Determining the Effect of a CBC-based Oxime on Cell Viability and Apoptosis in Sea Urchin Embryos

Natural products are an important source of existing and potential new anti-cancer drugs. We have previously shown that cannabichromene (CBC) oxime and several CBC oxime esters have potent anti-mitotic activity when used in bioassays with sea urchin embryos. In this study we explored the effect of the CBC oxime on cell viability and apoptosis in sea urchin embryos. Newly fertilized or gastrula stage embryos were combined with 10µM or 50uM CBC oxime as well as a DMSO only control. At various timepoints, samples of the embryos were removed from the cultures and stained with three different fluorescent dyes. NucBlue (ThermoFisher) was used to determine cell number, apoptotic effects were observed with CellEvent caspace3/7 (ThermoFisher), and cell viability was determined with Live-or-Dye (Biotium). As expected, there was a clear effect of the CBC oxime on the rate of cell division. The embryos exposed to both 10uM and 50uM CBC oxime showed a reduction in cell division compared to the controls, with an almost total inhibition in the higher concentration. Cell viability assays using the vital stain Live-or-Dye showed a concentration dependent effect of the CBC oxime on cell viability, with levels of cell death reaching almost 80% in the 50uM concentration by 3 hours after drug addition. Finally, staining with CellEvent caspace3/7, which indicates the presence of active caspase activity, demonstrated concentration dependent induction of apoptosis following exposure to the CBC oxime drug. Therefore, the loss of cell viability observed was due to apoptosis rather than necrosis. There are clear toxic effects seen when this drug is exposed to developing sea urchin embryos, suggesting that it might have potential use as a chemotherapy agent capable of inducing apoptosis in cancer cells. We plan to test this hypothesis on human cancer cell lines in the near future

220 fs Er-Yb:glass laser mode-locked by a broadband low-loss Si/Ge saturable absorber

We demonstrate femtosecond performance of an ultra-broadband high-index-contrast saturable Bragg reflector consisting of a silicon/silicon-dioxide/germanium structure that is fully compatible with CMOS processing. This device offers a reflectivity bandwidth of over 700 nm and sub-picosecond recovery time of the saturable loss. It is used to achieve mode-locking of an Er-Yb:glass laser centered at 1540 nm, generating 220 fs pulses, with the broadest output spectrum to date

Functional microRNA generated from a cytoplasmic RNA virus

MicroRNAs (miRNAs) are a class of small, non-coding RNAs that play a pivotal role in the regulation of posttranscriptional gene expression in a wide range of eukaryotic organisms. Although DNA viruses have been shown to encode miRNAs and exploit the cellular RNA silencing machinery as a convenient way to regulate viral and host gene expression, it is generally believed that this pathway is not available to RNA viruses that replicate in the cytoplasm of the cell because miRNA biogenesis is initiated in the nucleus. In fact, among the >200 viral miRNAs that have been experimentally verified so far, none is derived from an RNA virus. Here, we show that a cytoplasmic RNA virus can indeed encode and produce a functional miRNA. We introduced a heterologous miRNA-precursor stem-loop sequence element into the RNA genome of the flavivirus tick-borne encephalitis virus, and this led to the production of a functional miRNA during viral infection without impairing viral RNA replication. These findings demonstrate that miRNA biogenesis can be used by cytoplasmic RNA viruses to produce regulatory molecules for the modulation of the transcriptome

Numerical simulation of the impeller tip clearance effect on centrifugal compressor performance

