91 research outputs found
A Novel and Simple Method for Laboratory Diagnosis of Relapsing Fever Borreliosis
Relapsing fever caused by Borrelia bacteria is often obscured by malaria and incorrectly treated. Here a novel method for diagnosis is presented. The method is cheap, simple and requires minimal laboratory material. Despite its simplicity, the method shows surprisingly high sensitivity, detecting concentrations less than 10 bacteria/ml blood
Coevolution of non-fertile sperm and female receptivity in a butterfly.
Journal ArticlePublished versionOpen Access Article published originally in Biology Letters, October 2009, 5(5) pp 678-681, http://rsbl.royalsocietypublishing.org/content/5/5/678Sexual conflict can promote rapid evolution of male and female reproductive traits. Males of many polyandrous butterflies transfer nutrients at mating that enhances female fecundity, but generates sexual conflict over female remating due to sperm competition. Butterflies produce both normal fertilizing sperm and large numbers of non-fertile sperm. In the green-veined white butterfly, Pieris napi, non-fertile sperm fill the females' sperm storage organ, switching off receptivity and thereby reducing female remating. There is genetic variation in the number of non-fertile sperm stored, which directly relates to the female's refractory period. There is also genetic variation in males' sperm production. Here, we show that females' refractory period and males' sperm production are genetically correlated using quantitative genetic and selection experiments. Thus selection on male manipulation may increase the frequency of susceptible females to such manipulations as a correlated response and vice versa.Natural Environment Research Council (NERC)The Royal Societ
Coevolution of non-fertile sperm and female receptivity in a butterfly
Sexual conflict can promote rapid evolution of male and female reproductive traits. Males of many polyandrous butterflies transfer nutrients at mating that enhances female fecundity, but generates sexual conflict over female remating due to sperm competition. Butterflies produce both normal fertilizing sperm and large numbers of non-fertile sperm. In the green-veined white butterfly, Pieris napi, non-fertile sperm fill the females' sperm storage organ, switching off receptivity and thereby reducing female remating. There is genetic variation in the number of non-fertile sperm stored, which directly relates to the female's refractory period. There is also genetic variation in males' sperm production. Here, we show that females' refractory period and males' sperm production are genetically correlated using quantitative genetic and selection experiments. Thus selection on male manipulation may increase the frequency of susceptible females to such manipulations as a correlated response and vice versa
Tickborne Relapsing Fever Diagnosis Obscured by Malaria, Togo
Relapsing fever caused by Borrelia crocidurae and B. duttonii in Togo may be misdiagnosed
Fiberströ till mjölkkor – effekt på djurvälfärd, djurhälsa, mjölkkvalitet och kostnaden för strömedel
Genom att separera gödseln får man gödselfiber (fiberströ) som kan användas som strömedel till mjölkkorna. I denna studie jämförde vi 17 gårdar som använde fiberströ med 17 gårdar som använde såg-/kutterspån som strömedel i liggbås till mjölkkor. Fiberströ jämfört med såg-/kutterspån påverkade inte mjölkmängd, celltal i tankmjölk, djurvälfärd eller djurhälsa förutom att klövhälsan var bättre eftersom totala anmärkningar, klöveksem och klövsulesår var lägre. Totalantalet bakterier var högre i oanvänt fiberströ och i fiberströ från liggbåsen än för såg-/kutterspån men i tankmjölken var det ingen skillnad. Kostnaden för fiberströ varierade för gårdarna beroende på hur mycket fiberströ som producerades
A Novel Animal Model of Borrelia recurrentis Louse-Borne Relapsing Fever Borreliosis Using Immunodeficient Mice
Louse-borne relapsing fever (LBRF) borreliosis is caused by Borrelia recurrentis, and it is a deadly although treatable disease that is endemic in the Horn of Africa but has epidemic potential. Research on LBRF has been severely hampered because successful infection with B. recurrentis has been achieved only in primates (i.e., not in other laboratory or domestic animals). Here, we present the first non-primate animal model of LBRF, using SCID (-B, -T cells) and SCID BEIGE (-B, -T, -NK cells) immunocompromised mice. These animals were infected with B. recurrentis A11 or A17, or with B. duttonii 1120K3 as controls. B. recurrentis caused a relatively mild but persistent infection in SCID and SCID BEIGE mice, but did not proliferate in NUDE (-T) and BALB/c (wild-type) mice. B. duttonii was infectious but not lethal in all animals. These findings demonstrate that the immune response can limit relapsing fever even in the absence of humoral defense mechanisms. To study the significance of phagocytic cells in this context, we induced systemic depletion of such cells in the experimental mice by injecting them with clodronate liposomes, which resulted in uncontrolled B. duttonii growth and a one-hundred-fold increase in B. recurrentis titers in blood. This observation highlights the role of macrophages and other phagocytes in controlling relapsing fever infection. B. recurrentis evolved from B. duttonii to become a primate-specific pathogen that has lost the ability to infect immunocompetent rodents, probably through genetic degeneration. Here, we describe a novel animal model of B. recurrentis based on B- and T-cell-deficient mice, which we believe will be very valuable in future research on LBRF. Our study also reveals the importance of B-cells and phagocytes in controlling relapsing fever infection
Identification and Biosynthesis of Novel Male Specific Esters in the Wings of the Tropical Butterfly, Bicyclus martius sanaos
