Abstract
Two experiments were conducted to evaluate the effect of different corn milling methods for high-moisture and dry corn on finishing cattle performance, carcass traits, and nutrient ...digestion. In experiment 1, steers (N = 600 60 pens; initial body weight BW = 402 ± 17 kg) were fed for 134 d to evaluate the effect of milling method and corn type on performance and carcass characteristics. Treatments were evaluated as a 2 × 3 factorial design with factors being milling method (Automatic Ag roller mill ROLL or hammer mill HAMMER) and corn type (high-moisture HMC, dry DC, or 50:50 blend of HMC and DC BLEND). There were no milling method × corn type interactions for final BW, gain (ADG), or dry matter intake (DMI; P ≥ 0.32), but there tended to be an interaction for G:F (P = 0.09). Cattle fed ROLL HMC had 4.7% greater gain:feed (G:F; P ≤ 0.01) with 55% lower fecal starch (P < 0.01) compared to HAMMER HMC, whereas processing did not impact (P = 0.74) G:F in DC diets. There were no further effects (P ≥ 0.14) on performance or carcass traits regardless of milling method or corn type. In experiment 2, seven ruminally fistulated steers were utilized in a 4 × 7 incomplete Latin rectangle to evaluate the effects of DC or HMC processed with either ROLL or HAMMER (2 × 2 factorial treatment design) on nutrient digestion. Feeding HMC decreased the amount of excreted dry matter (DM) and organic matter (OM; P ≤ 0.01) regardless of mill type, but there was a tendency (P ≤ 0.13) for an interaction between corn type and mill type for DM and OM digestibility. There was no difference between milling treatments fed as HMC (P ≥ 0.69), but the HAMMER DC diet was more digestible than the ROLL DC (P = 0.05). As expected, HMC-based diets had greater (P < 0.01) starch digestibility compared to DC, but milling method had no impact on starch digestibility (P = 0.56). There were no differences (P = 0.56) in average ruminal pH, but HMC diets had greater variance (P = 0.04) and greater area less than pH 5.6 (P = 0.05) compared to DC based diets while milling method did not impact either (P > 0.33). Processing HMC with a roller mill improved G:F compared to processing with a hammer mill, but had little effect when corn was fed as dry corn or HMC:DC blend. Furthermore, feeding cattle HMC compared to DC increases nutrient digestibility, but milling method had little impact.
Using a roller mill improved feed efficiency of feedlot cattle when using high-moisture corn compared to a hammer mill, but milling type did not impact performance when processing dry corn. Digestion was improved for high-moisture compared to dry corn, but also increased risk of ruminal acidosis.
Lay Summary
Two experiments tested how processing of corn grain for finishing cattle influences growth performance and nutrient digestion. Producers can use corn in dry or high-moisture form but normally use either a hammer mill or roller mill. When using high-moisture corn, we observed a 5% improvement in gain:feed (G:F) for rolling as compared to hammer milling, which is likely due to more uniform particle size and improved digestion. Unlike the performance study, milling method did not impact digestion for high-moisture corn. Using a hammer-mill for dry corn improved digestion compared to rolling which was not supported by improved performance in the finishing study. Using high-moisture corn increases risk of ruminal acidosis compared to dry corn, but also improves feed efficiency if acidosis can be minimized.
This study made at Dumfries, SW Scotland, has revealed new information on the ecology and social structure of an urban colony of Lesser Black-backed and Herring Gulls Larus fuscus and L. argentatus. ...There has been a decline in the numbers of gulls nesting in Dumfries, contrary to a national trend of increasing numbers. These gulls nested socially and almost invariably had another pair within 100 m. Recruitment was almost totally confined to existing groups and new breeding areas were initiated by forming roosting groups on suitable sites. High-density groups were formed on flat roofs, usually on industrial and commercial properties, while low densities pairs occurred in residential areas and these pairs usually nested on chimneystacks. From 2000 to 2007, the public subjected nesting gulls to appreciable and increasing non-lethal disruption, mainly by nest and egg removal. This halved the overall breeding success and resulted in increased movement of nesting sites between years. However at sites not subjected to management, breeding success was high and movement was significantly lower. On low-density sites, nest-removal and proofing against nesting gulls mainly resulted in pairs moving a short distance, and did not reduce the numbers nesting in the immediate area. In contrast, synchronous removal of nests and eggs (or the prevention of breeding by netting or demolition) at high-density nesting sites caused desertion of the site. In the next breeding season, most of these displaced gulls failed to nest nearby, resulting in an appreciable reduction in density of gulls nesting in the immediate area. Further, the gulls did not move as a group elsewhere within the town. It is believed than many either failed to breed in the year after disruption or permanently emigrated from the town, an interpretation that is supported by two other studies. Surprisingly, few of the gulls that had their eggs and nest removed re-laid in that breeding season. These findings should be used to form the basis of non-lethal management of urban nesting gulls, which should be planned on an experimental basis to confirm and quantify the results from Dumfries.
