Stability domains for time-delay feedback control with latency

We generalize a known analytical method for determining the stability of periodic orbits controlled by time-delay feedback methods when latencies associated with the generation and injection of the feedback signal cannot be ignored. We discuss the case of extended time-delay autosynchronization (ETDAS) and show that nontrivial qualitative features of the domain of control observed in experiments can be explained by taking into account the effects of both the unstable eigenmode and a single stable eigenmode in the Floquet theory.Comment: 9 pages, 6 figures; Submitted to Physical Review

Inter-Modular Linkers play a crucial role in governing the biosynthesis of non-ribosomal peptides

Motivation: Non-ribosomal peptide synthetases (NRPSs) are modular enzymatic machines that catalyze the ribosome-independent production of structurally complex small peptides, many of which have important clinical applications as antibiotics, antifungals and anti-cancer agents. Several groups have tried to expand natural product diversity by intermixing different NRPS modules to create synthetic peptides. This approach has not been as successful as anticipated, suggesting that these modules are not fully interchangeable. Results: We explored whether Inter-Modular Linkers (IMLs) impact the ability of NRPS modules to communicate during the synthesis of NRPs. We developed a parser to extract 39 804 IMLs from both well annotated and putative NRPS biosynthetic gene clusters from 39 232 bacterial genomes and established the first IMLs database. We analyzed these IMLs and identified a striking relationship between IMLs and the amino acid substrates of their adjacent modules. More than 92% of the identified IMLs connect modules that activate a particular pair of substrates, suggesting that significant specificity is embedded within these sequences. We therefore propose that incorporating the correct IML is critical when attempting combinatorial biosynthesis of novel NRPS. Availability and implementation: The IMLs database as well as the NRPS-Parser have been made available on the web at https://nrps-linker.unc.edu. The entire source code of the project is hosted in GitHub repository (https://github.com/SWFarag/nrps-linker). Supplementary information: Supplementary data are available at Bioinformatics online

Time--delay autosynchronization of the spatio-temporal dynamics in resonant tunneling diodes

The double barrier resonant tunneling diode exhibits complex spatio-temporal patterns including low-dimensional chaos when operated in an active external circuit. We demonstrate how autosynchronization by time--delayed feedback control can be used to select and stabilize specific current density patterns in a noninvasive way. We compare the efficiency of different control schemes involving feedback in either local spatial or global degrees of freedom. The numerically obtained Floquet exponents are explained by analytical results from linear stability analysis.Comment: 10 pages, 16 figure

What lies beneath: exploring links between asylum policy and hate crime in the UK

This paper explores the link between increasing incidents of hate crime and the asylum policy of successive British governments with its central emphasis on deterrence. The constant problematisation of asylum seekers in the media and political discourse ensures that 'anti-immigrant' prejudice becomes mainstr earned as a common-sense response. The victims are not only the asylum seekers hoping for a better life but democratic society itself with its inherent values of pluralism and tolerance debased and destabilised

Extracellular K(+) rapidly controls NaCl cotransporter phosphorylation in the native distal convoluted tubule by Cl(-) -dependent and independent mechanisms.

