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81.
B K McNab 《The Quarterly review of biology》1988,63(1):25-54
The scaling of the basal rate of metabolism in mammals is reexamined. Both the power and level of the scaling function are sensitive to various factors that interact with body mass and rate of metabolism, including the precision of temperature regulation, food habits, and activity level. This sensitivity implies that the rate of metabolism is a highly plastic character in the course of evolution. Consequently, the singular effect of mass on the rate of metabolism is most effectively analyzed in ecologically and physiologically uniform sets of species, rather than in taxonomically defined groups, which often are ecologically and physiologically diverse. Otherwise, all fitted curves for mammals integrate a variety of competing factors, thereby reflecting the species used and denying unique analytic significance to the power in scaling relations. Kleiber's eutherian curve may represent a relatively uniform set of data because all the species included were domesticated and because selection for high rates of production (and high rates of metabolism) occurred in the process of domestication. In the analysis of scaling relationships, the standard error of estimate (Sy.x) is a more valuable measure of the residual variation than is (1.0-r2) because r2 is a non-linear measure of the conformation of data to the relation and because Sy.x, unlike r2, is independent of the units used in the scaling relationship. At present the best estimate indicates that total rate of metabolism scales proportionally to approximately m0.60 at small masses (less than 300 g), as long as small species do not enter torpor, and scales proportionally to approximately m0.75 at large masses (greater than or equal to 300 g). Physiological properties other than metabolism are potentially sensitive to secondary factors, so their scaling functions also would be most clearly defined for physiologically uniform groups of species. This view suggests that insight into the significance of scaling relations can be obtained by examining the residual variation around a scaling function as well as by examining conformation to the function. 相似文献
82.
Harriet R. Brown Peter Zeidman Peter Smittenaar Rick A. Adams Fiona McNab Robb B. Rutledge Raymond J. Dolan 《PloS one》2014,9(7)
By 2015, there will be an estimated two billion smartphone users worldwide. This technology presents exciting opportunities for cognitive science as a medium for rapid, large-scale experimentation and data collection. At present, cost and logistics limit most study populations to small samples, restricting the experimental questions that can be addressed. In this study we investigated whether the mass collection of experimental data using smartphone technology is valid, given the variability of data collection outside of a laboratory setting. We presented four classic experimental paradigms as short games, available as a free app and over the first month 20,800 users submitted data. We found that the large sample size vastly outweighed the noise inherent in collecting data outside a controlled laboratory setting, and show that for all four games canonical results were reproduced. For the first time, we provide experimental validation for the use of smartphones for data collection in cognitive science, which can lead to the collection of richer data sets and a significant cost reduction as well as provide an opportunity for efficient phenotypic screening of large populations. 相似文献
83.
Analytical data for the gum exudates from Acacia difficilis, A. dimidiata, A. eriopoda, A. maidenii, A. stipuligera, A. torulosa and A. tumida are presented. Of these, five are highly proteinaceous; they also have high methoxyl contents and very low rhamnose contents. In contrast, A. dimidiata shows no unusual analytical parameters, and A. maidenii gum has alowarabinose content and a high rhamnose content, thus having a sugar composition of the type first observed in the gum from A. saligna. The gum from A. maidenii is also of interest as its analytical data are closely similar to those for A. longifolia, the only other tetramerous member of the subseries Juliflorae to have been studied. The data reported extend even further the unusual ranges of analytical parameters found within the Juliflorae, and confirm its great heterogeneity and chemotaxonomic interest. 相似文献
84.
