Cis/Trans-Fatty Acid Content of Red Meats and the Related Effects on Meat Quality and Human Health

Red meats are often criticized as unhealthy based on their perceived high-fat content and saturated fatty acid composition. Uncertainties about the fatty acid composition and trans-fatty acid contents may discourage consumers to eat red meat, especially those living with non-communicable diseases such as cardiovascular diseases, hypertension and obesity (e.g. the metabolic syndrome). Previous studies have investigated the factors that influence the fat content and fatty acid composition of red meats, including the effects of species, age, nutrition, sex, production systems and growth promotants in animals, but the trans-fatty acid content of red meat has not been well studied to date. The purpose of this chapter is to review the fat content and fatty acid composition of red meats, with specific reference to its cis/trans-fatty acid content. Representative samples of beef sirloin steaks (n = 60) and lamb loin chops (n = 80) (the lumbar part of the longissimus dorsi muscle) were collected from carcasses from several randomly selected abattoirs in the Gauteng region of South Africa for proximate and fatty acid analyses. Results from this study confirm that the intramuscular fat content of red meats is low compared to most fat-containing processed foods. The lean component of beef and lamb contain a trivial proportion of TFA’s, consisting of vaccenic acid, rumenic acid and conjugated linoleic acid (CLA) isomers. The CLA’s in red meat are beneficial due to their antioxidant and anti-carcinogenic properties, so they should not strictly be considered in the TFA definition. This means that the TFA’s in red meats are negligible and pose no harm to human health. Labelling of red meats should be improved to convey this information to consumers

Effect of Bioregion on the Size and Production Efficiency of Bonsmara Cattle in Semi-Arid Parts of Southern Africa

The effects of bioregions in the semi-arid parts of Southern Africa on growth, size and reproduction efficiency of Bonsmara cows are investigated. The regional distribution of cattle influences the growth, size and reproduction efficiency of cows, and provides evidence for an optimal cow size for different bioregions. Effects of bioregion on growth and reproduction of extensive beef cattle is complex, because the proportion of variation in growth traits explained by bioregion, depends on the physiological stages of growth, e.g., birth, weaning, 12- or 18-month growth stages. For production efficiency, weaning- and yearling weights as well as age at first calving (AFC) and reproduction index (RI) were influenced most by bioregion. Management practices, such as livestock recording and improvement strategies, and better nutrition at weaning and yearling age, limit the negative effects of bioregion on cow growth and size. Genetic trends indicate that the efficiency of growth improved, but was associated with a decline in reproductive characteristics. Indiscriminate selection for growth traits in cattle adversely affects reproduction. The current data indicate that cows of medium size had the best reproduction rates. Acceptable reproduction of larger cows can be achieved with improved management and strategic feed supplementation, although more costly

Understanding Experimental Economics

Experiments have become a well-established methodological tool in economics. e development of experi- mental economics and the diversi cation of experimental methods have equipped economists with new and powerful means of scienti c investigation. eir worth is readily demonstrated in the exciting and promising results they have produced, and will continue to produce. Against the background of this success story, our selective discussion critically highlights four important aspects of experimentation in economics. We concen- trate on the role and importance of material incentives, potentially confounding experimenter demand e ects and strategies to minimise these, the no deception rule as well as the issue of external validity.

An empirical approach to modeling ion production rates in Titan's ionosphere II: Ion production rates on the nightside

Ionization of neutrals by precipitating electrons and ions is the main source of Titan's nightside ionosphere. This paper has two goals: (1) characterization of the role of electron impact ionization on the nightside ionosphere for different magnetospheric conditions and (2) presentation of empirical ion production rates determined using densities measured by the Cassini Ion and Neutral Mass Spectrometer on the nightside. The ionosphere between 1000 and 1400 km is emphasized. We adopt electron fluxes measured by the Cassini Plasma Spectrometer-Electron Spectrometer and the Magnetospheric Imaging Instrument as classified by Rymer et al. (2009). The current paper follows an earlier paper (Paper I), in which we investigated sources of Titan's dayside ionosphere and demonstrated that the photoionization process is well understood. The current paper (Paper II) demonstrates that modeled and empirical ionization rates on the nightside are in agreement with an electron precipitation source above 1100 km. Ion production rate profiles appropriate for different Saturnian magnetospheric conditions, as outlined by Rymer et al., are constructed for various magnetic field topologies. Empirical production rate profiles are generated for deep nightside flybys of Titan. The results also suggest that at lower altitudes (below 1100 km) another source, such as ion precipitation, is probably needed

