95 research outputs found

    Uncertainty and insurance in endogenous climate change

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    We investigate the economic impact of stochastic endogenous extreme events and insurance in a growth model. Our analytical results and computational experiments show that i) transparency of the insurance sector is the decisive requisite for abatement activities, implying substantial policy opportunities; ii) we can fully characterize and quantify the impact of uncertainty on the agent's decisions; iii) a decentralized economy will under-invest in abatement without adequate policy interventions; iv) precautionary beliefs on the frequency of extreme events lead to more sustainability; v) technical change does not change the ordering of the paths but leads to a more sustainable future; v) a social security system which prices insurance fairly is preferable to an insurance industry which provides insurance with an overhead

    Synchrony Dynamics During Initiation, Failure, and Rescue of the Segmentation Clock

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    The “segmentation clock” is thought to coordinate sequential segmentation of the body axis in vertebrate embryos. This clock comprises a multicellular genetic network of synchronized oscillators, coupled by intercellular Delta-Notch signaling. How this synchrony is established and how its loss determines the position of segmentation defects in Delta and Notch mutants are unknown. We analyzed the clock's synchrony dynamics by varying strength and timing of Notch coupling in zebra-fish embryos with techniques for quantitative perturbation of gene function. We developed a physical theory based on coupled phase oscillators explaining the observed onset and rescue of segmentation defects, the clock's robustness against developmental noise, and a critical point beyond which synchrony decays. We conclude that synchrony among these genetic oscillators can be established by simultaneous initiation and self-organization and that the segmentation defect position is determined by the difference between coupling strength and noise

    Accuracy of a magnetic resonance imaging‐based 3D printed stereotactic brain biopsy device in dogs

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    Background: Brain biopsy of intracranial lesions is often necessary to determine specific therapy. The cost of the currently used stereotactic rigid frame and optical tracking systems for brain biopsy in dogs is often prohibitive or accuracy is not sufficient for all types of lesion. Objectives: To evaluate the application accuracy of an inexpensive magnetic resonance imaging‐based personalized, 3D printed brain biopsy device. Animals: Twenty‐two dog heads from cadavers were separated into 2 groups according to body weight (20 kg). Methods: Experimental study. Two target points in each cadaver head were used (target point 1: caudate nucleus, target point 2: piriform lobe). Comparison between groups was performed using the independent Student's t test or the nonparametric Mann‐Whitney U Test. Results: The total median target point deviation was 0.83 mm (range 0.09‐2.76 mm). The separate median target point deviations for target points 1 and 2 in all dogs were 0.57 mm (range: 0.09‐1.25 mm) and 0.85 mm (range: 0.14‐2.76 mm), respectively. Conclusion and Clinical Importance: This magnetic resonance imaging‐based 3D printed stereotactic brain biopsy device achieved an application accuracy that was better than the accuracy of most brain biopsy systems that are currently used in veterinary medicine. The device can be applied to every size and shape of skull and allows precise positioning of brain biopsy needles in dogs

    Accuracy of a magnetic resonance imaging-based 3D printed stereotactic brain biopsy device in dogs

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    Background Brain biopsy of intracranial lesions is often necessary to determine specific therapy. The cost of the currently used stereotactic rigid frame and optical tracking systems for brain biopsy in dogs is often prohibitive or accuracy is not sufficient for all types of lesion. Objectives To evaluate the application accuracy of an inexpensive magnetic resonance imaging-based personalized, 3D printed brain biopsy device. Animals Twenty-two dog heads from cadavers were separated into 2 groups according to body weight (20 kg). Methods Experimental study. Two target points in each cadaver head were used (target point 1: caudate nucleus, target point 2: piriform lobe). Comparison between groups was performed using the independent Student's t test or the nonparametric Mann-Whitney U Test. Results The total median target point deviation was 0.83 mm (range 0.09-2.76 mm). The separate median target point deviations for target points 1 and 2 in all dogs were 0.57 mm (range: 0.09-1.25 mm) and 0.85 mm (range: 0.14-2.76 mm), respectively. Conclusion and Clinical Importance This magnetic resonance imaging-based 3D printed stereotactic brain biopsy device achieved an application accuracy that was better than the accuracy of most brain biopsy systems that are currently used in veterinary medicine. The device can be applied to every size and shape of skull and allows precise positioning of brain biopsy needles in dogs

    Effects on Bone and Muscle upon Treadmill Interval Training in Hypogonadal Male Rats

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    Testosterone deficiency in males is linked to various pathological conditions, including muscle and bone loss. This study evaluated the potential of different training modalities to counteract these losses in hypogonadal male rats. A total of 54 male Wistar rats underwent either castration (ORX, n = 18) or sham castration (n = 18), with 18 castrated rats engaging in uphill, level, or downhill interval treadmill training. Analyses were conducted at 4, 8, and 12 weeks postsurgery. Muscle force of the soleus muscle, muscle tissue samples, and bone characteristics were analyzed. No significant differences were observed in cortical bone characteristics. Castrated rats experienced decreased trabecular bone mineral density compared to sham-operated rats. However, 12 weeks of training increased trabecular bone mineral density, with no significant differences among groups. Muscle force measurements revealed decreased tetanic force in castrated rats at week 12, while uphill and downhill interval training restored force to sham group levels and led to muscle hypertrophy compared to ORX animals. Linear regression analyses showed a positive correlation between bone biomechanical characteristics and muscle force. The findings suggest that running exercise can prevent bone loss in osteoporosis, with similar bone restoration effects observed across different training modalities

    Sepsis related mortality of extremely low gestational age newborns after the introduction of colonization screening for multi-drug resistant organisms

