Transitions in synchronization states of model cilia through basal-connection coupling

Despite evidence for a hydrodynamic origin of flagellar synchronization between different eukaryotic cells, recent experiments have shown that in single multi-flagellated organisms, coordination hinges instead on direct basal body connections. The mechanism by which these connections leads to coordination, however, is currently not understood. Here we focus on the model biflagellate {\it Chlamydomonas reinhardtii}, and propose a minimal model for the synchronization of its two flagella as a result of both hydrodynamic and direct mechanical coupling. A spectrum of different types of coordination can be selected, depending on small changes in the stiffness of intracellular couplings. These include prolonged in-phase and anti-phase synchronization, as well as a range of multistable states induced by spontaneous symmetry breaking of the system. Linking synchrony to intracellular stiffness could lead to the use of flagellar dynamics as a probe for the mechanical state of the cell.Comment: 14 pages, 9 figure

Planning for a data base system to support satellite conceptual design

The conceptual design of an automated satellite design data base system is presented. The satellite catalog in the system includes data for all earth orbital satellites funded to the hardware stage for launch between 1970 and 1980, and provides a concise compilation of satellite capabilities and design parameters. The cost of satellite subsystems and components will be added to the base. Data elements are listed and discussed. Sensor and science and applications opportunities catalogs will be included in the data system. Capabilities of the BASIS storage, retrieval, and analysis system are used in the system design

Chronic diabetic peripheral neuropathic pain: psychometric properties of pain and physical function outcome measures

© 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. Background: Diabetic peripheral neuropathy (DPN) not only produces severe pain, tingling, and numbness sensation in the involved limbs, but also limits physical function due to loss of sensation. There are no recommended methods for clinical situations to measure these signs and symptoms. Studies with high methodological quality use the modified Brief Pain Inventory for Diabetic Peripheral Neuropathic pain (mBPI-DPN) scale and the short form Screening of Activity Limitations and Safety Awareness (sSALSA) scale for measuring these symptoms in DPN population. In order to capture a real change in the variables of interest, the psychometric properties of that measure should be within acceptable limits. As these two measures were not assessed for all of the psychometric properties, there was a need for further evaluation. Methods: Data were collected (n = 38 patients) in a longitudinal cohort study. Test–retest reliability (0–4 weeks) and Responsiveness- Minimal Clinically Important Difference (MCID) (0–12 weeks) were calculated between two sessions. Convergent validity was assessed (between mBPI-DPN pain interference and sSALSA scale). Results: Both measures demonstrated acceptable test–retest reliability (mBPI-DPN scale: ICC = 0.61, SEM = 12.92; the sSALSA scale: ICC = 0.81, SEM = 4.88) and convergent validity (Spearman’s correlation coefficient r = 0.62). The computational methods used in different methodologies to calculate MCID for the mBPI-DPN and the sSALSA scale were varied, hence the magnitude of derived MCID scores also varied. Conclusions: Our study have provided evidence to add to the scientific basis surrounding the use of mBPI-DPN and sSALSA scales in DPN population, but standardization of these measures in a larger population is required

Polyunsaturated fatty acids inhibit k_v1.4 by interacting with positively charged extracellular pore residues

Polyunsaturated fatty acids (PUFAs) modulate voltage-gated K(+) channel inactivation by an unknown site and mechanism. The effects of ω-6 and ω-3 PUFAs were investigated on the heterologously expressed K(v)1.4 channel. PUFAs inhibited wild-type K(v)1.4 during repetitive pulsing as a result of slowing of recovery from inactivation. In a mutant K(v)1.4 channel lacking N-type inactivation, PUFAs reversibly enhanced C-type inactivation (K(d), 15–43 μM). C-type inactivation was affected by extracellular H(+) and K(+) as well as PUFAs and there was an interaction among the three: the effect of PUFAs was reversed during acidosis and abolished on raising K(+). Replacement of two positively charged residues in the extracellular pore (H508 and K532) abolished the effects of the PUFAs (and extracellular H(+) and K(+)) on C-type inactivation but had no effect on the lipoelectric modulation of voltage sensor activation, suggesting two separable interaction sites/mechanisms of action of PUFAs. Charge calculations suggest that the acidic head group of the PUFAs raises the pK(a) of H508 and this reduces the K(+) occupancy of the selectivity filter, stabilizing the C-type inactivated state

Are Compression Stockings an Effective Treatment for Orthostatic Presyncope?

