147 research outputs found

    Inelastic scattering of broadband electron wave packets driven by an intense mid-infrared laser field

    Full text link
    Intense, 100 fs laser pulses at 3.2 and 3.6 um are used to generate, by multi-photon ionization, broadband wave packets with up to 400 eV of kinetic energy and charge states up to Xe+6. The multiple ionization pathways are well described by a white electron wave packet and field-free inelastic cross sections, averaged over the intensity-dependent energy distribution for (e,ne) electron impact ionization. The analysis also suggests a contribution from a 4d core excitation in xenon

    Water, Waste and Quality Management During Preparation and Processing of Vegetables

    Get PDF
    The research was designed to test and/or develop new systems of washing, peeling and blanching, develop methods of utilization of solid wastes, and find ways to reduce wastestrength of effluent without affecting quality of vegetables for processing. The highest wastestrength of effluent from vegetable processing in the region was found in plants that were canning Irish potatoes, dry beans and hominy. The high volumes of water used for washing spinach and leafy greens and the physical damage to the washed product is one of the major problems. Repetitive washing of spinach in the same water did not affect quality as long as there was sufficient rinsing after the second wash. The levels of COD, TSS, TS, SS, PO4 and NO3 did not build up to prohibitive levels by the reuse of water as long as adequate make-up water was added. Steam blanching, which leaches out much less soluble constituents, can be substituted for water blanching by using appropriate times and temperature for different vegetables. The greater retention of nutrients in steam blanched vegetables was demonstrated in different vegetables grown and processed under different conditions. Data from research on the canning of dry beans indicated that the high wastestrength can be reduced by shortening the soaking time, controlling the temperature of soaking and processing without blanching without changing the quality appreciably. It appears that the present method of hominy preparation and processing can be altered to reduce pollution. By dipping corn in 10% lye solution, followed by heating and scrubbing, corn can be peeled and bleached efficiently. Most of the heavy solid waste can be isolated before the final rinse of the peeled corn. The prototype leafy greens washing system decreased the use of water by 70% on spinach, turnip greens and mustard. Water quality data showed that wastestrength of the effluent from washing was reduced over 50%, as compared to industrial washers, primarily due to less physical breakage. Less nutrients were leached out in greens washed by the experimental washer than the industrial washer. High alkalinity solid wastes from peeling Irish and sweet potatoes can be fermented and stored as long as 9 months without any great change in carbohydrates and total dry matter. There was an increase in sugar content and a decrease in starch content during fermentation. The quality of the sweet potato waste appeared to be excellent after storage when mold inhibitor was sprayed on vats. Irish potato waste storage created more odor problems unless the fermentation temperature was controlled at 25 to 30°C

    Examination of the enterotoxigenic Escherichia coli population structure during human infection

    Get PDF
    Enterotoxigenic E. coli (ETEC) can cause severe diarrhea and death in children in developing countries; however, bacterial diversity in natural infection is uncharacterized. In this study, we explored the natural population variation of ETEC from individuals with cholera-like diarrhea. Genomic sequencing and comparative analysis of multiple ETEC isolates from twelve cases of severe diarrhea demonstrated clonal populations in the majority of subjects (10/12). In contrast, a minority of individuals (2/12) yielded phylogenomically divergent ETEC isolates. Detailed examination revealed that isolates also differed in virulence factor content. These genomic data suggest that severe, cholera-like ETEC infections are largely caused by a clonal population of organisms within individual patients. Additionally, the isolation of similar clones from geographically and temporally dispersed cases with similar clinical presentations suggests that some isolates are particularly suited for virulence. The identification of multiple genomically diverse isolates with variable virulence factor profiles from a single subject highlights the dynamic nature of ETEC, as well as a potential weakness in the examination of cultures obtained from a single colony in clinical settings. These findings have implications for vaccine design and provide a framework for the study of population variation in other human pathogens

    Src Inhibition Blocks c-Myc Translation and Glucose Metabolism to Prevent the Development of Breast Cancer

