Chlorella vulgaris (Chlorellaceae) does not secrete autoinhibitors at high cell densities

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141950/1/ajb211559.pd

Complete trails of co-authorship network evolution

The rise and fall of a research field is the cumulative outcome of its intrinsic scientific value and social coordination among scientists. The structure of the social component is quantifiable by the social network of researchers linked via co-authorship relations, which can be tracked through digital records. Here, we use such co-authorship data in theoretical physics and study their complete evolutionary trail since inception, with a particular emphasis on the early transient stages. We find that the co-authorship networks evolve through three common major processes in time: the nucleation of small isolated components, the formation of a tree-like giant component through cluster aggregation, and the entanglement of the network by large-scale loops. The giant component is constantly changing yet robust upon link degradations, forming the network's dynamic core. The observed patterns are successfully reproducible through a new network model

Impact of nephrolithiasis on kidney function.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.Kidney stone disease has been associated with reduced kidney function and chronic kidney disease (CKD). The objective of the study was to examine kidney function, body mass index (BMI) and the prevalence of cardiovascular disease, hypertension and diabetes in recurrent kidney stone formers.A cross-sectional, case-control study comparing measures of kidney function, BMI and comorbid conditions was conducted in 195 kidney stone patients aged 18 to 70 years with recurrent clinical stone events and 390 age- and gender-matched controls. Wilcoxon-Mann-Whitney, chi-square tests and analysis of covariance were used to compare serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) between the groups.The median age of stone formers was 51 (range, 19-70) years and 108 (55 %) were males. Seventy patients (36 %) had experienced 2-4 clinical stone events, 41 (21 %) 5-10 episodes and 84 (43 %) more than 10. The median SCr was 75 (41-140) μmol/L in the stone formers and 64 (34-168) μmol/L in the control group (p < 0.001). The mean eGFR was 87 ± 20 and 104 ± 22 mL/min/1.73 m(2) in the stone formers and controls, respectively (p < 0.001). After adjustment for body size and comorbid conditions, the difference in SCr and eGFR between cases and controls remained highly significant (p < 0.001). The prevalence of CKD was 9.3 % among stone formers compared with 1.3 % in the control group (P < 0.001). Hypertension and diabetes were significantly more prevalent among the cases that also had higher BMI than controls.Recurrent kidney stone formers have a significantly lower level of kidney function and a markedly higher prevalence of CKD than age- and gender-matched control subjects. The observed deleterious effect of kidney stones on kidney function appears to be independent of comorbid conditions.Landspitali University Hospital Research Fun

Upward Spirals of Mindfulness and Reappraisal: Testing the Mindfulness-to-Meaning Theory with Autoregressive Latent Trajectory Modeling

Psychol Inquiry 26(4):377–387, 2015b) proposes that mindfulness generates eudaimonic well-being by promoting positive reappraisal, the positive psychological process through which stressful events are re-construed as benign, meaningful, or growth-promoting. To test this hypothesis, we examined prospective relations between state mindfulness and positive reappraisal in a community sample participating in a mindfulness-based intervention (MBI). At seven weekly time points throughout the MBI, participants (N = 234) engaged in a 10-min mindfulness meditation exercise at home and completed a measure of the degree of state mindfulness experienced during the meditation, as well as a measure of their use of positive reappraisal over the previous week. Support for the mindful reappraisal hypothesis of the Mindfulness-to-Meaning Theory was found: in latent growth curve and multivariate autoregressive latent trajectory models, increases in the trajectory of state mindfulness experienced during meditation were significantly and robustly associated with more frequent use of positive reappraisal over the course of participation in the 8 week-long MBI. Thus, mindfulness and reappraisal may reciprocally enhance one another as interdependent components of a positive feedback loop whose structure might be best described as an upward spiral.The mindful reappraisal hypothesis of the Mindfulness-to-Meaning Theory (Garland et al. in Psychol Inquiry 26(4):293–314, 2015

Evaluation of rate law approximations in bottom-up kinetic models of metabolism.

BackgroundThe mechanistic description of enzyme kinetics in a dynamic model of metabolism requires specifying the numerical values of a large number of kinetic parameters. The parameterization challenge is often addressed through the use of simplifying approximations to form reaction rate laws with reduced numbers of parameters. Whether such simplified models can reproduce dynamic characteristics of the full system is an important question.ResultsIn this work, we compared the local transient response properties of dynamic models constructed using rate laws with varying levels of approximation. These approximate rate laws were: 1) a Michaelis-Menten rate law with measured enzyme parameters, 2) a Michaelis-Menten rate law with approximated parameters, using the convenience kinetics convention, 3) a thermodynamic rate law resulting from a metabolite saturation assumption, and 4) a pure chemical reaction mass action rate law that removes the role of the enzyme from the reaction kinetics. We utilized in vivo data for the human red blood cell to compare the effect of rate law choices against the backdrop of physiological flux and concentration differences. We found that the Michaelis-Menten rate law with measured enzyme parameters yields an excellent approximation of the full system dynamics, while other assumptions cause greater discrepancies in system dynamic behavior. However, iteratively replacing mechanistic rate laws with approximations resulted in a model that retains a high correlation with the true model behavior. Investigating this consistency, we determined that the order of magnitude differences among fluxes and concentrations in the network were greatly influential on the network dynamics. We further identified reaction features such as thermodynamic reversibility, high substrate concentration, and lack of allosteric regulation, which make certain reactions more suitable for rate law approximations.ConclusionsOverall, our work generally supports the use of approximate rate laws when building large scale kinetic models, due to the key role that physiologically meaningful flux and concentration ranges play in determining network dynamics. However, we also showed that detailed mechanistic models show a clear benefit in prediction accuracy when data is available. The work here should help to provide guidance to future kinetic modeling efforts on the choice of rate law and parameterization approaches

Guidelines for the assessment of efficacy of clinical hypnosis applications

Research on the efficacy of hypnosis applications continues to grow, but there remain major gaps between the science and clinical practice. One challenge has been a lack of consensus on which applications of hypnosis are efficacious based on research evidence. In 2018, 6 major hypnosis organizations collaborated to form the Task Force for Establishing Efficacy Standards for Clinical Hypnosis. This paper describes a Guideline for the Assessment of Efficacy of Clinical Hypnosis Applications developed by the Task Force, which makes 10 specific recommendations. The guideline is intended to be a tool for those who want to assess the quality of existing evidence on the efficacy of clinical hypnosis for any particular indication. The paper also discusses methodological issues in the interpretation and implementation of these guidelines. Future papers will report on the other products of the Hypnosis Efficacy Task Force, such as best practice recommendations for outcomes research in hypnosis and an international survey of researchers and clinicians on current practice and attitudes about hypnosis