Active-distributed temperature sensing to continuously quantify vertical flow in boreholes

We show how a distributed borehole flowmeter can be created from armored Fiber Optic cables with the Active-Distributed Temperature Sensing (A-DTS) method. The principle is that in a flowing fluid, the difference in temperature between a heated and unheated cable is a function of the fluid velocity. We outline the physical basis of the methodology and report on the deployment of a prototype A-DTS flowmeter in a fractured rock aquifer. With this design, an increase in flow velocity from 0.01 to 0.3 m s−1 elicited a 2.5°C cooling effect. It is envisaged that with further development this method will have applications where point measurements of borehole vertical flow do not fully capture combined spatiotemporal dynamics

Distributed temperature sensing as a down-hole tool in hydrogeology

Distributed Temperature Sensing (DTS) technology enables down-hole temperature monitoring to study hydrogeological processes at unprecedentedly high frequency and spatial resolution. DTS has been widely applied in passive mode in site investigations of groundwater flow, in-well flow, and subsurface thermal property estimation. However, recent years have seen the further development of the use of DTS in an active mode (A-DTS) for which heat sources are deployed. A suite of recent studies using A-DTS down-hole in hydrogeological investigations illustrate the wide range of different approaches and creativity in designing methodologies. The purpose of this review is to outline and discuss the various applications and limitations of DTS in down-hole investigations for hydrogeological conditions and aquifer geological properties. To this end, we first review examples where passive DTS has been used to study hydrogeology via down-hole applications. Secondly, we discuss and categorize current A-DTS borehole methods into three types. These are thermal advection tests, hybrid cable flow logging, and heat pulse tests. We explore the various options with regards to cable installation, heating approach, duration, and spatial extent in order to improve their applicability in a range of settings. These determine the extent to which each method is sensitive to thermal properties, vertical in well flow, or natural gradient flow. Our review confirms that the application of DTS has significant advantages over discrete point temperature measurements, particularly in deep wells, and highlights the potential for further method developments in conjunction with other emerging fiber optic based sensors such as Distributed Acoustic Sensing. This article is protected by copyright. All rights reserved

Genetic variability of the neogregarine apicystis bombi, an etiological agent of an emergent bumblebee disease

The worldwide spread of diseases is considered a major threat to biodiversity and a possible driver of the decline of pollinator populations, particularly when novel species or strains of parasites emerge. Previous studies have suggested that populations of introduced European honeybee (Apis mellifera) and bumblebee species (Bombus terrestris and Bombus ruderatus) in Argentina share the neogregarine parasite Apicystis bombi with the native bumblebee (Bombus dahlbomii). In this study we investigated whether A. bombi is acting as an emergent parasite in the non-native populations. Specifically, we asked whether A. bombi, recently identified in Argentina, was introduced by European, non-native bees. Using ITS1 and ITS2 to assess the parasite's intraspecific genetic variation in bees from Argentina and Europe, we found a largely unstructured parasite population, with only 15% of the genetic variation being explained by geographic location. The most abundant haplotype in Argentina (found in all 9 specimens of non-native species) was identical to the most abundant haplotype in Europe (found in 6 out of 8 specimens). Similarly, there was no evidence of structuring by host species, with this factor explaining only 17% of the genetic variation. Interestingly, parasites in native Bombus ephippiatus from Mexico were genetically distant from the Argentine and European samples, suggesting that sufficient variability does exist in the ITS region to identify continent-level genetic structure in the parasite. Thus, the data suggest that A. bombi from Argentina and Europe share a common, relatively recent origin. Although our data did not provide information on the direction of transfer, the absence of genetic structure across space and host species suggests that A. bombi may be acting as an emergent infectious disease across bee taxa and continents

Evaluating children's interactive products: principles and practices for interaction designers