Large emissions from floodplain trees close the Amazon methane budget

Wetlands are the largest global source of atmospheric methane (CH4), a potent greenhouse gas. However, methane emission inventories from the Amazon floodplain, the largest natural geographic source of CH4 in the tropics, consistently underestimate the atmospheric burden of CH4 determined via remote sensing and inversion modelling, pointing to a major gap in our understanding of the contribution of these ecosystems to CH4 emissions. Here we report CH4 fluxes from the stems of 2,357 individual Amazonian floodplain trees from 13 locations across the central Amazon basin. We find that escape of soil gas through wetland trees is the dominant source of regional CH4 emissions. Methane fluxes from Amazon tree stems were up to 200 times larger than emissions reported for temperate wet forests6 and tropical peat swamp forests, representing the largest non-ebullitive wetland fluxes observed. Emissions from trees had an average stable carbon isotope value (δ13C) of −66.2 ± 6.4 per mil, consistent with a soil biogenic origin. We estimate that floodplain trees emit 15.1 ± 1.8 to 21.2 ± 2.5 teragrams of CH4 a year, in addition to the 20.5 ± 5.3 teragrams a year emitted regionally from other sources. Furthermore, we provide a ‘top-down’ regional estimate of CH4 emissions of 42.7 ± 5.6 teragrams of CH4 a year for the Amazon basin, based on regular vertical lower-troposphere CH4 profiles covering the period 2010–2013. We find close agreement between our ‘top-down’ and combined ‘bottom-up’ estimates, indicating that large CH4 emissions from trees adapted to permanent or seasonal inundation can account for the emission source that is required to close the Amazon CH4 budget. Our findings demonstrate the importance of tree stem surfaces in mediating approximately half of all wetland CH4 emissions in the Amazon floodplain, a region that represents up to one-third of the global wetland CH4 source when trees are combined with other emission sources

An empirical approach to modeling ion production rates in Titan’s ionosphere I: Ion production rates on the dayside and globally

Titan's ionosphere is created when solar photons, energetic magnetospheric electrons or ions, and cosmic rays ionize the neutral atmosphere. Electron densities generated by current theoretical models are much larger than densities measured by instruments on board the Cassini orbiter. This model density overabundance must result either from overproduction or from insufficient loss of ions. This is the first of two papers that examines ion production rates in Titan's ionosphere, for the dayside and nightside ionosphere, respectively. The first (current) paper focuses on dayside ion production rates which are computed using solar ionization sources (photoionization and electron impact ionization by photoelectrons) between 1000 and 1400 km. In addition to theoretical ion production rates, empirical ion production rates are derived from CH4, CH3+, and CH4+ densities measured by the INMS (Ion Neutral Mass Spectrometer) for many Titan passes. The modeled and empirical production rate profiles from measured densities of N2+ and CH4+ are found to be in good agreement (to within 20%) for solar zenith angles between 15 and 90°. This suggests that the overabundance of electrons in theoretical models of Titan's dayside ionosphere is not due to overproduction but to insufficient ion losses

