Electronic transport through a quantum dot network

The conductance through a finite quantum dot network is studied as a function of inter-dot coupling. As the coupling is reduced, the system undergoes a transition from the antidot regime to the tight binding limit, where Coulomb resonances with on average increasing charging energies are observed. Percolation models are used to describe the conduction in the open and closed regime and contributions from different blockaded regions can be identified. A strong negative average magnetoresistance in the Coulomb blockade regime is in good quantitative agreement with theoretical predictions for magnetotunneling between individual quantum dots.Comment: 5 pages, 5 figure

Apparatus for growing crystals

An improved apparatus and method for growing crystals from a melt employing a heat pipe, consisting of one or more sections, each section serving to control temperature and thermal gradients in the crystal as it forms inside the pipe

Effects of naturopathic medicines on Multiplate and ROTEM: a prospective experimental pilot study in healthy volunteers

Of patients undergoing surgery, 22 to 57 % have been reported to be using naturopathic medicines. Several of these medicines have been reported to increase bleeding or enhance the effect of other drugs that increase bleeding. The Swedish Medical Products Agency recommends cessation of the use of the naturopathic medicines echinacea, fish oil, ginkgo biloba, ginseng, St. John's wort, valeriana and garlic 2 weeks before surgery. The aim of this pilot study was to examine the effects of these 7 naturopathic medicines in healthy humans by utilising multiple electrode aggregometer (Multiplate) and viscoelastic rotational thromboelastometer (ROTEM) to obtain data for sample size calculation before a larger trial

Etude et modélisation des potentiels du SAR basse fréquence pour l'exploration de la sub-surface en contexte aride

La télédétection radar a connu un grand développement ces dernières années, majoritairement pour l'observation de la Terre, mais également pour l'exploration planétaire. Alors que l'essentiel des applications à ce jour concerne l'étude des surfaces, le SAR permet, sous certaines conditions d'aridité, de scruter les sous-sols et c'est cette capacité que nous avons étudié plus en détail. L'objectif de notre travail était de valider, de façon expérimentale et théorique, un ensemble de techniques et de méthodes permettant d'étudier et de caractériser le sous-sol à distance. A partir de l'étude de deux sites tests (le Pyla, France et la région de Bir Safsaf, Egypte), nos travaux ont permis de mettre en évidence des structures enfouies (interface géologique, humidité du sous-sol) par des signatures caractéristiques et d'évaluer les performances de tels systèmes, laissant entrevoir des champs d'applications nouveaux et très vastes : ressource en eau, cartographie géologique, archéologie, etc.Up to now, radar remote-sensing have been mostly used for Earth-Observation. It is now used in investigation projects on solar system bodies as well. Most of applications usually concern surfaces but, in arid conditions, the SAR can help souding and analyzing the subsurface, and we particularly focused on this ability. Using experimental and theoritical approaches, the aim of our work was to validate a set of techniques and methods in order to quantitatively study and characterize the subsurface structures. From studies performed on two test-sites (the Pyla Dune in France and the Bir Safsaf region in Egypt), we put in evidence the presence of embedded structures (geological interface, moisture) and determined their characteristics. We also estimated the penetrating performances of such systems and studied a typical signature of the subsurface moisture. Our results are of interest for a wide range of applications like water resources prospection, geological mapping, archeology, etc

Unproceedings of the Fourth .Astronomy Conference (.Astronomy 4), Heidelberg, Germany, July 9-11 2012

The goal of the .Astronomy conference series is to bring together astronomers, educators, developers and others interested in using the Internet as a medium for astronomy. Attendance at the event is limited to approximately 50 participants, and days are split into mornings of scheduled talks, followed by 'unconference' afternoons, where sessions are defined by participants during the course of the event. Participants in unconference sessions are discouraged from formal presentations, with discussion, workshop-style formats or informal practical tutorials encouraged. The conference also designates one day as a 'hack day', in which attendees collaborate in groups on day-long projects for presentation the following morning. These hacks are often a way of concentrating effort, learning new skills, and exploring ideas in a practical fashion. The emphasis on informal, focused interaction makes recording proceedings more difficult than for a normal meeting. While the first .Astronomy conference is preserved formally in a book, more recent iterations are not documented. We therefore, in the spirit of .Astronomy, report 'unproceedings' from .Astronomy 4, which was held in Heidelberg in July 2012.Comment: 11 pages, 1 figure, .Astronomy 4, #dotastr

