Rooster’s Genetic Response to Immune Stimulation

Lipopolysaccharide (LPS), commonly used to mimic bacterial infection without using live bacteria, was injected into roosters from three genetically diverse lines and gene expression was measured at two time points post-injection. TLR4, MD-2, and MyD88 are three genes that are responsible for initiating the major immune pathway that responds to LPS. Results showed significant differences in gene expression at different times post-stimulation for both MyD88 and TLR4. The three chicken lines had different expression levels of TLR4 in response to LPS. This shows that there are genetic differences in this immune pathway. Further studies are needed, but it may be possible to use TLR4 expression information in the selection process. Overall, bacterial infections are a serious threat to chickens and a better understanding of this pathway will lead to beneficial, applied approaches in the poultry industry

Clean-up of cereal extracts for gas chromatography-tandem quadrupole mass spectrometry pesticide residues analysis using primary secondary amine and C18

The level of co-extracted matrix in wheat and oat extracts obtained by the QuEChERS method (EN 15662) is high and the occurrence of free fatty acids generates a major matrix peak in TIC chromatograms (rt. 13-22min). Matrix can compromise the analytical performance in pesticide analysis using GC-MS/MS. In order to reduce the amount and the effects of matrix we tested the effect of using six different amounts of primary secondary amine (PSA) (0, 25, 50, 100, 150 and 200mg/ml extract) with and without the addition of six different amounts of C18 (0, 25, 50, 100, 150 and 200mg/ml extract) in the dispersive solid phase extraction (dSPE) procedure. dSPE clean-up using 25mg/ml extract significantly reduced the major matrix peak observed for wheat extracts. Higher amounts of PSA reduced the analytical response for iprodione and malathion. For oat extract 50-150mg PSA/ml extract was needed to obtain equally low intensity of the matrix peak. For oat the analytical responses of the target pesticides generally increased with increasing amount of PSA. C18 had no significant effect on the intensity of the major matrix peaks and even resulted in lower analytical responses for several of the target pesticides. Based on the present study it is concluded that the optimal dSPE clean-up procedure employs 25mg PSA/ml extract for wheat and 150mg PSA/ml extract for oat

How Does the Sound Pressure Generated by Circumaural, Supra-aural, and Insert Earphones Differ for Adult and Infant Ears?

Objective: To determine how the ear canal sound pressure levels generated by circumaural, supra-aural, and insert earphones differ when coupled to the normal adult and infant ear. Design: The ratio between the sound pressure generated in an adult ear and an infant ear was calculated for three types of earphones: a circumaural earphone (Natus Medical, ALGO with Flexicoupler™), a supra-aural earphone (Telephonics, TDH-49 with MXAR cushion), and an insert earphone placed in the ear canal (Etymo↕tic Research, ER-3A). The calculations are based on (1) previously published measurements of ear canal impedances in adult and infant (ages 1, 3, 6, 12, and 24 months) ears (Keefe et al., 1993, Acoustic Society of America, 94:2617–2638), (2) measurements of the Thévenin equivalent for each earphone configuration, and (3) acoustic models of the ear canal and external ear. Results: Sound-pressure levels depend on the ear canal location at which they are measured. For pressures at the earphone: (1) Circumaural and supra-aural earphones produce changes between infant and adult ears that are less than 3 dB at all frequencies, and (2) insert earphones produce infant pressures that are up to 15 dB greater than adult pressures. For pressures at the tympanic membrane: (1) Circumaural and supra-aural earphones produce infant pressures that are within 2 dB of adult ears at frequencies below 2000 Hz and that are 5 to 7 dB smaller in infant ears than adult ears above 2000 Hz, and (2) insert earphones produce pressures that are 5 to 8 dB larger in infant ears than adult ears across all audiometric frequencies. Conclusions: Sound pressures generated by all earphone types (circumaural, supra-aural, and insert) depend on the dimensions of the ear canal and on the impedance of the ear at the tympanic membrane (e.g., infant versus adult). Specific conclusions depend on the location along the ear canal at which the changes between adult and infant ears are referenced (i.e., the earphone output location or the tympanic membrane). With circumaural and supra-aural earphones, the relatively large volume of air within the cuff of the earphone dominates the acoustic load that these earphones must drive, and differences in sound pressure generated in infant and adult ears are generally smaller than those with the insert earphone in which the changes in ear canal dimensions and impedance at the tympanic membrane have a bigger effect on the load the earphone must drive

Occurrence of volatile and non-volatile N-nitrosamines in processed meat products and the role of heat treatment

AbstractMost of the available data on the occurrence of N-nitrosamines (NA) in processed meat products have been generated in the 1980s and 1990s and especially data on the occurrence of non-volatile NA (NVNA) are scarce. Therefore we have studied the levels of volatile nitrosamines (VNA) and NVNA in processed meat products on the Danish market (N = 70) and for comparison also products on the Belgian market (N = 20). The effect of heat treatment on the NA levels, in selected samples, was also studied, in order to enable an evaluation of how preparation before consumption affects the levels of NA. For the Danish products the mean levels of the VNA were generally low (≤0.8  μg kg−1), whereas the mean levels of the NVNA were considerably higher (≤118 μg kg−1). Slightly higher mean levels were indicated for the Belgian products (i.e. VNA ≤1.5  μg kg−1 and NVNA ≤270 μg kg−1). The sums of VNA were higher than 10 μg kg−1 for one Danish sample and two Belgian samples. Levels of up to 2000 and 4000 μg kg−1 of N-nitroso-thiazolidine-4-carboxylic acid (NTCA) an NVNA occurred in the Danish and the Belgian samples, respectively. The majority of the Danish processed meat products contain NVNA but also VNA occur. The levels of NA are comparable with those reported in previous and recent studies; however the frequency in which they are found may be lower and thereby also the mean contents. The levels of N-nitrosopiperidine (NPIP) increased by frying and baking, whereas varying impacts were observed for N-nitrosoproline (NPRO), N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (NPYR), N-nitrosodiethylamine (NDEA) and N-nitrosomethylaniline (NMA) depending on the type of product and/or the heat treatment. The levels of the NVNA, NTCA and N-nitroso-2-methyl-thiazolidine 4-carboxylic acid (NMTCA) decreased after frying and baking