Development and evaluation of molecular-based assays for detecting Salmonella serovars in various food commodities

As a leading cause of foodborne illnesses and outbreaks, Salmonella poses a major public health risk in the United States and worldwide. Various food commodities including meat and poultry, eggs, and fresh produce can serve as the transmission vehicles for Salmonella infections. To better ensure the safety of these products and protect public health, rapid, accurate, and reliable detection methods for Salmonella are needed. Molecular-based methods like loop-mediated isothermal amplification (LAMP), have gained wide applications in Salmonella detection, owning to their rapidity, specificity, and sensitivity. However, there is a paucity of data on the robustness of these assays. And very recently, bioluminescence assay in real-time (BART) was used as a new and effective platform to detect LAMP products, and this combination has not been evaluated before. This dissertation research evaluated the robustness of two LAMP assays in comparison with PCR, examined the application of LAMP assays in detecting Salmonella specifically in food items, and developed a novel LAMP-BART assay for Salmonella detection. The LAMP assays achieved robust detection of Salmonella under abusive preparation and running temperatures, also demonstrated greater tolerance than PCR to various inhibitors. They achieved 100% accuracy among 185 strains. The limits of detection of LAMP for Salmonella strains belonging to ten serovars were 1 to 10 cells per reaction in pure culture, 100-fold more sensitive than PCR. In spiked egg homogenates, it could detect Salmonella serovars Enteritidis and Typhimurium down to 10^4 CFU/25 ml egg homogenates directly and 1 CFU/25 ml with 8 h enrichment. In spiked produce (cantaloupe, jalapeno pepper, tomatoes, sprouts, and lettuces), the detection limits ranged from 10^4 to 10^6 CFU/25 g produce, which were comparable to qPCR. Coupled with 6 to 8 h of enrichment, LAMP consistently detected in produce samples spiked with very low levels of Salmonella cells, with the exception of sprouts. Based on these evaluations and further development, LAMP demonstrated to be a rapid and robust alternative to PCR-based assays for Salmonella detection and could be adopted by food industries and regulatory agencies in routine product testing for Salmonella to improve product safety and protect public health

Vývoj trhu zelených dluhopisů v Číně

Chinese economic growth is very rapid. But the cost behind this growth is also becoming more and more apparent such as air pollution, In response to environmental challenges, green financial become one of the main ways to solve them. The main aim of this thesis is to evaluate the current bond market in China, the policy and development of the Chinese green bond market, compare domestic and foreign definitions and standards of green bond, and to assess the main role of green bonds in China. Although the green bond market has just started in China, it faces many difficulties. At present, there is still the challenge of the inconsistency of green project standards, the need to further standardize the certification system, and the transparency of information disclosure. The Chinese government, regulatory agencies, financial institutions and all sectors of the community are also working hard to make sure the healthy development of Chinese green bond market and occupy a place in the international green bond market.Čínský ekonomický růst je velmi rychlý. Náklady za tento růst se však stále více projevují formou znečištění ovzduší. V reakci na environmentální výzvy se zelená finanční politika stává jedním z hlavních způsobů, jak je vyřešit. Hlavním cílem této práce je zhodnotit současný trh s dluhopisy v Číně, politiku a vývoj čínského trhu s dluhopisy, srovnat domácí a zahraniční definice a standardy zelených dluhopisů a posoudit hlavní úlohu zelených dluhopisů v Číně. Ačkoli zelený trh dluhopisů v číně se teprve rozvíjí, čelí mnoha obtížím. V současné době stále existuje nejednotnost zelených projektových standardů, potřeba další standardizace certifikačního systému a transparentnost zveřejňování informací. Čínská vláda, regulační agentury, finanční instituce a všechna odvětví také pracují na zajištění zdravého vývoje čínského trhu s dluhopisy a zaujímají významné místo na mezinárodním trhu s zelenými dluhopisy.154 - Katedra financívelmi dobř

Refrigerated seawater depuration for reducing Vibrio parahaemolyticus contamination in raw Pacific oysters (Crassostrea gigas)