Syncope, or fainting, affects approximately 6.2% of the population, and is associated with significant comorbidity. Many syncopal events occur secondary to excessive venous pooling and capillary filtration in the lower limbs when upright. As such, a common approach to the management of syncope is the use of compression stockings. However, research confirming their efficacy is lacking. We aimed to investigate the effect of graded calf compression stockings on orthostatic tolerance

Adverse Childhood Experiences Among Females in Substance Use Treatment and Their Children: A Pilot Study

Women with substance use disorder (SUD) often have experienced adverse childhood experiences (ACEs). The intergenerational nature of ACEs also put their children at risk for experiencing ACEs. However, no research has explored the prevalence of ACEs in children whose mothers have SUD. This study assessed ACE scores in mothers with SUD and their children and compared them with non-SUD participants. Females with SUD were recruited from a treatment center (n = 50) and compared to females without SUD from the same area (n = 50). The ACE scores of the participants and their children were measured as well as sociodemographic variables. ANOVA and Fisher’s Exact tests were used to examine univariate differences. Multivariate regression models assessed the difference in ACE scores between the groups and their children and the relationship between maternal and child ACE scores while including sociodemographic confounders. The mean ACE score was significantly higher in SUD participants (4.9, SD = 2.9) when compared to non-SUD participants (1.9, SD = 2.0) after controlling for sociodemographic variables (p \u3c .01). Children of treatment participants also had significantly higher mean ACE scores (3.9, SD = 2.3) than children of comparison participants (1.3, SD = 2.0, p \u3c .01). Maternal ACE score was positively related to children’s ACE score after controlling for sociodemographic variables. Given the intergenerational nature of ACEs and their high burden in both mothers and children in substance use treatment, these preliminary findings suggest that mother–child trauma-informed interventions may be appropriate for this population

Individual bacteria in structured environments rely on phenotypic resistance to phage

This is the final version. Available on open access from Public Library of Science via the DOI in this recordData Availability: All relevant data are within the paper and its Supporting Information files.Bacteriophages represent an avenue to overcome the current antibiotic resistance crisis, but evolution of genetic resistance to phages remains a concern. In vitro, bacteria evolve genetic resistance, preventing phage adsorption or degrading phage DNA. In natural environments, evolved resistance is lower possibly because the spatial heterogeneity within biofilms, microcolonies, or wall populations favours phenotypic survival to lytic phages. However, it is also possible that the persistence of genetically sensitive bacteria is due to less efficient phage amplification in natural environments, the existence of refuges where bacteria can hide, and a reduced spread of resistant genotypes. Here, we monitor the interactions between individual planktonic bacteria in isolation in ephemeral refuges and bacteriophage by tracking the survival of individual cells. We find that in these transient spatial refuges, phenotypic resistance due to reduced expression of the phage receptor is a key determinant of bacterial survival. This survival strategy is in contrast with the emergence of genetic resistance in the absence of ephemeral refuges in well-mixed environments. Predictions generated via a mathematical modelling framework to track bacterial response to phages reveal that the presence of spatial refuges leads to fundamentally different population dynamics that should be considered in order to predict and manipulate the evolutionary and ecological dynamics of bacteria-phage interactions in naturally structured environments.Medical Research Council (MRC)Engineering and Physical Sciences Research Council (EPSRC)Gordon and Betty and Gordon Moore FoundationEuropean Research Council (ERC)Biotechnology and Biological Sciences Research Council (BBSRC)Natural Environment Research Council (NERC)Marie Skłodowska-Curie ActionsDefence Science and Technology Laboratory (Dstl)Royal Societ

The role of framing, agency and uncertainty in a focus-divide dilemma

How to prioritise multiple objectives is a common dilemma of daily life. A simple and effective decision rule is to focus resources when the tasks are difficult, and divide when tasks are easy. Nonetheless, in experimental paradigms of this dilemma, participants make highly variable and suboptimal strategic decisions when asked to allocate resources to two competing goals that vary in difficulty. We developed a new version in which participants had to choose where to park a fire truck between houses of varying distances apart. Unlike in the previous versions of the dilemma, participants approached the optimal strategy in this task. Three key differences between the fire truck version and previous versions of the task were investigated: (1) Framing (whether the objectives are familiar or abstract), by comparing a group who placed cartoon trucks between houses to a group performing the same task with abstract shapes; (2) Agency (how much of the task is under the participants’ direct control), by comparing groups who controlled the movement of the truck to those who did not; (3) Uncertainty, by adding variability to the driving speed of the truck to make success or failure on a given trial more difficult to predict. Framing and agency did not influence strategic decisions. When adding variability to outcomes, however, decisions shifted away from optimal. The results suggest choices become more variable when the outcome is less certain, consistent with exploration of response alternatives triggered by an inability to predict success

Torsion and vibration-torsion levels of the S1 and ground cation electronic states of para-fluorotoluene

We investigate the low-energy transitions (0–570 cm-1) of the S1 state of para-fluorotoluene (pFT) using a combination of resonance-enhanced multiphoton ionization (REMPI) and zero-kinetic-energy (ZEKE) spectroscopy and quantum chemical calculations. By using various S1 states as intermediate levels, we obtain zero-kinetic-energy (ZEKE) spectra. The differing activity observed allows detailed assignments to be made of both the cation and S1 low-energy levels. The assignments are in line with the recently-published work on toluene from the Lawrance group [J. Chem. Phys. 143, 044313 (2015)], which considered vibration-torsion coupling in depth for the S1 state of toluene. In addition, we investigate whether two bands that occur in the range 390–420 cm-1 are the result of a Fermi resonance; we present evidence for weak coupling between various vibrations and torsions that contribute to this region. This work has led to the identification of a number of misassignments in the literature, and these are corrected