102 research outputs found
A Novel Stable Isotope Approach for Determining the Impact of Thickening Agents on Water Absorption
Research on the bioavailability of water from thickened fluids has recently been published and it concluded that the addition of certain thickening agents (namely, modified maize starch, guar gum, and xanthan gum) does not significantly alter the absorption of water from the healthy, mature human gut. Using xanthan gum as an example, our âproof of conceptâ study describes a simple, accurate, and noninvasive alternative to the methodology used in that first study, and involves the measurement and comparison of the dilution space ratios of the isotopes 2H and 18O and subsequent calculation of total body water. Our method involves the ingestion of a thickening agent labeled with 2H 1Â day after ingestion of 18O. Analyses are based on the isotopic enrichment of urine samples collected prior to the administration of each isotope, and daily urine samples collected for 15Â days postdosing. We urge that further research is needed to evaluate the impact of various thickening agents on the bioavailability of water from the developing gut and in cases of gut pathology and recommend our methodology
Estimation of Influenza Vaccine Effectiveness from Routine Surveillance Data
BACKGROUND: Influenza vaccines are reviewed each year, and often changed, in an effort to maintain their effectiveness against drifted influenza viruses. There is however no regular review of influenza vaccine effectiveness during, or at the end of, Australian influenza seasons. It is possible to use a case control method to estimate vaccine effectiveness from surveillance data when all patients in a surveillance system are tested for influenza and their vaccination status is known. METHODOLOGY/PRINCIPAL FINDINGS: Influenza-like illness (ILI) surveillance is conducted during the influenza season in sentinel general practices scattered throughout Victoria, Australia. Over five seasons 2003-7, data on age, sex and vaccination status were collected and nose and throat swabs were offered to patients presenting within three days of the onset of their symptoms. Swabs were tested using a reverse transcriptase polymerase chain reaction (RT-PCR) test. Those positive for influenza were sent to the World Health Organization (WHO) Collaborating Centre for Reference and Research on Influenza where influenza virus culture and strain identification was attempted. We used a retrospective case control design in five consecutive influenza seasons, and estimated influenza vaccine effectiveness (VE) for patients of all ages to be 53% (95% CI 38-64), but 41% (95% CI 19-57) adjusted for age group and year. The adjusted VE for all adults aged at least 20 years, the age groups for whom a benefit of vaccination could be shown, was 51% (95% CI 34-63). Comparison of VE estimates with vaccine and circulating strain matches across the years did not reveal any significant differences. CONCLUSIONS/SIGNIFICANCE: These estimates support other field studies of influenza vaccine effectiveness, given that theoretical considerations suggest that these values may underestimate true effectiveness, depending on test specificity and the ratio of the influenza ILI attack rate to the non-influenza ILI attack rate. Incomplete recording of vaccination status and under-representation of children in patients from whom a swab was collected limit the data. Improvements have been implemented for prospective studies
Inventory and quantitative assessment of geosites and geodiversity sites: a review
"Published online: 15 January 2015"The inventory and quantitative assessment of the most valuable occurrences of geodiversity are essential steps in any geoconservation strategy and in the establishment of priorities in site management. Despite the existence of many site inventories applied to different scales (countries, municipalities, parks, etc.), the criteria used for their selection are often unclear and poorly defined. This paper proposes a new approach to the concepts of geosite and geodiversity site and reviews the procedures used in the development of a systematic site inventory applied to different scales and values. Procedures to achieve a numerical evaluation of the value and degradation risk of sites are reviewed and new criteria are proposed. Finally, guidelines are presented, bearing in mind the preparation of effective geodiversity inventories, to support geoparksâ strategies. This paper aims to contribute to a better understanding and use of the above-mentioned concepts, which are essential for the implementation of geoconservation actions worldwide.The author thanks Diamantino Pereira, Flavia Lima, and Paulo Pereira for fruitful discussions and insights; Teresa Mota for the English revision; and the reviewers for significant improvements of the first submitted version. This paper results of the research done at the University of Minho and at the Geology Centre of the University of Porto, partially founded by the Foundation for Science and Technology (Portugal), strategic project with reference PEst-OE/CTE/UI0039/2014
"Then you get a teacher" - Guidelines for excellence in teaching
Background: Current literature calls for the explicit teaching to health-science educators of the skills, knowledge and dispositions
that are required for successful teaching in higher education.