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references (leaves 47-49).Issued also on microfiche from Lange Micrographics.This thesis presents the numerical simulation of flow in centrifugal compressors. A three-dimensional Navier-Stokes solver was employed to simulate flow through two centrifugal compressors. The first compressor simulated was the NASA low speed centrifugal compressor (LSCC). The LSCC was selected as a test compressor because of the experimental data available. The numerically simulated data was compared to the experimental data to validate the flow solver. The numerical results were in good agreement with the experimental. The second compressor simulated was a Honeywell turbopump centrifugal compressor (HCC). The HCC was simulated for three tip clearances at six wheel speeds. Six operating conditions were investigated at each tip clearance and wheel speed. The data obtained from the HCC simulations was used to investigate the effect of tip clearance on compressor performance. Specifically, the total-total pressure ratio, mass flow rate and adiabatic efficiencies were tracked to see how each were affected by an increasing tip clearance. The results show that as the tip clearance was increased, the total-total pressure ratio, mass flow rate and adiabatic efficiencies all decreased for the same static-total pressure ratio. The pressure differences and temperature differences, from the pressure side to the suction side of the blade, and the vorticity were all explored as possible causes of this reduced performance. The pressure proved to be the biggest impactor on performance. The increased tip clearance let more flow leak across the blade tip. The leakage flow tried to homogenize the pressure difference across the blade. The overall effect resulted in a much lower pressure difference. The temperature remained nearly the same as the tip clearance increased. The vorticity increased, but this was also a result of the increased tip leakage flow. To aid in total-total pressure ratio predictions, the results for the HCC were put into compressor maps

Community Supported Agriculture : Towards a Flourishing Movement in Europe

As a response to the growing global sustainability challenges related to industrial agriculture, alternative approaches of food production and distribution are emerging. One approach that fosters direct consumer-producer relationships and sustainable local food production is known as Community Supported Agriculture (CSA). This study explored how the CSA movement can be supported strategically towards a flourishing movement in Europe. A qualitative research approach was chosen with a comparative element of the two countries with contrastive characteristics in terms of the degree of successfulness of the movement; with France being successful and Sweden having less success in terms of the number of CSAs. Semi-structured interviews were conducted with 21 CSA farmers, network members and researchers. The results revealed barriers and enablers for a flourishing movement under five overarching themes: (1) Definition, structure and operation (2) The direction of the movement (3) Social aspects (4) Knowledge and communication, and (5) Country-/region-specific aspects. Crucial factors and contrastive features between countries were identified and discussed in relation to how they hinder or enable a flourishing movement. Based on the findings, strategic guidelines were developed with the aim of contributing to CSA practitioners and leaders in Europe.

Yacon (Smallanthus sonchifolius Poepp. & Endl.) as a Novel Source of Health Promoting Compounds: Antioxidant Activity, Phytochemicals and Sugar Content in Flesh, Peel, and Whole Tubers of Seven Cultivars

The aim of this study was to evaluate the quality characteristics of seven yacon (Smallanthus sonchifolius Poepp. and Endl.) cultivars (Cajamarca, Cusco, Early White, Late Red, Morado, New Zealand and Quinault) cultivated in the southwest of Germany. The following phyto/chemical traits were investigated in different yacon tuber parts (flesh, peel, and whole tubers): total dry matter, sugar content (fructose, glucose, and sucrose content), total phenolic content (TPC), total flavonoid content (TFC), 2,20-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and Ferric reducing antioxidant power (FRAP). The results indicated a significant interaction between cultivar and tuber part on all of the examined traits (p < 0.0001). Of flesh and whole tuber, cv. Late Red, cv. Morado, and cv. Cajamarca had the highest TPC, TFC, DPPH radical scavenging activity, and FRAP. They also had relatively higher total sugar content. Cv. New Zealand had the lowest amount of sugars, TPC, TFC, DPPH radical scavenging activity, and FRAP, but the highest ABTS radical scavenging activity content in its flesh and whole tuber. Moreover, the results indicated that the peel of yacon tubers contained considerably high amounts of phytochemicals while possessing low sugar contents. Overall, this study provides a broad insight into the phyto/chemical content of yacon tubers from different cultivars, which can be used for further breeding programs, and the selection of proper cultivars for specific food product development

High energy and high average power optical fiber ultrafast beam delivery and compression (orale)

International audienc