133 research outputs found
Effects of dietary fat manipulation on cognition in mice and rats:protocol for a systematic review and meta-analysis
INTRODUCTION AND OBJECTIVE: The Western diet that comprises high levels of long-chain saturated fats and sugar is associated not only with metabolic disorders such as obesity and type 2 diabetes but also has been recently linked to brain changes and cognitive dysfunction. However, in animal studies, reported effects are variable, and the mechanisms underlying these effects are unclear. In the proposed review, we aim to summarise the diverse evidence of the effects of so-called ‘high-fat’ and ketogenic diets on behavioural measures of cognition in postweaning mice and rats, relative to animals on standard diets and to determine potential underlying mechanisms of high-fat diet-induced effects. SEARCH STRATEGY: A comprehensive search strategy was designed to retrieve studies reporting use of a high-fat or ketogenic diet in postweaning mice and rats that included cognitive assessments. Three databases (Medline, SCOPUS and Web of Science) were searched and 4487 unique references were retrieved. SCREENING AND ANNOTATION: Studies were screened for inclusion by two independent reviewers, with 330 studies retained for analysis. Characteristics of disease model choice, experimental design, intervention use and outcome assessment are to be extracted using the Systematic Review Facility (http://syrf.org.uk/) tool. Studies will be assessed for study quality and risk of bias and confidence of mechanistic involvement. DATA MANAGEMENT AND REPORTING: For cognitive outcomes, effect sizes will be calculated using normalised mean difference and summarised using a random effects model. The contribution of potential sources of heterogeneity to the observed effects of diet on cognition will be assessed using multivariable meta-regression, with partitioning of heterogeneity as a sensitivity analysis. A preliminary version of this protocol was published on 9 April 2019 on the Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies website (http://www.dcn.ed.ac.uk/camarades/research.html%23protocols). ETHICS AND DISSEMINATION: No ethical approval is required as there are no subjects in the proposed study
Using habitat models to identify marine Important Bird and Biodiversity Areas for Chinstrap penguins in the South Orkney Islands
Tracking individual marine predators can provide vital information to aid the identification of important activity (foraging, commuting, rafting, resting, etc.) hotspots and therefore also to delineate priority sites for conservation. However, in certain locations (e.g. Antarctica) many marine mammal or seabird colonies remain untracked due to logistical constraints, and the colonies that are studied may not be the most important in terms of conservation priorities. Using data for one of the most abundant seabirds in the Antarctic as a case study (the Chinstrap penguin Pygoscelis antarcticus), we tested the use of correlative habitat models (used to predict distribution around untracked colonies) to overcome this limitation, and to enable the identification of important areas at-sea for colonies where tracking data are not available. First, Important Bird and Biodiversity Areas (IBA) were identified using a standardised, published approach using empirical data from birds tracked from colonies located in the South Orkney Islands. Subsequently, novel approaches using predicted distributions of Chinstrap penguins derived from habitatcorrelative habitat models were applied to identify important marine areas, and the results compared with the IBAs. Data were collected from 4 colonies over 4 years and during different stages of the breeding season. Results showed a high degree of overlap between the areas identified as important by observed data (IBAs) and by predicted distributions, revealing that habitat preference models can be used with a high degree of confidence to identify marine IBAs for these penguins. We provide a new method for designating a network of marine IBAs for penguins in Antarctic waters, based on outputs from habitatcorrelative habitat models when tracking data are not available. This can contribute to an evidence-based and precautionary approach to aid the management framework for Antarctic fisheries and for the protection of birds
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Notes on a Portable Rock Art Piece from Western Nevada
