Median concentration of total PBDEs in maternal serum, paternal serum, umbilical cord serum, and breast milk samples were 12, 12, 17, and 6.1 ng/g lipid weight (lw) in Vallecas and 9.7, 12, 15, and 5.5 ng/g lw in Getafe. The median value found in placentas was 1.9 ng/g lw (in Vallecas). BDE 47 was the predominant congener in serum samples (maternal, paternal, and umbilical cord), while BDE 209 was predominant in placenta and breast milk samples. BDEs 196 and 197 were detected in most of the placenta and breast milk samples. The results show that PBDEs, like other POPs, can cross the placenta barrier, although the speed of the process seems to differ for each PBDE congeners. The total PBDE concentrations found in this study are consistent with research reported elsewhere. They are in the same range as those recently reported by other European and Asian studies and lower than those conducted in the U.S.A. No significant differences were found (p > 0.05) between regions, sexes, and ages, while statistically significant differences (p < 0.05) were found between maternal serum, umbilical cord serum, and breast milk samples. The presence of PBDEs in cord blood and placenta samples indicates that there is prenatal exposure of PBDEs, which could continue after birth via breast milk.
We present an experimental study of a flock passing through a narrow door. Video monitoring of daily routines in a farm has enabled us to collect a sizable amount of data. By measuring the time lapse between the passage of consecutive animals, some features of the flow regime can be assessed. A quantitative definition of clogging is demonstrated based on the passage time statistics. These display broad tails, which can be fitted by power laws with a relatively large exponent. On the other hand, the distribution of burst sizes robustly evidences exponential behavior. Finally, borrowing concepts from granular physics and statistical mechanics, we evaluate the effect of increasing the door size and the performance of an obstacle placed in front of it. The success of these techniques opens new possibilities regarding their eventual extension to the management of human crowds.
SummaryFrom February to July of 1994, 328 faecal samples from 32 herds were collected and verotoxin-producingEscherichia coli(VTEC) found on 84% of the farms. The proportion of animals infected varied from 0–63%. VTEC were recovered from 52 (20%) of 257 cows and from 16 (23%) of 71 calves. Although the VTEC belonged to 25 different serogroups, 7 (O8. O20, O22, O77, O113, O126 and O162) accounted for 46% of strains. Nearly 45% of the 83 bovine VTEC strains belonged to serogroups associated with haemorrhagic colitis and haemolytic uraernic syndrome in humans. However, only 2 (2%) of 83 VTEC strains isolated from cattle belonged to enterohaemorrhagicE. coli(EHEC) serotypes (O26:H11 and O157:H7), and only 8 (10%) were positive for the attaching and effacingE. coli (eae)gene sequence. Polymerase chain reaction (PCR) showed that 17 (20%) of VTEC strains carried VT1 genes. 43 (52%) possessed VT2 genes, and 23 (28%) carried both VT1 and VT2 genes. Characterization of VTEC isolates revelated a heterogeneous population in terms of serogroup and toxin type in the positive herds. This study confirms that healthy cattle are a reservoir of VTEC, but, the absence ofeaegenes in most bovine VTEC strains suggests that they may be less virulent for humans thaneae-positive EHEC.
For the first time in Europe, both European-wide and country-specific levels of urinary Bisphenol A (BPA) were obtained through a harmonized protocol for participant recruitment, sampling and quality controlled biomarker analysis in the frame of the twin projects COPHES and DEMOCOPHES. 674 child-mother pairs were recruited through schools or population registers from six European member states (Belgium, Denmark, Luxembourg, Slovenia, Spain and Sweden). Children (5-12 y) and mothers donated a urine sample. Information on socio-demographic characteristics, life style, dietary habits, and educational level of the parents was provided by mothers. After exclusion of urine samples with creatinine values below 300 mg/L or above 3000 mg/L, 653 children and 639 mothers remained for which BPA was measured. The geometric mean (with 95% confidence intervals) and 90th percentile were calculated for BPA separately in children and in mothers and were named "European reference values". After adjustment for confounders (age and creatinine), average exposure values in each country were compared with the mean of the "European reference values" by means of a weighted analysis of variance. Overall geometric means of all countries (95% CI) adjusted for urinary creatinine, age and gender were 2.04 (1.87-2.24) µg/L and 1.88 (1.71-2.07) µg/L for children (n=653) and mothers (n=639), respectively. Multiple regression analysis was used to identify significant environmental, geographical, personal or life style related determinants. Consumption of canned food and social class (represented by the highest educational level of the family) were the most important predictors for the urinary levels of BPA in mothers and children. The individual BPA levels in children were significantly correlated with the levels in their mothers (r=0.265, p<0.001), which may suggest a possible common environmental/dietary factor that influences the biomarker level in each pair. Exposure of the general European population was well below the current health-based guidance values and no participant had BPA values higher than the health-based guidance values.
SUMMARYTwo groups of 32 laying hens (Hyssex Brown) and two groups of 32 23-day-old (Hybro) broiler chickens were fed 2.5 and 5 parts/10 6 of aflatoxin in their diet for 4, 8, 16 and 32 days; 16 hens and 32 chicks were maintained as control groups (0 parts/10 6 ). After the intoxication period, a clearance period was established of 1, 2, 4 and 8 days. Relative weights of liver and kidneys significantly increased in intoxicated hens, but not in broiler chickens. Histological lesions in both types of bird consisted of hepatic cell vacuolation with fatty infiltration. There was a significant decrease (P< 0.001) in egg production in the 5 parts/10 6 group, which started to recover during the clearance period. No morbidity or mortality due to the aflatoxicosis were observed in either type of bird. In intoxicated laying hens, cholesterol levels were not significantly (P> 0.05) different from control values, but triglyceride levels decreased (P< 0.001) in both intoxicated groups. The effect of aflatoxin on calcium and phosphorus levels was important, because on the 4th day their values decreased significantly. Aspartate aminotransferase (AST) serum levels remained normal, whereas alanino aminotransferase (ALT) activity decreased in both intoxicated groups. The activity of serum lactic dehydrogenase (LDH) and gammaglutamil transferase (GGT) increased significantly. In intoxicated broiler chickens, aflatoxins did not alter (P> 0.05) the biochemical parameters studied, except that the serum calcium concentration was lower in the 5 parts/10 6 group. These data indicated that in intoxicated laving hens, a severe clinical biochemical alteration was produced, and that this together with the hepatic lesions observed in hens and broilers may aid disease diagnosis.
In a recent work [Phys. Rev. E 91, 022808 (2015)] it was reported that placing an obstacle in front of a gate has a beneficial effect in the flow of sheep through it. Here, we extend such results by implementing three different obstacle positions. We have observed that the flow is improved in two cases, while it worsens in the other one; the last instance happens when the obstacle is too close to the door. In this situation, the outcomes suggest that clogging develops between the doorjamb and the obstacle, contrary to the cases when the obstacle is farther, in which case clogging always occurs at the very door. The effectiveness of the obstacle (a strategy put forward to alleviate clogging in emergency exits) is therefore quite sensitive to its location. In addition, the study of the temporal evolution of the flow rate as the test develops makes evident a steady behavior during the entire duration of the entrance. This result is at odds with recent findings in human evacuation tests where the flow rate varies over time, therefore challenging the fairness of straightforward comparisons between pedestrian behavior and animal experimental observations.
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