Fernanda C. Dórea C. Anne Muckle David Kelton JT. McClure Beverly J. McEwen W. Bruce McNab Javier Sanchez Crawford W. Revie 《PloS one》2013,8(3)
Background
Recent focus on earlier detection of pathogen introduction in human and animal populations has led to the development of surveillance systems based on automated monitoring of health data. Real- or near real-time monitoring of pre-diagnostic data requires automated classification of records into syndromes–syndromic surveillance–using algorithms that incorporate medical knowledge in a reliable and efficient way, while remaining comprehensible to end users.Methods
This paper describes the application of two of machine learning (Naïve Bayes and Decision Trees) and rule-based methods to extract syndromic information from laboratory test requests submitted to a veterinary diagnostic laboratory.Results
High performance (F1-macro = 0.9995) was achieved through the use of a rule-based syndrome classifier, based on rule induction followed by manual modification during the construction phase, which also resulted in clear interpretability of the resulting classification process. An unmodified rule induction algorithm achieved an F1-micro score of 0.979 though this fell to 0.677 when performance for individual classes was averaged in an unweighted manner (F1-macro), due to the fact that the algorithm failed to learn 3 of the 16 classes from the training set. Decision Trees showed equal interpretability to the rule-based approaches, but achieved an F1-micro score of 0.923 (falling to 0.311 when classes are given equal weight). A Naïve Bayes classifier learned all classes and achieved high performance (F1-micro = 0.994 and F1-macro = .955), however the classification process is not transparent to the domain experts.Conclusion
The use of a manually customised rule set allowed for the development of a system for classification of laboratory tests into syndromic groups with very high performance, and high interpretability by the domain experts. Further research is required to develop internal validation rules in order to establish automated methods to update model rules without user input. 相似文献85.
A comparison of isoprene and monoterpene emission rates from the perennial bioenergy crops short‐rotation coppice willow and Miscanthus and the annual arable crops wheat and oilseed rape
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Biogenic volatile organic compounds (BVOC) emissions from bioenergy crops may differ from those of conventional crops. We compared emission rates of isoprene and a number of monoterpenes from the lignocellulosic bioenergy crops short‐rotation coppice (SRC) willow and Miscanthus, with the conventional crops wheat and oilseed rape. BVOC emission rates were measured via dynamic vegetation enclosure and GC‐MS analysis approximately monthly between April 2010 and August 2012 at a location in England and from SRC willow at two locations in Scotland. The largest BVOC emission rates were measured from willow in England and varied between years. Isoprene emission rates varied between μg g?1 h?1. Of the monoterpenes detected from willow, α‐pinene emission rates were highest (μg g?1 h?1), followed by μg g?1 h?1 for δ‐3‐carene, μg g?1 h?1 for β‐pinene and μg g?1 h?1 for limonene. BVOC emission rates measured in Scotland were much lower. Low emission rates of isoprene and α‐pinene were measured from Miscanthus in 2010 (μg g?1 h?1 and μg g?1 h?1, respectively) but were not detected in subsequent years. Emission rates from wheat of isoprene were negligible but relatively high for monoterpenes (μg g?1 h?1 and μg g?1 h?1 for α‐pinene and limonene, respectively). No significant emission rates of BVOCs were measured from oilseed rape. The measured emission rates followed a clear seasonal trend. Crude extrapolations based solely on data gathered here indicate that isoprene emissions from willow could correspond to 0.004–0.03% (UK) and 0.76–5.5% (Europe) of current global isoprene if 50% of all land potentially available for bioenergy crops is planted with willow. 相似文献
86.
Dino Numerato Giovanni Fattore Fabrizio Tediosi Rinaldo Zanini Mikko Peltola Helen Banks Péter Mihalicza Liisa Lehtonen Sofia Sveréus Richard Heijink S?ren Toksvig Klitkou Eilidh Fletcher Amber van der Heijden Fredrik Lundberg Eelco Over Unto H?kkinen Timo T. Sepp?l? 《PloS one》2015,10(6)
The objective of this paper was to compare health outcomes and hospital care use of very low birth weight (VLBW), and very preterm (VLGA) infants in seven European countries. Analysis was performed on linkable patient-level registry data from seven European countries between 2006 and 2008 (Finland, Hungary, Italy (the Province of Rome), the Netherlands, Norway, Scotland, and Sweden). Mortality and length of stay (LoS) were adjusted for differences in gestational age (GA), sex, intrauterine growth, Apgar score at five minutes, parity and multiple births. The analysis included 16,087 infants. Both the 30-day and one-year adjusted mortality rates were lowest in the Nordic countries (Finland, Sweden and Norway) and Scotland and highest in Hungary and the Netherlands. For survivors, the adjusted average LoS during the first year of life ranged from 56 days in the Netherlands and Scotland to 81 days in Hungary. There were large differences between European countries in mortality rates and LoS in VLBW and VLGA infants. Substantial data linkage problems were observed in most countries due to inadequate identification procedures at birth, which limit data validity and should be addressed by policy makers across Europe. 相似文献
87.