The genetic map of each Caenorhabditis elegans chromosome has a central gene cluster (less pronounced on the X chromosome) that contains most of the mutationally defined genes. Many linkage group ...termini also have clusters, though involving fewer loci. We examine the factors shaping the genetic map by analyzing the rate of recombination and gene density across the genome using the positions of cloned genes and random cDNA clones from the physical map. Each chromosome has a central gene-dense region (more diffuse on the X) with discrete boundaries, flanked by gene-poor regions. Only autosomes have reduced rates of recombination in these gene-dense regions. Cluster boundaries appear discrete also by recombination rate, and the boundaries defined by recombination rate and gene density mostly, but not always, coincide. Terminal clusters have greater gene densities than the adjoining arm but similar recombination rates. Thus, unlike in other species, most exchange in C. elegans occurs in gene-poor regions. The recombination rate across each cluster is constant and similar; and cluster size and gene number per chromosome are independent of the physical size of chromosomes. We propose a model of how this genome organization arose.
To determine whether a program incorporating smoking intervention and use of an inhaled bronchodilator can slow the rate of decline in forced expiratory volume in 1 second (FEV1) in smokers aged 35 ...to 60 years who have mild obstructive pulmonary disease.
Randomized clinical trial. Participants randomized with equal probability to one of the following groups: (1) smoking intervention plus bronchodilator, (2) smoking intervention plus placebo, or (3) no intervention.
Ten clinical centers in the United States and Canada.
A total of 5887 male and female smokers, aged 35 to 60 years, with spirometric signs of early chronic obstructive pulmonary disease.
Smoking intervention: intensive 12-session smoking cessation program combining behavior modification and use of nicotine gum, with continuing 5-year maintenance program to minimize relapse. Bronchodilator: ipratropium bromide prescribed three times daily (two puffs per time) from a metered-dose inhaler.
Rate of change and cumulative change in FEV1 over a 5-year period.
Participants in the two smoking intervention groups showed significantly smaller declines in FEV1 than did those in the control group. Most of this difference occurred during the first year following entry into the study and was attributable to smoking cessation, with those who achieved sustained smoking cessation experiencing the largest benefit. The small noncumulative benefit associated with use of the active bronchodilator vanished after the bronchodilator was discontinued at the end of the study.
An aggressive smoking intervention program significantly reduces the age-related decline in FEV1 in middle-aged smokers with mild airways obstruction. Use of an inhaled anticholinergic bronchodilator results in a relatively small improvement in FEV1 that appears to be reversed after the drug is discontinued. Use of the bronchodilator did not influence the long-term decline of FEV1.
Abstract Objectives: To evaluate the potential effect of computer support on general practitioners' management of familial breast and ovarian cancer, and to compare the effectiveness of two different ...types of computer program. Design: Crossover experiment with balanced block design. Participants: Of a random sample of 100 general practitioners from Buckinghamshire who were invited, 41 agreed to participate. From these, 36 were selected for a fully balanced study. Interventions: Doctors managed 18 simulated cases: 6 with computerised decision support system Risk Assessment in Genetics (RAGs), 6 with Cyrillic (an established pedigree drawing program designed for clinical geneticists), and 6 with pen and paper. Main outcome measures: Number of appropriate management decisions made (maximum 6), mean time taken to reach a decision, number of pedigrees accurately drawn (maximum 6). Secondary measures were method of support preferred for particular aspects of managing family histories of cancer; importance of specific information on cancer genetics that might be provided by an “ideal computer program.” Results: RAGs resulted in significantly more appropriate management decisions (median 6) than either Cyrillic (median 3) or pen and paper (median 3); median difference between RAGs and Cyrillic 2.5 (95% confidence interval 2.0 to 3.0; P<0.0001). RAGs also resulted in significantly more accurate pedigrees (median 5) than both Cyrillic (median 3.5) and pen and paper (median 2); median difference between RAGs and Cyrillic 1.5 (1.0 to 2.0; P<0.0001). The time taken to use RAGs (median 178 seconds) was 51 seconds longer per case (95% confidence interval 36 to 65; P<0.0001) than pen and paper (median 124 seconds) but was less than Cyrillic (median 203 seconds; difference 23. (5 to 43; P=0.02)). 33 doctors (92% (78% to 98%)) preferred using RAGs overall. The most important elements of an “ideal computer program” for genetic advice in primary care were referral advice, the capacity to create pedigrees, and provision of evidence and explanations to support advice. Conclusions: RAGs could enable general practitioners to be more effective gatekeepers to genetics services, empowering them to reassure the majority of patients with a family history of breast and ovarian cancer who are not at increased genetic risk.
