59 research outputs found

    Epidemiological impact of waning immunization on a vaccinated population

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    This is an epidemiological SIRV model based study that is de- signed to analyze the impact of vaccination in containing infection spread, in a 4-tiered population compartment comprised of susceptible, infected, recov- ered and vaccinated agents. While many models assume a lifelong protection through vaccination, we focus on the impact of waning immunization due to conversion of vaccinated and recovered agents back to susceptible ones. Two asymptotic states exist, the \disease-free equilibrium" and the \endemic equi- librium" and we express the transitions between these states as function of the vaccination and conversion rates and using the basic reproduction number. We nd that the vaccination of newborns and adults have dierent consequences on controlling an epidemic. Also, a decaying disease protection within the re- covered sub-population is not sucient to trigger an epidemic on the linear level. We perform simulations for a parameter set modelling a disease with waning immunization like pertussis. For a diusively coupled population, a transition to the endemic state can proceed via the propagation of a traveling infection wave, described successfully within a Fisher-Kolmogorov framework

    The Complete Genome Sequence of Thermoproteus tenax: A Physiologically Versatile Member of the Crenarchaeota

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    Here, we report on the complete genome sequence of the hyperthermophilic Crenarchaeum Thermoproteus tenax (strain Kra 1, DSM 2078(T)) a type strain of the crenarchaeotal order Thermoproteales. Its circular 1.84-megabase genome harbors no extrachromosomal elements and 2,051 open reading frames are identified, covering 90.6% of the complete sequence, which represents a high coding density. Derived from the gene content, T. tenax is a representative member of the Crenarchaeota. The organism is strictly anaerobic and sulfur-dependent with optimal growth at 86 degrees C and pH 5.6. One particular feature is the great metabolic versatility, which is not accompanied by a distinct increase of genome size or information density as compared to other Crenarchaeota. T. tenax is able to grow chemolithoautotrophically (CO2/H-2) as well as chemoorganoheterotrophically in presence of various organic substrates. All pathways for synthesizing the 20 proteinogenic amino acids are present. In addition, two presumably complete gene sets for NADH:quinone oxidoreductase (complex I) were identified in the genome and there is evidence that either NADH or reduced ferredoxin might serve as electron donor. Beside the typical archaeal A(0)A(1)-ATP synthase, a membrane-bound pyrophosphatase is found, which might contribute to energy conservation. Surprisingly, all genes required for dissimilatory sulfate reduction are present, which is confirmed by growth experiments. Mentionable is furthermore, the presence of two proteins (ParA family ATPase, actin-like protein) that might be involved in cell division in Thermoproteales, where the ESCRT system is absent, and of genes involved in genetic competence (DprA, ComF) that is so far unique within Archaea

    Vacuum evaporable spin crossover complexes physicochemical properties in the crystalline bulk and in thin films deposited from the gas phase

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    Vacuum-evaporable Fe(ii) complexes exhibit greatly different spin-crossover behaviour in thin films deposited from the gas phase and the crystalline bulk.</p

    Long-term outcomes in women with polycystic ovary syndrome initially randomized to receive laparoscopic electrocautery of the ovaries or ovulation induction with gonadotrophins

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    Item does not contain fulltextBACKGROUND: Long-term effects of laparoscopic electrocautery of the ovaries are unknown. To study the long-term effects of laparoscopic electrocautery of the ovaries and gonadotrophins, we followed women with clomiphene-resistant polycystic ovary syndrome (PCOS) randomly allocated to one of these treatments until 8-12 years after their initial treatment. METHODS: Between February 1998 and October 2001 168 women with clomiphene citrate-resistant PCOS were included in a randomized controlled trial comparing an electrocautery strategy to a strategy starting with rFSH. In 2009 these women were contacted about their reproductive outcome and menstrual cycle regularity. Analysis was by intention-to-treat. We compared time to conception resulting in live birth, subsequent pregnancies, ectopic and multiple pregnancies, menopause, as well as minimal and maximal menstrual cycle length. RESULTS: After 8-12 years, the cumulative proportion of women with a first child was 86% in women who had been allocated to electrocautery versus 81% in women who had been allocated to immediate rFSH [relative ratio (RR): 1.1; 95% confidence interval (CI): 0.92-1.2]. Treatment with electrocautery resulted in a significantly lower need for stimulated cycles to reach a live birth; 53% after electrocautery versus 76% after rFSH (RR: 0.69; 95% CI: 0.55-0.88).The cumulative proportion of women with a second child was 61% after electrocautery versus 46% after immediate rFSH (RR: 1.4; 95% CI: 1.00-1.9). Overall, there were 7 twins out of 134 deliveries (5%) after electrocautery versus 10 twins out of 124 deliveries (8%) in the rFSH group (RR: 0.65; 95% CI: 0.25-1.6). Fifty-four per cent of the women allocated to electrocautery had a regular menstrual cycle 8-12 years after randomization versus 36% in those allocated to rFSH (RR: 1.5; 95% CI: 0.87-2.6). CONCLUSION: In women with clomiphene-resistant PCOS, laparoscopic electrocautery of the ovaries is as effective as ovulation induction with FSH treatment in terms of live births, but reduces the need for ovulation induction or ART in a significantly higher proportion of women and increases the chance for a second child. Clinicians may use these data when informing clomiphene-resistant anovulatory women about treatment options
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