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We report the results of a computer enumeration that found that there are 3155 perfect 1-factorisations (P1Fs) of the complete graph
. Of these, 89 have a nontrivial automorphism group (correcting an earlier claim of 88 by Meszka and Rosa [‘Perfect 1-factorisations of
with nontrivial automorphism group’, J. Combin. Math. Combin. Comput.47 (2003), 97–111]). We also (i) describe a new invariant which distinguishes between the P1Fs of
, (ii) observe that the new P1Fs produce no atomic Latin squares of order 15 and (iii) record P1Fs for a number of large orders that exceed prime powers by one.
Shiga toxin-producing Escherichia coli (STEC) infections pose a substantial health and economic burden worldwide. To target interventions to prevent foodborne infections, it is important to determine the types of foods leading to illness. Our objective was to determine the food sources of STEC globally and for the six World Health Organization regions. We used data from STEC outbreaks that have occurred globally to estimate source attribution fractions. We categorised foods according to their ingredients and applied a probabilistic model that used information on implicated foods for source attribution. Data were received from 27 countries covering the period between 1998 and 2017 and three regions: the Americas (AMR), Europe (EUR) and Western-Pacific (WPR). Results showed that the top foods varied across regions. The most important sources in AMR were beef (40%; 95% Uncertainty Interval 39–41%) and produce (35%; 95% UI 34–36%). In EUR, the ranking was similar though with less marked differences between sources (beef 31%; 95% UI 28–34% and produce 30%; 95% UI 27–33%). In contrast, the most common source of STEC in WPR was produce (43%; 95% UI 36–46%), followed by dairy (27%; 95% UI 27–27%). Possible explanations for regional variability include differences in food consumption and preparation, frequency of STEC contamination, the potential of regionally predominant STEC strains to cause severe illness and differences in outbreak investigation and reporting. Despite data gaps, these results provide important information to inform the development of strategies for lowering the global burden of STEC infections.
Shiga toxin-producing Escherichia coli (STEC) infections are a significant public health issue, with foodborne transmission causing >1 million illnesses worldwide each year. We conducted a systematic review and meta-analysis (PROSPERO registry # CRD42017074239), to determine the relative association of different food types with sporadic illnesses caused by STEC. Searches were conducted from 01 August to 30 September 2017, using bibliographic and grey literature databases, websites and expert consultation. We identified 22 case-control studies of sporadic STEC infection in humans, from 10 countries within four World Health Organization subregions, from 1985 to 2012. We extracted data from 21 studies, for 237 individual measures in 11 food categories and across three status types (raw or undercooked, not raw and unknown). Beef was the most significant food item associated with STEC illness in the Americas and Europe, but in the Western Pacific region, chicken was most significant. These findings were not significantly moderated by the raw or cooked status of the food item, nor the publication year of the study. Data from the African, South-East Asian and Eastern Mediterranean subregions were lacking and it is unclear whether our results are relevant to these regions.
The Fluvial Archives Group (FLAG) was founded in 1996 to bring together researchers looking at the development of fluvial systems over multiple timescales and global spatial scales. Fluvial archives of various types are important not just because they provide insights into past landscape dynamics, e.g., driven by climate or crustal processes, but also because they frequently contain fossil or archaeological material for which they provide stratigraphic control. Since 1996, FLAG has evolved from a research group of the British Quaternary Research Association into an organisation with around 500 members in over 20 countries. The research group held 12 biennial meetings, comprising both presentations and field excursions, as well as multiple themed sessions at international conferences. These had resulted by 2017 in 19 journal special issues, all fully detailed by Cordier et al. (2017). The goals of FLAG are: provision of a community for discussion of key issues concerning fluvial archives, including organising the aforementioned biennial discussion/field meetings, sessions at relevant international conferences, and special issues of journals; continued promotion of the value of fluvial archives by means of readily accessible published information; and coordination of activity with other research groupings with overlapping interests, e.g., by co-convening sessions and collaborating on publications.
Exercise has potential to mitigate morbidity in knee osteoarthritis (OA). Participants with knee OA were randomized to a Square-stepping Exercise (SSE) group (2x/week for 24 weeks) or a control group. We assessed the feasibility of SSE and its effectiveness on symptoms (WOMAC), balance (Fullerton), mobility, and walking speed at 12 and 24 weeks. The SSE group had a 49.3% attendance rate and trended toward improvement in the 30-second chair stand at 12 (F = 1.8, p = .12, ηp2 = 0.16), and 24 weeks, (F = 3.4, p = .09, ηp2 = 0.18), and walking speed at 24 weeks, compared to controls. There were no differences in symptoms or balance. The low attendance and recruitment demonstrated limited feasibility of SSE in adults with knee OA. Trends suggest the potential for SSE to improve lower extremity functional fitness and walking speed. SSE should be further studied for effectiveness on symptoms and balance, in addition to improving feasibility.
