Detecting alternative attractors in ecosystem dynamics

Saterberg and McCann introduce a time-series method to test whether systems exhibit alternative dynamical attractors. Through simulated and experimental data from a planktonic predator-prey system, their results show that if population dynamics are induced by internal factors to the system, then alternative dynamical attractors can be detected.Dynamical systems theory suggests that ecosystems may exhibit alternative dynamical attractors. Such alternative attractors, as for example equilibria and cycles, have been found in the dynamics of experimental systems. Yet, for natural systems, where multiple biotic and abiotic factors simultaneously affect population dynamics, it is more challenging to distinguish alternative dynamical behaviors. Although recent research exemplifies that some natural systems can exhibit alternative states, a robust methodology for testing whether these constitute distinct dynamical attractors is currently lacking. Here, using attractor reconstruction techniques we develop such a test. Applications of the methodology to simulated, experimental and natural time series data, reveal that alternative dynamical behaviors are hard to distinguish if population dynamics are governed by purely stochastic processes. However, if population dynamics are brought about also by mechanisms internal to the system, alternative attractors can readily be detected. Since many natural populations display evidence of such internally driven dynamics, our approach offers a method for empirically testing whether ecosystems exhibit alternative dynamical attractors

Show me the data: the pilot UK Research Data Registry

The UK Research Data (Metadata) Registry pilot project is implementing a prototype registry for the UK's research data assets, enabling the holdings of subject-based data centres and institutional data repositories alike to be searched from a single location. The purpose of the prototype is to prove the concept of the registry and uncover challenges that will need to be addressed if and when the registry is developed into a sustainable service. The prototype is being tested using metadata records harvested from nine UK data centres and the data repositories of nine UK universities

Physician burnout among West Virginia primary care providers

TITLE: Physician burnout among West Virginia primary care providers INTRODUCTION: Work related burnout is highly prevalent in US physicians and linked to adverse effects on patients, providers and organizations. This study measures burnout in West Virginia (WV) primary care providers, allowing for comparison of results to a similar, recent study of US physicians. METHODS: Anonymous survey through email that included Maslach Burnout Inventory, demographic, workload, and practice characteristics. Responses were analyzed using JMP Pro 13. Analysis used JMP Pro 13 for descriptive statistics, chi-square and regression modeling. RESULTS: Subjects = 110, female/male ratio 1.4, all primary care physicians (PCP), or advanced practice registered nurses or physician assistants (APRN/PA). PCP and APRN/PA differed on sex ratio (p /= 65 vs under 0.178 (p 0.032). Severe burnout in WV PCP was 57.6% and in all US physicians 43.9% (p 0.015). The OR for severe burnout in PCP versus APRN/PA was 2.89 (p 0.039). Burnout in PCP \u3e APRN in rural (p 0.046) but not urban. Private practice 17.6% in our population, 48% US physicians (p 0.0003). Burnout increased linearly with work hours (p 0.003). Self-estimate of burnout correlated with MBI results (p \u3c0.0001). DISCUSSION/CONCLUSION: Severe burnout was highly prevalent in this high risk specialty serving a patient population at risk in regards to poverty, age and medical complexity. This community had a low rate of private practice, fewer providers over age 65, a higher rate of burnout in physicians compared to APRN/PA, and a linear association of burnout to work hours. There was also validation of a single question burnout screening tool. High risk community systems could be a reservoir for burnout research and improvement there could reduce costs and improve outcomes

Exposure to caspofungin activates Cap and Hog pathways in Candida albicans.

