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Dietary Zn has significant impacts on the growth and development of breeding rams. The objectives of this study were to evaluate the effects of dietary Zn source and concentration on serum Zn concentration, growth performance, wool traits and reproductive performance in rams. Forty-four Targhee rams (14 months; 68 ± 18 kg BW) were used in an 84-day completely randomized design and were fed one of three pelleted dietary treatments: (1) a control without fortified Zn (CON; n = 15; ~1 × NRC); (2) a diet fortified with a Zn amino acid complex (ZnAA; n = 14; ~2 × NRC) and (3) a diet fortified with ZnSO4 (ZnSO4; n = 15; ~2 × NRC). Growth and wool characteristics measured throughout the course of the study were BW, average daily gain (ADG), dry matter intake (DMI), feed efficiency (G : F), longissimus dorsi muscle depth (LMD), back fat (BF), wool staple length (SL) and average fibre diameter (AFD). Blood was collected from each ram at four time periods to quantify serum Zn and testosterone concentrations. Semen was collected 1 to 2 days after the trial was completed. There were no differences in BW (P = 0.45), DMI (P = 0.18), LMD (P = 0.48), BF (P = 0.47) and AFD (P = 0.9) among treatment groups. ZnSO4 had greater (P ≤ 0.03) serum Zn concentrations compared with ZnAA and CON treatments. Rams consuming ZnAA had greater (P ≤ 0.03) ADG than ZnSO4 and CON. There tended to be differences among groups for G : F (P = 0.06), with ZnAA being numerically greater than ZnSO4 and CON. Wool staple length regrowth was greater (P < 0.001) in ZnSO4 and tended to be longer (P = 0.06) in ZnAA treatment group compared with CON. No differences were observed among treatments in scrotal circumference, testosterone, spermatozoa concentration within ram semen, % motility, % live sperm and % sperm abnormalities (P ≥ 0.23). Results indicated beneficial effects of feeding increased Zn concentrations to developing Targhee rams, although Zn source elicited differential responses in performance characteristics measured.
This article involved a broad search of applied sciences for milestone technologies we deem to be the most significant innovations applied by the North American pork industry, during the past 10 to 12 years. Several innovations shifted the trajectory of improvement or resolved significant production limitations. Each is being integrated into practice, with the exception being gene editing technology, which is undergoing the federal approval process. Advances in molecular genomics have been applied to gene editing for control of porcine reproductive and respiratory syndrome and to identify piglet genome contributions from each parent. Post-cervical artificial insemination technology is not novel, but this technology is now used extensively to accelerate the rate of genetic progress. A milestone was achieved with the discovery that dietary essential fatty acids, during lactation, were limiting reproduction. Their provision resulted in a dose-related response for pregnancy, pregnancy maintenance and litter size, especially in maturing sows and ultimately resolved seasonal infertility. The benefit of segregated early weaning (12 to 14 days of age) was realized for specific pathogen removal for genetic nucleus and multiplication. Application was premature for commercial practice, as piglet mortality and morbidity increased. Early weaning impairs intestinal barrier and mucosal innate immune development, which coincides with diminished resilience to pathogens and viability later in life. Two important milestones were achieved to improve precision nutrition for growing pigs. The first involved the updated publication of the National Research Council nutrient requirements for pigs, a collaboration between scientists from America and Canada. Precision nutrition advanced further when ingredient description, for metabolically available amino acids and net energy (by source plant), became a private sector nutrition product. The past decade also led to fortuitous discoveries of health-improving components in ingredients (xylanase, soybeans). Finally, two technologies converged to facilitate timely detection of multiple pathogens in a population: oral fluids sampling and polymerase chain reaction (PCR) for pathogen analysis. Most critical diseases in North America are now routinely monitored by oral fluid sampling and prepared for analysis using PCR methods.
