Bright Giant Pulses from the Crab Nebula Pulsar: Statistical Properties, Pulse Broadening and Scattering due to the Nebula

We report observations of Crab giant pulses made with the Australia Telescope Compact Array and a baseband recorder system, made simultaneously at two frequencies, 1300 and 1470 MHz. These observations were sensitive to pulses with amplitudes \ga 3 kJy and widths \ga 0.5 $\mu$s. Our analysis led to the detection of more than 700 such bright giant pulses over 3 hours, and using this large sample we investigate their amplitude, width, arrival time and energy distributions. The brightest pulse detected in our data has a peak amplitude of $\sim$ 45 kJy and a width of $\sim$ 0.5 $\mu$s, and therefore an inferred brightness temperature of $\sim 10^{35}$ K. The duration of giant-pulse emission is typically $\sim$1 $\mu$s, however it can also be as long as 10 $\mu$s. The pulse shape at a high time resolution (128 ns) shows rich diversity and complexity in structure and is marked by an unusually low degree of scattering. We discuss possible implications for scattering due to the nebula, and for underlying structures and electron densities.Comment: 8 pages, 8 figures, Accepted for publication in Ap

Examining the Ethical Environment in Higher Education

Higher Education Institutions (HEIs) across the world have found themselves faced with new challenges on issues of ethics. Much of this has been centred on issues of assessment: plagiarism, buying essays, sharing/lending of previously passed work and the stealing of marked/returned work of others. Institutions still treat academic misconduct as largely a behavioural difficulty rather than an issue of ethics (or education), suggesting that academia places a far greater emphasis on combating new forms of dishonesty than it does on encouraging ethical habits and a healthy ethical environment. To date, the majority of research in this area has examined these forms of academic misconduct from the point of view of the student and/or the university, with the perspective of academics receiving very limited attention. Our hypothesis is that academics are perhaps best placed to provide the education needed to create and sustain an ethical environment, and we argue that being ‘ethically aware’ is a critical factor in the development of academic competence for all parties. This study adds to existing research in three ways: firstly, by highlighting the importance of an overall framework for an ethical environment within HEIs; secondly, by suggesting an ecological model of key parties (the university, students and academics) with responsibility for this environment in assessment; and thirdly, by including new evidence (generated by a survey of academics) to extend our understanding of their views on these issues

The feasibility of canine rabies elimination in Africa: dispelling doubts with data

<p><b>Background:</b> Canine rabies causes many thousands of human deaths every year in Africa, and continues to increase throughout much of the continent.</p> <p><b>Methodology/Principal Findings:</b> This paper identifies four common reasons given for the lack of effective canine rabies control in Africa: (a) a low priority given for disease control as a result of lack of awareness of the rabies burden; (b) epidemiological constraints such as uncertainties about the required levels of vaccination coverage and the possibility of sustained cycles of infection in wildlife; (c) operational constraints including accessibility of dogs for vaccination and insufficient knowledge of dog population sizes for planning of vaccination campaigns; and (d) limited resources for implementation of rabies surveillance and control. We address each of these issues in turn, presenting data from field studies and modelling approaches used in Tanzania, including burden of disease evaluations, detailed epidemiological studies, operational data from vaccination campaigns in different demographic and ecological settings, and economic analyses of the cost-effectiveness of dog vaccination for human rabies prevention.</p> <p><b>Conclusions/Significance:</b> We conclude that there are no insurmountable problems to canine rabies control in most of Africa; that elimination of canine rabies is epidemiologically and practically feasible through mass vaccination of domestic dogs; and that domestic dog vaccination provides a cost-effective approach to the prevention and elimination of human rabies deaths.</p&gt

Determining the Effects of Tryptophan Biomass on Growth Performance of 25- to 50-lb Nursery Pigs

