Search for the ideal laying hen for organic and free range systems

Since 1960 the majority of commercial layers are housed in cages. Non-cage housing started to appear again from 1980 onwards and increases in importance. It is questionable if birds bred to perform in cages are also suited for free range housing. We examined the performance of current genotypes in free range systems (organic and conventional) by an inventory among laying hen farmers in Switzerland, The Netherlands and France (325 flocks on 275 farms) and organised workshops with farmers to discuss their ideas on breeding goals (‘the ideal hen’) for free range systems

Haltungsbedingungen, Leistung und Gesundheit von gängigen Legehennen-Genotypen in Öko- und Freilandhaltungen in Frankreich, der Schweiz und den Niederlanden

In Switzerland, France and The Netherlands 257 farmers keeping free ranging laying hens (organic and conventional) were interviewed with regard to genotype of the hens, management conditions and performance. In total, 21 different genotypes were present on the farms. The overall effect of system (organic vs. conventional) on egg production and mortality was significant, with higher mortality and lower egg production among organic hens. White hens tended to perform better and have a better feather cover than brown hens. Silver hens appeared to have a higher mortality and lower production per hen housed. In group discussions, farmers preferred a more robust, heavier hen with good intake capacity and good persistence. In organic systems, this hen type is more economic according to model calculations

Sputum Glucose and Glycemic Control in Cystic Fibrosis-Related Diabetes: A Cross-Sectional Study

Cystic fibrosis-related diabetes affects up to half of cystic fibrosis patients and is associated with increased mortality and more frequent pulmonary exacerbations. However, it is unclear to what degree good glycemic control might mitigate these risks and clinical outcomes have not previously been studied in relation to glucose from the lower airways, the site of infection and CF disease progression. We initially hypothesized that diabetic cystic fibrosis patients with glycosylated hemoglobin (HbA_(1c)) > 6.5% have worse pulmonary function, longer and more frequent exacerbations and also higher sputum glucose levels than patients with HbA_(1c) ≤ 6.5% or cystic fibrosis patients without diabetes. To test this, we analyzed spontaneously expectorated sputum samples from 88 cystic fibrosis patients. The median sputum glucose concentration was 0.70 mM (mean, 4.75 mM; range, 0-64.6 mM). Sputum glucose was not correlated with age, sex, body mass index, diabetes diagnosis, glycemic control, exacerbation frequency or length, or pulmonary function. Surprisingly, sputum glucose was highest in subjects with normal glucose tolerance, suggesting the dynamics of glycemic control, sputum glucose and pulmonary infections are more complex than previously thought. Two-year mean HbA_(1c) was positively correlated with the length of exacerbation admission (p 6.5% were hospitalized on average 6 days longer than those with HbA_(1c) ≤ 6.5% (p < 0.01). Current clinical care guidelines for cystic fibrosis-related diabetes target HbA_(1c) ≤ 7% to limit long-term microvascular damage, but more stringent glycemic control (HbA_(1c) ≤ 6.5%) may further reduce the short-term pulmonary complications

Trace incorporation of heavy water reveals slow and heterogeneous pathogen growth rates in cystic fibrosis sputum

Effective treatment for chronic infections is undermined by a significant gap in understanding of the physiological state of pathogens at the site of infection. Chronic pulmonary infections are responsible for the morbidity and mortality of millions of immunocompromised individuals worldwide, yet drugs that are successful in laboratory culture are far less effective against pathogen populations persisting in vivo. Laboratory models, upon which preclinical development of new drugs is based, can only replicate host conditions when we understand the metabolic state of the pathogens and the degree of heterogeneity within the population. In this study, we measured the anabolic activity of the pathogen Staphylococcus aureus directly in the sputum of pediatric patients with cystic fibrosis (CF), by combining the high sensitivity of isotope ratio mass spectrometry with a heavy water labeling approach to capture the full range of in situ growth rates. Our results reveal S. aureus generation times with a median of 2.1 d, with extensive growth rate heterogeneity at the single-cell level. These growth rates are far below the detection limit of previous estimates of CF pathogen growth rates, and the rates are slowest in acutely sick patients undergoing pulmonary exacerbations; nevertheless, they are accessible to experimental replication within laboratory models. Treatment regimens that include specific antibiotics (vancomycin, piperacillin/tazobactam, tobramycin) further appear to correlate with slow growth of S. aureus on average, but follow-up longitudinal studies must be performed to determine whether this effect holds for individual patients

