Turbulence accelerates the growth of drinking water biofilms

Biofilms are found at the inner surfaces of drinking water pipes and, therefore, it is essential to understand biofilm processes to control their formation. Hydrodynamics play a crucial role in shaping biofilms. Thus, knowing how biofilms form, develop and disperse under different flow conditions is critical in the successful management of these systems. Here, the development of biofilms after 4 weeks, the initial formation of biofilms within 10 h and finally, the response of already established biofilms within 24-h intervals in which the flow regime was changed, were studied using a rotating annular reactor under three different flow regimes: turbulent, transition and laminar. Using fluorescence microscopy, information about the number of microcolonies on the reactor slides, the surface area of biofilms and of extracellular polymeric substances and the biofilm structures was acquired. Gravimetric measurements were conducted to characterise the thickness and density of biofilms, and spatial statistics were used to characterise the heterogeneity and spatial correlation of biofilm structures. Contrary to the prevailing view, it was shown that turbulent flow did not correlate with a reduction in biofilms; turbulence was found to enhance both the initial formation and the development of biofilms on the accessible surfaces. Additionally, after 24-h changes of the flow regime it was indicated that biofilms responded to the quick changes of the flow regime. Overall, this work suggests that different flow conditions can cause substantial changes in biofilm morphology and growth and specifically that turbulent flow can accelerate biofilm growth in drinking water

An independently validated nomogram for isocitrate dehydrogenase-wild-type glioblastoma patient survival.

BackgroundIn 2016, the World Health Organization reclassified the definition of glioblastoma (GBM), dividing these tumors into isocitrate dehydrogenase (IDH)-wild-type and IDH-mutant GBM, where the vast majority of GBMs are IDH-wild-type. Nomograms are useful tools for individualized estimation of survival. This study aimed to develop and independently validate a nomogram for IDH-wild-type patients with newly diagnosed GBM.MethodsData were obtained from newly diagnosed GBM patients from the Ohio Brain Tumor Study (OBTS) and the University of California San Francisco (UCSF) for diagnosis years 2007-2017 with the following variables: age at diagnosis, sex, extent of resection, concurrent radiation/temozolomide (TMZ) status, Karnofsky Performance Status (KPS), O6-methylguanine-DNA methyltransferase (MGMT) methylation status, and IDH mutation status. Survival was assessed using Cox proportional hazards regression, random survival forests, and recursive partitioning analysis, with adjustment for known prognostic factors. The models were developed using the OBTS data and independently validated using the UCSF data. Models were internally validated using 10-fold cross-validation and externally validated by plotting calibration curves.ResultsA final nomogram was validated for IDH-wild-type newly diagnosed GBM. Factors that increased the probability of survival included younger age at diagnosis, female sex, having gross total resection, having concurrent radiation/TMZ, having a high KPS, and having MGMT methylation.ConclusionsA nomogram that calculates individualized survival probabilities for IDH-wild-type patients with newly diagnosed GBM could be useful to physicians for counseling patients regarding treatment decisions and optimizing therapeutic approaches. Free software for implementing this nomogram is provided: https://gcioffi.shinyapps.io/Nomogram_For_IDH_Wildtype_GBM_H_Gittleman/

Pressure-induced isostructural phase transition of metal-doped silicon clathrates

We propose an atomistic model for the pressure-induced isostructural phase transition of metal-doped silicon clathrates, Ba8Si46 and K8Si46, that has been observed at 14 GPa and 23 GPa, respectively. The model explains successfully the equation of state, transition pressure, change of Raman spectra and dependence on the doped cations as well as the effects of substituting Si(6c) atoms with noble metals.Comment: 5 pages, two coumn, 5 figures. See http://www.iitaka.org/down.html for more informatio

Step Right Up: Using Consumer Decision Making Theory to Teach Research Process in the Electronic Age

The legal academy has framed legal research as a professional skill, and much research pedagogy centers around replicating a controlled professional environment to allow students to learn how to do research by simulating legal practice. Although this is a valid way to conceptualize research, it is not the only way. Another way to conceptualize research is as a consumer transaction. Legal information is, in many ways, a product that information providers market to lawyers and students, as the promotions and contests that LexisNexis and Westlaw sponsor demonstrate. Once legal information is understood as a product, the process of research can be seen as a purchase transaction, and research instruction can be seen as a form of consumer education. This article approaches research from a consumer perspective. It sets the stage by explaining why legal information is a consumer product and analyzing changes in the information marketplace that have affected research process. The article then explains consumer decision making theory. It demonstrates why this is an appropriate vehicle for describing the research process and explains the marketing, cultural, psychological, situational, personal, and social influences that affect consumer choice in the research context. The advantages of approaching research from a consumer perspective are addressed next, followed by an exploration of ways to incorporate consumer decision making theory into research pedagogy. The article concludes that making students better consumers of legal information will help them become better professionals

Relationships of Hydrological and Soil Conditions to Red Oak Acorn Yield in the Lower Mississippi Alluvial Valley and Mississippi Interior Flatwoods Regions

Red oak (Quercus spp.) acorns provide food for wildlife and are propagules for regeneration of these trees. Annual yield of acorns varies temporally and site-specifically. I examined acorn yield in relation to hydrology and soils of hardwood bottomlands at five sites in the Mississippi Alluvial Valley and a site in the Mississippi Interior Flatwoods Region during fall-winter 2012-2013. Acorn yield varied among sites (mean = 44.9 acorns/m2; SE = 6.7; CV = 14.9%). Duration of flooding during the growing season differed among sites which influenced soil characteristics. Acorn yield varied inversely with number of days sites were inundated during the growing season (R2 = 0.6725; P = 0.0456; n = 6) during 2012-2013. Managers should consider alleviating growing season flooding of red oaks, which may increase acorn yield and sustain red oaks and other bottomland hardwoods