41 research outputs found

    Cluster Approximation for the Farey Fraction Spin Chain

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    We consider the Farey fraction spin chain in an external field hh. Utilising ideas from dynamical systems, the free energy of the model is derived by means of an effective cluster energy approximation. This approximation is valid for divergent cluster sizes, and hence appropriate for the discussion of the magnetizing transition. We calculate the phase boundaries and the scaling of the free energy. At h=0h=0 we reproduce the rigorously known asymptotic temperature dependence of the free energy. For h0h \ne 0, our results are largely consistent with those found previously using mean field theory and renormalization group arguments.Comment: 17 pages, 3 figure

    Use of gonadotropin releasing hormone (GnRH) vaccines for behavioural and reproductive control in managed Asian elephant Elephas maximus and African elephant Loxodonta africana populations

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    Because of their size and reproductive anatomy, surgical castration is not a practical option in adult elephants. However, similar to other species in human care, the effects of gonadectomy are desired in specific situations. This may be for contraceptive purposes, or for behavioural or veterinary management of elephants in human care or wild elephants managed in small reserves. Research into non‐surgical contraceptive measures for wild and domestic animals has resulted in an array of hormonal and immunological options to downregulate gonadal function. Driven by the production‐animal industry, commercial gonadotrophin releasing hormone (GnRH) vaccines are readily and cheaply available. This immunocontraceptive is effective in both males and females as it inhibits gonadotrophic hormone release and, thus, downstream stimulation of testicles and ovaries. Here, available studies from the past 10 years on the GnRH vaccine application in male and female elephants are reviewed. Furthermore, we add our own experience gathered from the treatment of male African elephants Loxodonta africana and female Asian elephants Elephas maximus in human care. The GnRH vaccine offers a viable approach for various management purposes. It should be noted that the GnRH vaccine was not primarily designed as a reversible contraceptive. Therefore, its use must be well justified on an individual basis and the effects closely monitored.https://zslpublications.onlinelibrary.wiley.com/journal/174810902020-07-01hj2020Anatomy and PhysiologyProduction Animal Studie

    Nonhuman primates across sub-Saharan Africa are infected with the yaws bacterium Treponema pallidum subsp. pertenue

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    Dear Editor, The bacterium Treponema pallidum (TP) causes human syphilis (subsp. pallidum; TPA), bejel (subsp. endemicum; TEN), and yaws (subsp. pertenue; TPE) (1). Although syphilis has reached a worldwide distribution (2), bejel and yaws have remained endemic diseases. Bejel affects individuals in dry areas of Sahelian Africa and Saudi Arabia, whereas yaws affects those living in the humid tropics (1). Yaws is currently reported as endemic in 14 countries, and an additional 84 countries have a known history of yaws but lack recent epidemiological data (3,4). Although this disease was subject to global eradication efforts in the mid-20th century, it later reemerged in West Africa, Southern Asia, and the Pacific region (5). New large-scale treatment options triggered the ongoing second eradication campaign, the goal of which is to eradicate yaws globally by 2020 (5). References: (1) Giacani, L. & Lukehart, S.A. The endemic treponematoses. Clin. Microbiol. Rev. 27, 89–115 (2014). (2) Arora, N. et al. Origin of modern syphilis and emergence of a pandemic Treponema pallidum cluster. Nat. Microbiol. 2, 16245 (2016). (3) Marks, M. Yaws: towards the WHO eradication target. Trans. R Soc. Trop. Med. Hyg. 110, 319–320 (2016). (4) World Health Organization. Eradication of yaws: procedures for verification and certification of interruption of transmission (World Health Organization, Geneva, 2018). (5) Asiedu, K., Fitzpatrick, C. & Jannin, J. Eradication of yaws: historical efforts and achieving WHO’s 2020 target. PLoS Negl. Trop. Dis. 8, e3016 (2014)

