Development of a globally optimised model of the cerebral arteries

The cerebral arteries are difficult to reproduce from first principles, featuring interwoven territories, and intricate layers of grey and white matter with differing metabolic demand. The aim of this study was to identify the ideal configuration of arteries required to sustain an entire brain hemisphere based on minimisation of the energy required to supply the tissue. The 3D distribution of grey and white matter within a healthy human brain was first segmented from Magnetic Resonance Images. A novel simulated annealing algorithm was then applied to determine the optimal configuration of arteries required to supply brain tissue. The model is validated through comparison of this ideal, entirely optimised, brain vasculature with the known structure of real arteries. This establishes that the human cerebral vasculature is highly optimised; closely resembling the most energy efficient arrangement of vessels. In addition to local adherence to fluid dynamics optimisation principles, the optimised vasculature reproduces global brain perfusion territories with well defined boundaries between anterior, middle and posterior regions. This validated brain vascular model and algorithm can be used for patient-specific modelling of stroke and cerebral haemodynamics, identification of sub-optimal conditions associated with vascular disease, and optimising vascular structures for tissue engineering and artificial organ design

Looking again at Taiwan's Lü Hsiu-lien: A female vice president or a feminist vice president?

In 2000, Lü Hsiu-lien was elected Taiwan's first female vice president, adding to the striking successes of Asian women in electoral politics. Lü differs from the majority of Asia's "ruling women" in two key respects: she was elected without reliance on "dynastic descent" and she has a long track record as a feminist activist. Her position as both a pioneering feminist and a female vice president prompts us to ask whether she was able to promote a pro-woman agenda during her tenure as vice president. We conclude that despite constraints on Lü's pursuit of an overt feminist agenda-including the patriarchal political culture and a gap between Lü and Taiwan's contemporary feminist movement-she is significant as a female leader who transcends both the Asian dynastic model and the tokenistic model of women as "flower vases," while also contributing vitally to the development of an indigenous Taiwanese feminist theory

Gamma Rays from Star Formation in Clusters of Galaxies

Star formation in galaxies is observed to be associated with gamma-ray emission. The detection of gamma rays from star-forming galaxies by the Fermi Large Area Telescope (LAT) has allowed the determination of a functional relationship between star formation rate and gamma-ray luminosity (Ackermann et. al. 2012). Since star formation is known to scale with total infrared (8-1000 micrometers) and radio (1.4 GHz) luminosity, the observed infrared and radio emission from a star-forming galaxy can be used to quantitatively infer the galaxy's gamma-ray luminosity. Similarly, star forming galaxies within galaxy clusters allow us to derive lower limits on the gamma-ray emission from clusters, which have not yet been conclusively detected in gamma rays. In this study we apply the relationships between gamma-ray luminosity and radio and IR luminosities derived in Ackermann et. al. 2012 to a sample of galaxy clusters from Ackermann et. al. 2010 in order to place lower limits on the gamma-ray emission associated with star formation in galaxy clusters. We find that several clusters have predicted lower limits on gamma-ray emission that are within an order of magnitude of the upper limits derived in Ackermann et. al. 2010 based on non-detection by Fermi-LAT. Given the current gamma-ray limits, star formation likely plays a significant role in the gamma-ray emission in some clusters, especially those with cool cores. We predict that both Fermi-LAT over the course of its lifetime and the future Cherenkov Telescope Array will be able to detect gamma-ray emission from star-forming galaxies in clusters.Comment: 17 pages, 2 figures, 2 tables. Minor revisions made to match version accepted to Ap

Reviewing the epigenetics of schizophrenia

Background: Epigenetic research in mental health has grown exponentially during the last decade and holds what some claim are “revolutionary” potentials for the development of new interdisciplinary models of mental ill health. Schizophrenia is the most appropriate diagnosis against which to assess progress in this regard. Method: Papers on epigenetics and schizophrenia identified in a systematic literature search are subject to a conceptually-driven narrative review that assesses the relations between schizophrenia and epigenetics; considers some issues associated with empirical studies; and thereby identifies key assumptions guiding this research. Findings: The revolutionary potentials of epigenetics are thus far not being realised due to various influences, including a preponderance of hypotheses that begin from a primarily biological question; the “condensation” of environmental influences and their effective reduction to their molecular consequences; and a frequent reliance upon animal studies that effectively preclude some important influences already established as relevant to this diagnosis. Conclusion: Epigenetic research in schizophrenia (and mental health generally) could benefit from being more thoroughly interdisciplinary, from testing hypotheses that foreground social as well as biological influences, and from reconsidering its reliance upon psychiatric diagnoses

Simulated annealing approach to vascular structure with application to the coronary arteries

Do the complex processes of angiogenesis during organism development ultimately lead to a near optimal coronary vasculature in the organs of adult mammals? We examine this hypothesis using a powerful and universal method, built on physical and physiological principles, for the determination of globally energetically optimal arterial trees. The method is based on simulated annealing, and can be used to examine arteries in hollow organs with arbitrary tissue geometries. We demonstrate that the approach can generate in silico vasculatures which closely match porcine anatomical data for the coronary arteries on all length scales, and that the optimized arterial trees improve systematically as computational time increases. The method presented here is general, and could in principle be used to examine the arteries of other organs. Potential applications include improvement of medical imaging analysis and the design of vascular trees for artificial organs

Clinical significance, challenges and limitations in using artificial intelligence for electrocardiography-based diagnosis