Heat stress due to increasing extremes in ambient temperature and humidity results in reduced semen quality in boars. This has caused reduced efficiency of the swine industry, requiring more boars to breed the same number of sows. Vitamins such as vitamin C (VC) and E (VE) have been shown to improve semen quality in boars. Recently, vitamin D has been shown to improve semen quality in boars. The purpose of this experiment was to evaluate the effects of increased supplemental vitamins on boar reproduction during the summer season in a commercial boar stud. One hundred and sixty Pig Improvement Company (PIC) terminal line boars (n = 32 per treatment) and 39 maternal, heat-sensitive boars (n = 7 or 8 per treatment) were randomly allocated to treatment and fed a corn and soybean meal-based diet adjusted based on individual boar body condition score. A control (CNT) diet was used that met PIC recommendations for boars. Increased supplementation of specific vitamins was given in the form of a top-dress and consisted of CNT wheat middlings, CNT plus VC (560 mg/day), CNT plus 25-hydroxy vitamin D3 (VD) (125 µg/day), CNT plus VE (275 mg/day) and CNT plus VC, VD and VE (CDE). The experiment was split into three periods based on maximum daily high temperatures in the barn, where period 1 was weeks 1 to 4, period 2 was weeks 5 to 11 and period 3 was weeks 12 to 14. Semen was collected from boars as needed using the stud’s normal production schedule and was analyzed for sperm quantity and quality characteristics. There were no dietary effects on semen volume, sperm concentration or total sperm production (P ≥ 0.553). Total motility of sperm was not impacted by diet (P = 0.115); although, VC tended (P = 0.064) to have a greater progressive motility than CDE. Percentages of morphologically normal sperm and normal acrosomes were not affected by dietary supplementation (P ≥ 0.157). Period effects were observed for most semen quality parameters, with quality generally becoming reduced over time. The present study demonstrates that increased supplementation of vitamins beyond PIC recommendations was not beneficial for boar reproduction during the summer.
Gut cell losses contribute to overall feed efficiency due to the energy requirement for cell replenishment. Intestinal epithelial cells are sloughed into the intestinal lumen as digesta passes through the gastrointestinal tract, where cells are degraded by endonucleases. This leads to fragmented DNA being present in faeces, which may be an indicator of gut cell loss. Therefore, measuring host faecal DNA content could have potential as a non-invasive marker of gut cell loss and result in a novel technique for the assessment of how different feed ingredients impact upon gut health. Faecal calprotectin (CALP) is a marker of intestinal inflammation. This was a pilot study designed to test a methodology for extracting and quantifying DNA from pig faeces, and to assess whether any differences in host faecal DNA and CALP could be detected. An additional aim was to determine whether any differences in the above measures were related to the pig performance response to dietary yeast-enriched protein concentrate (YPC). Newly weaned (∼26.5 days of age) Large White × Landrace × Pietrain piglets (8.37 kg ±1.10, n = 180) were assigned to one of four treatment groups (nine replicates of five pigs), differing in dietary YPC content: 0% (control), 2.5%, 5% and 7.5% (w/w). Pooled faecal samples were collected on days 14 and 28 of the 36-day trial. Deoxyribonucleic acid was extracted and quantitative PCR was used to assess DNA composition. Pig genomic DNA was detected using primers specific for the pig cytochrome b (CYTB) gene, and bacterial DNA was detected using universal 16S primers. A pig CALP ELISA was used to assess gut inflammation. Dietary YPC significantly reduced feed conversion ratio (FCR) from weaning to day 14 (P<0.001), but not from day 14 to day 28 (P = 0.220). Pig faecal CYTB DNA content was significantly (P = 0.008) reduced in YPC-treated pigs, with no effect of time, whereas total faecal bacterial DNA content was unaffected by diet or time (P>0.05). Faecal CALP levels were significantly higher at day 14 compared with day 28, but there was no effect of YPC inclusion and no relationship with FCR. In conclusion, YPC reduced faecal CYTB DNA content and this correlated positively with FCR, but was unrelated to gut inflammation, suggesting that it could be a non-invasive marker of gut cell loss. However, further validation experiments by an independent method are required to verify the origin of pig faecal CYTB DNA as being from sloughed intestinal epithelial cells.
Hematite (α-Fe2O3) powder compacts have been subjected to controlled, quantitative high pressure shock loading at peak pressures from 8-27 GPa and preserved for post shook analysis. The broadened x-ray diffraction peak profiles have been analyzed to determine the residual lattice strain and the coherent crystallite sizes. Maximum modification effects are observed near 17 GPa with strain values near 3 x 10-3 and size values near 200 Å suggesting annealing at higher shock pressure, resulting from the higher shock temperature.
Todays demand for rapid trace element analysis in pollution control and resource materials has led to the development of a completely automatic, very sensitive and stable Si(Li) X-ray analyzer. The key element, a transmission target tube, which has inherently a very clean monochromatic X-ray output, has been studied in view of efficiency, sensitivity and stability. The transmission target tube requires different operating criteria than conventional X-ray tubes. An analysis was made to “explain” these differences using fundamental X-ray physics. Studies included various experiments directly applied to practical problems in analysis of pollutants and mineral resource materials.
