Reliable, precise and accurate estimates of disease severity are important for predicting yield loss, monitoring and forecasting epidemics, for assessing crop germplasm for disease resistance, and ...for understanding fundamental biological processes including co-evolution. Disease assessments that are inaccurate and/or imprecise might lead to faulty conclusions being drawn from the data, which in turn can lead to incorrect actions being taken in disease management decisions. Plant disease can be quantified in several different ways. This review considers plant disease severity assessment at the scale of individual plant parts or plants, and describes our current understanding of the sources and causes of assessment error, a better understanding of which is required before improvements can be targeted. The review also considers how these can be identified using various statistical tools. Indeed, great strides have been made in the last thirty years in identifying the sources of assessment error inherent to visual rating, and this review highlights ways that assessment errors can be reduced-particularly by training raters or using assessment aids. Lesion number in relation to area infected is known to influence accuracy and precision of visual estimates-the greater the number of lesions for a given area infected results in more overestimation. Furthermore, there is a widespread tendency to overestimate disease severity at low severities (<10%). Both interrater and intrarater reliability can be variable, particularly if training or rating aids are not used. During the last eighty years acceptable accuracy and precision of visual disease assessments have often been achieved using disease scales, particularly because of the time they allegedly save, and the ease with which they can be learned, but recent work suggests there can be some disadvantages to their use. This review considers new technologies that offer opportunity to assess disease with greater objectivity (reliability, precision, and accuracy). One of these, visible light photography and digital image analysis has been increasingly used over the last thirty years, as software has become more sophisticated and user-friendly. Indeed, some studies have produced very accurate estimates of disease using image analysis. In contrast, hyperspectral imagery is relatively recent and has not been widely applied in plant pathology. Nonetheless, it offers interesting and potentially discerning opportunities to assess disease. As plant disease assessment becomes better understood, it is against the backdrop of concepts of reliability, precision and accuracy (and agreement) in plant pathology and measurement science. This review briefly describes these concepts in relation to plant disease assessment. Various advantages and disadvantages of the different approaches to disease assessment are described. For each assessment method some future research priorities are identified that would be of value in better understanding the theory of disease assessment, as it applies to improving and fully realizing the potential of image analysis and hyperspectral imagery.
We investigate, for two water models displaying a liquid-liquid critical point, the relation between changes in dynamic and ther-modynamic anomalies arising from the presence of the liquid-liquid ...critical point. We find a correlation between the dynamic crossover and the locus of specific heat maxima$C_{P}^{max}$("Widom line") emanating from the critical point. Our findings are consistent with a possible relation between the previously hypothesized liquid-liquid phase transition and the transition in the dynamics recently observed in neutron scattering experiments on confined water. More generally, we argue that this connection between$C_{P}^{max}$and dynamic crossover is not limited to the case of water, a hydrogen bond network-forming liquid, but is a more general feature of crossing the Widom line. Specifically, we also study the Jagla potential, a spherically symmetric two-scale potential known to possess a liquid-liquid critical point, in which the competition between two liquid structures is generated by repulsive and attractive ramp interactions.
Supercooled water exhibits a breakdown of the Stokes-Einstein relation between the diffusion constant D and the alpha relaxation time τα. For water simulated with two different potentials, TIP5P and ...ST2, we find that the temperature of the decoupling of diffusion and alpha relaxation correlates with the temperature of the maximum in specific heat that corresponds to crossing the Widom line TW(P). Specifically, we find that our results for Dτα/T collapse onto a single "master curve" if temperature is replaced by T - TW(P). We further find that the size of the mobile molecule clusters (dynamical heterogeneities) increases sharply near TW(P). Moreover, our calculations of mobile particle cluster size <n(t*)>w for different pressures, where t* is the time for which the mobile particle cluster size is largest, also collapse onto a single master curve if T is replaced by T - TW(P). The crossover to a more locally structured low density liquid (LDL) as T rightward arrow TW(P) appears to be well correlated both with the breakdown of the Stokes-Einstein relation and with the growth of dynamic heterogeneities. Our results are consistent with the possibility that the breakdown of the SE relation in supercooled water at low pressures is associated with the hypothesized liquid-liquid phase transition.
Abstract
Exercise referral schemes aim to increase physical activity amongst inactive individuals with or at risk of long-term health conditions. Yet many patients referred to these schemes (by ...health professionals) fail to take up the exercise opportunities on offer. Understanding factors influencing uptake to exercise referral schemes may help improve future attendance. Using the Socio-Ecological Model as a framework, this qualitative study aimed to explore factors influencing uptake to an exercise referral scheme based in the North West of England. Semi-structured interviews were conducted with referred patients (n = 38) about their reasons for referral, interactions with referring health professionals, events following referral and ideas to improve future uptake. Data were analysed thematically and mapped onto the constructs of the Socio-Ecological Model. Factors reported to influence uptake included intrapersonal (past PA experiences, motivation, competing priorities), interpersonal (scheme explanations, support) and organizational influences (scheme promotion, communication between service, cost). Whilst several intrapersonal-level factors influenced patient decisions to uptake the exercise referral scheme, modifiable interpersonal and organizational factors were identified as potential targets for intervention. Recommendations are made for improving awareness of exercise referral schemes and for enhancing communication between referring practitioners, patients and referral scheme staff.
This European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) position statement provides a comprehensive guide for health care providers to manage percutaneous endoscopic ...gastrostomy tubes in a safe, effective, and appropriate way.
Relevant literature from searches of PubMed, CINAHL, and recent guidelines was reviewed. In the absence of evidence, recommendations reflect the expert opinion of the authors. Final consensus was obtained by multiple e-mail exchange and during 3 face-to-face meetings of the gastroenterology committee of the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition.
Endoscopically placed gastrostomy devices are essential in the management of children with feeding and nutritional problems. The article focuses on practical issues such as indications and contraindications.
The decision to place an endoscopic gastrostomy has to be made by an appropriate multidisciplinary team, which then provides active follow-up and care for the child and the device.
Polymorphic Phase Transitions in Liquids and Glasses Poole, Peter H.; Grande, Tor; Angell, C. Austen ...
Science (American Association for the Advancement of Science),
01/1997, Letnik:
275, Številka:
5298
Journal Article
Recenzirano
The possibilities of observing liquid polymorphism are examined. Theoretical and computer simulation studies provide evidence for polymorphism in tetrahedral liquids.
Elephants are capable of vocal learning Poole, Joyce H; Tyack, Peter L; Stoeger-Horwath, Angela S ...
Nature (London),
03/2005, Letnik:
434, Številka:
7032
Journal Article
Recenzirano
There are a few mammalian species that can modify their vocalizations in response to auditory experience -- for example, some marine mammals use vocal imitation for reproductive advertisement, as ...birds sometimes do. Here we describe two examples of vocal imitation by African savannah elephants, Loxodonta africana, a terrestrial mammal that lives in a complex fission-fusion society. Our findings favour a role for vocal imitation that has already been proposed for primates, birds, bats and marine mammals: it is a useful form of acoustic communication that helps to maintain individual-specific bonds within changing social groupings. PUBLICATION ABSTRACT
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