Assessing Bottlenecks in Vertically Organized Beef Systems

Agribusiness,

Effects of low level military training flights on wading bird colonies in Florida

During 1983 and 1984 the effect of low level military training flights on the establishment. size and reproductive success of wading bird colonies was studied in Florida. Based on the indirect evidence of colony distributions and turnover rates in relation to military areas (training routes designated to 500 feet or less above ground level and military operations areas). there was no demonstrated effect of military activity on wading bird colony establishment or size on a statewide basis. Colony distributions were random with respect to military areas and turnover rates were within 2% when military and non-military areas were compared. Colony distributions and turnover rates, however. were related to the amount and type.Les tuer-tne or freshwater) of wetland. respectively. During two breeding seasons the behavioral responses and reproductive success of selected species were monitored in a non-habituated treatment colony (military overflights) and a control colony (no overflights). Breeding wading birds responded to F-16 overflights at 420 knots indicated airspeed. 82-84% maximum rpm. 500 feet above ground level and sound levels ranging from 55-100 dBA by exhibiting no response. looking up or changing position (usually to an alert posture): no productivity limiting responses were observed. High-nesting Great Egrets responded more than other species, nestling Great Egrets and Cattle Egrets responded significantly (r <.05) more intensely than adults of their respective species, and adults responded less during incubation and late chick-rearing than at other times. In addition, no differences in adult attendance, aggressive interactions or chick feeding rates were observed to result from F-16 overflights. No evidence of habituation to overflights was noted. Humans entering the colony or airboats approaching the colony vicinity elicited the most severe responses (flushing and panic flights) observed at both sites. Since relatively little coastal military activity occurs at low levels ( ~500 ft) and only one Brown Pelican colony (5-6% of the breeding population) was located in such an area, the reproductive success of five, more lIexposedll study species (Great Egrets, Snowy Egrets, Tricolored Herons, Little Blue Herons, Cattle Egrets) nesting in interior freshwater colonies was studied. Reproductive activity including such factors as nest success, nestling survival, nestling mortality, and nesting chronology was independent of F-16 overflights but related to ecological factors including colony location, colony characteristics and climatology. The responses to and effects of F-16 overflights, as reported here, should not be considered representative of military aircraft at lower altitudes or greater noise levels. (194 pages

The impact of consanguinity on neonatal and infant health

Marriage between biological relatives is widely popular in many parts of the world, with over 1000 million people living in countries where 20–50+% of unions are contracted between couples related as second cousins or closer. Consanguinity is, however, a controversial topic, in part due to public misunderstanding, complicated by often exaggerated past estimates of the adverse health outcomes. While some consanguineous couples are at high risk of conceiving a child with a genetic disorder, they are a small minority. Thus a multi-population meta-analysis has indicated an excess infant death rate of 1.1% in the progeny of first cousins, and even this figure may be compromised by inadequate control for non-genetic variables. The benefits as well as the disadvantages of consanguineous marriage are assessed and discussed, with specific consideration given to the health of migrant communities in Western countries, among whom first cousin marriage remains preferential

A Bayesian model for classifying all differentially expressed proteins simultaneously in 2D PAGE gels

Background: Two-dimensional polyacrylamide gel electrophoresis (2D PAGE) is commonly used to identify differentially expressed proteins under two or more experimental or observational conditions. Wu et al (2009) developed a univariate probabilistic model which was used to identify differential expression between Case and Control groups, by applying a Likelihood Ratio Test (LRT) to each protein on a 2D PAGE. In contrast to commonly used statistical approaches, this model takes into account the two possible causes of missing values in 2D PAGE: either (1) the non-expression of a protein; or (2) a level of expression that falls below the limit of detection.Results: We develop a global Bayesian model which extends the previously described model. Unlike the univariate approach, the model reported here is able treat all differentially expressed proteins simultaneously. Whereas each protein is modelled by the univariate likelihood function previously described, several global distributions are used to model the underlying relationship between the parameters associated with individual proteins. These global distributions are able to combine information from each protein to give more accurate estimates of the true parameters. In our implementation of the procedure, all parameters are recovered by Markov chain Monte Carlo (MCMC) integration. The 95% highest posterior density (HPD) intervals for the marginal posterior distributions are used to determine whether differences in protein expression are due to differences in mean expression intensities, and/or differences in the probabilities of expression.Conclusions: Simulation analyses showed that the global model is able to accurately recover the underlying global distributions, and identify more differentially expressed proteins than the simple application of a LRT. Additionally, simulations also indicate that the probability of incorrectly identifying a protein as differentially expressed (i.e., the False Discovery Rate) is very low. The source code is available at https://github.com/stevenhwu/BIDE-2D

Novel methods for spatial prediction of soil functions within landscapes (SP0531)

Previous studies showed that soil patterns could be predicted in agriculturally managed landscapes by modelling and extrapolating from extensive existing but related integrated datasets. Based on these results we proposed to develop and apply predictive models of the relationships between environmental data and known soil patterns to predict capacity for key soil functions within diverse landscapes for which there is little detailed underpinning soil information available. Objectives were: To develop a high-level framework in which the non-specialist user-community could explore questions. To generate digital soil maps for three selected catchments at a target resolution of 1:50000 to provide the base information for soil function prediction. To use a modelling approach to predict the performance of key soil functions in catchments undergoing change but where only sparse or low resolution soil survey data are available. To use a modelling approach to assess the impact of different management scenarios and/or environmental conditions on the delivery of multiple soil functions within a catchment. To create a detailed outline of the requirements for ground-truthing to test the predicted model outputs at a catchment scale. To contribute to the development of a high-level framework for decision makers

