Supplemental vitamin B-12 enhances the neural response to sensory stimulation in the barrel cortex of healthy rats but does not affect spontaneous neural activity

Background: Although vitamin B-12 (B-12) is known to contribute to the structural and functional development of the brain, it is unclear if B-12 supplementation has any beneficial effect in healthy populations in terms of enhanced neurological status of the brain or improved cognitive function. Objectives: We investigated the effect of dietary supplementation of B-12 on the cortical neural activity of well-nourished young adult rats and tested the hypothesis that B-12 supplementation in healthy rats may reduce sensory evoked neural activity due to enhanced inhibition. Methods: Female Lister Hooded rats weighing between 190g to 265g (2 to 4 months old) were included in the study. The experimental group was fed with B-12 (Cyanocobalamin) enriched water at a concentration of 1mg/L, and the control (CON) group with tap water for 3 weeks. Animals were then anaesthetised and cortical neural responses to whisker stimulation were recorded in vivo using a multi-channel micro-electrode, from which local field potentials (LFPs) were extracted. Results: Somatosensory evoked LFP was enhanced 25% in the B-12 group (4.13±0.24mV) compared with the CON group (3.30±0.21mV) (P=0.02). Spontaneous neural activity did not differ between groups; frequency spectra at each frequency bin of interest did not pass the cluster-forming threshold at the 5% significance level. Conclusions: These findings do not provide evidence supporting the hypothesis of decreased neural activity due to B-12 supplementation. As the spontaneous neural activity was unaffected, the increase in somatosensory evoked LFP may be due to enhanced afferent signal reaching the barrel cortex from the whisker pad, indicating that B-12 supplemented rats may have enhanced sensitivity to sensory stimulation compared to the CON group. We suggest that this enhancement might be the result of lowered sensory threshold, although the underlying mechanism has yet to be elucidated

Major Radiodiagnostic Imaging in Pregnancy and the Risk of Childhood Malignancy: A Population-Based Cohort Study in Ontario

In a record-linkage study, Joel Ray and colleagues examine the association between diagnostic imaging during pregnancy and later childhood cancers

Creating a Model of the Earth System (MOTES): Some Experiences with Parallel ABM

It is argued that certain kinds of problem in modern society impose a requirement on ABM to represent all human agents on the planet. Eleven reason are given, including the need for realism in social models, the importance of boundary conditions and scale, the need for global social justice, the existence of global scale dynamics created by and impacting directly on individuals, and the need to interface with other global models in order to address pressing problems such as climate change and ecosystem destruction. An indication of the difficulties involved in creating such models is given, drawing on experience of creating models with RepastHPC. The paper concludes by suggesting that rather than creating ever more model platforms and frameworks, what we need is a series of shared and collectively developed models, in a similar way to existing traffic models or, models of the physical parts of the earth system

THE SYSTEMATIC COMPARISON OF AGENT-BASED POLICY MODELS– IT’S TIME WE GOT OUR ACT TOGETHER!

The recent Covid crisis has led to a surge of new model development and a renewed interest in the use of models as policy tools. While this is in some senses welcome, the sudden appearance of many new models presents a problem in terms of their assessment, the appropriateness of their application and reconciling any differences in outcome. Even if they appear similar, their underlying assumptions may differ, their initial data might not be the same, policy options may be applied in different ways, stochastic effects explored to a varying extent, and model outputs presented in any number of different forms. As a result, it can be unclear what aspects of variations in output between models are results of mechanistic, parameter or data differences. Any comparison between models is made tricky by differences in experimental design and selection of output measures

Defining mangrove-fisheries: A typology from the Perancak Estuary, Bali, Indonesia.

This study develops a definition of what mangrove-fisheries can encompass, incorporating a broad range of their possible characteristics. A detailed case study was conducted to develop a typology of mangrove-fishing in the Perancak Estuary, Bali, Indonesia, using interview surveys to investigate the fishing activities associated with mangroves. This case study demonstrated the complexity that a mangrove-fishery can entail, where fishing is connected to the mangrove forest by fishers of multiple sectors, functions, locations and temporal scales. Through a comparison with other mangrove-fishing communities in Bali, it also highlighted that mangrove-fisheries are variable even when in close proximity. With particular reference to this case study, a framework was developed as a flexible tool for identifying the multiple dimensions of a mangrove-fishery in a local context. Following this framework should encourage researchers and managers to look outside of the groups of fishers traditionally expected to benefit from mangrove fishing. This will enable the development of a broader definition of mangrove-fisheries in a site specific way. Identifying the full scope of fishers that contribute to or benefit from a mangrove-fishery is the first step towards building management measures that reflect the interests of groups of fishers that may otherwise remain under-represented. This is in line with international efforts for sustainability, especially in promoting small-scale fishers' access to sustainable resources under the UN Sustainable Development Goals

Space-time clustering of childhood cancer around the residence at birth

Previously, we identified space-time clustering in certain childhood cancers around diagnosis residence. These findings provided support for the involvement of environmental agents in etiological processes occurring close to diagnosis. We have reanalyzed the same British population-based dataset. The aim of the study was to determine whether there was space-time clustering around the residence at birth in relation to time of birth and separately from time of diagnosis. A total of 29,553 cases, diagnosed during the period 1969-1993, were examined by a second-order procedure based on K-functions. Locations were birth addresses, but separately, both dates of birth and diagnosis were analyzed. There was statistically significant space-time clustering for Hodgkin lymphoma (HL) and central nervous system (CNS) tumors (p = 0.047 and 0.01, respectively, based on birth date) and for total leukemia at ages 1-4 years only, Non-Hodgkin lymphoma (NHL) and Wilms tumor (p = 0.01, 0.02 and 0.006, respectively, based on diagnosis date). These results, interpreted together with other epidemiological evidence, suggest an etiological role for environmental factors focused around birth address for certain childhood cancers. For HL and CNS tumors, findings suggest that etiological exposures occurred at similar ages or in utero. For leukemia, NHL and Wilms tumor there is support for exposures occurring at similar times before diagnosis. For leukemia, HL, NHL and CNS tumors, but not Wilms tumor, the findings are consistent with infectious hypotheses