This paper reports and discusses the results of a computer modeling study on powder diffraction profile analysis for crystallite size and strain of polycrystalline materials. The results of this computer modeling show that if the spans of diffraction profiles in reciprocal space (1/d) are not carefully chosen, an overestimation on size and an underestimation on strain may result in analysis by both the Warren-Averbach and the Hall-Williamson methods. A general way to eliminate such errors based on profile fitting and regeneration is presented and discussed in this paper.
Energy dispersive X-ray spectrometry has the potential for making very rapid analyses of multi-element samples. In order to fully exploit this capability several studies have been carried out with the goal of improving performance at high input count rates. A refined amplifier permits operation at input count rates up to 80000 per second with minimal peak shift and distortion. Optimum choice of tube parameters and filters permits utilization of a single Mo transmission target tube to analyze a broad range of elements in minimum time. Use of a pulsed tube further reduces the time required for analysis without sacrifice of precision or resolution. Dead time necessarily increases with increasing input count rate. It can be reduced by selecting a short amplifier time constant, but only with a loss of resolution. Digital processing permits recovery of the lost resolution. Some illustrations are given of spectra that have been processed on-line using a computer based multi-channel analyzer.
Good education requires student experiences that deliver lessons about practice as well as theory and that encourage students to work for the public good—especially in the operation of democratic institutions (Dewey 1923; Dewy 1938). We report on an evaluation of the pedagogical value of a research project involving 23 colleges and universities across the country. Faculty trained and supervised students who observed polling places in the 2016 General Election. Our findings indicate that this was a valuable learning experience in both the short and long terms. Students found their experiences to be valuable and reported learning generally and specifically related to course material. Postelection, they also felt more knowledgeable about election science topics, voting behavior, and research methods. Students reported interest in participating in similar research in the future, would recommend other students to do so, and expressed interest in more learning and research about the topics central to their experience. Our results suggest that participants appreciated the importance of elections and their study. Collectively, the participating students are engaged and efficacious—essential qualities of citizens in a democracy.
Reflecting on the theme of ‘Empire and Christianity’, this article compares two periods in the Catholic mission to China. The first period, between 1583 and 1800, was characterized by the accommodation of European missionaries to the laws, culture and customs of the Chinese empire during the Ming and Qing dynasties. The work of the Jesuits, in particular, demonstrated a method of evangelization in which Christian teachings could be accommodated to the political realities of Late Imperial China as exemplified by the work of Matteo Ricci, Ferdinand Verbiest, Tomas Pereira, Joachim Gerbillon and many generations of Jesuits and missionaries of other religious orders. The Chinese Rites Controversy, however, disrupted this accommodation between Christianity and empire in China. Despite tacit toleration in the capital, Christianity was outlawed after 1705. After the suppression of the Society of Jesus in 1773, Catholicism in China became increasingly indigenized. In 1842, after the defeat of the Qing empire by the British in the First Opium War, the prohibition of Christianity was lifted. Both Catholic and Protestant missionaries entered China, backed by Western diplomatic and military power. This led to the confrontation between China and Christianity, culminating in the 1900 Boxer Uprising. A concerted effort to indigenize Christianity in the early twentieth century ultimately failed, resulting in the separation of Christianity in China from global Christianity after 1950.
The move towards group housing of gestating sows has highlighted a number of welfare issues associated with social interactions that are directly related to management and pen design. For example feeding method and total space can impact on both behaviour and performance. Individual feeding stalls combined with a straw based lying area and dunging passage have production and behavioural advantages at feeding time by providing safety from aggressive pen mates. Anecdotal observations would suggest that they also provide an alternative lying space. However, in practice many feeders are either kept closed when not being used or are located in areas that do not provide a good thermal environment. This experiment was designed to evaluate environmental and social factors affecting the choice of lying behaviour of sows with and without access to feeding stalls throughout the day.