Caspofungin is a member of the echinocandin group of antifungals and inhibits the activity of B-glucan synthase thus disrupting cell wall formation and function. While the potent antifungal activity of this agent is well established, this paper analyzed the response of Candida albicans to caspofungin. Exposure of yeast cells to 0.19 μg/ml caspofungin for 1 to 4 h induced nuclear translocation of Cap1p which was confirmed by Western blotting and confocal microscopy. Caspofungin-treated cells demonstrated increased expression of a number of genes associated with the oxidative stress response, including glutathione reductase (GLR1), mitochondrial processing protease (MAS1) and manganese-superoxide dismutase (SOD2) as well as elevated activity of glutathione reductase and superoxide dismutase. Caspofungin treatment also leads to the nuclear localization of Hog1p as visualized by Western blot using anti-phospho-p38 MAPK (Thr180/Tyr182) antibody. This translocation event lead to increased mRNA levels of catalase (CAT1) but not alkyl hydroperoxide reductase (AHP1). The activity of catalase was increased and reached a maximum at 2 h. In addition, pre-exposure of C. albicans to hydrogen peroxide (0.5 mM, 60 min) conferred an increased tolerance to caspofungin. The data presented here highlight the potent antifungal activity of caspofungin and demonstrate that upon exposure to this agent, C. albicans activates the Cap and Hog pathways in an attempt to limit the oxidative and osmotic stresses associated with this drug

ENHANCED VIDEO AND WEB CONFERENCING SECURITY FOR DUAL ACCOUNT ENDPOINTS

Dual account video and web conferencing endpoints have both a personal user account and a shared room account that are registered on the same device. When such an endpoint joins a meeting (e.g., after completing a pairing process) it raises a number of security, etc. challenges. To address these types of challenges, various solutions are presented herein through several techniques. In particular, the techniques may include support for devices utilizing proximity in a reverse fashion (i.e., personal mode endpoints may use ultrasound pairing to detect that the personal user is in proximity to a device and allow them to perform authenticated actions directly using the device’s user interface (UI)). The techniques may further provide a way of pairing personal devices with clients without the need for ultrasound or manual pairing

Revising Ecological Assumptions About Human Papillomavirus Interactions And Type Replacement

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.jtbi.2013.12.028 © 2014. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/The controversy over whether vaccine-targeted HPV types will be replaced by other oncogenic, non-vaccine-targeted types remains unresolved. This is in part because little is known about the ecology of HPV types. Patient data has been interpreted to suggest independence or facilitative interactions between types and therefore replacement is believed to be unlikely. With a novel mathematical model, we investigated which HPV type interactions and their immune responses gave qualitatively similar patterns frequently observed in patients. To assess the possibility of type replacement, vaccination was added to see if non-vaccine-targeted types increased their 'niche'. Our model predicts that independence and facilitation are not necessary for the coexistence of types inside hosts, especially given the patchy nature of HPV infection. In fact, independence and facilitation inadequately represented co-infected patients. We found that some form of competition is likely in natural co-infections. Hence, non-vaccine-targeted types that are not cross-reactive with the vaccine could spread to more patches and can increase their viral load in vaccinated hosts. The degree to which this happens will depend on replication and patch colonization rates. Our results suggest that independence between types could be a fallacy, and so without conclusively untangling HPV within-host ecology, type replacement remains theoretically viable. More ecological thinking is needed in future studies.Canadian Institutes of Health Researc

Metal complexes of 1,10-phenanthroline-5,6-dione alter the susceptibility of the yeast Candida albicans to Amphotericin B and Miconazole

Growth of the pathogenic yeast Candida albicans in sub-MIC (minimum inhibitory concentration) levels of Cu(ClO4)2 · 6H2O and [Cu(phendio)3](ClO4)2 · 4H2O (phendio = 1,10-phenanthroline-5,6-dione) increased the concentration of miconazole and amphotericin B required to achieve the MIC90 whereas pre-growth in AgClO4 and [Ag(phendio)2]ClO4 resulted in a small decrease in the relevant MIC90 values. The copper complexes reduce the oxygen consumption of C. albicans while the silver complexes increase oxygen consumption. In addition, pregrowth of cells in the copper complexes resulted in a lower ergosterol content while the silver complexes induced an elevation in ergosterol synthesis. The ability of copper and silver complexes to alter the susceptibility of C. albicans to miconazole and amphotericin B may be influenced by their action on respiration, since reduced respiration rates correlate with reduced cellular ergosterol which is the target for amphotericin B. Lower levels of ergosterol have previously been associated with elevated tolerance to this drug. In the case of reduced sensitivity to miconazole, tolerance may be mediated by lower ergosterol synthesis giving rise to fewer toxic side products once biosynthesis is inhibited by miconazole