A total of 315 barrows (DNA; 200 × 400; initially 24.9 lb) were used in a 21-d growth trial evaluating the effects of feeding TRP Pro (CJ America-Bio, Downers Grove, IL) as a source of Trp on nursery pig performance. Pigs were weaned at approximately 21 d of age, placed in pens based on initial body weight (BW), and fed common starter diets for 21 d. On d 21 after weaning, considered d 0 of the study, pigs were weighed and pens were allotted to 1 of 4 dietary treatments with 5 pigs per pen and 15 or 16 pens per treatment. Dietary treatments included a negative control (16% SID Trp:Lys ratio), positive control (21% SID Trp:Lys ratio from crystalline Trp), or diets containing Trp with biomass to provide 21 or 23.5% standardized ileal digestible (SID) Trp:Lys ratios (included at 0.104 or 0.156% of the diet, respectively). Diets were corn-soybean meal-based and contained 1.25% SID Lys with other amino acids set to meet or exceed NRC requirement estimates. The TRP Pro contained 60% Trp per the supplier’s specifications. Growth data were analyzed as a randomized complete block design using the PROC GLIMMIX procedure of SAS with pen as the experimental unit. Overall (d 0 to 21), pigs fed the 21% Trp:Lys ratio from crystalline Trp or Trp with biomass had increased (P \u3c 0.05) average daily gain (ADG) compared to pigs fed the negative control diet, with pigs fed the 23.5% Trp:Lys ratio with biomass intermediate. There was no evidence for difference in overall average daily feed intake (ADFI); however, pigs fed the 21% Trp:Lys ratio from Trp with biomass had improved (P \u3c 0.05) feed efficiency (F/G) compared to the negative control diet, with others intermediate. In conclusion, TRP Pro appears to be a suitable alternative to crystalline Trp in nursery pig diets but further evaluation at higher inclusion levels is needed

The MacGyver effect: alive and well in health services research?

<p>Abstract</p> <p>Background</p> <p>In a manner similar to the television action hero MacGyver, health services researchers need to respond to the pressure of unpredictable demands and constrained time frames. The results are often both innovative and functional, with the creation of outputs that could not have been anticipated in the initial planning and design of the research.</p> <p>Discussion</p> <p>In the conduct of health services research many challenges to robust research processes are generated as a result of the interface between academic research, health policy and implementation agendas. Within a complex and rapidly evolving environment the task of the health services researcher is, therefore, to juggle sometimes contradictory pressures to produce valid results.</p> <p>Summary</p> <p>This paper identifies the MacGyver-type dilemmas which arise in health services research, wherein innovation may be called for, to maintain the intended scientific method and rigour. These 'MacGyver drivers' are framed as opposing issues from the perspective of both academic and public policy communities. The ideas expressed in this paper are illustrated by four examples from research projects positioned at the interface between public policy strategy and academia.</p

Genomic tailoring of autogenous poultry vaccines to reduce Campylobacter from farm to fork

Campylobacter is a leading cause of food-borne gastroenteritis worldwide, linked to the consumption of contaminated poultry meat. Targeting this pathogen at source, vaccines for poultry can provide short-term caecal reductions in Campylobacter numbers in the chicken intestine. However, this approach is unlikely to reduce Campylobacter in the food chain or human incidence. This is likely as vaccines typically target only a subset of the high genomic strain diversity circulating among chicken flocks, and rapid evolution diminishes vaccine efficacy over time. To address this, we used a genomic approach to develop a whole-cell autogenous vaccine targeting isolates harbouring genes linked to survival outside of the host. We hyper-immunised a whole major UK breeder farm to passively target offspring colonisation using maternally-derived antibody. Monitoring progeny, broiler flocks revealed a near-complete shift in the post-vaccination Campylobacter population with an ~50% reduction in isolates harbouring extra-intestinal survival genes and a significant reduction of Campylobacter cells surviving on the surface of meat. Based on these findings, we developed a logistic regression model that predicted that vaccine efficacy could be extended to target 65% of a population of clinically relevant strains. Immuno-manipulation of poultry microbiomes towards less harmful commensal isolates by competitive exclusion, has major potential for reducing pathogens in the food production chain

Tandem quadruplication of HMA4 in the zinc (Zn) and cadmium (Cd) hyperaccumulator noccaea caerulescens