Structure-Guided Approach to Relieving Transcriptional Repression in Resistance to Thyroid Hormone α
Beatriz Romartinez-Alonso Maura Agostini Heulyn Jones Jayde McLellan D. Eilidh Sood Nicholas Tomkinson Federica Marelli Ilaria Gentile W. Edward Visser Erik Schoenmakers Louise Fairall Martin Privalsky Carla Moran Luca Persani Krishna Chatterjee John W. R. Schwabe 《Molecular and cellular biology》2022,42(2)
88.
Rate of oxygen consumption was measured in five bulbuls (Family Pycnonotidae) from western Uganda to evaluate whether this group is indeed characterized by the very low basal rates of metabolism previously reported. For three of these species, body temperature and rate of metabolism were measured as a function of ambient temperature from 10°C to 35°C. In these species body temperature was highly variable, and declined with ambient temperature in Andropadus virens. Such variation, in conjunction with behavioral adjustments, may reduce heat loss at low ambient temperatures. Body mass accounted for 98 percent of the variation in the basal rates of metabolism presented here. Basal rates in these species ranged from 81 to 90 percent of values predicted by the Aschoff–Pohl relationship for passerines, whereas previous measurements ranged from 56 to 72 percent of predicted values. This difference may reflect differences in species or measurement techniques, which, if the latter, suggests that the reduction in metabolic rate in this family may be less than originally thought. These data underline the importance of continued data collection on the metabolism of tropical birds, few of which have been measured to date. 相似文献
89.
Epidemiological Typing of Campylobacter Isolates from Meat Processing Plants by Pulsed-Field Gel Electrophoresis, Fatty Acid Profile Typing, Serotyping, and Biotyping
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M. Steele B. McNab L. Fruhner S. DeGrandis D. Woodward J. A. Odumeru 《Applied microbiology》1998,64(7):2346-2349
Campylobacter spp. are a leading cause of bacterial gastroenteritis. Foods of animal origin, particularly undercooked poultry, are common sources of Campylobacter species associated with disease in humans. A collection of 110 Campylobacter jejuni and 31 C. coli human and environmental isolates from different Ontario, Canada, abattoirs were analyzed by pulsed-field gel electrophoresis, fatty acid profile typing, and biotyping. Previously collected serotyping data for the same isolates were also analyzed in this study. Pulsed-field gel electrophoresis was found to be the most discriminatory of the typing methods, followed by serotyping, fatty acid profile typing, and biotyping. A wide variety of typing profiles were observed within the isolates, suggesting that several different Campylobacter sp. strains were present within the abattoirs. 相似文献
90.
Australian gum specimens from Acacia saliciformis, A. xanthina, A. rostellifera, A. murrayana (two specimens differing in the mode of initiation of gum exudation), A. georginae, A. cyclops, A. implexa, and an un-named species (Maslin ‘P31’) have been analysed. The first four of these are placed within Bentham's Series 1, subseries 6F, A. georginae within subseries 7E, and the remainder within subseries 7F. These data extend considerably the ranges of the analytical parameters reported previously for phyllodine species. The molecular weights of the gums from A. cyclops and A. implexa are much higher than those reported earlier for South African specimens; this may affect some taxonomic deductions based on their examination. The gum composition of A. saligna can no longer be regarded as atypical of a phyllodinous species; a suggestion that A. saligna should be transferred to the section Juliflorae may require reconsideration. The major difference between the specimens of gum from A. murrayana lies in their nitrogenous content. Data are reported for the amino acid compositions of the gums from A. saliciformis and A. xanthina. 相似文献