Naresuan University Journal
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Energy efficiency in heterogeneous networks
No full textHeterogeneous network (HetNet) deployment is considered a de facto solution for meeting the ever increasing mobile traffic demand. However, excessive power usage in such networks is a critical issue, particularly for the mobile operators. Characterizing the fundamental energy efficiency (EE) performance of HetNets is therefore important for the design of green wireless systems. In this paper, we address the EE optimization problem for downlink two-tier HetNets comprised of a single macro-cell and multiple pico-cells. Considering a heterogeneous real-time and non-real-time traffic, transmit beamforming design and power allocation policies are jointly considered in order to optimize the system energy efficiency. The EE resource allocation problem under consideration is a mixed combinatorial and non-convex optimization problem, which is extremely difficult to solve. In order to reduce the computational complexity, we decompose the original problem with multiple inequality constraints into multiple optimization problems with single inequality constraint. For the latter problem, a two-layer resource allocation algorithm is proposed based on the quasiconcavity property of EE. Simulation results confirm the theoretical findings and demonstrate that the proposed resource allocation algorithm can efficiently approach the optimal EE
Age-related frailty and its association with biological markers of ageing.
No full textBACKGROUND: The relationship between age-related frailty and the underlying processes that drive changes in health is currently unclear. Considered individually, most blood biomarkers show only weak relationships with frailty and ageing. Here, we examined whether a biomarker-based frailty index (FI-B) allowed examination of their collective effect in predicting mortality compared with individual biomarkers, a clinical deficits frailty index (FI-CD), and the Fried frailty phenotype. METHODS: We analyzed baseline data and up to 7-year mortality in the Newcastle 85+ Study (n = 845; mean age 85.5). The FI-B combined 40 biomarkers of cellular ageing, inflammation, haematology, and immunosenescence. The Kaplan-Meier estimator was used to stratify participants into FI-B risk strata. Stability of the risk estimates for the FI-B was assessed using iterative, random subsampling of the 40 FI-B items. Predictive validity was tested using Cox proportional hazards analysis and discriminative ability by the area under receiver operating characteristic (ROC) curves. RESULTS: The mean FI-B was 0.35 (SD, 0.08), higher than the mean FI-CD (0.22; SD, 0.12); no participant had an FI-B scor
Metabarcoding analysis of home composts reveals distinctive fungal communities with a high number of unassigned sequences
No full textHome composting has been strongly advocated in the UK, Europe and North America to divert organic waste away from conventional waste processing. Despite this, little attention has been given to microbial communities and their diversity in these systems. In this study, we examined the diversity of fungal species in 10 different domestic composts by 454 tag-encoded pyrosequencing. We report the recovery of 478 different MOTUs from the 10 composts with an average of 176.7 ± 19.6 MOTUs per compost and an average of 12.9 ± 3.8 unique MOTUs per sample. Microascales (17.21%), Hypocreales (16.76%), Sordariales (14.89%), Eurotiales (11.25%) and Mortierellales (7.38%) were the dominant orders in the community with Pseudallescheria (9.52%), Penicillium (8.43%) Mortierella (3.60%) and Fusarium (3.31%) being the most abundant genera. Fungal communities in home composts were substantially different to large-scale commercial composts, with thermophilic and thermotolerant fungi present in much lower numbers. Significantly, 46.2% of all sequences were identified as uncultured fungi or could not be assigned above the family level suggesting there are a high number of new genera and species in these environments still to be described
Public Opinion, Responsiveness and Constraint: Britain's Three Immigration Policy Regimes
No full textWe examine the link between public opinion and policy in the UK over the past 30 years. We show that public views about immigration are responsive to changes in immigration levels and differences between migrant groups, and that policy-makers are sensitive to these changes. Policy-makers look to respond to the public mood on migration, but face growing constraints in doing so. The interaction of public opinion, policy and constraint has produced three distinct policy regimes. In the first, from 1982 to 1997, policy-makers faced few constraints, immigration was tightly controlled and the public were unconcerned about the issue. In the second, from 1997 to 2004, migration policy was selectively liberalised in response to external and interest group pressures, producing increasing inflows and growing public demands for restriction. In the third, from 2004 to the time of writing, public demand for restriction is strong but policymakers face significant constraints in responding. In all periods, policy-makers seek to focus restriction on the migrant streams most opposed by the public, but as they have lost discretionary power over the issue they have been forced to take action against more economically valuable and socially accepted migrant streams. The growing constraints on policy-makers have therefore sharpened the trade-off between the ‘responsive’ government of meeting public demands for immigrations restriction and the ‘responsible’ government goal of providing for the needs of a flexible, globally integrated econom
The photochemical mechanism of a B12-dependent photoreceptor protein
No full textThe coenzyme B-12-dependent photoreceptor protein, CarH, is a bacterial transcriptional regulator that controls the biosynthesis of carotenoids in response to light. On binding of coenzyme B-12 the monomeric apoprotein forms tetramers in the dark, which bind operator DNA thus blocking transcription. Under illumination the CarH tetramer dissociates, weakening its affinity for DNA and allowing transcription. The mechanism by which this occurs is unknown. Here we describe the photochemistry in CarH that ultimately triggers tetramer dissociation; it proceeds via a cob(III)alamin intermediate, which then forms a stable adduct with the protein. This pathway is without precedent and our data suggest it is independent of the radical chemistry common to both coenzyme B-12 enzymology and its known photochemistry. It provides a mechanistic foundation for the emerging field of B-12 photobiology and will serve to inform the development of a new class of optogenetic tool for the control of gene expression
ManUniCast: A Real-Time Weather and Air-Quality Forecasting Portal and App for Teaching
No full textManUniCast is a real-time weather and air-quality forecasting portal developed for education and outreach at the University of Manchester. The web portal manunicast.com displays model output from a WRF simulation with 20-km horizontal grid spacing over the North Atlantic and Europe, including a 4-km nest over the UK and Ireland. The portal also displays output from a WRF-Chem simulation at 12-km grid spacing over the UK. The portal displays over 60 different meteorological, chemical and composition quantities. Both the portal and an accompanying mobile app are free. Educational opportunities for incorporating ManUniCast into existing courses are discussed
Clustering of pain and its associations with health in people aged 50 years and older: cross-sectional results from the North Staffordshire Osteoarthritis Project.