Vitamin D is obtained by cattle from the diet and from skin production via UVB exposure from sunlight. The vitamin D status of the cow impacts the vitamin D content of the milk produced, much like human breast milk, with seasonal variation in the vitamin D content of milk well documented. Factors such as changes in husbandry practices therefore have the potential to impact the vitamin D content of milk. For example, a shift to year-round housing from traditional practices of cattle being out to graze during the summer months and housed during the winter only, minimises exposure to the sun and has been shown to negatively influence the vitamin D content of the milk produced. Other practices such as changing dietary sources of vitamin D may also influence the vitamin D content of milk, and evidence exists to suggest genetic factors such as breed can cause variation in the concentrations of vitamin D in the milk produced. The present review aims to provide an overview of the current understanding of how genetic and environmental factors influence the vitamin D content of the milk produced by dairy cattle. A number of environmental and genetic factors have previously been identified as having influence on the nutritional content of the milk produced. The present review highlights a need for further research to fully elucidate how farmers could manipulate the factors identified to their advantage with respect to increasing the vitamin D content of milk and standardising it across the year.
Positive psychological constructs have been associated with reduced suicidal ideation, and interventions to cultivate positive feelings have the potential to reduce suicide risk. This study compares the efficacy of a 6-week, telephone-based positive psychology (PP) intervention against a cognition-focused (CF) control intervention among patients recently hospitalized for depression and suicidal ideation or behavior.
A total of 65 adults with a current major depressive episode reporting suicidal ideation or a recent suicide attempt were enrolled from participating in-patient psychiatric units. Prior to discharge, participants were randomized to the PP (n = 32) or CF (n = 33) intervention. In both interventions, participants received a treatment manual, performed weekly PP (e.g. gratitude letter) or CF (e.g. recalling daily events) exercises, and completed weekly one-on-one telephone sessions over 6 weeks. Between-group differences in hopelessness (primary outcome), depression, suicidality and positive psychological constructs at 6 and 12 weeks were tested using mixed-effects models accounting for intensity of post-hospitalization psychiatric treatment.
Compared with PP, the CF intervention was associated with significantly greater improvements in hopelessness at 6 weeks (β = −3.15, 95% confidence interval −6.18 to −0.12, effect size = −0.84, p = 0.04), but not 12 weeks. Similarly, the CF intervention led to greater improvements in depression, suicidal ideation, optimism and gratitude at 6 and 12 weeks.
Contrary to our hypothesis, the CF intervention was superior to PP in improving hopelessness, other suicide risk factors and positive psychological constructs during a key post-discharge period among suicidal patients with depression. Further study of this CF intervention is warranted in populations at high suicide risk.
(Solar Phys.). On 1973 January 11, a flare near the west limb of the Sun caused a coronal disturbance which was observed with a unique variety of instruments. Radio observations of a type II and a moving type IV burst were obtained by the CSIRO Division of Radiophysics at Culgoora, Australia; white-light observations of a large, moving cloud were made by the U.S. Naval Research Laboratory coronagraph on OSO-7; K-corona observations of a decrease in coronal density were made by the High Altitude Observatory at Mauna Loa, Hawaii and Hα observations of a flare spray were made by the Institute for Astronomy, University of Hawaii at Haleakala (and also by H.A.O.).
Crannell et al. (1978) have reported an observed correlation between the time profiles and flux densities of impulsive hard X-ray and microwave solar bursts. We report here on a significant correlation between the flux density of extended bursts of hard X-rays and micowaves. These extended events follow after impulsive bursts and last much longer (see e.g. Fig. 1, Frost and Dennis 1971). However, as extended bursts only occur during very large flares the number of cases available for study is small. The significance of our observations follows from the suggestion of Wild et al. (1963) that the extended bursts are evidence for a second-phase acceleration process in the corona. We show that the observed characteristics of these extended microwave bursts (viz. a rather flat spectrum below a turnover frequency which is independent of intensity) can be explained by gyro-synchrotron radiation from the same population of energetic (E ≈ 100 keV) electrons as those emitting (thin-target) X-ray bremsstrahlung. A detailed source model is discussed in a companion paper (Nelson and Stewart 1979 — Paper B).
We present an overview of the survey for radio emission from active stars that has been in progress for the last six years using the observatories at Fleurs, Molonglo, Parkes and Tidbinbilla. The role of complementary optical observations at the Anglo-Australian Observatory, Mount Burnett, Mount Stromlo and Siding Spring Observatories and Mount Tamborine are also outlined. We describe the different types of star that have been included in our survey and discuss some of the problems in making the radio observations.
A circular letter was sent out to all members of the Commission in December 1937, to which the majority have replied. While work is going on steadily in the Observatories where meridian observations are carried out, comparatively few catalogues have been published since 1935. In view of the very full report made three years ago it is only necessary to draw attention to the progress which has been made in the interval.