    Verbleib von Soziologie-AbsolventInnen der Philipps-Universität Marburg

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    Soziologie ist an der Philipps-Universität in den 1960er Jahren als akademisches Studienfach entstanden und ab 1972 ausgebaut worden. Neben den beiden Kernbereichen 'Soziologische Theorien' und 'Methoden empirischer Sozialforschung' konnten Studierende Ende der 1990er Jahre zwischen sechs speziellen Soziologien ihre Schwerpunktsetzung wählen. Nach 30 Jahren Soziologie-Studium in Marburg erschien es sinnvoll, Daten und Informationen über den Verbleib der bisherigen Absolventinnen und Absolventen zusammenzutragen. Dieser Aufgabe stellte sich eine Gruppe von Soziologiestudierenden im Grundstudium (2./3. bzw. 3./4. Fachsemester) zusammen mit ihrem Tutor und ihrer Dozentin im Rahmen eines über zwei Semester laufenden Empirischen Praktikums (Oktober 2003 bis Juli 2004). In Anlehnung an Verbleibs- und Studienabbruchs-Studien anderer Hochschulen wurden Fragestellungen für verschiedene Teiluntersuchungen und Erhebungsinstrumente entwickelt, Interviewtechniken trainiert, Daten erhoben und quantitativ bzw. qualitativ ausgewertet sowie der abschließende Forschungsbericht geschrieben. Die Grundgesamtheit wurde (wegen der schwierigen Adressrecherche) auf die Abschlussjahrgänge 1990 bis 2003 beschränkt. Durchgeführt wurden: eine postalische Fragebogenuntersuchung aller erreichbaren AbsolventInnen (realisiert 88 Befragungen); drei berufsbiografische Interviews mit AbsolventInnenen der Jahre 1991-1996-2001; vier perspektivische Leitfadeninterviews (problemzentriert) mit AbsolventInnen des Jahres 2003; zwei Leitfadeninterviews mit einem Abbrecher bzw. einem Studienfachwechsler; Experteninterviews mit potenziellen ArbeitgebervertreterInnen. Für die Analysen wurden je nach Datenstandard statistische Verfahren, qualitative Inhaltsanalyse oder sequenzielle Analyse eingesetzt. Die Befunde ermöglichen Einschätzungen hinsichtlich der damaligen Diplom- und Magisterstudiengänge in Marburg - hinsichtlich Bachelor- und Master-Studiengängen oder für andere Hochschulen müsste eine Studie entsprechend modifiziert werden

    Consolidated briefing of biochemical ethanol production from lignocellulosic biomass

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    AbstractBioethanol production is one pathway for crude oil reduction and environmental compliance. Bioethanol can be used as fuel with significant characteristics like high octane number, low cetane number and high heat of vaporization. Its main drawbacks are the corrosiveness, low flame luminosity, lower vapor pressure, miscibility with water, and toxicity to ecosystems. One crucial problem with bioethanol fuel is the availability of raw materials. The supply of feedstocks for bioethanol production can vary season to season and depends on geographic locations. Lignocellulosic biomass, such as forest-based woody materials, agricultural residues and municipal waste, is prominent feedstock for bioethanol cause of its high availability and low cost, even though the commercial production has still not been established. In addition, the supply and the attentive use of microbes render the bioethanol production process highly peculiar. Many conversion technologies and techniques for biomass-based ethanol production are under development and expected to be demonstrated. In this work a technological analysis of the biochemical method that can be used to produce bioethanol is carried out and a review of current trends and issues is conducted

    Complete genome sequences of two strains of Treponema pallidum subsp. pertenue from Indonesia: Modular structure of several treponemal genes.

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    BACKGROUND:Treponema pallidum subsp. pertenue (TPE) is the causative agent of yaws, a multistage disease endemic in tropical regions in Africa, Asia, Oceania, and South America. To date, seven TPE strains have been completely sequenced and analyzed including five TPE strains of human origin (CDC-2, CDC 2575, Gauthier, Ghana-051, and Samoa D) and two TPE strains isolated from the baboons (Fribourg-Blanc and LMNP-1). This study revealed the complete genome sequences of two TPE strains, Kampung Dalan K363 and Sei Geringging K403, isolated in 1990 from villages in the Pariaman region of Sumatra, Indonesia and compared these genome sequences with other known TPE genomes. METHODOLOGY/PRINCIPAL FINDINGS:The genomes were determined using the pooled segment genome sequencing method combined with the Illumina sequencing platform resulting in an average coverage depth of 1,021x and 644x for the TPE Kampung Dalan K363 and TPE Sei Geringging K403 genomes, respectively. Both Indonesian TPE strains were genetically related to each other and were more distantly related to other, previously characterized TPE strains. The modular character of several genes, including TP0136 and TP0858 gene orthologs, was identified by analysis of the corresponding sequences. To systematically detect genes potentially having a modular genetic structure, we performed a whole genome analysis-of-occurrence of direct or inverted repeats of 17 or more nucleotides in length. Besides in tpr genes, a frequent presence of repeats was found in the genetic regions spanning TP0126-TP0136, TP0856-TP0858, and TP0896 genes. CONCLUSIONS/SIGNIFICANCE:Comparisons of genome sequences of TPE Kampung Dalan K363 and Sei Geringging K403 with other TPE strains revealed a modular structure of several genomic loci including the TP0136, TP0856, and TP0858 genes. Diversification of TPE genomes appears to be facilitated by intra-strain genome recombination events
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