Fauna Europaea: Diptera -Brachycera
Link to publication Citation for published version (APA): Pape, T., Beuk, P., Pont, A. C., Shatalkin, A. I., Ozerov, A. L., Woźnica, A. J., ... de Jong, Y. (2015). Fauna Europaea: 3, [e4187]. https://doi.org/10.3897/BDJ.3.e4187 General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Abstract Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant multicellular European terrestrial and freshwater animals and their geographical distribution at the level of countries and major islands (east of the Urals and excluding the Caucasus region). The Fauna Europaea project comprises about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. Fauna Europaea represents a huge effort by more than 400 contributing taxonomic specialists throughout Europe and is a unique (standard) reference suitable for many user communities in science, government, industry, nature conservation and education. The Diptera-Brachycera is one of the 58 Fauna Europaea major taxonomic groups, and data have been compiled by a network of 55 specialists. Within the two-winged insects (Diptera), the Brachycera constitute a monophyletic group, which is generally given rank of suborder. The Brachycera may be classified into the probably paraphyletic 'lower brachyceran grade' and the monophyletic Eremoneura. The latter contains the Empidoidea, the Apystomyioidea with a single Nearctic species, and the Cyclorrhapha, which in turn is divided into the paraphyletic 'aschizan grade' and the monophyletic Schizophora. The latter is traditionally divided into the paraphyletic 'acalyptrate grade' and the monophyletic Calyptratae. Our knowledge of the European fauna of Diptera-Brachycera varies tremendously among families, from the reasonably well known hoverflies (Syrphidae) to the extremely poorly known scuttle flies (Phoridae). There has been a steady growth in our knowledge of European Diptera for the last two centuries, with no apparent slow down, but there is a shift towards a larger fraction of the new species being found among the families of the nematoceran grade (lower Diptera), which due to a larger number of small-sized species may be considered as taxonomically more challenging. Most of Europe is highly industrialised and has a high human population density, and the more fertile habitats are extensively cultivated. This has undoubtedly increased the extinction risk for numerous species of brachyceran flies, yet with the recent re-discovery of Thyreophora cynophila (Panzer), there are no known cases of extinction at a European level. However, few national Red Lists have extensive information on Diptera. For the Diptera-Brachycera, data from 96 families containing 11,751 species are included in this paper
Numerical Modelling of Fuel Sprays
The way the fuel is introduced into the combustion chamber is one of the most important parameters for the power output and the generation of emissions in the combustion of liquid fuels. The interaction beween the turbulent gas flow field and the liquid fuel droplets, the vaporisation of them and the mixing of the gaseous fuel with the ambient air that are vital parameters in the combustion process. The use of numerical calculations is an important tool to better understand these complex interacting phenomena. This thesis reports on the numerical modelling of fuel sprays in non-reacting cases using an own developed spray module. The spray module uses the stochastic parcel method to represent the spray. The module was made in such manner that it could by coupled with different gas flow solver. Results obtained from four different gas flow solver are presented in the thesis, including the use of two different kinds of turbulence models. In the first part the spray module is coupled with a k-epsilon based 2-D cylindrical gas flow solver. A thorough sensitivity analysis was performed on the spray and gas flow solver parameters, such as grid size dependence and sensitivity to initial values of k-epsilon. The results of the spray module were also compared to results from other spray codes, e.g. the well known KIVA code. In the second part of this thesis the spray was injected into a turbulent and fully developed crossflow studied. The spray module was attached to a LES (Large Eddy Simulation) based flow solvers enabling the study of the complex structures and time dependent phenomena involved in spray in crossflows. It was found that the spray performs an oscillatory motion and that the Strouhal number in the wake was about 0.1. Different spray breakup models were evaluated by comparing with experimental results
Review of the Nordic Gymnocheta Robineau-Desvoidy (Diptera, Tachinidae) with report of two species new to Europe
The genus Gymnocheta Robineau-Desvoidy, 1830 (Diptera, Tachinidae) has until now been represented by two species in Europe, G. viridis (Fallén, 1810) and G. magna Zimin, 1958. Two species are newly recorded from Finland and Sweden, Gymnocheta lucida Zimin, 1958 and G. zhelochovtsevi Zimin, 1958, both previously known only from the Russian Far East and Japan. These four European species are redescribed and illustrated, including the first description of the female of G. zhelochovtsevi. A key is provided to seven of the eight described species of Palaearctic Gymnocheta. The holotype of G. viridis was examined and found to differ from the present concept of the species, instead matching the concept of the more recently described G. magna. In the interests of nomenclatural stability, the two names are maintained in their current usage pending a request to the International Commission on Zoological Nomenclature to replace the current holotype of G. viridis with a neotype that corresponds to the long-established concept of that species
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