Vibrio parahaemolyticus is a seafood-borne pathogen that can cause gastroenteritis in humans. This study investigated the effectiveness of refrigerated seawater (5°C) depuration on reducing V. parahaemolyticus in raw Pacific oysters (Crassostrea gigas). Raw Pacific oysters were inoculated with a mixed culture of five clinical strains of V. parahaemolyticus and depurated with cold seawater (5°C) in a pilot scale recirculating system. The refrigerated seawater depuration was more efficient in reducing V. parahaemolyticus contamination in oysters harvested in winter than in summer. Populations of V. parahaemolyticus in oysters harvested in winter were reduced by >1.2 log MPN/g after 24 h of depuration in refrigerated seawater. Reductions of V. parahaemolyticus in the oysters increased to about 2.3 log MPN/g after 48 h and reached 3.1 log after 96 h of the process. However, it required 144 h of depuration in the refrigerated seawater to achieve a 3-log (MPN/g) reduction of V. parahaemolyticus in oysters harvested in summer. The efficacies of refrigerated seawater depuration in reducing V. parahaemolyticus were determined at a rate of 0.0211-log/h in oysters harvested in the summer and 0.0362-log/h in oysters harvested in the winter. This is probably due to the differences between water temperatures of the oyster harvest site (7-9ºC in winter, 16-17ºC in summer) and the refrigerated seawater (5ºC). Because of the increased temperature difference in the summer, it would require a longer time for oysters to adjust their biological activity to the new environment. Depuration of raw oysters in recirculated refrigerated seawater (5ºC) for up to 144 h did not cause a noticeable fatality of oysters, but increased their ability to survive in subsequent cold storage. The process also reduced fecal coliform contamination in oysters from 10³ MPN/g to less than 20 MPN/g. When oysters were stored in a refrigerator, 90% of oysters with or without depuration treatment survived after 7 days. However, the survival rate of oysters that had not been depurated in refrigerated seawater dropped sharply from 90 % to 44% after 9 days while 87% of depurated oysters remained alive after the same period of storage. No viable but nonculturable (VBNC) cells of V. parahaemolyticus were detected in the oysters depurated in refrigerated seawater for 144 h by reverse transcriptase polymerase chain reaction (RT-PCR) and multiplex PCR. Refrigerated seawater (5ºC) depuration can be used as a simple and economical post-harvest treatment for reducing V. parahaemolyticus contamination in oysters. This process can easily be adopted by the shellfish industry for producing safe oysters for consumers and to reduce V. parahaemolyticus infection associated with raw oyster consumption

The Extent of Distraction of Cell Phone Conversations for Passengers in Simulated Flight

Currently, passengers are forbidden from making cell phone calls during flights in the United States due to safety concerns. However, some related research has demonstrated that the interference of cell phone use with avionics and ground network is minimal or can be eliminated by using modern technology. Although conversing on the cell phone does not cause electronic interference, the distraction of a passenger caused by a cell phone may negatively impact safety. The cell phone calls have been found to affect people’s attention and performance. In-flight announcements are popular methods to inform commercial airliner passengers of their situation and aircraft’s status. If a passenger’s attention is distracted from the announcements by the phone call, it would inhibit the passenger from being aware of important information. The purpose of this study was to compare the extent of safety compliance (checking seatbelts, raising tray tables) and retention of announcements among three groups: cell phone conversation, face-to-face conversation (i.e., talking with the passenger next to them), and control. Findings revealed that the cell phone group and the face-to-face group recalled less information from safety announcement and complied with safety behaviors to a lesser degree than the control group. The face-to-face group was not safer than the cell phone group on any measure. Lifting the cell phone ban should be considered. Additional research in regard to safety implications of passengers engaged in conversation warrants further study

Rapid detection of Salmonella in food and feed by coupling loop-mediated isothermal amplification with bioluminescent assay in real-time

Salmonella is among the most significant pathogens causing food and feed safety concerns. This study examined the rapid detection of Salmonella in various types of food and feed samples by coupling loop-mediated isothermal amplification (LAMP) with a novel reporter, bioluminescent assay in real-time (BART). Performance of the LAMP-BART assay was compared to a conventional LAMP and the commercially available 3M Molecular Detection Assay (MDA) Salmonella. The LAMP-BART assay was 100 % specific among 178 strains (151 Salmonella and 27 non-Salmonella) tested. The detection limits were 36 cells per reaction in pure culture and 104 to 106 CFU per 25 g in spiked food and feed samples without enrichment, which were comparable to those of the conventional LAMP and 3M MDA Salmonella but 5–10 min faster. Ground turkey showed a strong inhibition on 3M MDA Salmonella, requiring at least 108 CFU per 25 g for detection. The correlation between Salmonella cell numbers and LAMP-BART signals was high (R 2 = 0.941–0.962), suggesting good quantification capability. After 24 h enrichment, all three assays accurately detected 1 to 3 CFU per 25 g of Salmonella among five types of food (cantaloupe, ground beef, ground turkey, shell eggs, and tomato) and three types of feed (cattle feed, chicken feed, and dry dog food) examined. However, 101 CFU per 25 g was required for cattle feed when tested by 3M MDA Salmonella. The Salmonella LAMP-BART assay was rapid, specific, sensitive, quantitative, and robust. Upon further validation, it may become a valuable tool for routine screening of Salmonella in various types of food and feed samples.https://doi.org/10.1186/s12866-016-0730-

Mitochondrial Protein PINK1 Positively Regulates RLR Signaling

The serine/threonine kinase phosphatase and tensin homolog (PTEN)-induced putative kinase 1(PINK1) controls mitochondrial quality and plays a vital role in the pathogenesis of early-onset Parkinson's disease. However, whether PINK1 has functions in innate antiviral immunity is largely unknown. Here, we report that viral infection down regulates PINK1 expression in macrophages. PINK1 knockdown results in decreased cytokine production and attenuated IRF3 and NF-κB activation upon viral infection. PINK1 promotes the retinoic-acid-inducible gene I (RIG-I)-like receptors (RLR)-triggered immune responses in a kinase domain-dependent manner. Furthermore, PINK1 associates with TRAF3 via the kinase domain and inhibits Parkin-mediated TRAF3 K48-linked proteasomal degradation. In addition, PINK1 interacts with Yes-associated protein 1 (YAP1) upon viral infection and impairs YAP1/IRF3 complex formation. Collectively, our results demonstrate that PINK1 positively regulates RIG-I triggered innate immune responses by inhibiting TRAF3 degradation and relieving YAP-mediated inhibition of the cellular antiviral response