Nature uses molybdenum-containing enzymes to catalyze oxygen atom transfer (OAT) from water to organic substrates. In these enzymes, the two electrons that are released during the reaction are ...rapidly removed, one at a time, by spatially separated electron transfer units. Inspired by this design, a Ru(II)–Mo(VI) dyad was synthesized and characterized, with the aim of accelerating the rate-determining step in the cis-dioxo molybdenum-catalyzed OAT cycle, the transfer of an oxo ligand to triphenyl phosphine, via a photo-oxidation process. The dyad consists of a photoactive bis(bipyridyl)-phenanthroline ruthenium moiety that is covalently linked to a bioinspired cis-dioxo molybdenum thiosemicarbazone complex. The quantum yield and luminescence lifetimes of the dyad Ru(bpy)2(L 2 )MoO2(solv)2+ were determined. The major component of the luminescence decay in MeCN solution (τ = 1149 ± 2 ns, 67%) corresponds closely to the lifetime of excited Ru(bpy)2(phen-NH2)2+, while the minor component (τ = 320 ± 1 ns, 31%) matches that of Ru(bpy)2(H2-L 2 )2+. In addition, the (spectro)electrochemical properties of the system were investigated. Catalytic tests showed that the dyad-catalyzed OAT from dimethyl sulfoxide to triphenyl phosphine proceeds significantly faster upon irradiation with visible light than in the dark. Methylviologen acts as a mediator in the photoredox cycle, but it is regenerated and hence only required in stoichiometric amounts with respect to the catalyst rather than sacrificial amounts. It is proposed that oxidative quenching of the photoexcited Ru unit, followed by intramolecular electron transfer, leads to the production of a reactive one-electron oxidized catalyst, which is not accessible by electrochemical methods. A significant, but less pronounced, rate enhancement was observed when an analogous bimolecular system was tested, indicating that intramolecular electron transfer between the photosensitizer and the catalytic center is more efficient than intermolecular electron transfer between the separate components.
A performance analysis of algorithms for maximum likelihood estimation of channel parameters for orthogonal frequency-division multiplexing packet detection and synchronization is presented. The ...detection and synchronization algorithms, which are based on the use of a pilot symbol, are described in Coulson (2001). The performance analyses concentrate on operation in additive white Gaussian noise channels, and the accuracy of these analyses are demonstrated using experimental and simulation data. Methods to extend these analyses to frequency flat multipath fading channels are presented.
Capsule The vantage point survey methods used in the 1999–2002 surveys of urban nesting large gulls in Britain and Ireland appreciably underestimated numbers, resulting in lower national totals and ...exaggerated national population changes, because they did not account for a substantial proportion of undetected nests. Aims To evaluate the efficiency of various survey methods for urban nesting large gulls. Methods Vantage point and street surveys of Herring and Lesser Black-backed Gulls Larus argentatus and Larus fuscus nests were made in six urban conurbations and used to compare detection efficiencies. Some nests missed by both methods were later identified by the presence of unfledged chicks. In later years, the numbers of nests which were actually missed was determined by using a ‘cherry-picker’ which allowed all nests to be located in Dumfries. The proportion of nests on industrial and commercial buildings was recorded. Results Vantage point and street surveys missed an appreciable number of nests and had average maximum nest detection rates of 78% and 48%, respectively. Combining the two methods raised the efficiency to a maximum of 88%. The detection rate varied inversely with the proportion of nest sites that were on commercial or industrial sites. The complete census of nests in Dumfries in 2013–14 showed that vantage point surveys detected only 75% of nests, while the combination of the two survey methods increased the detection rate to 84%. Conclusion Vantage point surveys markedly underestimate numbers of nesting large gulls. Surveys were less effective on conurbations where nesting gulls used a high proportion of industrial and commercial properties. Therefore the 1999–2002 national surveys in Britain and Ireland underestimated the numbers of urban nesting Herring and Lesser Black-backed Gulls and, as a result, may have exaggerated the national trends in abundance of both species. More intensive methods are required in surveys of urban nesting gulls and correction factors need to be established from very high vantage points by use of cherry-pickers or aerial surveillance.
As part of our effort to sequence the 100-megabase (Mb) genome of the nematode Caenorhabditis elegans, we have completed the nucleotide sequence of a contiguous 2,181,032 base pairs in the central ...gene cluster of chromosome III. Analysis of the finished sequence has indicated an average density of about one gene per five kilobases; comparison with the public sequence databases reveals similarities to previously known genes for about one gene in three. In addition, the genomic sequence contains several intriguing features, including putative gene duplications and a variety of other repeats with potential evolutionary implications.
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