Recombinant yeast as a functional tool for understanding bitterness and cucurbitacin biosynthesis in watermelon (Citrullus spp.)

Cucurbitacins are a group of bitter‐tasting oxygenated tetracyclic triterpenes that are produced in the family Cucurbitaceae and other plant families. The natural roles of cucurbitacins in plants are probably related to defence against pathogens and pests. Cucurbitadienol, a triterpene synthesized from oxidosqualene, is the first committed precursor to cucurbitacins produced by a specialized oxidosqualene cyclase termed cucurbitadienol synthase. We explored cucurbitacin accumulation in watermelon in relation to bitterness. Our findings show that cucurbitacins are accumulated in bitter‐tasting watermelon, Citrullus lanatus var. citroides, as well as in their wild ancestor, C. colocynthis, but not in non‐bitter commercial cultivars of sweet watermelon (C. lanatus var. lanatus). Molecular analysis of genes expressed in the roots of several watermelon accessions led to the isolation of three sequences (CcCDS1, CcCDS2 and ClCDS1), all displaying high similarity to the pumpkin CpCPQ, encoding a protein previously shown to possess cucurbitadienol synthase activity. We utilized the Saccharomyces cerevisiae strain BY4743, heterozygous for lanosterol synthase, to probe for possible encoded cucurbitadienol synthase activity of the expressed watermelon sequences. Functional expression of the two sequences isolated from C. colocynthis (CcCDS1 and CcCDS2) in yeast revealed that only CcCDS2 possessed cucurbitadienol synthase activity, while CcCDS1 did not display cucurbitadienol synthase activity in recombinant yeast. ClCDS1 isolated from C. lanatus var. lanatus is almost identical to CcCDS1. Our results imply that CcCDS2 plays a role in imparting bitterness to watermelon. Yeast has been an excellent diagnostic tool to determine the first committed step of cucurbitacin biosynthesis in watermelon. Copyright © 2014 John Wiley & Sons, Ltd.     

Effect of ozone and sodium hydroxide treatments on some chemical characteristics of cotton straw

Cotton straw (CS) was treated with ozone or sodium hydroxide, and the effect of treatments on the organic acid and monosaccharide composition and on the chromat-ographic characteristics of alkali lignin was studied. The concentrations of formic and acetic acids in the ozonised CS were 3.98 and 1.36 g 100 g^?1 organic matter (OM) respectively. Oxalic acid was not detected. A high content of uronic acids (9.78 g 100 g^?1 OM) was found in CS. The overall decrease in total monosaccharides in the ozonated CS was very small (5%) with the matrix constituents being principally affected. The 8% sodium hydroxide treatment exerted a very limited effect on the composition of CS cell walls. Ozonation increased the content of soluble carbohydrates from 9.2 to 21.8%; this was contributed mainly by the hemicellulose fraction. Alkali lignin was extracted from CS and was fractionated by gel chromatography. The elution pattern of alkali lignin was very similar for the treated and untreated materials. The three peaks coincided at an average mol. wt of 40 000, as judged from the use of dextran standards.     

Effects of including NaOH-treated corn straw as a substitute for wheat hay in the ration of lactating cows on performance,digestibility, and rumen microbial profile

This study measured the effects of including 5% NaOH-treated corn straw (T-CS) as a substitute for 15% wheat hay in the control total mixed ration (TMR) of lactating cows on performance, digestibility, and rumen microbial profile. Two groups of 21 cows each, similar in initial performance, were fed individually 1 of the 2 TMR examined. Voluntary dry matter intake of cows fed the control TMR was 4.3% higher than that of the T-CS cows, but in vivo dry matter and organic matter digestibilities of both groups were similar. Crude protein digestibility was higher in the control cows but digestibility of neutral detergent fiber polysaccharides (cellulose and hemicelluloses) was higher in the T-CS TMR. This was followed by 4.6% reduction in rumination time of the T-CS group. A slightly higher milk yield was observed in the control cows compared with the T-CS group; however, milk fat and milk protein content were higher in cows fed the T-CS TMR. This was reflected in 1.3% increase in energy-corrected milk yield and 5.34% increase in production efficiency (energy-corrected milk yield/intake) of the T-CS cows compared with the control. Welfare of the cows, as assessed by length of daily recumbence time, was improved by feeding the T-CS TMR relative to the control group. As a whole, the rumen bacterial community was significantly modulated in the T-CS group in the experimental period compared with the preexperimental period, whereas the bacterial community of the control group remained unchanged during this period. Out of the 8 bacterial species that were quantified using real-time PCR, a notable decrease in cellulolytic bacteria was observed in the T-CS group, as well as an increase in lactic acid-utilizing bacteria. These results illustrate the effect of T-CS on the composition of rumen microbiota, which may play a role in improving the performance of the lactating cow.     