Role of follistatin-like 1 levels and functions in calcific aortic stenosis

BackgroundCalcific aortic valve disease (CAVD) is a progressive disease resulting in severe calcific aortic stenosis (AS), and there is increasing interest in the discovery of novel biomarkers to identify patients with potential future calcific AS at an early stage. This study aimed to determine whether follistatin-like 1 (FSTL1) is associated with calcific AS events and its exact role in aortic valve calcification.MethodsA prospective observational cohort study involving 656 patients was performed to investigate the relationship between serum FSTL1 and calcific AS incidence during a follow-up of 5 years. Furthermore, we detected FSTL1 levels in valvular interstitial cells (VICs) from calcified valves and explored the effects of FSTL1 on VIC osteogenic differentiation in vitro as well as the signaling pathways involved.ResultsDuring a median follow-up of 5 years, lower FSTL1 levels were associated with a significantly higher risk of calcific AS events (log rank test, P = 0.007). In addition, Cox multivariable regression analyses verified the predictive value of FSTL1 after adjusting for both demographic features and laboratory confounders. Consistent with our results for serum, a lower concentration of FSTL1 was observed in calcified human valves (n = 11) and mainly colocalized with VICs. Recombinant human FSTL1 (rhFSTL1) stimulation inhibited calcium deposition, alkaline phosphatase (ALP) activity, and osteogenic gene expression partly through the downregulation of the ERK1/2 pathway.ConclusionTaken together, this study provides a strong rationale to consider FSTL1 as a potential therapeutic target for calcific AS

The Effect of Heat-Moisture Treatment Changed the Binding of Starch, Protein and Lipid in Rice Flour to Affect Its Hierarchical Structure and Physicochemical Properties

Highlights HMT promoted the binding between starch, protein and lipid. • The gelatinization viscosity of HMT rice flour was sharply increased when the proteins were removed. • Proteins played a critical role in the physicochemical changes of HMT rice flour. This study investigated the effect of removing proteins, lipids and starch on the structure, physicochemical properties and digestion properties of rice flour (with 30% moisture) treated with heat moisture treatment (HMT). According to the results, HMT caused the adhesion and agglomeration of the rice flour, promoted the binding between starch, protein and lipid molecular chains and led to the formation of complexes (especially starch-lipid complexes), which hindered the removal of non-starch components. Compared to the untreated rice flour, the HMT treated lipid-removal rice flour had small changes in their crystallinity, gelatinization temperature and viscosity property. After removing protein, the crystallinity, peak viscosity, final viscosity, breakdown and starch digestibility were sharply increased. In particular, the peak viscosity increased from 811 cP to 1746 cP and the enthalpy change increased from 5.33 J/g to 10.18 J/g. These findings are helpful in understanding the contribution of removing endogenous proteins and lipids to the physicochemical changes of HMT treated rice flour during its heating process and thus can be helpful in controlling the quality of rice flour through HMT

Roles of MSH2 and MSH6 in cadmium-induced G2/M checkpoint arrest in Arabidopsis roots

DNA mismatch repair (MMR) proteins have been implicated in sensing and correcting DNA damage, and in governing cell cycle progression in the presence of structurally anomalous nucleotide lesions induced by different stresses in mammalian cells. Here, Arabidopsis seedlings were grown hydroponically on 0.5 × MS media containing cadmium (Cd) at 0–4.0 mg L−1 for 5 d. Flow cytometry results indicated that Cd stress induced a G2/M cell cycle arrest both in MLH1-, MSH2-, MSH6-deficient, and in WT roots, associated with marked changes of G2/M regulatory genes, including ATM, ATR, SOG1, BRCA1, WEE1, CYCD4; 1, MAD2, CDKA;1, CYCB1; 2 and CYCB1; 1. However, the Cd-induced G2/M phase arrest was markedly diminished in the MSH2- and MSH6-deficient roots, while a lack of MLH1 had no effect on Cd-induced G2 phase arrest relative to that in the wild type roots under the corresponding Cd stress. Expression of the above G2/M regulatory genes was altered in MLH1, MSH2 and MSH6-deficient roots in response to Cd treatment. Furthermore, Cd elicited endoreplication in MSH2- and MSH6-deficient roots, but not in MLH1-deficient Arabidopsis roots. Results suggest that MSH2 and MSH6 may act as direct sensors of Cd-mediated DNA damage. Taken together, we conclude that MSH2 and MSH6, but not MLH1, components of the MMR system are involved in the G2 phase arrest and endoreplication induced by Cd stress in Arabidopsis roots