94 research outputs found
Uncertainty and insurance in endogenous climate change
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
The âsegmentation clockâ 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 imagingâbased 3D printed stereotactic brain biopsy device in dogs
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 imagingâbased personalized, 3D printed brain biopsy device.
Animals:
Twentyâtwo dog heads from cadavers were separated into 2 groups according to body weight (20âkg).
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'sât test or the nonparametric MannâWhitney U Test.
Results:
The total median target point deviation was 0.83âmm (range 0.09â2.76âmm). The separate median target point deviations for target points 1 and 2 in all dogs were 0.57âmm (range: 0.09â1.25âmm) and 0.85âmm (range: 0.14â2.76âmm), respectively.
Conclusion and Clinical Importance:
This magnetic resonance imagingâbased 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
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 (20âkg).
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'sât test or the nonparametric Mann-Whitney U Test.
Results
The total median target point deviation was 0.83âmm (range 0.09-2.76âmm). The separate median target point deviations for target points 1 and 2 in all dogs were 0.57âmm (range: 0.09-1.25âmm) and 0.85âmm (range: 0.14-2.76âmm), 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
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
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 (19â180), 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
Opportunities for improving animal welfare in rodent models of epilepsy and seizures
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.
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
Prefrontal response and frontostriatal functional connectivity to monetary reward in abstinent alcohol-dependent young adults
Although altered function in neural reward circuitry is widely proposed in models of addiction, more recent conceptual views have emphasized the role of disrupted response in prefrontal regions. Changes in regions such as the orbitofrontal cortex, medial prefrontal cortex, and dorsolateral prefrontal cortex are postulated to contribute to the compulsivity, impulsivity, and altered executive function that are central to addiction. In addition, few studies have examined function in these regions during young adulthood, when exposure is less chronic than in typical samples of alcohol-dependent adults. To address these issues, we examined neural response and functional connectivity during monetary reward in 24 adults with alcohol dependence and 24 psychiatrically healthy adults. Adults with alcohol dependence exhibited less response to the receipt of monetary reward in a set of prefrontal regions including the medial prefrontal cortex, lateral orbitofrontal cortex, and dorsolateral prefrontal cortex. Adults with alcohol dependence also exhibited greater negative correlation between function in each of these regions and that in the nucleus accumbens. Within the alcohol-dependent group, those with family history of alcohol dependence exhibited lower mPFC response, and those with more frequent drinking exhibited greater negative functional connectivity between the mPFC and the nucleus accumbens. These findings indicate that alcohol dependence is associated with less engagement of prefrontal cortical regions, suggesting weak or disrupted regulation of ventral striatal response. This pattern of prefrontal response and frontostriatal connectivity has consequences for the behavior patterns typical of addiction. Furthermore, brain-behavior findings indicate that the potential mechanisms of disruption in frontostriatal circuitry in alcohol dependence include family liability to alcohol use problems and more frequent use of alcohol. In all, these findings build on the extant literature on reward-circuit function in addiction and suggest mechanisms for disrupted function in alcohol dependence. © 2014 Forbes et al
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