Associations between CXCR1 polymorphisms and pathogen-specific incidence rate of clinical mastitis,test-day somatic cell count,and test-day milk yield

The CXCR1 gene plays an important role in the innate immunity of the bovine mammary gland. Associations between single nucleotide polymorphisms (SNP) CXCR1c.735C>G and c.980A>G and udder health have been identified before in small populations. A fluorescent multiprobe PCR assay was designed specifically and validated to genotype both SNP simultaneously in a reliable and cost-effective manner. In total, 3,106 cows from 50 commercial Flemish dairy herds were genotyped using this assay. Associations between genotype and detailed phenotypic data, including pathogen-specific incidence rate of clinical mastitis (IRCM), test-day somatic cell count, and test-day milk yield (MY) were analyzed. Staphylococcus aureus IRCM tended to associate with SNP c.735C>G. Cows with genotype c.735GG had lower Staph. aureus IRCM compared with cows with genotype c.735CC (rate ratio = 0.35, 95% confidence interval = 0.14–0.90). Additionally, a parity-specific association between Staph. aureus IRCM and SNP c.980A>G was detected. Heifers with genotype c.980GG had a lower Staph. aureus IRCM compared with heifers with genotype c.980AG (rate ratio = 0.15, 95% confidence interval = 0.04–0.56). Differences were less pronounced in multiparous cows. Associations between CXCR1 genotype and somatic cell count were not detected. However, MY was associated with SNP c.735C>G. Cows with genotype c.735GG out-produced cows with genotype c.735CC by 0.8 kg of milk/d. Results provide a basis for further research on the relation between CXCR1 polymorphism and pathogen-specific mastitis resistance and MY.     

Nuclear Export Inhibitor KPT-8602 Synergizes with PARP Inhibitors in Escalating Apoptosis in Castration Resistant Cancer Cells

Aberrant nuclear protein transport, often observed in cancer, causes mislocalization-dependent inactivation of critical cellular proteins. Earlier we showed that overexpression of exportin 1 is linked to higher grade and Gleason score in metastatic castration resistant prostate cancer (mCRPC). We also showed that a selective inhibitor of nuclear export (SINE) selinexor and second generation eltanexor (KPT-8602) could suppress mCRPC growth, reduce androgen receptor (AR), and re-sensitize to androgen deprivation therapy. Here we evaluated the combination of KPT-8602 with PARP inhibitors (PARPi) olaparib, veliparib and rucaparib in 22rv1 mCRPC cells. KPT-8602 synergized with PARPi (CI < 1) at pharmacologically relevant concentrations. KPT-8602-PARPi showed superior induction of apoptosis compared to single agent treatment and caused up-regulation of pro-apoptotic genes BAX, TP53 and CASPASE 9. Mechanistically, KPT-8602-PARPi suppressed AR, ARv7, PSA and AR targets FOXA1 and UBE2C. Western blot analysis revealed significant down-regulation of AR, ARv7, UBE2C, SAM68, FOXA1 and upregulation of cleaved PARP and cleaved CASPASE 3. KPT-8602 with or without olaparib was shown to reduce homologous recombination-regulated DNA damage response targets including BRCA1, BRCA2, CHEK1, EXO1, BLM, RAD51, LIG1, XRCC3 and RMI2. Taken together, this study revealed the therapeutic potential of a novel combination of KPT-8602 and PARP inhibitors for the treatment of mCRPC.     

Preparation of La1−xSrxMnO3 nanoparticles by sonication-assisted coprecipitation

La_1−xSr_xMnO₃ (x=0.3) (LSM) nanoparticles were prepared by a sonication-assisted coprecipitation method. The coprecipitation reaction is carried out with ultrasound radiation. Lower sintering temperatures are required for the sonication-assisted product. Fully crystallized LSM with an average particle size 24 nm is obtained after the as-prepared mixture is annealed at 900 °C for 2 h. Magnetic properties indicate that the transition temperature from the paramagnetic to ferromagnetic state of the sample is quite sharp and occurs at 366 K for samples annealed for 2 h at 900 and 1100 °C.     

Reliability of HTO based high-voltage gate stacks for flash memories

We report on the excellent reliability performance of high-voltage (HV) gate stacks comprised of a thin thermal oxide and a thicker HTO layer. Time-to-breakdown of the developed stacks exceeded corresponding values for thermal HV oxides of the same thickness. Peculiarities of current relaxation in course of electrical stress tests are interpreted by injected charge trapping in HTO and new trap generation. Charge trapping in optimized HTO is low and guarantees reliable device operation.     

Earthquakes: Risk, damage and recovery

This paper identifies earthquake risk, damage and recovery plans; stresses the vulnerability of the electric power system and its disruption impact on society; and puts forward some general guidelines to minimize earthquake damage.     

Weapons systems analysis,part II: Simulation techniques and models

The simulation techniques, languages or models best suited for a particular simulation study depend upon the characteristics of the system and the programming skill of the individual conducting the study. This paper identifies, defines, evaluates and classifies a spectrum of simulation techniques that are applicable to weapons systems analysis and air defense weaponry.