A Measurement of the Temperature-Density Relation in the Intergalactic Medium Using a New Lyman-alpha Absorption Line Fitting Method

The evolution of the temperature in the intergalactic medium is related to the reionization of hydrogen and helium, and has important consequences for our understanding of the Lya forest and of galaxy formation in gravitational models of large-scale structure. We measure the temperature-density relation of intergalactic gas from Lya forest observations of eight quasar spectra with high resolution and signal-to-noise ratio, using a new line fitting technique to obtain a lower cutoff of the distribution of line widths from which the temperature is derived. We carefully test the accuracy of this technique to recover the gas temperature with a hydrodynamic simulation. The temperature at redshift z=(3.9, 3.0, 2.4) is best determined at densities slightly above the mean: T_star=(20200\pm2700, 20200\pm1300, 22600\pm1900)K (statistical error bars) for gas density (in units of the mean density) Delta_star=(1.42\pm0.08, 1.37\pm0.11, 1.66\pm0.11). The power-law index of the temperature-density relation, defined by T=T_star(Delta/Delta_star)^{gamma-1}, is gamma-1= (0.43\pm0.45, 0.29\pm0.30, 0.52\pm0.14) for the same three redshifts. The temperature at the fixed over-density Delta=1.4 is T_1.4=(20100\pm2800, 20300\pm1400, 20700\pm1900)K. These temperatures are higher than expected for photoionized gas in ionization equilibrium with a cosmic background, and can be explained by a gradual additional heating due to on-going HeII reionization. The measurement of the temperature reduces one source of uncertainty in the lower limit to the baryon density implied by the observed mean flux decrement. We find that the temperature cannot be reliably measured for under-dense gas, because the velocities due to expansion always dominate the widths of the corresponding weak lines.Comment: submitted to Ap

The influence of contextual factors on running performance in female Australian football match-play

The influence of contextual factors on running performance in female Australian football match-play. J Strength Cond Res 33(9): 2488–2495, 2019—Given the recent growth of the professional status among multiple female football codes, the aim of this study is to investigate the effects of contextual factors on activity profiles and pacing strategies in female Australian football (AF) players. Thirty-five female AF players participated in this study. Global positioning system analysis was completed over 1 competitive season. Matches were separated into eight 10-minute periods. Greater distances were covered during the first half irrespective of playing position (effect size [ES] = 0.39–0.50, Likelihood ≥90%). Throughout a number of periods half-backs (defensive players) covered greater distances during losses (ES ≥ 0.74, Likelihood ≥92%) and against top 3 opponents (ES ≥ 1.0, Likelihood ≥97%). Midfielders and half-backs covered greater distances (ES ≥ 0.49, Likelihood ≥89%) in the final match period in winning compared with losing matches. A reduction in player work rate is evident during the second half of matches. The influence of contextual factors varied across positional groups. However, it is clear that coaches could use player rotation both early in the match in an attempt to delay the effect of fatigue and more frequently during the second half to increase running intensity

Investigating interfacial electron transfer in dye-sensitized NiO using vibrational spectroscopy

Understanding what influences the formation and lifetime of charge-separated states is key to developing photoelectrochemical devices. This paper describes the use of time-resolved infrared absorption spectroscopy (TRIR) to determine the structure and lifetime of the intermediates formed on photoexcitation of two organic donor–π–acceptor dyes adsorbed to the surface of NiO. The donor and π-linker of both dyes is triphenylamine and thiophene but the acceptors differ, maleonitrile (1) and bodipy (2). Despite their structural similarities, dye 1 outperforms 2 significantly in devices. Strong transient bands in the fingerprint region (1 and 2) and nitrile region (2300–2000 cm−1) for 1 enabled us to monitor the structure of the excited states in solution or adsorbed on NiO (in the absence and presence of electrolyte) and the corresponding kinetics, which are on a ps–ns timescale. The results are consistent with rapid (<1 ps) charge-transfer from NiO to the excited dye (1) to give exclusively the charge-separated state on the timescale of our measurements. Conversely, the TRIR experiments revealed that multiple species are present shortly after excitation of the bodipy chromophore in 2, which is electronically decoupled from the thiophene linker. In solution, excitation first populates the bodipy singlet excited state, followed by charge transfer from the triphenylamine to the bodipy. The presence and short lifetime (τ ≈ 30 ps) of the charge-transfer excited state when 2 is adsorbed on NiO (2|NiO) suggests that charge separation is slower and/or less efficient in 2|NiO than in 1|NiO. This is consistent with the difference in performance between the two dyes in dye-sensitized solar cells and photoelectrochemical water splitting devices. Compared to n-type materials such as TiO2, less is understood regarding electron transfer between dyes and p-type metal oxides such as NiO, but it is evident that fast charge-recombination presents a limit to the performance of photocathodes. This is also a major challenge to photocatalytic systems based on a “Z-scheme”, where the catalysis takes place on a µs–s timescale