Interactive products designed for childrenwhether toys, games, educational products, or websitesare increasingly embedded in childrens lives and school experiences. Making these products safe, effective, and entertaining requires new methodologies for carrying out sound and unbiased evaluations for these users with unique requirements, environments, and ethical considerations. This book directly addresses this need by thoroughly covering the evaluation of all types of interactive technology for children. Based on the authors' workshops, conference courses, and own design experience and research, this highly practical book reads like a handbook, while being thoroughly grounded in the latest research. Throughout, the authors illustrate techniques and principles with numerous mini case studies and highlight practical information in tips and exercises and conclude with three in-depth case studies. Essential reading for usability experts, product developers, and researchers in the field. * Presents an essential background in child development and child psychology, particularly as they relate to technology. * Captures best practices for observing and surveying children, training evaluators, and capturing the child user experience using audio and visual technology. * Examines ethical and legal issues involved in working with children and offers guidelines for effective risk management

Evaluating Interactive Products with and for Children

Interactive products designed for children—whether toys, games, educational products, or websites—are increasingly embedded in children’s lives and school experiences. Making these products safe, effective, and entertaining requires new methodologies for carrying out sound and unbiased evaluations for these users with unique requirements, environments, and ethical considerations. This book directly addresses this need by thoroughly covering the evaluation of all types of interactive technology for children. Based on the authors' workshops, conference courses, and own design experience and research, this highly practical book reads like a handbook, while being thoroughly grounded in the latest research. Throughout, the authors illustrate techniques and principles with numerous mini case studies and highlight practical information in tips and exercises and conclude with three in-depth case studies. Essential reading for usability experts, product developers, and researchers in the field

Thigh-length compression stockings and DVT after stroke

Controversy exists as to whether neoadjuvant chemotherapy improves survival in patients with invasive bladder cancer, despite randomised controlled trials of more than 3000 patients. We undertook a systematic review and meta-analysis to assess the effect of such treatment on survival in patients with this disease

Synthrusting metamorphism, cooling, and erosion of the Himalayan Kathmandu Complex, Nepal

In this paper we tackle some of the outstanding problems of the Himalaya, in particular the external zone in the Kathmandu Complex, using an integrated approach involving field mapping, microstructure, thermobarometry, and geochronology. The result is a new model showing the evolution of one major Main Central Thrust: therefore we refute suggestions that the Kathmandu Complex is a klippe or separate thrust sheet. Compared to the Main Central Thrust sheet in the High Himalaya, the Kathmandu Complex shows differences in deformational and metamorphic features and timing of metamorphism that are consistent with its position some 100 km south of the High Himalaya, fairly near the leading edge. Unless there was substantial volume loss between the time of peak metamorphism and the beginning of thrusting then our geobarometry results indicate that the Main Central Thrust wedge was similar to 40 km thick on the northern side of the Kathmandu Complex and &lt;20 km thick on me southern margin. Initiation of the: Main Central Thrust occurred at &lt;similar to&gt;22 Ma possibly during the closing stages of peak amphibolite facies metamorphism; slip at elevated temperature (500 degrees -600 degreesC) continued until similar to 14 Ma. This is a little longer than has previously been proposed. In marked contrast to the famous inverted metamorphism on the Main Central Thrust in the High Himalaya, the metamorphic zonal scheme in the Kathmandu Complex is right way up with the exception of a thin zone of greenschist facies thrust related dynamically metamorphosed rocks at the base. These mylonites postdate the high-grade regional amphibolite metamorphism and give an illusion of inverted metamorphism. A likely reason for the contrast is that the Main Central Thrust cut up section toward the foreland and therefore at Kathmandu, carries high levels in the metamorphic structure. Our model involves reactivation of the Main Central Thrust at 7-8 Ma as inferred from published monazite and mica ages, but because the Kathmandu rocks show no evidence for high-temperature reactivation at this time, we presume that the: late reactivation involved only the internal High Himalaya zone while the Main Central Thrust was inactive in the external Kathmandu zone. We attempt to quantify rates of cooling, exhumation and thrusting during rime period 22 Ma to the present.</p