Lessons to be learned from the coherent photoproduction of pseudoscalar mesons

We study the coherent photoproduction of pseudoscalar mesons---particularly of neutral pions---placing special emphasis on the various sources that put into question earlier nonrelativistic-impulse-approximation calculations. These include: final-state interactions, relativistic effects, off-shell ambiguities, and violations to the impulse approximation. We establish that, while distortions play an essential role in the modification of the coherent cross section, the uncertainty in our results due to the various choices of optical-potential models is relatively small (of at most 30%). By far the largest uncertainty emerges from the ambiguity in extending the many on-shell-equivalent representations of the elementary amplitude off the mass shell. Indeed, relativistic impulse-approximation calculations that include the same pionic distortions, the same nuclear-structure model, and two sets of elementary amplitudes that are identical on-shell, lead to variations in the magnitude of the coherent cross section by up to factors of five. Finally, we address qualitatively the assumption of locality implicit in most impulse-approximation treatments, and suggest that the coherent reaction probes---in addition to the nuclear density---the polarization structure of the nucleus.Comment: Manuscript is 27 pages long and includes 11 eps figure

Evaluation of a dedicated dual phased-array surface coil using a black-blood FSE sequence for high resolution MRI of the carotid vessel wall

Purpose: To investigate the ability of magnetic resonance imaging (MRI) to visualize the carotid vessel wall using a phased-array coil and a black-blood (BB) fast spin-echo (FSE) sequence. Materials and Methods: The phased-array coil was compared with a three-inch coil. Images from volunteers were evaluated for artifacts, wall layers, and wall signal intensity. Signal intensity and homogeneity of atherosclerosis were assessed. Lumen diameter and vessel area were measured. Results: Comparison between the phased-array coil and the three-inch coil showed a 100% increase in signal-to-noise ratio. BB-FSE imaging resulted in good delineation between blood and vessel wall. Most volunteers had a two-layered vessel wall with a hyperintense inner layer. MRI showed both homogeneous hyperintense and heterogeneous plaques, which consisted of a main hyperintense part with hypointense spots and/or intermediate regions. MRI lumen and area measurements were performed easily. Conclusion: High resolution MRI of carotid atherosclerosis is feasible with a phased-array coil and a BB-FSE sequence

The year in cardiology 2014: peripheral circulation

In 2014, the debate on the indication of revascularization in case of asymptomatic carotid disease continued, while another one regarding the use of surgery vs. stenting addressed some new issues regarding the long-term cardiac risk of these patients. Renal arteries interventions trials were disappointing, as neither renal denervation nor renal artery stenting was found associated with better blood pressure management or outcome. In contrast, in lower-extremities artery disease, the endovascular techniques represent in 2014 major alternatives to surgery, even in distal arteries, with new insights regarding the interest of drug-eluting balloons. Regarding the aorta, the ESC published its first guidelines document on the entire vessel, emphasizing on the role of every cardiologist for screening abdominal aorta aneurysm during echocardiography. Among vascular wall biomarkers, the aorta stiffness is of increasing interest with new data and meta-analysis confirming its ability to stratify risk, whereas carotid intima-media thickness showed poor performances in terms of reclassifying patients into risk categories beyond risk scores. Regarding the veins, new data suggest the interest of D-dimers and residual venous thrombosis to help the decision of anti-coagulation prolongation or discontinuation after the initial period of treatment for deep vein thrombosi

Assessing the Effects of Genetic Selection for Porcine Circovirus Type 2 Resistance or Feed Additives on Nursery and Grow-Finish Pig Performance

The swine industry is ever evolving as it strives to produce healthy, wholesome pork for consumers. As such, the industry is constantly looking for ways to improve production and reduce costs. This includes using novel feed ingredients to reduce cost and improve animal health, genetic selection for increased performance, and vaccines to attenuate or prevent illness. Research plays a significant role in assessing the effectiveness of these strategies. Overall, the objective of this thesis was to assess how genetic selection, vaccines, and feed additives may impact growth performance, health, nutrient digestibility, and the microbiome. In Chapter 2, pigs were either infected with or vaccinated for PCV2. Fecal samples taken from these pigs were used to assess changes in the microbiome. Overall, the microbiome did not differ at the phylum level, although some organisms were shown to be positively and negatively associated with growth and IgG production. In Chapter 3, experiments were performed to assess the impact of genetic selection for PCV2 resistance on nursery and long-term performance of pigs. Pigs resistant to PCV2 infection had reduced viremia and IgG production. Despite no overall effect on growth performance, the resistant genotypes were found to have lower production costs, especially when infected with PCV2. In Chapter 4, pigs were supplemented with tryptophan to improve postweaning response. Tryptophan improved feed efficiency in experiment 1 and reduced production costs. Tryptophan did not provide the same benefit in experiment 2. Supplementation of tryptophan numerically increased Lactobacillus abundance in experiment 1, but not in experiment 2. In Chapter 5, a series of cell culture experiments were performed to assess the effects of rhamnolipids on IPEC-J2 cells and jejunal explants. Rhamnolipid concentrations exceeding 0.01% were found to be cytotoxic. Lower concentrations were found to be less cytotoxic, but reduced transepithelial resistance in a dose dependent fashion. Secretion of interleukin-8, a marker of inflammation, was observed to be similar to control and LPS samples. Jejunum explants treated with 0.5% rhamnolipid had an IL-8 response higher than controls. Advisor: Thomas E. Burke