Zinc (Zn) and cadmium (Cd) hyperaccumulation may have evolved twice in the Brassicaceae, in Arabidopsis halleri and in the Noccaea genus. Tandem gene duplication and deregulated expression of the Zn transporter, HMA4, has previously been linked to Zn/Cd hyperaccumulation in A. halleri. Here, we tested the hypothesis that tandem duplication and deregulation of HMA4 expression also occurs in Noccaea. A Noccaea caerulescens genomic library was generated, containing 36,864 fosmid pCC1FOSTM clones with insert sizes ~20–40 kbp, and screened with a PCR-generated HMA4 genomic probe. Gene copy number within the genome was estimated through DNA fingerprinting and pooled fosmid pyrosequencing. Gene copy numbers within individual clones was determined by PCR analyses with novel locus specific primers. Entire fosmids were then sequenced individually and reads equivalent to 20-fold coverage were assembled to generate complete whole contigs. Four tandem HMA4 repeats were identified in a contiguous sequence of 101,480 bp based on sequence overlap identities. These were flanked by regions syntenous with up and downstream regions of AtHMA4 in Arabidopsis thaliana. Promoter-reporter b-glucuronidase (GUS) fusion analysis of a NcHMA4 in A. thaliana revealed deregulated expression in roots and shoots, analogous to AhHMA4 promoters, but distinct from AtHMA4 expression which localised to the root vascular tissue. This remarkable consistency in tandem duplication and deregulated expression of metal transport genes between N. caerulescens and A. halleri, which last shared a common ancestor >40 mya, provides intriguing evidence that parallel evolutionary pathways may underlie Zn/Cd hyperaccumulation in Brassicaceae

Improving Performance of Finishing Pigs with Added Valine, Isoleucine, and Tryptophan: Validating a Meta-Analysis Model

Based on a recent meta-analysis, we hypothesized that increased dietary Val, Ile, or Trp could correct possible amino acid interactions caused by high dietary Leu in diets containing high levels of corn protein, namely dried distillers grains with solubles (DDGS). A total of 1,200 pigs (PIC TR4 × (Fast LW × PIC L02); initially 74.0 ± 1.38 lb) were used in a 103-d study. The 6 dietary treatments were corn-soybean meal- DDGS-based diets as follows: 1) low level of Lys-HCl (HSBM), 2) high Lys-HCl and moderate Ile, Val, Trp (NC; AA above NRC4 estimates), 3) moderate Lys-HCl and high Ile, Val, Trp (PC), and 4) PC with either increased L-Val (PC+Val), 5) L-Ile (PC+Ile), or 6) L-Trp (PC+Trp). Diets contained 30% DDGS until pigs reached approximately 217 lb, and then pigs were fed diets with 20% DDGS until market. Data were analyzed as a randomized complete block design using the lmer function in the lme4 package in R with pen considered as the experimental unit, body weight, and pen location as a blocking factor, and treatment as a fixed effect with 10 replicates/treatment. In the grower period, ADG was greater (P \u3c 0.05) for the pigs fed HSBM and PC+Val diets than the NC with PC, PC+Ile, and PC+Trp intermediate. Pigs fed HSBM were more (P \u3c 0.05) efficient than the NC and PC with PC+Val, PC+Ile, and PC+Trp being intermediate. In the late finisher period, ADG was greater (P \u3c 0.05) for pigs fed PC+Ile than that of the NC with HSBM, PC, PC+Val, and PC+Trp intermediate. Pigs fed PC+Val had greater (P \u3c 0.05) ADFI than the NC with HSBM, PC, PC+Ile, and PC+Trp being intermediate. However, PC+Ile pigs were more (P \u3c 0.05) efficient than PC+Val pigs with HSBM, NC, PC, and PC+Trp being intermediate. Overall, final body weight (BW), average daily gain (ADG), and hot carcass weight (HCW) were greater (P \u3c 0.05) for pigs fed HSBM, PC+Val, and PC+Ile diets than the NC with PC and PC+Trp intermediate. Pigs fed the PC+Val diet had greater (P \u3c 0.05) average daily feed intake (ADFI) than the NC with pigs fed HSBM, PC, PC+Ile, and PC+Trp intermediate. No differences were detected between treatments for overall F/G or other carcass characteristics. In conclusion, increasing Val or Ile in high Lys- HCl-DDGS-based diets improved growth performance and final BW compared with pigs fed diets containing high levels of Lys-HCl without added Val and Ile. These results demonstrate that the negative effects of high Leu concentrations in corn-DDGS-based diets can be corrected by increasing the ratios of Val and Ile to Lys