High dietary potassium (K(+) ) intake dephosphorylates and inactivates the NaCl cotransporter (NCC) in the renal distal convoluted tubule (DCT). Using several ex vivo models, we show that physiological changes in extracellular K(+) , similar to those occurring after a K(+) rich diet, are sufficient to promote a very rapid dephosphorylation of NCC in native DCT cells. Although the increase of NCC phosphorylation upon decreased extracellular K(+) appears to depend on cellular Cl(-) fluxes, the rapid NCC dephosphorylation in response to increased extracellular K(+) is not Cl(-) -dependent. The Cl(-) -dependent pathway involves the SPAK/OSR1 kinases, whereas the Cl(-) independent pathway may include additional signalling cascades. A high dietary potassium (K(+) ) intake causes a rapid dephosphorylation, and hence inactivation, of the thiazide-sensitive NaCl cotransporter (NCC) in the renal distal convoluted tubule (DCT). Based on experiments in heterologous expression systems, it was proposed that changes in extracellular K(+) concentration ([K(+) ]ex ) modulate NCC phosphorylation via a Cl(-) -dependent modulation of the with no lysine (K) kinases (WNK)-STE20/SPS-1-44 related proline-alanine-rich protein kinase (SPAK)/oxidative stress-related kinase (OSR1) kinase pathway. We used the isolated perfused mouse kidney technique and ex vivo preparations of mouse kidney slices to test the physiological relevance of this model on native DCT. We demonstrate that NCC phosphorylation inversely correlates with [K(+) ]ex , with the most prominent effects occurring around physiological plasma [K(+) ]. Cellular Cl(-) conductances and the kinases SPAK/OSR1 are involved in the phosphorylation of NCC under low [K(+) ]ex . However, NCC dephosphorylation triggered by high [K(+) ]ex is neither blocked by removing extracellular Cl(-) , nor by the Cl(-) channel blocker 4,4'-diisothiocyano-2,2'-stilbenedisulphonic acid. The response to [K(+) ]ex on a low extracellular chloride concentration is also independent of significant changes in SPAK/OSR1 phosphorylation. Thus, in the native DCT, [K(+) ]ex directly and rapidly controls NCC phosphorylation by Cl(-) -dependent and independent pathways that involve the kinases SPAK/OSR1 and a yet unidentified additional signalling mechanism

Impact of a school-based intervention to promote fruit intake: a cluster randomized controlled trial

OBJECTIVE: There is evidence that fruit consumption among school children is below the recommended levels. This study aims to examine the effects of a dietary education intervention program me, held by teachers previously trained in nutrition, on the consumption of fruit as a dessert at lunch and dinner, among children 6-12 years old. STUDY DESIGN: This is a randomized trial with the schools as the unit of randomisation. METHODS: A total of 464 children (239 female, 6-12years) from seven elementary schools participated in this cluster randomized controlled trial. Three schools were allocated to the intervention and four to the control group. For the intervention schools, we delivered professional development training to school teachers (12 sessions of 3 h each). The training provided information about nutrition, healthy eating, the importance of drinking water and healthy cooking activities. After each session, teachers were encouraged to develop classroom activities focused on the learned topics. Sociodemographic was assessed at baseline and anthropometric, dietary intake and physical activity assessments were performed at baseline and at the end of the intervention. Dietary intake was evaluated by a 24-h dietary recall and fruit consumption as a dessert was gathered at lunch and dinner. RESULTS: Intervened children reported a significant higher intake in the consumption of fruit compared to the controlled children at lunch (P = 0.001) and at dinner (P = 0.012), after adjusting for confounders. CONCLUSIONS: Our study provides further support for the success of intervention programmes aimed at improving the consumption of fruit as a dessert in children.CIEC – Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), Portuga

Sources of variability in childhood obesity indicators and related behaviors

The purpose of this study was to describe sources of variability in obesity-related variables in 6022 children aged 9-11 years from 12 countries. The study design involved recruitment of students, nested within schools, which were nested within study sites. Height, weight and waist circumference (WC) were measured and body mass index (BMI) was calculated; sleep duration and total and in-school moderate-to-vigorous physical activity (MVPA) and sedentary time were measured by accelerometry; and diet scores were obtained by questionnaire. Variance in most variables was largely explained at the student level: BMI (91.9%), WC (93.5%), sleep (75.3%), MVPA (72.5%), sedentary time (76.9%), healthy diet score (88.3%), unhealthy diet score (66.2%), with the exception of in-school MVPA (53.8%) and in-school sedentary time (25.1%). Variance explained at the school level ranged from 3.3% for BMI to 29.8% for in-school MVPA, and variance explained at the site level ranged from 3.2% for WC to 54.2% for in-school sedentary time. In general, more variance was explained at the school and site levels for behaviors than for anthropometric traits. Given the variance in obesity-related behaviors in primary school children explained at school and site levels, interventions that target policy and environmental changes may enhance obesity intervention efforts.Peer reviewe

