Conductance fingerprint of Majorana fermions in the topological Kondo effect

We consider an interacting nanowire/superconductor heterostructure attached to metallic leads. The device is described by an unusual low-energy model involving spin-1 conduction electrons coupled to a nonlocal spin-1/2 Kondo impurity built from Majorana fermions. The topological origin of the resulting Kondo effect is manifest in distinctive non-Fermi-liquid (NFL) behavior, and the existence of Majorana fermions in the device is demonstrated unambiguously by distinctive conductance lineshapes. We study the physics of the model in detail, using the numerical renormalization group, perturbative scaling and abelian bosonization. In particular, we calculate the full scaling curves for the differential conductance in AC and DC fields, onto which experimental data should collapse. Scattering t-matrices and thermodynamic quantities are also calculated, recovering asymptotes from conformal field theory. We show that the NFL physics is robust to asymmetric Majorana-lead couplings, and here we uncover a duality between strong and weak coupling. The NFL behavior is understood physically in terms of competing Kondo effects. The resulting frustration is relieved by inter-Majorana coupling which generates a second crossover to a regular Fermi liquid.Comment: 17 pages, 8 figure

The EpiTect Methyl qPCR Assay as novel age estimation method in forensic biology

Human aging is associated with epigenetic modification of the genome. DNA methylation at cytosines appears currently as the best characterised modification that occurs during the mammalian lifetime. Such methylation changes at regulatory region can provide insights to track contributor age for criminal investigation. The EpiTect Methyl II PCR system (QIAGEN) was used to compare methylation levels of CpG islands in the promoter regions of a number of age related genes, of which four successfully showed changes across the lifespan (NPTX2, KCNQ1DN, GRIA2 and TRIM58). This technique is based on the detection of remaining input genome after digestion with a methylation-sensitive restriction enzyme. This study examined DNA specimens from 80 female subjects of various ages (18-91 years) obtained from blood, using primers designed to flank the studied gene loci. The data obtained from DNA methylation quantification showed successful discrimination among volunteered ages. Overall, the difference between predicted and real age was about 11 years and absolute mean differences (AMD) was only 7.2 years error. We suggest the EpiTect system can be used as fast and simple innovative tool in future forensic age estimation

Multiple configurations and fluctuating trophic control in the Barents Sea food-web

The Barents Sea is a subarctic shelf sea which has experienced major changes during the past decades. From ecological time-series, three different food-web configurations, reflecting successive shifts of dominance of pelagic fish, demersal fish, and zooplankton, as well as varying trophic control have been identified in the last decades. This covers a relatively short time-period as available ecological time-series are often relatively short. As we lack information for prior time-periods, we use a chance and necessity model to investigate if there are other possible configurations of the Barents Sea food-web than those observed in the ecological time-series, and if this food-web is characterized by a persistent trophic control. We perform food-web simulations using the Non-Deterministic Network Dynamic model (NDND) for the Barents Sea, identify food-web configurations and compare those to historical reconstructions of food-web dynamics. Biomass configurations fall into four major types and three trophic pathways. Reconstructed data match one of the major biomass configurations but is characterized by a different trophic pathway than most of the simulated configurations. The simulated biomass displays fluctuations between bottom-up and top-down trophic control over time rather than persistent trophic control. Our results show that the configurations we have reconstructed are strongly overlapping with our simulated configurations, though they represent only a subset of the possible configurations of the Barents Sea food-web.publishedVersio

Combined effects of temperature and fishing mortality on the Barents Sea ecosystem stability

Temporal variability in abundance and composition of species in marine ecosystems results from a combination of internal processes, external drivers, and stochasticity. One way to explore the temporal variability in an ecosystem is through temporal stability, measured using the inverse of the coefficient of variation for biomass of single species. The effect of temperature and fisheries on the variability of the Barents Sea food web is still poorly understood. To address this question, we simulate the possible dynamics of Barents Sea food web under different temperature and fishery scenarios using a simple food-web model (Non-Deterministic Network Dynamic [NDND]). The NDND model, which is based on chance and necessity (CaN), defines the state space of the ecosystem using its structural constraints (necessity) and explores it stochastically (chance). The effects of temperature and fisheries on stability are explored both separately and combined. The simulation results suggest that increasing temperature has a negative effect on species biomass and increasing fisheries triggers compensatory dynamics of fish species. There is a major intra-scenario variability in temporal stability, while individual scenarios of temperature and fisheries display a weak negative impact and no effect on stability, respectively. However, combined scenarios indicate that fisheries amplify the effects of temperature on stability, while increasing temperature leads to a shift from synergistic to antagonistic effects between these two drivers

Development of a core outcome set for use in determining the overall success of gastroschisis treatment.