Submillimeter Number Counts From Statistical Analysis of BLAST Maps

We describe the application of a statistical method to estimate submillimeter galaxy number counts from confusion limited observations by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). Our method is based on a maximum likelihood fit to the pixel histogram, sometimes called 'P(D)', an approach which has been used before to probe faint counts, the difference being that here we advocate its use even for sources with relatively high signal-to-noise ratios. This method has an advantage over standard techniques of source extraction in providing an unbiased estimate of the counts from the bright end down to flux densities well below the confusion limit. We specifically analyse BLAST observations of a roughly 10 sq. deg. map centered on the Great Observatories Origins Deep Survey South (GOODS-S) field. We provide estimates of number counts at the three BLAST wavelengths, 250, 350, and 500 microns; instead of counting sources in flux bins we estimate the counts at several flux density nodes connected with power-laws. We observe a generally very steep slope for the counts of about -3.7 at 250 microns and -4.5 at 350 and 500 microns, over the range ~0.02-0.5 Jy, breaking to a shallower slope below about 0.015 Jy at all three wavelengths. We also describe how to estimate the uncertainties and correlations in this method so that the results can be used for model-fitting. This method should be well-suited for analysis of data from the Herschel satellite.Comment: Accepted for publication in the Astrophysical Journal; see associated data and other papers at http://blastexperiment.info

Protracted Respiratory Failure in a Case of Global Spinal Syringomyelia and Chiari Malformation Following Administration of Diazepam: Illustrative Case

BACKGROUND: Syringomyelia is defined as dilation of the spinal cord\u27s central canal and is often precipitated by skull base herniation disorders. Although respiratory failure (RF) can be associated with skull base abnormalities due to brainstem compression, most cases occur in pediatric patients and quickly resolve. The authors report the case of an adult patient with global spinal syringomyelia and Chiari malformation who developed refractory RF after routine administration of diazepam. OBSERVATIONS: A 31-year-old female presented with malnutrition, a 1-month history of right-sided weakness, and normal respiratory dynamics. After administration of diazepam prior to magnetic resonance imaging (MRI), she suddenly developed hypercapnic RF followed MRI and required intubation. MRI disclosed a Chiari malformation type I and syrinx extending from C1 to the conus medullaris. After decompressive surgery, her respiratory function progressively returned to baseline status, although 22 months after initial benzodiazepine administration, the patient continues to require nocturnal ventilation. LESSONS: Administration of central nervous system depressants should be closely monitored in patients with extensive syrinx formation given the potential to exacerbate diminished central respiratory drive. Early identification of syrinx in the context of Chiari malformation and hemiplegia should prompt clinical suspicion of underlying respiratory compromise and early involvement of intensive care consultants

BLAST: Correlations in the Cosmic Far-Infrared Background at 250, 350, and 500 microns Reveal Clustering of Star-Forming Galaxies

We detect correlations in the cosmic far-infrared background due to the clustering of star-forming galaxies in observations made with the Balloon-borne Large Aperture Submillimeter Telescope, BLAST, at 250, 350, and 500 microns. We perform jackknife and other tests to confirm the reality of the signal. The measured correlations are well fit by a power law over scales of 5-25 arcminutes, with Delta I/I = 15.1 +/- 1.7%. We adopt a specific model for submillimeter sources in which the contribution to clustering comes from sources in the redshift ranges 1.3 <= z <= 2.2, 1.5 <= z <= 2.7, and 1.7 <= z <= 3.2, at 250, 350, and 500 microns, respectively. With these distributions, our measurement of the power spectrum, P(k_theta), corresponds to linear bias parameters, b = 3.8 +/- 0.6, 3.9 +/- 0.6 and 4.4 +/- 0.7, respectively. We further interpret the results in terms of the halo model, and find that at the smaller scales, the simplest halo model fails to fit our results. One way to improve the fit is to increase the radius at which dark matter halos are artificially truncated in the model, which is equivalent to having some star-forming galaxies at z >= 1 located in the outskirts of groups and clusters. In the context of this model we find a minimum halo mass required to host a galaxy is log (M_min / M_sun) = 11.5 (+0.4/-0.1), and we derive effective biases $b_eff = 2.2 +/- 0.2, 2.4 +/- 0.2, and 2.6 +/- 0.2, and effective masses log (M_eff / M_sun) = 12.9 +/- 0.3, 12.8 +/- 0.2, and 12.7 +/- 0.2, at 250, 350, and 500 microns, corresponding to spatial correlation lengths of r_0 = 4.9, 5.0, and 5.2 +/- 0.7 h^-1 Mpc, respectively. Finally, we discuss implications for clustering measurement strategies with Herschel and Planck.Comment: Accepted for publication in the Astrophysical Journal. Maps and other results available at http://blastexperiment.info