Microbial Quality and Pathogen Decontamination Strategies for Locally-Grown, Fresh Produce from West Virginia and Kentucky

This study aimed to evaluate the microbiological quality/safety of fresh produce from farmers\u27 markets (FM) and assess the post-harvest washing practice with antimicrobials to inactivate Salmonella and Listeria monocytogenes on fresh produce. In study I, 212 produce samples were tested for the presence of Salmonella and Listeria spp. using modified FDA-BAM methods. Aerobic plate counts (APCs), total coliforms (TCCs), and yeast/molds were analyzed on petri-films. Among the 212 samples, the APCs, TCCs, and yeast/molds were 3.72-5.63, 3.67-5.47, and 3.07-4.13 log CFU/g, respectively, with spinach containing the highest (P\u3c0.05) populations. Among all tested samples, Salmonella enterica spp. enterica was detected on 18.6% of spinach, 10.9% of tomatoes, 18.5% of peppers, and 56.3% of cantaloupes, which is much higher than previous reported. Only 3.78% of the samples were confirmed for Listeria spp., and 50% of them were identified as L. monocytogenes, based on multiplex PCR results. Due to the high percentage of pathogens detected on the farmers\u27 marker produce, an evaluation of post-harvest produce washing with various antimicrobials was conducted in study II. Specifically, spinach, tomatoes, green peppers and cucumbers were inoculated with S. Typhimurium and Tennessee or L. monocytogenes and washed in tap water, vinegar water (10%), lactic acid (5%), a lactic and citric acid blend (2.5%), and sodium hypochlorite (200 ppm) for 30 sec or unwashed. Vinegar water (10%) showed better (P\u3c0.05) reduction of S. Typhimurium and Tennessee on tomatoes and cucumbers, and L. monocytogenes on tomatoes and peppers than tap water. The three antimicrobials reached an additional reduction level of 0.9 to 2.7 (S. Typhimurium and Tennessee) and 0.2 to 1.4 log CFU/g ( L. monocytogenes) compared to tap water. Lactic acid caused the greatest (P\u3c0.05) reduction of S. Typhimurium and Tennessee on spinach and green peppers, and sodium hypochlorite showed the great (P\u3c0.05) reduction of L. monocytogenes on cucumbers. The results supplied important information for FM vendors to develop post-harvest protocols to control foodborne pathogens

Efficient Burst Raw Denoising with Variance Stabilization and Multi-frequency Denoising Network

With the growing popularity of smartphones, capturing high-quality images is of vital importance to smartphones. The cameras of smartphones have small apertures and small sensor cells, which lead to the noisy images in low light environment. Denoising based on a burst of multiple frames generally outperforms single frame denoising but with the larger compututional cost. In this paper, we propose an efficient yet effective burst denoising system. We adopt a three-stage design: noise prior integration, multi-frame alignment and multi-frame denoising. First, we integrate noise prior by pre-processing raw signals into a variance-stabilization space, which allows using a small-scale network to achieve competitive performance. Second, we observe that it is essential to adopt an explicit alignment for burst denoising, but it is not necessary to integrate a learning-based method to perform multi-frame alignment. Instead, we resort to a conventional and efficient alignment method and combine it with our multi-frame denoising network. At last, we propose a denoising strategy that processes multiple frames sequentially. Sequential denoising avoids filtering a large number of frames by decomposing multiple frames denoising into several efficient sub-network denoising. As for each sub-network, we propose an efficient multi-frequency denoising network to remove noise of different frequencies. Our three-stage design is efficient and shows strong performance on burst denoising. Experiments on synthetic and real raw datasets demonstrate that our method outperforms state-of-the-art methods, with less computational cost. Furthermore, the low complexity and high-quality performance make deployment on smartphones possible.Comment: Accepted for publication in International Journal of Computer Visio

PTEN is involved in modulation of vasculogenesis in early chick embryos

Summary PTEN is a tumor suppressor gene that is mutated and/or deleted in many types of tumor. This gene also plays a very distinct role in the early stages of embryonic development such as cell migration, proliferation and migration. Nevertheless, little is known of the function of PTEN in vasculogenesis during chick embryonic development. In this study, we used in situ hybridization to first demonstrate the expression pattern of PTEN during gastrulation. PTEN was found mainly expressed in the blood islands of area opaca, the neural tube and mesodermal structures. Overexpression of PTEN obstructed the epithelial–mesenchymal transition (EMT) process in the primitive streak. EMT is the first prerequisite required for the emigration of hemangioblasts during vasculogenesis. When PTEN expression was silenced, we observed that it produced an adverse effect on mesodermal cell emigration to the extra-embryonic blood islands. In addition, we also demonstrated that even if the perturbed-PTEN cells did not affect the formation of blood islands, migrant mesodermal cells overexpressing wt PTEN-GFP had difficulties integrating into the blood islands. Instead, these cells were either localized on the periphery of the blood islands or induced to differentiate into endothelial cells if they managed to integrate into blood islands. Development of the intra-embryonic primary vascular plexus was also affected by overexpression of PTEN. We proposed that it was elevated PTEN lipid phosphatase activity that was responsible for the morphogenetic defects induced by PTEN overexpression. In this context, we did not find PTEN affecting VEGF signaling. In sum, our study has provided evidence that PTEN is involved in vasculogenesis during the early stages of chick embryo development

Penaeid shrimp genome provides insights into benthic adaptation and frequent molting

Crustacea, the subphylum of Arthropoda which dominates the aquatic environment, is of major importance in ecology and fisheries. Here we report the genome sequence of the Pacific white shrimp Litopenaeus vannamei, covering similar to 1.66 Gb (scaffold N50 605.56 Kb) with 25,596 protein-coding genes and a high proportion of simple sequence repeats (>23.93%). The expansion of genes related to vision and locomotion is probably central to its benthic adaptation. Frequent molting of the shrimp may be explained by an intensified ecdysone signal pathway through gene expansion and positive selection. As an important aquaculture organism, L. vannamei has been subjected to high selection pressure during the past 30 years of breeding, and this has had a considerable impact on its genome. Decoding the L. vannamei genome not only provides an insight into the genetic underpinnings of specific biological processes, but also provides valuable information for enhancing crustacean aquaculture

Geometric phases for wave packets in a uniform magnetic field

A wave packet of a charged particle always make cyclic circular motion in a uniform magnetic field, just like a classical particle. The nonadiabatic geometric phase for an arbitrary wave packet can be expressed in terms of the mean value of a number operator. For a large class of wave packets, the geometric phase is proportional to the magnetic flux encircled by the orbit of the wave packet. For more general wave packets, however, the geometric phase contains an extra term.Comment: REVTeX4, 7 pages, no figur

TradAO: A visual analytics system for trading algorithm optimization

With the wide applications of algorithmic trading, it has become critical for traders to build a winning trading algorithm to beat the market. However, due to the lack of efficient tools, traders mainly rely on their memory to manually compare the algorithm instances of a trading algorithm and further select the best trading algorithm instance for the real trading deployment. We work closely with industry practitioners to discover and consolidate user requirements and develop an interactive visual analytics system for trading algorithm optimization. Structured expert interviews are conducted to evaluateTradAOand a representative case study is documented for illustrating the system effectiveness. To the best of our knowledge, previous financial data visual analyses have mainly aimed to assist investment managers in investment portfolio analysis but have neglected the need of traders in developing trading algorithms for portfolio execution.TradAOis the first visual analytics system that assists users in comprehensively exploring the performances of a trading algorithm with different parameter settings.Comment: 5 pages, 2 figure