Interleukin-5 Potentiates Sulfidopeptide Leukotriene Production by Human Eosinophils

Interleukin-5 (IL-5) has been shown to be a selective eosinophil growth and differentiation factor. In the present study, the effect of recombinant human IL-5 on human eosinophil sulfidopeptide leukotriene production was investigated. IL-5 did not affect leukotriene synthesis in unstimulated eosinophils. However, IL-5 potentiated leukotriene synthesis by eosinophils stimulated with serum treated zymosan (STZ) or the calcium ionophore A23187 by 69% and 135%, respectively. The priming effect of IL-5 was dose dependent, with significant stimulation occurring at 1 000 U/ml for STZ and 100-1 000 U/ml for A23187. Pre-incubation with IL-5 did not increase leukotriene synthesis further

Connecting flow structures and heat flux in turbulent Rayleigh-B\'enard convection

The aspect ratio (\Gamma) dependence of the heat transfer (Nusselt number Nu in dimensionless form) in turbulent (two-dimensional) Rayleigh-B\'enard convection is numerically studied in the regime $0.4 \le \Gamma \le 1.25$ for Rayleigh numbers $10^7 \le Ra \le Ra^{9}$ and Prandtl numbers Pr =0.7 (gas) and 4.3 (water). Nu (\Gamma) shows a very rich structure with sudden jumps and sharp transitions. We connect these structures to the way the flow organizes itself in the sample and explain why the aspect ratio dependence of Nu is more pronounced for small Pr. Even for fixed \Gamma different turbulent states (with different resulting Nu) can exist, between which the flow can or cannot switch. In the latter case the heat transfer thus depends on the initial conditions.Comment: 4 pages, 6 figure

Comparison of computational codes for direct numerical simulations of turbulent Rayleigh-B\'enard convection

Computational codes for direct numerical simulations of Rayleigh-B\'enard (RB) convection are compared in terms of computational cost and quality of the solution. As a benchmark case, RB convection at $Ra=10^8$ and $Pr=1$ in a periodic domain, in cubic and cylindrical containers is considered. A dedicated second-order finite-difference code (AFID/RBflow) and a specialized fourth-order finite-volume code (Goldfish) are compared with a general purpose finite-volume approach (OpenFOAM) and a general purpose spectral-element code (Nek5000). Reassuringly, all codes provide predictions of the average heat transfer that converge to the same values. The computational costs, however, are found to differ considerably. The specialized codes AFID/RBflow and Goldfish are found to excel in efficiency, outperforming the general purpose flow solvers Nek5000 and OpenFOAM by an order of magnitude with an error on the Nusselt number $Nu$ below $5\%$. However, we find that $Nu$ alone is not sufficient to assess the quality of the numerical results: in fact, instantaneous snapshots of the temperature field from a near wall region obtained for deliberately under-resolved simulations using Nek5000 clearly indicate inadequate flow resolution even when $Nu$ is converged. Overall, dedicated special purpose codes for RB convection are found to be more efficient than general purpose codes.Comment: 12 pages, 5 figure

Detection of noroviruses in foods: a study on virus extraction procedures in foods implicated in outbreaks of human gastroenteritis.

Disease outbreaks in which foods are epidemiologically implicated as the common source are frequently reported. Noroviruses and enteric hepatitis A viruses are among the most prevalent causative agents of foodborne diseases. However, the detection of these viruses in foods other than shellfish is often time-consuming and unsuccessful. In this study, three virus concentration methods were compared: polyethylene glycol (PEG) plus NaCl, ultracentrifugation, and ultrafiltration. Two RNA extraction methods, TRIzol and RNeasy Mini Kit (Qiagen), were compared for detection of viruses in whipped cream and lettuce (as representatives of the dairy and vegetable-fruit food groups, respectively). A seeding experiment with canine calicivirus was conducted to determine the efficiency of each virus extraction procedure. The PEG-NaCl-TRIzol method was most efficient for the detection of viruses in whipped cream and the ultracentrifugation-RNeasy-Mini Kit procedure was best for detection on lettuce. Based on the seeding experiments, food items implicated in norovirus-associated gastroenteritis outbreaks were subjected to the optimal procedure for a specific composition and matrix. No noroviruses were detected in the implicated food items, possibly because the concentration of virus on the food item was too low or because of the presence of inhibitory factors. For each food group, a specific procedure is optimal. Inhibitory factors should be controlled in these procedures because they influence virus detection in food

A Systematic Review of Hepatitis E Virus Detection in Camels

Simple Summary: Acute hepatitis, which is a rising public health issue globally, is mostly caused by the hepatitis E virus (HEV). There is a potential risk of camel-borne zoonotic HEV infection in the desert regions of the Middle East and Africa, where camels frequently interact with human populations and camel-derived food products constitute a component of the food chain. To better understand the current state of this subject, the current work's objective is to provide a scientific review of the detection of HEV genotypes seven and eight in camels around the world. Until today, no review paper has been published compiling and discussing the reports available on HEV in camels. More studies are required to ascertain the prevalence of HEV infection in camels worldwide. Additionally, because camels are utilized as a form of transportation in many countries and because HEV in these animals may pose a threat to public health, there is a possibility of foodborne transmission through contaminated camel products. Hepatitis E virus (HEV) represents a major cause of acute hepatitis and is considered an emerging public health problem around the world. In the Middle East's and Africa's arid regions, where camels frequently interact with human populations and camel-derived food products are a component of the food chain, camel-borne zoonotic HEV infection is a potential threat. To date, no review paper has been published on HEV in camels. As such, the purpose of the current work is to provide a scientific review of the identification of HEV genotypes seven and eight in camels worldwide to have a better understanding of the current status of this topic and to identify gaps in the current knowledge. Searches were carried out in the electronic databases PubMed, Mendeley, Web of Science, and Scopus, including studies published until 31 December 2022 (n = 435). Once the databases were checked for duplicate papers (n = 307), the exclusion criteria were applied to remove any research that was not relevant (n = 118). As a result, only 10 papers were found to be eligible for the study. Additionally, in eight of the ten studies, the rates of HEV infection were found to be between 0.6% and 2.2% in both stool and serum samples. Furthermore, four studies detected HEV genotype seven in dromedary camels, and two studies have shown HEV genotype eight in Bactrian camels. Interestingly, these genotypes were recently reported in camels from the Middle East and China, where one human infection with HEV genotype seven has been associated with the consumption of contaminated camel meat and milk. In conclusion, more research will be needed to determine the prevalence of HEV infection in camels around the world as well as the risk of foodborne transmission of contaminated camel products. As camels are utility animals in several countries, HEV in these animals may pose a potential risk to public health.This research was funded by Fundacao para Ciencia e Tecnologia (FCT), grant number 2021.09461.BD

First Test of Lorentz Invariance in the Weak Decay of Polarized Nuclei

A new test of Lorentz invariance in the weak interactions has been made by searching for variations in the decay rate of spin-polarized 20Na nuclei. This test is unique to Gamow-Teller transitions, as was shown in the framework of a recently developed theory that assumes a Lorentz symmetry breaking background field of tensor nature. The nuclear spins were polarized in the up and down direction, putting a limit on the amplitude of sidereal variations of the form |(\Gamma_{up} - \Gamma_{down})| / (\Gamma_{up} + \Gamma_{down}) < 3 * 10^{-3}. This measurement shows a possible route toward a more detailed testing of Lorentz symmetry in weak interactions.Comment: 11 pages, 6 figure