Background: Gastroschisis research is limited in quality by the presence of significant heterogeneity in outcome measure reporting (PloS One 10(1):e0116908, 2015). Using core outcome sets in research is one proposed method for addressing this problem (Trials 13:103, 2012; Clin Rheumatol 33(9):1313-1322, 2014; Health Serv Res Policy 17(1):1-2, 2012). Ultimately, standardising outcome measure reporting will improve research quality and translate into improvements in patient care.Methods/design: Candidate outcome measures have been identified through systematic reviews. These outcome measures will form the starting point for an online, three-phase Delphi process that will be carried out in parallel by three panels of experts. Panel 1 is a neonatal panel, panel 2 is a non-neonatal panel and panel 3 is a lay panel.In round 1, experts will be asked to score the previously identified outcome measures from 1–9 based on how important they think the measures are in determining the overall success of their/their child’s/their patient’s gastroschisis treatment.In round 2, experts will be presented with the same list of outcome measures and with graphical representations of how their panel scored that outcome in round 1. They will be asked to re-score the outcome measure taking into account how important other members of their panel felt it to be. In round 3, experts will again be asked to re-score each outcome measure, but this time they will receive a graphical representation of the distribution of scores from all three panels which they should take into account when re-scoring.Following round 3 of the Delphi process, 40 experts will be invited to attend a face-to-face consensus meeting. Participants will be invited in a purposive manner to obtain balance between the different panels. The results of the Delphi process will be discussed, and outcomes re-scored. Outcome measures where?&gt;?70 % of the participants at the meeting scored them as 7–9 and?&lt;?15 % scored them as 1–3 will form the core outcome set.Discussion: Development of a core outcome set will help to reduce the heterogeneity of the outcome measure reporting in gastroschisis. This will increase the quality of research taking place and ultimately improve care provided to infants with gastroschisis.<br/

Quantification of global mitochondrial DNA methylation levels and inverse correlation with age at two CpG sites

Mammalian ageing features biological attrition evident at cellular, genetic and epigenetic levels. Mutation of mitochondrial DNA, and nuclear DNA methylation changes are well established correlates of ageing. The methylation of mitochondrial DNA (mtDNA) is a new and incompletely described phenomenon with unknown biological control and significance. Here we describe the bisulphite sequencing of mtDNA from 82 individuals aged 18-91 years. We detected low and variable levels of mtDNA methylation at 54 of 133 CpG sites interrogated. Regression analysis of methylation levels at two CpG sites (M1215 and M1313) located within the 12S ribosomal RNA gene showed an inverse correlation with subject age suggesting their utility as epigenetic markers of ageing

Exploring variation in ambulance calls and conveyance rates for adults with diabetes mellitus who contact the Northern Ireland Ambulance Service: a retrospective database analysis

BACKGROUND: People with diabetes frequently contact the ambulance service about acute problems. Overall, treating diabetes and its associated complications costs the NHS 10% of the annual budget. Reducing unnecessary hospital admissions and ambulance attendances is a high priority policy for the NHS across the UK. This study aimed to determine the characteristics of emergency calls for people with diabetes who contact the ambulance service and are subsequently conveyed to hospital by the Northern Ireland Ambulance Service (NIAS). METHODS: A retrospective dataset from the NIAS was obtained from the NIAS Trust’s Command and Control system relating to calls where the final complaint group was ‘Diabetes’ for the period 1 January 2017 to 23 November 2019. RESULTS: Of a total 11,396 calls related to diabetes, 63.2% of callers to the NIAS were conveyed to hospital. Over half of the calls related to males, with 35.5% of callers aged 60–79. The more deprived areas had a higher frequency of calls and conveyance to hospital, with this decreasing as deprivation decreased. Calls were evenly distributed across the week, with the majority of calls originating outside of GP working hours, although callers were more likely to be conveyed to hospital during working hours. Calls from healthcare professionals were significantly more likely to be conveyed to hospital, despite accounting for the minority of calls. CONCLUSION: This research found that older males were more likely to contact the ambulance service but older females were more likely to be conveyed to hospital. The likelihood of conveyance increased if the call originated from an HCP or occurred during GP working hours. The availability of alternative care pathways has the potential to reduce conveyance to hospital, which has been particularly important during the COVID-19 pandemic. Integration of data is vitally important to produce high quality research and improve policy and practice in this area

Primase-polymerases are a functionally diverse superfamily of replication and repair enzymes

Until relatively recently, DNA primases were viewed simply as a class of proteins that synthesize short RNA primers requisite for the initiation of DNA replication. However, recent studies have shown that this perception of the limited activities associated with these diverse enzymes can no longer be justified. Numerous examples can now be cited demonstrating how the term 'DNA primase' only describes a very narrow subset of these nucleotidyltransferases, with the vast majority fulfilling multifunctional roles from DNA replication to damage tolerance and repair. This article focuses on the archaeo-eukaryotic primase (AEP) superfamily, drawing on recently characterized examples from all domains of life to highlight the functionally diverse pathways in which these enzymes are employed. The broad origins, functionalities and enzymatic capabilities of AEPs emphasizes their previous functional misannotation and supports the necessity for a reclassification of these enzymes under a category called primase-polymerases within the wider functional grouping of polymerases. Importantly, the repositioning of AEPs in this way better recognizes their broader roles in DNA metabolism and encourages the discovery of additional functions for these enzymes, aside from those highlighted here