No full textOBJECTIVE: Most pain in patients aged ≥50 years affects multiple sites and yet the predominant mode of presentation is single-site syndromes. The aim of this study was to investigate if pain sites form clusters in this population and if any such clusters are associated with health factors other than pain. SETTING: Six general practices in North Staffordshire, UK. DESIGN: Cross-sectional, postal questionnaire, study. PARTICIPANTS: Community-dwelling adults aged ≥50 years registered at the general practices. MAIN OUTCOMES MEASURES: Number of pain sites was measured by asking participants to shade sites of pain lasting ≥1 day in the past 4 weeks on a blank body manikin. Health factors measured included anxiety and depression (Hospital and Anxiety Depression Scale), cognitive complaint (Sickness Impact Profile) and sleep. Pain site clustering was investigated using latent class analysis. Association of clusters with health factors, adjusted for age, sex, body mass index and morbidities, was analysed using multinomial regression models. RESULTS: 13 986 participants (adjusted response 70.6%) completed a questionnaire, of whom 12 408 provided complete pain data. Four clusters of participants were identified: (1) low number of pain sites (36.6%), (2) medium number of sites with no back pain (31.5%), (3) medium number of sites with back pain (17.9%) and (4) high number of sites (14.1%). Compared to Cluster 1, other clusters were associated with poor health. The strongest associations (relative risk ratios, 95% CI) were with Cluster 4: depression (per unit change in score) 1.11 (1.08 to 1.14); cognitive complaint 2.60 (2.09 to 3.24); non-restorative sleep 4.60 (3.50 to 6.05). CONCLUSIONS: These results indicate that in a general population aged ≥50 years, pain forms four clusters shaped by two dimensions-number of pain sites (low, medium, high) and, within the medium cluster, the absence or presence of back pain. The usefulness of primary care treatment approaches based on this simple classification should be investigated
Targeting astrocytes in major depression.
No full textAstrocytes represent a highly heterogeneous population of neural cells primarily responsible for the homeostasis of the CNS. Astrocytes express multiple receptors for neurotransmitters, including the serotonin 5-HT2B receptors and interact with neurones at the synapse. Astroglia contribute to neurological diseases through homeostatic response, neuroprotection and reactivity. In major depression, astrocytes show signs of degeneration and are decreased in numbers, which may lead to a misbalance in neurotransmission and aberrant synaptic connectivity. In this review, we summarize astroglia-specific effects of major antidepressants and outline future strategies for astroglia-specific therapy in neuropsychiatric disorders
Validation of the SO2 camera for high temporal and spatial resolution monitoring of SO2 emissions
No full textGround-based measurements of sulfur dioxide (SO2) are a key part of monitoring networks at many volcanic centers. SO2 camera systems represent an attractive addition to conventional spectroscopic methods such as COSPEC or DOAS, because they offer higher sampling rates (up to 1 Hz) and two-dimensional concentration mapping which provides additional contextual information for emission rate calculation and interpretation. Here we present the results of an SO2 camera development project and corresponding validation experiment conducted at a coal-burning power plant in Arizona (USA), where the emissions are independently measured. Emissions of SO2 and other acid gases are regulated in the United States, and hourly data are publicly reported by the US Environmental Protection Agency (EPA). We measured the emissions from two exhaust stacks that had an average combined rate of 8.2 +/- 2.1 x 10(-2) kg s(-1) (7 +/- 1.8 t d(-1)) over a period of 3 h. Masses integrated from our dataset are within 10-20% of the emissions reported by the EPA. The contextual information contained in the images allowed the identification and measurement of the individual plumes from each stack. Measured emission rates decrease with increasing distance from the source, pointing to an apparent loss of SO2 primarily by gas dilution processes, with SO2 concentrations dropping below the detection limit at the edge of the plume at distances > 200 m from the source. Cross-sections very close to the vent (within 50 m; similar to 2 vent diameters), through the optically thick condensing part of the plume, yielded emission rates lower than those reported to the EPA. This near-vent discrepancy is interpreted to be the result of light dilution effects due to attenuation and reflections off the surface of the condensing plume. This work is the first reported validation of emission rate measurements produced by an SO2 camera in a volcano-like geometry, and demonstrates that reliable emission rates can be measured, but also emphasizes the importance of the selection of the cross-section locations. (C) 2014 Elsevier B.V. All rights reserved