The variation in morphology of perennial ryegrass cultivars throughout the grazing season and effects on organic matter digestibility

peer-reviewedThe grass plant comprises leaf, pseudostem, true stem (including inflorescence) and dead material. These components differ in digestibility, and variations in their relative proportions can affect sward quality. The objective of this study was to determine the change in the proportion and organic matter digestibility (OMD) of leaf, pseudostem, true stem and dead components of four perennial ryegrass cultivars (two tetraploids: Astonenergy and Bealey and two diploids: Abermagic and Spelga) throughout a grazing season. The DM proportions and in vitro OMD of leaf, pseudostem, true stem and dead in all cultivars were determined during ten grazing rotations between May 2011 and March 2012. There was an interaction between rotation and cultivar for leaf, pseudostem, true stem and dead proportions. In May and June, Astonenergy had the highest leaf and lowest true stem proportion (P pseudostem > true stem > dead. Bealey had the highest combined leaf and pseudostem proportion 0·92, which explains why it had the highest OMD. In this study, the tetraploid cultivars had the highest leaf and pseudostem proportion and OMD. For accurate descriptions of a sward in grazing studies and to accurately determine sward morphological composition, pseudostem should be separated from true stem, particularly during the reproductive stage when true stem is present

Portable vibration exciter

Gas-driven vibration exciter produces a sinusoidal excitation function controllable in frequency and in amplitude. It allows direct vibration testing of components under normal loads, removing the possibility of component damage due to high static pressure

Gastrointestinal tract size, total-tract digestibility, and rumen microflora in different dairy cow genotypes

peer-reviewedThe superior milk production efficiency of Jersey (JE) and Jersey × Holstein-Friesian (JE × HF) cows compared with Holstein-Friesian (HF) has been widely published. The biological differences among dairy cow genotypes, which could contribute to the milk production efficiency differences, have not been as widely studied however. A series of component studies were conducted using cows sourced from a longer-term genotype comparison study (JE, JE × HF, and HF). The objectives were to (1) determine if differences exist among genotypes regarding gastrointestinal tract (GIT) weight, (2) assess and quantify whether the genotypes tested differ in their ability to digest perennial ryegrass, and (3) examine the relative abundance of specific rumen microbial populations potentially relating to feed digestibility. Over 3 yr, the GIT weight was obtained from 33 HF, 35 JE, and 27 JE × HF nonlactating cows postslaughter. During the dry period the cows were offered a perennial ryegrass silage diet at maintenance level. The unadjusted GIT weight was heavier for the HF than for JE and JE × HF. When expressed as a proportion of body weight (BW), JE and JE × HF had a heavier GIT weight than HF. In vivo digestibility was evaluated on 16 each of JE, JE × HF, and HF lactating dairy cows. Cows were individually stalled, allowing for the total collection of feces and were offered freshly cut grass twice daily. During this time, daily milk yield, BW, and dry matter intake (DMI) were greater for HF and JE × HF than for JE; milk fat and protein concentration ranked oppositely. Daily milk solids yield did not differ among the 3 genotypes. Intake capacity, expressed as DMI per BW, tended to be different among treatments, with JE having the greatest DMI per BW, HF the lowest, and JE × HF being intermediate. Production efficiency, expressed as milk solids per DMI, was higher for JE than HF and JE × HF. Digestive efficiency, expressed as digestibility of dry matter, organic matter, N, neutral detergent fiber, and acid detergent fiber, was higher for JE than HF. In grazing cows (n = 15 per genotype) samples of rumen fluid, collected using a transesophageal sampling device, were analyzed to determine the relative abundance of rumen microbial populations of cellulolytic bacteria, protozoa, and fungi. These are critically important for fermentation of feed into short-chain fatty acids. A decrease was observed in the relative abundance of Ruminococcus flavefaciens in the JE rumen compared with HF and JE × HF. We can deduce from this study that the JE genotype has greater digestibility and a different rumen microbial population than HF. Jersey and JE × HF cows had a proportionally greater GIT weight than HF. These differences are likely to contribute to the production efficiency differences among genotypes previously reported

What Doesn’t Kill You

The purpose of this exploratory study was to examine the relationship between adverse childhood experiences (ACEs) and resilience in a sample (n=139) of Masters of Social Work (MSW) students. Perceived stress, religious faith, experiential avoidance, and mindfulness were also examined as correlates of resilience. Resilience scores for the MSW students were comparable to general population and college student norms, but ACEs and perceived stress scores were higher. Despite a broad literature supporting associations of high ACE scores with varied measures of physical and psychological problems, this study paradoxically showed a positive relationship between higher ACE scores and resilience. Regression analysis indicated a model including age, ACE scores, experiential avoidance, religious faith, and perceived stress explained 39.2% of the variance in resilience scores. Prior adverse childhood experiences and stronger religious faith are associated with increased resilience, while experiential avoidance and perceived stress are associated with lower resilience. This study provides further evidence that many students come to social work education with substantial trauma histories and experience considerable stress during their studies. Results suggest that social work educators should acknowledge risks associated with avoidant coping, and provide learning experiences aimed at developing students’ capacities for increased awareness and acceptance of challenging experiences—their own and others

Comparison of routes for achieving parenteral access with a focus on the management of patients with Ebola virus disease.