    Get PDF
    Preventing breast cancer will require the development of targeted strategies that can effectively block disease progression. Tamoxifen and aromatase inhibitors are effective in addressing estrogen receptor–positive (ER+) breast cancer development, but estrogen receptor–negative (ER−) breast cancer remains an unmet challenge due to gaps in pathobiologic understanding. In this study, we used reverse-phase protein array to identify activation of Src kinase as an early signaling alteration in premalignant breast lesions of women who did not respond to tamoxifen, a widely used ER antagonist for hormonal therapy of breast cancer. Src kinase blockade with the small-molecule inhibitor saracatinib prevented the disorganized three-dimensional growth of ER− mammary epithelial cells in vitro and delayed the development of premalignant lesions and tumors in vivo in mouse models developing HER2+ and ER− mammary tumors, extending tumor-free and overall survival. Mechanistic investigations revealed that Src blockade reduced glucose metabolism as a result of an inhibition in ERK1/2–MNK1–eIF4E–mediated cap-dependent translation of c-Myc and transcription of the glucose transporter GLUT1, thereby limiting energy available for cell growth. Taken together, our results provide a sound rationale to target Src pathways in premalignant breast lesions to limit the development of breast cancers

    Differential Expression of miRNAs in Response to Topping in Flue-Cured Tobacco (Nicotiana tabacum) Roots

    Get PDF
    Topping is an important cultivating measure for flue-cured tobacco, and many genes had been found to be differentially expressed in response to topping. But it is still unclear how these genes are regulated. MiRNAs play a critical role in post-transcriptional gene regulation, so we sequenced two sRNA libraries from tobacco roots before and after topping, with a view to exploring transcriptional differences in miRNAs.Two sRNA libraries were generated from tobacco roots before and after topping. Solexa high-throughput sequencing of tobacco small RNAs revealed a total of 12,104,207 and 11,292,018 reads representing 3,633,398 and 3,084,102 distinct sequences before and after topping. The expressions of 136 conserved miRNAs (belonging to 32 families) and 126 new miRNAs (belonging to 77 families) were determined. There were three major conserved miRNAs families (nta-miR156, nta-miR172 and nta-miR171) and two major new miRNAs families (nta-miRn2 and nta-miRn26). All of these identified miRNAs can be folded into characteristic miRNA stem-loop secondary hairpin structures, and qRT-PCR was adopted to validate and measure the expression of miRNAs. Putative targets were identified for 133 out of 136 conserved miRNAs and 126 new miRNAs. Of these miRNAs whose targets had been identified, the miRNAs which change markedly (>2 folds) belong to 53 families and their targets have different biological functions including development, response to stress, response to hormone, N metabolism, C metabolism, signal transduction, nucleic acid metabolism and other metabolism. Some interesting targets for miRNAs had been determined.The differential expression profiles of miRNAs were shown in flue-cured tobacco roots before and after topping, which can be expected to regulate transcripts distinctly involved in response to topping. Further identification of these differentially expressed miRNAs and their targets would allow better understanding of the regulatory mechanisms for flue-cured tobacco response to topping

    Erratum to: EuPRAXIA Conceptual Design Report – Eur. Phys. J. Special Topics 229, 3675-4284 (2020), https://doi.org/10.1140/epjst/e2020-000127-8

    Get PDF
    International audienceThe online version of the original article can be found at http://https://doi.org/10.1140/epjst/e2020-000127-8</A

    The bile salt glycocholate induces global changes in gene and protein expression and activates virulence in enterotoxigenic Escherichia coli

    Get PDF
    Pathogenic bacteria use specific host factors to modulate virulence and stress responses during infection. We found previously that the host factor bile and the bile component glyco-conjugated cholate (NaGCH, sodium glycocholate) upregulate the colonization factor CS5 in enterotoxigenic Escherichia coli (ETEC). To further understand the global regulatory effects of bile and NaGCH, we performed Illumina RNA-Seq and found that crude bile and NaGCH altered the expression of 61 genes in CS5 + CS6 ETEC isolates. The most striking finding was high induction of the CS5 operon (csfA-F), its putative transcription factor csvR, and the putative ETEC virulence factor cexE. iTRAQ-coupled LC-MS/MS proteomic analyses verified induction of the plasmid-borne virulence proteins CS5 and CexE and also showed that NaGCH affected the expression of bacterial membrane proteins. Furthermore, NaGCH induced bacteria to aggregate, increased their adherence to epithelial cells, and reduced their motility. Our results indicate that CS5 + CS6 ETEC use NaGCH present in the small intestine as a signal to initiate colonization of the epithelium
    corecore