Cardiovascular diseases are one of the leading global causes of mortality. Currently, clinicians rely on their own analyses or automated analyses of the electrocardiogram (ECG) to obtain a diagnosis. However, both approaches can only include a finite number of predictors and are unable to execute complex analyses. Artificial intelligence (AI) has enabled the introduction of machine and deep learning algorithms to compensate for the existing limitations of current ECG analysis methods, with promising results. However, it should be prudent to recognize that these algorithms also associated with their own unique set of challenges and limitations, such as professional liability, systematic bias, surveillance, cybersecurity, as well as technical and logistical challenges. This review aims to increase familiarity with and awareness of AI algorithms used in ECG diagnosis, and to ultimately inform the interested stakeholders on their potential utility in addressing present clinical challenges

Bad Medicine: A Panel

Papers presented: Spread the News, Do Not Abuse by Alanah Raianne Williams, Alex Do, Emma Erskine, Page Lemont & Sarah Zaidi Abuse needs to be spoken about. The community needs to take action against it, if someone does not, who will? Who will be there to protect the victims of these demeaning situations? This project focuses on the types of abuse, what abuse is, the reason they do it, how it affects the victim\u27s life, and what things can be done to stop it. Awareness and resources are the main focuses of this research project. The video focuses on statistics regarding the mistreatment of different genders, races, and age groups that are affected, as the interview provides an insight of a real experience that represent the truth of the issue. Use of Electronic Cigarettes and Vaping and Their Effect on the Lungs and Lung Function by Van Chung, Joiada Munoz, and Chelsey Damasco This paper analyzes and compiles ten separate, published articles or scholarly journals that report results from research conducted in a scientific laboratory, interviews and censuses gathered from subjects, and statistics about the usage of electronic cigarettes (e-cigarette) and vaping. It is the purpose of this paper to examine the separate articles in order to form a cohesive and cumulative report on the effects of e-cigarettes on the pulmonary system, in particular, the lungs themselves, especially on adolescent development. The articles vary on the degree to which e-cigarettes are harmful as well as the standing of current E-cigarette users and their level of dependence on nicotine usage; however, all articles present some form of caution in which e-cigarettes should be used. In order to fully understand how e-cigarettes and vaping affect lung function, every aspect of said process should be studied including production and manufacturing, the procedure of a working e-cigarette, and the outcome

Coordination complexes as molecular glue for immobilization of antibodies on cyclic olefin copolymer surfaces

A novel metal-based chelating method has been used to provide an order of magnitude increase in immunoassay performance on cyclic olefin copolymer (COC) plastics compared with passive binding. COCs are hydrophobic, and without surface modification they are often unsuitable for applications where protein adhesion is desired. When interacting with the bare plastic, the majority of the bound proteins will be denatured and become nonfunctional. Many of the surface modification techniques reported to date require costly equipment setup or the use of harsh reaction conditions. Here, we have successfully demonstrated the use of a simple and quick metal chelation method to increase the sensitivity, activity, and efficiency of protein binding to COC surfaces. A detailed analysis of the COC surfaces after activation with the metal complexes is presented, and the immunoassay performance was studied using three different antibody pairs

Measurement of the Electronic Thermal Conductance Channels and Heat Capacity of Graphene at Low Temperature

The ability to transport energy is a fundamental property of the two-dimensional Dirac fermions in graphene. Electronic thermal transport in this system is relatively unexplored and is expected to show unique fundamental properties and to play an important role in future applications of graphene, including optoelectronics, plasmonics, and ultrasensitive bolometry. Here, we present measurements of bipolar thermal conductances due to electron diffusion and electron-phonon coupling and infer the electronic specific heat, with a minimum value of 10k_B (10^(−22)  J/K) per square micron. We test the validity of the Wiedemann-Franz law and find that the Lorenz number equals 1.32×(π^2/3)(kB/^e)^2. The electron-phonon thermal conductance has a temperature power law T^2 at high doping levels, and the coupling parameter is consistent with recent theory, indicating its enhancement by impurity scattering. We demonstrate control of the thermal conductance by electrical gating and by suppressing the diffusion channel using NbTiN superconducting electrodes, which sets the stage for future graphene-based single-microwave photon detection

Litter inputs, but not litter diversity, maintain soil processes in degraded tropical forests — a cross-continental comparison

Land-use change in tropical forests can reduce biodiversity and ecosystem carbon (C) storage, but although changes in aboveground biomass C in human-modified tropical forests are well-documented, patterns in the dynamics and storage of C belowground are less well characterised. To address this, we used a reciprocal litter transplant experiment to assess litter decomposition and soil respiration under distinct litter types in forested or converted habitats in Panama, Central America, and in Sabah, Malaysian Borneo. The converted habitats comprised a large clearing on the Panama Canal and oil palm plantation in Borneo; forested habitats comprised a 60-year old secondary forest in Panama and a disturbed forest in Borneo that was selectively logged until 2008. In each habitat, we installed mesocosms and litterbags with litter collected from old-growth forest, secondary forest or an introduced species: Elaeis guineensis in Borneo and Saccharum spontaneum in Panama. We measured litter mass loss, soil respiration, and soil microbial biomass during nine months at each site. Decomposition differed markedly between habitat types and between forest vs. introduced litter, but the decay rates and properties of old-growth and secondary forest litters in the forest habitats were remarkably similar, even across continents. Slower decomposition of all litter types in the converted habitats was largely explained by microclimate, but the faster decay of introduced litter was linked to lower lignin content compared to the forest litter. Despite marked differences in litter properties and decomposition, there was no effect of litter type on soil respiration or microbial biomass. However, regardless of location, litter type, and differences in soil characteristics, we measured a similar decline in microbial activity and biomass in the absence of litter inputs. Interestingly, whereas microbial biomass and soil respiration increased substantially in response to litter inputs in the forested habitats and the converted habitat in Panama, there was little or no corresponding increase in the converted habitat in Borneo, indicating that soil recovery capacity had declined substantially in oil palm plantations. Overall, our results suggest that litter inputs are essential to preserve key soil processes, but litter diversity may be less important, especially in highly disturbed habitats