Dehydration is an important cause of death in patients with Ebola virus disease (EVD). Parenteral fluids are often required in patients with fluid requirements in excess of their oral intake. The peripheral intravenous route is the most commonly used method of parenteral access, but inserting and maintaining an intravenous line can be challenging in the context of EVD. Therefore it is important to consider the advantages and disadvantages of different routes for achieving parenteral access (e.g. intravenous, intraosseous, subcutaneous and intraperitoneal). To compare the reliability, ease of use and speed of insertion of different parenteral access methods. We ran the search on 17 November 2014. We searched the Cochrane Injuries Group's Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily, Ovid MEDLINE(R) and Ovid OLDMEDLINE(R), Embase Classic + Embase (OvidSP), CINAHL (EBSCOhost), clinicaltrials.gov and screened reference lists. Randomised controlled trials comparing different parenteral routes for the infusion of fluids or medication. Two review authors examined the titles and abstracts of records obtained by searching the electronic databases to determine eligibility. Two review authors extracted data from the included trials and assessed the risk of bias. Outcome measures of interest were success of insertion; time required for insertion; number of insertion attempts; number of dislodgements; time period with functional access; local site reactions; clinicians' perception of ease of administration; needlestick injury to healthcare workers; patients' discomfort; and mortality. For trials involving the administration of fluids we also collected data on the volume of fluid infused, changes in serum electrolytes and markers of renal function. We rated the quality of the evidence as 'high', 'moderate', 'low' or 'very low' according to the GRADE approach for the following outcomes: success of insertion, time required for insertion, number of dislodgements, volume of fluid infused and needlestick injuries. We included 17 trials involving 885 participants. Parenteral access was used to infuse fluids in 11 trials and medications in six trials. None of the trials involved patients with EVD. Intravenous and intraosseous access was compared in four trials; intravenous and subcutaneous access in 11; peripheral intravenous and intraperitoneal access in one; saphenous vein cutdown and intraosseous access in one; and intraperitoneal with subcutaneous access in one. All of the trials assessing the intravenous method involved peripheral intravenous access.We judged few trials to be at low risk of bias for any of the assessed domains.Compared to the intraosseous group, patients in the intravenous group were more likely to experience an insertion failure (risk ratio (RR) 3.89, 95% confidence interval (CI) 2.39 to 6.33; n = 242; GRADE rating: low). We did not pool data for time to insertion but estimates from the trials suggest that inserting intravenous access takes longer (GRADE rating: moderate). Clinicians judged the intravenous route to be easier to insert (RR 0.15, 95% CI 0.04 to 0.61; n = 182). A larger volume of fluids was infused via the intravenous route (GRADE rating: moderate). There was no evidence of a difference between the two routes for any other outcomes, including adverse events.Compared to the subcutaneous group, patients in the intravenous group were more likely to experience an insertion failure (RR 14.79, 95% CI 2.87 to 76.08; n = 238; GRADE rating: moderate) and dislodgement of the device (RR 3.78, 95% CI 1.16 to 12.34; n = 67; GRADE rating: low). Clinicians also judged the intravenous route as being more difficult to insert and patients were more likely to be agitated in the intravenous group. Patients in the intravenous group were more likely to develop a local infection and phlebitis, but were less likely to develop erythema, oedema or swelling than those in the subcutaneous group. A larger volume of fluids was infused into patients via the intravenous route. There was no evidence of a difference between the two routes for any other outcome.There were insufficient data to reliably determine if the risk of insertion failure differed between the saphenous vein cutdown (SVC) and intraosseous method (RR 4.00, 95% CI 0.51 to 31.13; GRADE rating: low). Insertion using SVC took longer than the intraosseous method (MD 219.60 seconds, 95% CI 135.44 to 303.76; GRADE rating: moderate). There were no data and therefore there was no evidence of a difference between the two routes for any other outcome.There were insufficient data to reliably determine the relative effects of intraperitoneal or central intravenous access relative to any other parenteral access method. There are several different ways of achieving parenteral access in patients who are unable meet their fluid requirements with oral intake alone. The quality of the evidence, as assessed using the GRADE criteria, is somewhat limited because of the lack of adequately powered trials at low risk of bias. However, we believe that there is sufficient evidence to draw the following conclusions: if peripheral intravenous access can be achieved easily, this allows infusion of larger volumes of fluid than other routes; but if this is not possible, the intraosseous and subcutaneous routes are viable alternatives. The subcutaneous route may be suitable for patients who are not severely dehydrated but in whom ongoing fluid losses cannot be met by oral intake.A film to accompany this review can be viewed here (http://youtu.be/ArVPzkf93ng)