Important Bird and Biodiversity Areas (IBAs) are sites identified as being globally important for the conservation of bird populations on the basis of an internationally agreed set of criteria. We present the first review of the development and spread of the IBA concept since it was launched by BirdLife International (then ICBP) in 1979 and examine some of the characteristics of the resulting inventory. Over 13,000 global and regional IBAs have so far been identified and documented in terrestrial, freshwater and marine ecosystems in almost all of the world’s countries and territories, making this the largest global network of sites of significance for biodiversity. IBAs have been identified using standardised, data-driven criteria that have been developed and applied at global and regional levels. These criteria capture multiple dimensions of a site’s significance for avian biodiversity and relate to populations of globally threatened species (68.6% of the 10,746 IBAs that meet global criteria), restricted-range species (25.4%), biome-restricted species (27.5%) and congregatory species (50.3%); many global IBAs (52.7%) trigger two or more of these criteria. IBAs range in size from < 1 km2 to over 300,000 km2 and have an approximately log-normal size distribution (median = 125.0 km2, mean = 1,202.6 km2). They cover approximately 6.7% of the terrestrial, 1.6% of the marine and 3.1% of the total surface area of the Earth. The launch in 2016 of the KBA Global Standard, which aims to identify, document and conserve sites that contribute to the global persistence of wider biodiversity, and whose criteria for site identification build on those developed for IBAs, is a logical evolution of the IBA concept. The role of IBAs in conservation planning, policy and practice is reviewed elsewhere. Future technical priorities for the IBA initiative include completion of the global inventory, particularly in the marine environment, keeping the dataset up to date, and improving the systematic monitoring of these sites.
40% of people with dementia have disturbed sleep but there are currently no known effective treatments. Studies of sleep hygiene and light therapy have not been powered to indicate feasibility and acceptability and have shown 40–50% retention. We tested the feasibility and acceptability of a six-session manualized evidence-based non-pharmacological therapy; Dementia RElAted Manual for Sleep; STrAtegies for RelaTives (DREAMS-START) for sleep disturbance in people with dementia.
We conducted a parallel, two-armed, single-blind randomized trial and randomized 2:1 to intervention: Treatment as Usual. Eligible participants had dementia and sleep disturbances (scoring ≥4 on one Sleep Disorders Inventory item) and a family carer and were recruited from two London memory services and Join Dementia Research. Participants wore an actiwatch for two weeks pre-randomization. Trained, clinically supervised psychology graduates delivered DREAMS-START to carers randomized to intervention; covering Understanding sleep and dementia; Making a plan (incorporating actiwatch information, light exposure using a light box); Daytime activity and routine; Difficult night-time behaviors; Taking care of your own (carer's) sleep; and What works? Strategies for the future. Carers kept their manual, light box, and relaxation recordings post-intervention. Outcome assessment was masked to allocation. The co-primary outcomes were feasibility (≥50% eligible people consenting to the study) and acceptability (≥75% of intervention group attending ≥4 intervention sessions).
In total, 63out of 95 (66%; 95% CI: 56–76%) eligible referrals consented between 04/08/2016 and 24/03/2017; 62 (65%; 95% CI: 55–75%) were randomized, and 37 out of 42 (88%; 95% CI: 75–96%) adhered to the intervention.
DREAM-START for sleep disorders in dementia is feasible and acceptable.
Hill (Twin Research and Human Genetics, Vol. 21, 2018, 84–88) presented a critique of our recently published paper in Cell Reports entitled ‘Large-Scale Cognitive GWAS Meta-Analysis Reveals Tissue-Specific Neural Expression and Potential Nootropic Drug Targets’ (Lam et al., Cell Reports, Vol. 21, 2017, 2597–2613). Specifically, Hill offered several interrelated comments suggesting potential problems with our use of a new analytic method called Multi-Trait Analysis of GWAS (MTAG) (Turley et al., Nature Genetics, Vol. 50, 2018, 229–237). In this brief article, we respond to each of these concerns. Using empirical data, we conclude that our MTAG results do not suffer from ‘inflation in the FDR [false discovery rate]’, as suggested by Hill (Twin Research and Human Genetics, Vol. 21, 2018, 84–88), and are not ‘more relevant to the genetic contributions to education than they are to the genetic contributions to intelligence’.