As with all Great Basin carved effigies, the piece may be classed as rather crude and experimental. A best guess at its species would be mountain sheep, an assessment with which Tuohy (personal communication) is in accord. As Wellmann (1979:56) has noted, mountain sheep are by far the most common animal portrayed in petroglyphs of the Great Basin. They are also the most faithfully executed and accurately rendered of all the quadrupeds, allowing for their easy modern-day recognition. Most other petroglyphic portrayals of animals are more aptly described as amorphous zoomorphs. Such figures could represent abstractions of known species, totally mythical or imaginary "dream" species, or non-realistic composites of the above. Such terms could also be used to interpret the piece described herein. It is suggested that such pieces would receive more attention if they were perceived as a type of rock art. Although portable, and admittedly at the other end of the spectrum from pictographs, petroglyphs, and geoglyphs (intaglios), they are nevertheless made of stone and are generally felt to be functionally magico-religious. If placed under the rock-art rubric they might become more attractive as objects of serious interpretive efforts
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Radiocarbon dates from CA-Mrn-152
In general, excavations at Mrn-152, which were conducted in 1972 and 1973, produced few time-sensitive artifacts, but those identified range from the Early through the Late Horizon, as defined elsewhere in central California. The close agreement of the three dates reported here indicates that there may have been an early occupation of Marin County, yet to be fully discovered and described, that is comparable to that of the Berkeley facies
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Radiocarbon dates from CA-Mrn-152
In general, excavations at Mrn-152, which were conducted in 1972 and 1973, produced few time-sensitive artifacts, but those identified range from the Early through the Late Horizon, as defined elsewhere in central California. The close agreement of the three dates reported here indicates that there may have been an early occupation of Marin County, yet to be fully discovered and described, that is comparable to that of the Berkeley facies
Does paddle force applied during defibrillation meet advanced life support guidelines of the European Resuscitation Council?
Objectives: to determine whether paddle force applied during defibrillation meets the 12 kg (?120 N) force recommended by the advanced life support (ALS) guidelines of the European Resuscitation Council (ERC). Materials and methods: an adult mannequin was ‘defibrillated’ using standard defibrillation paddles instrumented to measure paddle force. Paddle force was recorded at the time the discharge buttons on the paddle handles were depressed. Results: 54 doctors and nurses performed simulated defibrillation on a mannequin. Median sternal paddle force was 60.6 N (range 26.1–132.8 N) and median apical paddle force was 59.5 N (range 18.6–118.5 N). Only 3/54 operators (5.6%) applied sternal paddle force equal to or in excess of ERC recommendations. No operator applied apical paddle force equal to or in excess of ERC recommendations. Conclusions: force applied to defibrillation paddles does not meet guidelines of the European Resuscitation Council. Greater emphasis during advanced life support training should be placed on the importance of firm paddle force during defibrillation
How often should defibrillation pads be changed?: the effect of evaporative drying
Objective: In order to minimise transthoracic impedance (TTI) during defibrillation, water-based pads are used to improve conductivity between metal defibrillation paddles and skin. Subjectively, these pads appear to dry very quickly; an effect that may lead to an increase in TTI due to poorer conduction between paddles and skin. This study was carried out to assess the effect of evaporative drying of defibrillation pads on TTI. Materials and methods: TTI was measured at 5–10 min intervals in 20 adult male volunteers across 3M defibrillation pads (2346N) placed in the anterior–apical position. Measurements of TTI were made at 30 kHz using a Bodystat® MultiScan 5000 monitor at end-expiration. A third pad was placed on the left precordium and its mass recorded each time a TTI measurement was made. Results: The median age of subjects was 22 years (range 21–52 years) and their median body mass index was 23.1 kg m?2 (range 18.4–42.8 kg m?2). Median room temperature was 23.0°C (range 19.0–24.0°C) and the median humidity was 31.0% (range 28.0–48.0%). 3M defibrillation pads had an initial mean mass of 25.14 g (S.D.±0.41 g). Changes in defibrillation pad mass due to evaporative loss occurred immediately and rapidly, with all measurements being significantly lower than the baseline value. Mean baseline TTI was 63.6 ? (S.D.±13.7 ?). After 30 min a statistically significant (P=0.012) rise of 1.4 ? (2.2%), was observed corresponding to a 12.6% decrease in pad mass, after which TTI continued to increase in a linear fashion. Conclusion: In the absence of a defibrillation current, 3M defibrillation pads can safely be left on the chest wall for at least 25 min in a typical hospital environment before evaporative drying results in a significant increase in transthoracic impedance
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