Engaging without over-powering: A case study of a FLOSS project

This is the post-print version of the published chapter. The original publication is available at the link below. Copyright @ 2010 IFIP International Federation for Information Processing.The role of Open Source Software (OSS) in the e-learning business has become more and more fundamental in the last 10 years, as long as corporate and government organizations have developed their educational and training programs based on OSS out-of-the-box tools. This paper qualitatively documents the decision of the largest UK e-learning provider, the Open University, to adopt the Moodle e-learning system, and how it has been successfully deployed in its site after a multi-million investment. A further quantitative study also provides evidence of how a commercial stakeholder has been engaged with, and produced outputs for, the Moodle community. Lessons learned from this experience by the stakeholders include the crucial factors of contributing to the OSS community, and adapting to an evolving technology. It also becomes evident how commercial partners helped this OSS system to achieve the transition from an “average” OSS system to a successful multi-site, collaborative and community-based OSS project

Exact Bayesian curve fitting and signal segmentation.

We consider regression models where the underlying functional relationship between the response and the explanatory variable is modeled as independent linear regressions on disjoint segments. We present an algorithm for perfect simulation from the posterior distribution of such a model, even allowing for an unknown number of segments and an unknown model order for the linear regressions within each segment. The algorithm is simple, can scale well to large data sets, and avoids the problem of diagnosing convergence that is present with Monte Carlo Markov Chain (MCMC) approaches to this problem. We demonstrate our algorithm on standard denoising problems, on a piecewise constant AR model, and on a speech segmentation problem

Determinants of passive antibody efficacy in SARS-CoV-2 infection: a systematic review and meta-analysis

Background: Randomised controlled trials of passive antibodies as treatment and prophylaxis for COVID-19 have reported variable efficacy. However, the determinants of efficacy have not been identified. We aimed to assess how the dose and timing of administration affect treatment outcome. Methods: In this systematic review and meta-analysis, we extracted data from published studies of passive antibody treatment from Jan 1, 2019, to Jan 31, 2023, that were identified by searching multiple databases, including MEDLINE, PubMed, and ClinicalTrials.gov. We included only randomised controlled trials of passive antibody administration for the prevention or treatment of COVID-19. To compare administered antibody dose between different treatments, we used data on in-vitro neutralisation titres to normalise dose by antibody potency. We used mixed-effects regression and model fitting to analyse the relationship between timing, dose and efficacy. Findings: We found 58 randomised controlled trials that investigated passive antibody therapies for the treatment or prevention of COVID-19. Earlier clinical stage at treatment initiation was highly predictive of the efficacy of both monoclonal antibodies (p<0·0001) and convalescent plasma therapy (p=0·030) in preventing progression to subsequent stages, with either prophylaxis or treatment in outpatients showing the greatest effects. For the treatment of outpatients with COVID-19, we found a significant association between the dose administered and efficacy in preventing hospitalisation (relative risk 0·77; p<0·0001). Using this relationship, we predicted that no approved monoclonal antibody was expected to provide more than 30% efficacy against some omicron (B.1.1.529) subvariants, such as BQ.1.1. Interpretation: Early administration before hospitalisation and sufficient doses of passive antibody therapy are crucial to achieving high efficacy in preventing clinical progression. The relationship between dose and efficacy provides a framework for the rational assessment of future passive antibody prophylaxis and treatment strategies for COVID-19. Funding: The Australian Government Department of Health, Medical Research Future Fund, National Health and Medical Research Council, the University of New South Wales, Monash University, Haematology Society of Australia and New Zealand, Leukaemia Foundation, and the Victorian Government

Structure of the NheA Component of the Nhe Toxin from Bacillus cereus: Implications for Function

The structure of NheA, a component of the Bacillus cereus Nhe tripartite toxin, has been solved at 2.05 Å resolution using selenomethionine multiple-wavelength anomalous dispersion (MAD). The structure shows it to have a fold that is similar to the Bacillus cereus Hbl-B and E. coli ClyA toxins, and it is therefore a member of the ClyA superfamily of α-helical pore forming toxins (α-PFTs), although its head domain is significantly enlarged compared with those of ClyA or Hbl-B. The hydrophobic β-hairpin structure that is a characteristic of these toxins is replaced by an amphipathic β-hairpin connected to the main structure via a β-latch that is reminiscent of a similar structure in the β-PFT Staphylococcus aureus α-hemolysin. Taken together these results suggest that, although it is a member of an archetypal α-PFT family of toxins, NheA may be capable of forming a β rather than an α pore