Tuning the Nigerian Slit Gong

An experimental and theoretical investigation of the Nigerian slit gong is reported. It is shown that in tuning the gong the artisan ensures that the frequencies of the two lowest mechanical resonances are nearly coincident with the frequencies of two of the acoustic resonances of the internal cavity. Four possible tuning parameters are identified and the effects of changing these parameters is discussed

Responses of Birds to Humans at a Coastal Barrier Beach: Napatree Point, Rhode Island

Human activity is one of the most important factors affecting disturbance to birds that use coastal barrier beaches in southern New England. The barrier beach at Napatree Point, RI, provides important breeding habitat for several bird species, key stopover habitat for thousands of migrating shorebirds, and is also a popular destination for people. Anecdotal evidence suggested that walkers, joggers, dogs, and watercraft were disrupting birds that foraged and roosted at this site. Our objectives were to characterize the frequency and sources of disturbance to birds and use this information to develop management recommendations to minimize the frequency of human disturbances to birds at Napatree Point. We conducted 106 hours of observation from May through August in 2013. Of 211 flight responses, the most common sources of disturbance to birds were beach walkers (57.8%), motorboats (8.5%), kayaks (8.5%), bird watchers (7.6%), and anglers (6.2%). Birds typically flushed when pedestrians (e.g., walkers, bird watchers, and anglers) were within 39 ± 24 m (median ± inter-quartile range) and watercraft (e.g., motorboats and kayaks) were within 38 ± 33 m. Flight responses were positively correlated with the number of people on the beach and the number of boats in the area. Disturbances to birds peaked in July when human visitation was highest. Using a spatially explicit density map of flight-initiation distance vectors, we identified the most important area to set as a buffer zone for human access if managers seek to reduce the frequency of human disturbances to birds at Napatree Point

The Social Structure, Ecology and Pathogens of Bats in the UK

This thesis examines the ecology, parasites and pathogens of three insectivorous bat species in Wytham Woods, Oxfordshire; Myotis nattereri (Natterer’s bat), M. daubentonii (Daubenton’s bat) and Plecotus auritus (Brown long-eared bat). The population structure was assessed by monitoring associations between ringed individuals, utilising recent advances in social network analysis. Populations of both M. daubentonii and M. nattereri were found to subdivide into tight-knit social groups roosting within small areas of a continuous woodland (average minimum roost home range of 0.23km2 and 0.17km2 respectively). If this population structure is a general attribute of these species it may make them more sensitive to small scale habitat change than previously thought and has implications for how diseases may spread through the population. M. daubentonii had a strong preference for roosts close to water, away from woodland edge and in areas with an easterly aspect. The factors driving roost choice in M. nattereri and P. auritus remain elusive. The segregation of M. daubentonii into bachelor and nursery colonies was not a result of the exclusion of males from roosts close to water by females, or variation in microclimate preferences between the sexes, as was predicted. Body condition (weight/forearm length) was correlated with host characteristics including age and reproductive status, and weather variables. Astroviruses and Coronaviruses, which have characteristics typical of zoonotic viruses, were identified in UK bat species for the first time. Coronaviruses identified formed species-specific clades while Astroviruses were highly diverse. Though not closely related to human viruses these are potential zoonotic diseases of the future. Models of Coronavirus and ectoparasite distribution suggest individual attributes (e.g. sex and age) and population structure (e.g. the formation of nursery and bachelor colonies) are important predictors of parasite and pathogen prevalence. This study characterises a system that offers many opportunities for future research including studies of sociality, disease modelling and conservation management

Study of some factors affecting efficiency of reproduction in dairy cattle serviced by artificial insemination

This bulletin is a report on Department of Dairy Husbandry research project number 89 entitled 'Increasing the effectiveness of artificial insemination as a means of improving dairy cattle'--P. [2].Includes bibliographical references (pages 40-42)