Aims: This paper draws on evidence from an Oral Hygiene department at a South African university in order to
illustrate these teaching-competency needs. Insights from the evidence are synthesised with current literature regarding best
teaching practice, in support of an appropriate framework for the development of teaching competencies to health-science
educators.
Description: A qualitative approach, using a case study, was adopted. The cohort comprised fifteen students in the first-year Oral
Hygiene cohort class and the ten educators who taught their programme. Data was collected through semistructured interviews
and open-ended questionnaires. The topics that emerged from the combined analysis of the interviews and the questionnaires
were organised into a grid so that common themes could be identified. Current literature regarding teaching and learning was used
as a framework for interpreting the empirical evidence, from which three categories emerged. The first category included
suggestions from students regarding what to do to teach better. A review of the literature indicates that these competencies can be
effectively learnt from self-help guides. The second category included requests for skills development. Literature review suggests
that these might effectively be learnt from single-event workshops facilitated by more able peers. Responses in the final category
highlighted the need for an underpinning theory of teaching and learning, and signalled the need for a more theoretically
grounded and detailed approach to teacher development.
Conclusion: The framework developed from the empirical study and current literature makes it possible for individual clinical
teachers, and staff developers, to construct teaching-competency development plans that are pertinent to individual teachersâ
needs, relevant and practical, educationally sound, and cost-effective in terms of time and effort
Risk-taking attitudes and their association with process and outcomes of cardiac care: a cohort study
<p>Abstract</p> <p>Background</p> <p>Prior research reveals that processes and outcomes of cardiac care differ across sociodemographic strata. One potential contributing factor to such differences is the personality traits of individuals within these strata. We examined the association between risk-taking attitudes and cardiac patients' clinical and demographic characteristics, the likelihood of undergoing invasive cardiac procedures and survival.</p> <p>Methods</p> <p>We studied a large inception cohort of patients who underwent cardiac catheterization between July 1998 and December 2001. Detailed clinical and demographic data were collected at time of cardiac catheterization and through a mailed survey one year post-catheterization. The survey included three general risk attitude items from the Jackson Personality Inventory. Patients' (n = 6294) attitudes toward risk were categorized as risk-prone versus non-risk-prone and were assessed for associations with baseline clinical and demographic characteristics, treatment received (i.e., medical therapy, coronary artery bypass graft (CABG) surgery, percutaneous coronary intervention (PCI)), and survival (to December 2005).</p> <p>Results</p> <p>2827 patients (45%) were categorized as risk-prone. Having risk-prone attitudes was associated with younger age (p < .001), male sex (p < .001), current smoking (p < .001) and higher household income (p < .001). Risk-prone patients were more likely to have CABG surgery in unadjusted (Odds Ratio [OR] = 1.21; 95% CI 1.08â1.36) and adjusted (OR = 1.18; 95% CI 1.02â1.36) models, but were no more likely to have PCI or any revascularization. Having risk-prone attitudes was associated with better survival in an unadjusted survival analysis (Hazard Ratio [HR] = 0.78 (95% CI 0.66â0.93), but not in a risk-adjusted analysis (HR = 0.92, 95% CI 0.77â1.10).</p> <p>Conclusion</p> <p>These exploratory findings suggest that patient attitudes toward risk taking may <b>contribute to </b>some of the documented differences in use of invasive cardiac procedures. An awareness of these associations could help healthcare providers as they counsel patients regarding cardiac care decisions.</p
Phonotactic response of female crickets on the Kramer treadmill: methodology, sensory and behavioural implications
