1,451 research outputs found
Napping in English preschool children and the association with parentsā attitudes
Background: Age-independent variability in childrensā napping duration may be influenced by parental preference and attitudes and childrensā availability or lack of opportunity to nap. Our study examined English preschool childrensā napping duration, frequency and location, and the association of daily nap duration with parentsā attitudes towards napping. Methods: Parents of three-year-old children in deprived and nondeprived areas of a town in North-East England were interviewed regarding their attitudes towards child napping and completed four-day and five night sleep diaries documenting their childrensā daytime and nighttime sleep. Results: Of 84 children, half had at least one nap during the four-day study period (median [interquartile range] daily nap duration across all children was 1 [21] min; for nappers only was 21 [34] min). Naps tended to be infrequent and short and few (6%) occurred in a bedroom. Children whose parents allowed or encouraged napping had significantly longer daily nap duration (n=25, median [interquartile range] daily nap duration 21 [34] min) compared to those whose parents tried to prevent them from napping (n=29, 1 [21] min), and those whose parents reported that children did not want to nap (n=30, 0 [0] min) (U=23.21; p<.001). Conclusion: Positive parental attitude towards napping was associated with longer child nap duration. Napping appeared to be mainly sporadic and opportunistic and was negatively perceived and prevented by one-third of parents. The consequences of premature nap cessation are not known; given the importance of sufficient sleep in childhood, we should possibly consider enabling young children to nap more freely
Balancing Bounded Treewidth Circuits
Algorithmic tools for graphs of small treewidth are used to address questions
in complexity theory. For both arithmetic and Boolean circuits, it is shown
that any circuit of size and treewidth can be
simulated by a circuit of width and size , where , if , and otherwise. For our main construction,
we prove that multiplicatively disjoint arithmetic circuits of size
and treewidth can be simulated by bounded fan-in arithmetic formulas of
depth . From this we derive the analogous statement for
syntactically multilinear arithmetic circuits, which strengthens a theorem of
Mahajan and Rao. As another application, we derive that constant width
arithmetic circuits of size can be balanced to depth ,
provided certain restrictions are made on the use of iterated multiplication.
Also from our main construction, we derive that Boolean bounded fan-in circuits
of size and treewidth can be simulated by bounded fan-in
formulas of depth . This strengthens in the non-uniform setting
the known inclusion that . Finally, we apply our
construction to show that {\sc reachability} for directed graphs of bounded
treewidth is in
Nutrient (C, N and P) enrichment induces significant changes in the soil metabolite profile and microbial carbon partitioning
The cycling of soil organic matter (SOM) and carbon (C) within the soil is governed by the presence of key macronutrients, particularly nitrogen (N) and phosphorus (P). The relative ratio of these nutrients has a direct effect on the potential rates of microbial growth and nutrient processing in soil and thus is fundamental to ecosystem functioning. However, the effect of changing soil nutrient stoichiometry on the small organic molecule (i.e., metabolite) composition and cycling by the microbial community remains poorly understood. Here, we aimed to disentangle the effect of stoichiometrically balanced nutrient addition on the soil metabolomic profile and apparent microbial carbon use efficiency (CUE) by adding a labile C source (glucose) in combination with N and/or P. After incorporation of the added glucose into the microbial biomass (48 h), metabolite profiling was undertaken by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). 494 metabolites were identified across all treatments mainly consisting of lipids (n = 199), amino acids (n = 118) and carbohydrates (n = 43), >97% of which showed significant changes in concentration between at least one treatment. Overall, glucose-C addition generally increased the synthesis of other carbohydrates in soil, while addition of C and N together increased peptide synthesis, indicative of protein formation and turnover. The combination of C and P significantly increased the number of fatty acids synthesised. There was no significant change in the PLFA-derived microbial community structure or microbial biomass following C, N and P addition. Further, N addition led to an increase in glucose-C partitioning into anabolic processes (i.e., increased CUE), suggesting the microbial community was N, but not P limited. Based on the metabolomic profiles observed here, we conclude that inorganic nutrient enrichment causes substantial shifts in both primary and secondary metabolism within the microbial community, leading to changes in resource flow and thus soil functioning, however, the microbial community illustrated significant metabolic flexibility
Genetic partitioning of interleukin-6 signalling in mice dissociates Stat3 from Smad3-mediated lung fibrosis
Idiopathic pulmonary fibrosis (IPF) is a fatal disease that is unresponsive to current therapies and characterized by excessive collagen deposition and subsequent fibrosis. While inflammatory cytokines, including interleukin (IL)-6, are elevated in IPF, the molecular mechanisms that underlie this disease are incompletely understood, although the development of fibrosis is believed to depend on canonical transforming growth factor (TGF)-Ī² signalling. We examined bleomycin-induced inflammation and fibrosis in mice carrying a mutation in the shared IL-6 family receptor gp130. Using genetic complementation, we directly correlate the extent of IL-6-mediated, excessive Stat3 activity with inflammatory infiltrates in the lung and the severity of fibrosis in corresponding gp130757F mice. The extent of fibrosis was attenuated in B lymphocyte-deficient gp130757F;ĀµMTā/ā compound mutant mice, but fibrosis still occurred in their Smad3ā/ā counterparts consistent with the capacity of excessive Stat3 activity to induce collagen 1Ī±1 gene transcription independently of canonical TGF-Ī²/Smad3 signalling. These findings are of therapeutic relevance, since we confirmed abundant STAT3 activation in fibrotic lungs from IPF patients and showed that genetic reduction of Stat3 protected mice from bleomycin-induced lung fibrosis
Parity violating pion electroproduction off the nucleon
Parity violating (PV) contributions due to interference between and
exchange are calculated for pion electroproduction off the nucleon. A
phenomenological model with effective Lagrangians is used to determine the
resulting asymmetry for the energy region between threshold and
resonance. The resonance is treated as a Rarita-Schwinger field with
phenomenological transition currents. The background contributions
are given by the usual Born terms using the pseudovector Lagrangian.