Serum homocysteine, vitamin B 12 and folic acid levels in different types of glaucoma

BACKGROUND: This study was performed to compare levels of serum homocysteine (Hcy), vitamin B12 and folic acid in patients with primary open-angle glaucoma (POAG), pseudoexfoliative glaucoma (PEXG), normotensive glaucoma (NTG) and healthy controls. METHODS: Twentyfive patients with POAG, 24 with PEXG, and 18 with NTG, along with 19 control healthy subjects were included this prospective study. Levels of serum Hcy were measured using immunoassay, and those of serum vitamin B12 and folic acid were measured using competitive chemiluminescent enzyme immunoassay. RESULTS: The mean Hcy concentration in the PEXG group was significantly higher (P < 0.001) as compared to the other groups. There were no significant differences with respect to the mean Hcy concentrations among other groups (P > 0.05). There were no statistical differences in serum vitamin B12 levels among POAG, PEXG, NTG and control subjects (P > 0.05). The mean serum folic acid level was significantly lower in the subjects with PEXG (P < 0.009). However, the mean folic acid concentrations among the other groups did not differ significantly (P > 0.05). CONCLUSION: Elevated levels of Hcy in PEXG may explain the role of endothelial dysfunction among patients with PEXG

Regulation of human intestinal T-cell responses by type 1 interferon-STAT1 signaling is disrupted in inflammatory bowel disease

This work was supported by a research fellowship grant from the Crohn’s and Colitis in Childhood Research Association (CICRA) and a small project grant from Crohn’s and Colitis UK (CCUK). We would like to acknowledge Professor Ian Sanderson, who helped with the initial design of this work, and provided important support throughout. We would also like to thank Dr Gary Warne for his advice and assistance in the use of the sorting by flow cytometry. We would also like to thank Dr Raj Lahiri and Professor Graham Foster for the kind gift of the primers for the ISGs (2’5’ OAS and MxA)

Wellness through a comprehensive Yogic breathing program – A controlled pilot trial

<p>Abstract</p> <p>Background</p> <p>Increasing rates of psychosocial disturbances give rise to increased risks and vulnerability for a wide variety of stress-related chronic pain and other illnesses. Relaxation exercises aim at reducing stress and thereby help prevent these unwanted outcomes. One of the widely used relaxation practices is yoga and yogic breathing exercises. One specific form of these exercises is Sudarshan Kriya and related practices (SK&P) which are understood to have favourable effects on the mind-body system. The goal of this pilot study was to design a protocol that can investigate whether SK&P can lead to increased feeling of wellness in healthy volunteers.</p> <p>Methods</p> <p>Participants were recruited in a small university city in Sweden and were instructed in a 6-day intensive program of SK&P which they practiced daily for six weeks. The control group was instructed to relax in an armchair each day during the same period. Subjects included a total of 103 adults, 55 in the intervention (SK&P) group and 48 in the control group. Various instruments were administered before and after the intervention. Hospital Anxiety Depression Scale measured the degree of anxiety and depression, Life Orientation Test measured dispositional optimism, Stress and Energy Test measured individual's energy and stress experiences. Experienced Deviation from Normal State measured the experience of altered state of consciousness.</p> <p>Results</p> <p>There were no safety issues. Compliance was high (only 1 dropout in the SK&P group, and 5 in the control group). Outcome measures appeared to be appropriate for assessing the differences between the groups. Subjective reports generally correlated with the findings from the instruments. The data suggest that participants in the SK&P group, but not the control group, lowered their degree of anxiety, depression and stress, and also increased their degree of optimism (ANOVA; p < 0.001). The participants in the yoga group experienced the practices as a positive event that induced beneficial effects.</p> <p>Conclusion</p> <p>These data indicate that the experimental protocol that is developed here is safe, compliance level is good, and a full scale trial is feasible. The data obtained suggest that adult participants may improve their wellness by learning and applying a program based on yoga and yogic breathing exercises; this can be conclusively assessed in a large-scale trial.</p> <p>Trial Registration</p> <p>Australian Clinical Trial Registry ACTRN012607000175471.</p