Since population-level variation in female mating preferences can shape intraspecific communication systems within the context of sexual selection it is essential to quantify these preferences and their sources of variation. We calculated individual female response functions for four male calling song traits in the field cricket Gryllus bimaculatus, by performing untethered phonotaxis measurements on a spherical locomotor compensator (Kramer treadmill). Firstly, we quantify the population-level sources of phonotactic variation and correct for factors that adversely affect this measurement. Secondly, we develop methodology for the characterisation of individual female phonotactic response functions suitable for population-level analyses and demonstrate the applicability of our method with respect to recent literature on Orthopteran acoustic communication. Phonotaxis towards a preferred stimulus on different occasions is highly repeatable, with lower repeatabilities away from the most preferred signal traits. For certain male signal traits, female preference and selectivity are highly repeatable. Although phonotactic response magnitude deteriorated with age, preference functions of females remained the same during their lifetimes. Finally, the limitations of measuring phonotaxis using a spherical locomotor compensator are described and discussed with respect to the estimation of the selectivity of female response
Male Responses to Conspecific Advertisement Signals in the Field Cricket Gryllus rubens (Orthoptera: Gryllidae)
In many species males aggregate and produce long-range advertisement signals to attract conspecific females. The majority of the receivers of these signals are probably other males most of the time, and male responses to competitors' signals can structure the spatial and temporal organization of the breeding aggregation and affect male mating tactics. I quantified male responses to a conspecific advertisement stimulus repeatedly over three age classes in Gryllus rubens (Orthoptera: Gryllidae) in order to estimate the type and frequency of male responses to the broadcast stimulus and to determine the factors affecting them. Factors tested included body size, wing dimorphism, age, and intensity of the broadcast stimulus. Overall, males employed acoustic response more often than positive phonotactic response. As males aged, the frequency of positive phonotactic response decreased but that of the acoustic response increased. That is, males may use positive phonotaxis in the early stages of their adult lives, possibly to find suitable calling sites or parasitize calling males, and then later in life switch to acoustic responses in response to conspecific advertisement signals. Males with smaller body size more frequently exhibited acoustic responses. This study suggests that individual variation, more than any factors measured, is critical for age-dependent male responses to conspecific advertisement signals
Universal Primers Used for Species Identification of Foodstuff of Animal Origin: Effects of Oligonucleotide Tails on PCR Amplification and Sequencing Performance
M13 universal non-homologous oligonucleotide tails incorporated into universal primers have been shown to improve amplification and sequencing performance. However, a few protocols use these tails in the field of food inspection. In this study, two types of M13 tails (by Steffens and Messing) were selected to assess their benefits using universal cytochrome oxidase subunit I (COI) and 16S ribosomal RNA gene (16SrRNA) primers in standard procedures. The primer characteristics were tested in silico. Then, using 20 DNA samples of edible species (birds, fishes, and mammals), their performance during PCR amplification (band recovery and intensity) and sequencing (sequence recovery, length, and Phred score) was assessed and compared. While 16SrRNA tailed and non-tailed primers performed similarly, differences were found for COI primers. Messingâs tails negatively affected the reaction outputs, while Steffensâ tails significantly improved the band intensity and the length of the final contigs based on the individual bidirectional read sequence. This different performance could be related to a destabilization effect of certain tails on primers with unfavorable mismatches on the annealing region. Even though our results cannot be generalized because the tail performances are strictly dependent on laboratory conditions, they show that appropriate tails can improve the overall throughput of the analysis, supporting food traceabilit
Detecting macroecological patterns in bacterial communities across independent studies of global soils
This study and participants were funded in part by ERC Adv grant 26055290 (KSR, WHvdP); BBSRC David Phillips Fellowship (BB/L02456X/1) (FTDV); ERC Grant Agreements 242658 [BIOCOM] and 647038 [BIODESERT] (FTM); the European Regional Development Fund (Centre of Excellence EcolChange) (JD); Yorkshire Agricultural Society, Nafferton Ecological Farming Group, and the Northumbria University Research Development Fund (CHO); BBSRC Training Grant (BB/K501943/1) (CH); Wallenberg Academy Fellowship (KAW 2012.0152), Formas (214-2011-788) and VetenskapsrÄdet (612-2011-5444) (ED); the Glastir Monitoring & Evaluation Programme (Contract reference: C147/2010/11) and the full support of the GMEP team on the Glastir project (DLJ, SC, DAR)
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