Numerical results for the asymmetry are presented.Comment: 17 pages, RevTeX, 6 figures (in separate file figs.uu), uses epsf,
accepted for publication in Z. Phys.
A unique bacteriohopanetetrol stereoisomer of marine anammox
Anaerobic ammonium oxidation (anammox) is a major process of bioavailable nitrogen removal from marine systems. Previously, a bacteriohopanetetrol (BHT) isomer, with unknown stereochemistry, eluting later than BHT using high performance liquid chromatography (HPLC), was detected in āCa. Scalindua profundaā and proposed as a biomarker for anammox in marine paleo-environments. However, the utility of this BHT isomer as an anammox biomarker is hindered by the fact that four other, non-anammox bacteria are also known to produce a late-eluting BHT stereoisomer. The stereochemistry in Acetobacter pasteurianus, Komagataeibacter xylinus and Frankia sp. was known to be 17Ī², 21Ī²(H), 22R, 32R, 33R, 34R (BHT-34R). The stereochemistry of the late-eluting BHT in Methylocella palustris was unknown. To determine if marine anammox bacteria produce a unique BHT isomer, we studied the BHT distributions and stereochemistry of known BHT isomer producers and of previously unscreened marine (āCa. Scalindua brodeaeā) and freshwater (āCa. Brocadia sp.ā) anammox bacteria using HPLC and gas chromatographic (GC) analysis of acetylated BHTs and ultra high performance liquid chromatography (UHPLC)-high resolution mass spectrometry (HRMS) analysis of non-acetylated BHTs. The 34R stereochemistry was confirmed for the BHT isomers in Ca. Brocadia sp. and Methylocella palustris. However, āCa. Scalindua sp.ā synthesise a stereochemically distinct BHT isomer, with still unconfirmed stereochemistry (BHT-x). Only GC analysis of acetylated BHT and UHPLC analysis of non-acetylated BHT distinguished between late-eluting BHT isomers. Acetylated BHT-x and BHT-34R co-elute by HPLC. As BHT-x is currently only known to be produced by āCa. Scalindua spp.ā, it may be a biomarker for marine anammox
Force-Extension Relations for Polymers with Sliding Links
Topological entanglements in polymers are mimicked by sliding rings
(slip-links) which enforce pair contacts between monomers. We study the
force-extension curve for linear polymers in which slip-links create additional
loops of variable size. For a single loop in a phantom chain, we obtain exact
expressions for the average end-to-end separation: The linear response to a
small force is related to the properties of the unstressed chain, while for a
large force the polymer backbone can be treated as a sequence of Pincus--de
Gennes blobs, the constraint effecting only a single blob. Generalizing this
picture, scaling arguments are used to include self-avoiding effects.Comment: 4 pages, 5 figures; accepted to Phys. Rev. E (Brief Report
Educating Health Professionals about Disability: A Review of Interventions
Health professionals need to understand the human rights and health needs of disabled people. This review of evidence on interventions demonstrates that a range of often innovative approaches have been trialled. Lectures by faculty are less effective in changing attitudes than contact with disabled people themselves. Existing examples of good practice need to be scaled up, and better and more long-term evaluations of impact are required
Digital Cognitive Behavioral Therapy for Insomnia in Women With Chronic Migraines
Objective/Background: Insomnia commonly co-occurs with chronic migraines (CM). Non-pharmacological treatments for insomnia in CM patients remain understudied. This is a proof-of-concept study, which aims to evaluate the feasibility, acceptability, and preliminary efficacy of a digital cognitive behavioral therapy for insomnia (dCBT-I) for individuals with CM and insomnia (CM-I) in the United States. Methods: We recruited 42 females with CM-I symptoms from a U.S.-based observational cohort and from the general population via advertisements. Within a multiple baseline design, participants were randomized to receive dCBT-I after 2, 4, or 6Ā weeks of completing baseline sleep diaries. DCBT-I was scrutinized against benchmarks for completion rates (ā„90% to complete dCBT-I), acceptability (ā„80% to find dCBT-I acceptable), and posttreatment changes in insomnia symptoms (ā„50% indicating a clinically relevant improvement in their insomnia symptoms). As a secondary measure, we also reported percentage of individuals reverting to episodic migraines. Results: Out of 42 randomized, 35 (83.3%) completed dCBT-I within the 12Ā weeks provided. Of these completers, 33 (94.3%) reported being satisfied (nĀ =Ā 16) or very satisfied (nĀ =Ā 17) with treatment. Additionally, 65.7% of completers responded to treatment as per universally accepted criteria for insomnia. Lastly, 34% of completers reverted from CM to episodic migraine. Conclusion: This study provides evidence for the feasibility and acceptability of dCBT-I in patients with CM-I complaints. Effects of improving insomnia and migraines were suggested. These results indicate that a randomized controlled trial is needed to determine the efficacy of dCBT-I in CM patients
- ā¦