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    Background: In 2013 German infection surveillance guidelines recommended weekly colonization screening for multidrug-resistant (MDRO) or highly epidemic organisms for neonatal intensive care units (NICUs) and extended hygiene measures based on screening results. It remains a matter of debate whether screening is worth the effort. We therefore aimed to evaluate sepsis related outcomes before and after the guideline update. Methods: The German Neonatal Network (GNN) is a prospective cohort study including data from extremely preterm infants between 22 + 0 and 28 + 6 gestational weeks born in 62 German level III NICUs. Results: Infants treated after guideline update (n = 8.903) had a lower mortality (12.5% vs. 13.8%, p = 0.036), reduced rates for clinical sepsis (31.4 vs. 42.8%, p < 0.001) and culture-proven sepsis (14.4% vs. 16.5%, p = 0.003) as compared to infants treated before update (n = 3.920). In a multivariate logistic regression analysis, nine pathogens of cultureproven sepsis were associated with sepsis-related death, e.g. Pseudomonas aeruginosa [OR 59 (19–180), p < 0.001)]. However, the guideline update had no significant effect on pathogen-specific case fatality, total sepsis-related mortality and culture-proven sepsis rates with MDRO. While the exposure of GNN infants to cefotaxime declined over time (31.1 vs. 40.1%, p < 0.001), the treatment rate with meropenem was increased (31.6 vs. 26.3%, p < 0.001). Conclusions: The introduction of weekly screening and extended hygiene measures is associated with reduced sepsis rates, but has no effects on sepsis-related mortality and sepsis with screening-relevant pathogens. The high exposure rate to meropenem should be a target of antibiotic stewardship programs

    Is neoadjuvant chemotherapy followed by surgery the appropriate treatment for esophagogastric signet ring cell carcinomas? A systematic review and meta-analysis

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    BackgroundThe impact of neoadjuvant chemotherapy (nCTX) on survival and tumor response in patients with esophagogastric signet ring cell carcinoma (SRCC) is still controversial.MethodsTwo independent reviewers performed a systematic literature search in Medline, CENTRAL, and Web of Science including prospective and retrospective two-arm non-randomized and randomized controlled studies (RCTs). Data was extracted on overall survival (OS) and tumor regression in resected esophagogastric SRCC patients with or without nCTX. Survival data was analyzed using published hazard ratios (HR) if available or determined it from other survival data or survival curves. OS and histopathological response rates by type of tumor (SRCC vs. non-SRCC) were also investigated.ResultsOut of 559 studies, ten (1 RCT, 9 non-RCTs) were included in this meta-analysis (PROSPERO CRD42022298743) investigating 3,653 patients in total. The four studies investigating survival in SRCC patients treated with nCTX + surgery vs. surgery alone showed no survival benefit for neither intervention, but heterogeneity was considerable (HR, 1.01; 95% CI, 0.61–1.67; p = 0.98; I2 = 89%). In patients treated by nCTX + surgery SRCC patients showed worse survival (HR, 1.45; 95% CI, 1.21–1.74; p &lt; 0.01) and lower rate of major histopathological response than non-SRCC patients (OR, 2.47; 95% CI, 1.78–3.44; p &lt; 0.01).ConclusionThe current meta-analysis could not demonstrate beneficial effects of nCTX for SRCC patients. Histopathological response to and survival benefits of non-taxane-based nCTX seem to be lower in comparison to non-SRC esophagogastric cancer. However, certainty of evidence is low due to the scarcity of high-quality trials. Further research is necessary to determine optimal treatment for SRCC patients.Systematic Review Registrationhttps://www.crd.york.ac.uk/, PROSPERO (CRD42022298743)

    Opportunities for improving animal welfare in rodent models of epilepsy and seizures

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    Animal models of epilepsy and seizures, mostly involving mice and rats, are used to understand the pathophysiology of the different forms of epilepsy and their comorbidities, to identify biomarkers, and to discover new antiepileptic drugs and treatments for comorbidities. Such models represent an important area for application of the 3Rs (replacement, reduction and refinement of animal use). This report provides background information and recommendations aimed at minimising pain, suffering and distress in rodent models of epilepsy and seizures in order to improve animal welfare and optimise the quality of studies in this area. The report includes practical guidance on principles of choosing a model, induction procedures, in vivo recordings, perioperative care, welfare assessment, humane endpoints, social housing, environmental enrichment, reporting of studies and data sharing. In addition, some model-specific welfare considerations are discussed, and data gaps and areas for further research are identified. The guidance is based upon a systematic review of the scientific literature, survey of the international epilepsy research community, consultation with veterinarians and animal care and welfare officers, and the expert opinion and practical experience of the members of a Working Group convened by the United Kingdom's National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs)

    SDHA gain-of-function engages inflammatory mitochondrial retrograde signaling via KEAP1-Nrf2.

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    Whether screening the metabolic activity of immune cells facilitates discovery of molecular pathology remains unknown. Here we prospectively screened the extracellular acidification rate as a measure of glycolysis and the oxygen consumption rate as a measure of mitochondrial respiration in B cells from patients with primary antibody deficiency. The highest oxygen consumption rate values were detected in three study participants with persistent polyclonal B cell lymphocytosis (PPBL). Exome sequencing identified germline mutations in SDHA, which encodes succinate dehydrogenase subunit A, in all three patients with PPBL. SDHA gain-of-function led to an accumulation of fumarate in PPBL B cells, which engaged the KEAP1-Nrf2 system to drive the transcription of genes encoding inflammatory cytokines. In a single patient trial, blocking the activity of the cytokine interleukin-6 in vivo prevented systemic inflammation and ameliorated clinical disease. Overall, our study has identified pathological mitochondrial retrograde signaling as a disease modifier in primary antibody deficiency
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