A nonparaxial investigation for propagation characteristics of q-Gaussian laser beam in rippled density plasma is studied by considering the relativistic nonlinearity. The field distribution in the medium is expressed in terms of q parameter and beam width parameter f. Nonlinear parabolic partial differential equation governing the evolution of complex envelope in slowly varying approximation is solved in a modulated density profile. Analytical theory of self-focusing including higher order terms in the expansion of dielectric function up to fourth order is developed and the variation of beam width parameter f with the distance of propagation for different parameters is studied. One may note that increased value of density ripple, laser intensity and depth of modulation, increases self-focusing whereas a lower value of q shows strong self-focusing. A comparative study between paraxial and nonparaxial study has also conducted. This study is useful for research in high energy density physics.
The object of the experiment to be reported was to determine the extent to which intake and eating behaviour are influenced by differences in the ratio of nitrogen (N) to water soluble carbohydrates (WSC) in the feed and the liquid phase of boli obtained from oesophageal fistulae. Four feeds were chosen as being likely to cover a range of N to WSC ratios in the liquid phase; these were frozen lucerne, lucerne silage, grass silage and grass silage treated with formaldehyde (46 g/100 g crude protein).
Ruminant animal production faces numerous challenges and it seems that both economic and biological benefits will be derived from moving food characterization from simple energy and protein-based approaches to those which assess nutrient supply in some detail. In vitro systems will need to reflect this change and this paper considers in particular, the need for estimations of rumen volatile fatty acids and microbial protein supplies. Emphasis is placed on the possibility that in vitro techniques can be used to provide biochemical data which can themselves be used in mathematical models of wider processes. This paper also examines the need for in vitro techniques to reflect the microbial!animal response to the physical structure of foods and also the requirement for in vitro approaches which ask why a food has a certain value rather than simply what the value is. In vitro techniques also have a substantial role outside the digestive tract in predicting factors such as voluntary food intake and some aspects of tissue metabolism and some of these aspects are considered. Tor practical application in vitro techniques will need to provide value for money and be compatible as parameters in mathematical models to have an impact at farm level. In this regard physical in vitro techniques such as NIRS seem to have enormous potential.
Glucose and acetate are two of the most important metabolites which supply energy to ruminant tissues. Minimal quantities of glucose are absorbed from the alimentary tract and thus glucose requirements must be met through synthesis from gluconeogenic precursors. One such precursor is protein and, in the two experiments to be reported, the effect of varying protein supply on both glucose and acetate metabolism was studied. In experiment 1, protein supply was varied by the addition of two levels of fishmeal to a grass silage diet while in experiment 2, two diets (perennial ryegrass and white clover) known to supply widely different amounts of absorbed protein were compared.
In the tropics, fodder trees and shrubs are a very important source of nutrients, especially nitrogen. In vitro gas production methods used for food evaluation were originally developed for investigation of temperate forages and used a nitrogen-rich medium. Evaluation of fodder tree leaves in this medium may mask the effect of their nitrogen which it is important to understand. This trial studied the fermentation of a range of tropical fodder trees and shrubs in both nitrogen-rich and nitrogen-free media, in order to identify the main chemical entities contributing to gas production and the time within which such contributions were most important.
Previous work in animal nutrition has focused on single foods and assumed additivity during in vitro fermentation. In the tropics, farmers are likely to offer mixtures of foods, including tree fodders, which may not be simply additive in nutritional terms. There is little information about the nutritional interactions between tropical foods. The objective of this research was to test the existence of associative effects of mixtures of tropical fodder tree leaves.
Ruminants in many less developed countries may consume poor quality roughages such as straws, stovers and senescent native pasture as a major part of their diet, particularly during the dry season when high-quality forages are in short supply. The majority of these roughages are high in fibre, low in protein and the intake of digestible nutrients often is not enough to meet maintenance requirements. Intake and digestibility of poor-quality roughages may be increased by supplementation. The response to supplementation can be attributed to an increase in the supply of nitrogen and/or readily fermentable carbohydrate, resulting in an increase in rumen cellulolytic micro-organisms and therefore enhanced fibre degradation.