Effect of added zinc in diets with ractopamine hydrochloride on growth performance, carcass characteristics, and ileal mucosal inflammation mRNA expression of finishing pigs

Citation: Paulk, C. B., Burnett, D. D., Tokach, M. D., Nelssen, J. L., Dritz, S. S., Derouchey, J. M., . . . Gonzalez, J. M. (2015). Effect of added zinc in diets with ractopamine hydrochloride on growth performance, carcass characteristics, and ileal mucosal inflammation mRNA expression of finishing pigs. Journal of Animal Science, 93(1), 185-196. doi:10.2527/jas2014-8286Two experiments were conducted to determine the effects of increasing the dietary Zn content on growth performance, carcass characteristics, plasma Zn, and ileal mucosal inflammation mRNA expression of finishing pigs fed diets containing ractopamine HCl (RAC; Elanco Animal Health, Greenfield, IN). In Exp. 1, 312 pigs (327 × 1050; PIC, Hendersonville, TN; 94 kg BW) were used in a 27-d study. There were 2 pigs per pen and 26 pens per treatment. Treatments included a corn–soybean meal diet (control; 0.66% standardized ileal digestible [SID] Lys); a diet (0.92% SID Lys) with 10 mg/kg RAC; and the RAC diet plus 50, 100, or 150 mg Zn/kg from ZnO or 50 mg Zn/kg from a Zn AA complex (ZnAA; Availa-Zn; Zinpro, Eden Prairie, MN). All diets also contained 83 mg Zn/kg from ZnSO4 in the trace mineral premix. Pigs fed the RAC diet without added Zn had increased (P &lt; 0.05) ADG, G:F, HCW, carcass yield, and loin weight compared with pigs fed the control diet. Increasing Zn from ZnO in diets containing RAC tended to increase (linear, P = 0.067) G:F and loin weight (quadratic, P = 0.064). Pigs fed diets with 50 mg Zn/kg from ZnAA tended to have increased (P = 0.057) ADG compared with pigs fed the RAC diet. In Exp. 2, 320 pigs (327 × 1050; PIC; 98 kg BW) were used in a 35-d study. There were 2 pigs per pen and 20 pens per treatment. Treatments included a control diet (0.66% SID Lys); a diet (0.92% SID Lys) with 10 mg/ kg RAC; or the RAC diet plus 75, 150, and 225 mg Zn/ kg from ZnO or ZnAA. All diets also contained 55 mg Zn/kg from ZnSO4 from the trace mineral premix. Pigs fed the RAC diet had increased (P &lt; 0.05) ADG, G:F, HCW, loin depth, percentage lean, and liver weight compared with pigs fed the control diet. No Zn level or source effects or level × source interactions were observed for growth performance. A Zn level × source interaction (quadratic, P = 0.007) was observed in liver Zn concentrations. This resulted from liver Zn concentrations plateauing at 150 mg Zn/kg when ZnO was supplemented, while there was a linear increase when using ZnAA. Increasing Zn in diets containing RAC increased (linear, P &lt; 0.05) plasma Zn on d 18 and 32. The expression of IL-1? was increased (P = 0.014) in mucosa of pigs fed the RAC diet compared with those fed the control diet. Expression of IL-1? decreased (linear, P = 0.026) in the mucosa of pigs fed increasing added Zn. In conclusion, adding Zn to diets containing RAC resulted in a trend for improved growth performance of pigs in 1 of 2 experiments. Also, additional Zn increased plasma Zn and reduced IL-1?. © 2015 American Society of Animal Science. All rights reserved