp and phyllaries on germination of E. acrolasia and E. gmelinii, respectively, were determined. Low percentages of 20-day-old seeds of E. acrolasia and K. linearis were non-dormant and germinated to low percentages over the range of temperatures, whereas all seeds of E. gmelinii were dormant. As seeds of the three species afterripened, they germinated over the range of temperatures. Whether seeds germinated in autumn or spring depended on the amount of sand moisture. Mechanical resistance of the pericarp and phyllaries reduced germination of E. acrolasia and E. gmelinii, respectively. Temperature requirements for germination as seeds come out of dormancy do not correspond to any of the known five types of non-deep physiological dormancy (PD). Thus, a sixth type is recognized in which germination occurs over the same range of temperatures in the early and late stages of dormancy break. Type 6 allows seeds to germinate at high or at low temperatures, whenever sand moisture is non-limiting.

Several studies have compared seed banks of the different morphs of heteromorphic species, but none of them was on an amphi-basicarpic species. Our primary aim was to compare the relative ability of aerial and basal diaspores of an amphi-basicarpic species to form a seed bank. We compared the seed-bank dynamics of basal and aerial diaspores of three populations of the cold-desert annual Ceratocarpus arenarius growing in the Junggar Desert in north-western China. A 2.5-year experimental garden study compared germination phenology and retention of viability in basal (a) and aerial (c and f) morphs. Aerial morphs formed a modified Thompson and Grime type III seed bank (small proportion of seeds carried over to next year) and the basal morph a modified type IV seed bank (large proportion of seeds carried over to next year). Seeds germinated only in spring, and cumulative germination percentages were f>c>a (year 1), f = c>a (year 2) and f = c = a (year 3). The relationship between length of germination period, retention of viability during burial and relative ability to form a persistent seed bank was basal morph > aerial morphs. The results of this seed-bank study on C. arenarius are in full agreement with those published previously on seed dispersal and dormancy in this species. Thus, strong additional support is provided for a high risk–low risk germination strategy in this cold-desert annual.

Many studies have compared diaspore dispersal ability and degree of dormancy in the two diaspores of dimorphic plant species. A primary goal of these studies was to determine if germination and dispersal characteristics of the two morphs fit within a high risk–low risk (bet-hedging) life-history strategy, i.e. high dispersal/low dormancy in one morph versus low dispersal/high dormancy in the other one. In a survey of 26 papers on 28 diaspore dimorphic species, we found that in 12 of the studies, which were published between 1978 and 2008, seeds were stored, and thus possibly afterripened, before they were tested for germination. The 14 papers that tested fresh seeds were published between 1963 and 2010. Failure to test fresh seeds likely resulted in misinterpretation of the diaspore dispersal/dormancy strategy in some of the species investigated. We conclude that it is imperative that fresh seeds be tested for germination in order to be certain that the correct relationship between dispersal and dormancy is elucidated, and thus that the correct interpretation is made concerning life-history strategy and bet-hedging, in dimorphic species.

We studied physical properties of titanium hafnium oxide (TixHf1-xO2) alloy thin films deposited by pulsed DC reactive magnetron sputtering with AC substrate bias. Thin films of two end oxides, hafnium oxides (HfO2) and titanium oxides (TiO2), and their alloys TixHf1-xO2 with a range of compositions deposited with and without the substrate bias were compared to study the dependence of physical properties of the thin films on the substrate bias. Structural, chemical and optical properties of the thin films were analyzed to assess inter-relationship among these properties. Thin films deposited with the AC substrate bias consistently show much higher refractive index and significantly lower optical extinction coefficient than those of thin films deposited without the substrate bias suggesting that characteristic microstructures developed in these thin films are responsible for the differences in the optical properties.

Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.