634 research outputs found
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Atmospheric observations of the water vapour continuum in the near-infrared windows between 2500 and 6600 cm-1
Water vapour continuum absorption is potentially important for both closure of the Earth's energy budget and remote sensing applications. Currently, there are significant uncertainties in its characteristics in the near-infrared atmospheric windows at 2.1 and 1.6 µm. There have been several attempts to measure the continuum in the laboratory; not only are there significant differences amongst these measurements, but there are also difficulties in extrapolating the laboratory data taken at room temperature and above to temperatures more widely relevant to the atmosphere. Validation is therefore required using field observations of the real atmosphere. There are currently no published observations in atmospheric conditions with enough water vapour to detect a continuum signal within these windows or where the self-continuum component is significant. We present observations of the near-infrared water vapour continuum from Camborne, UK, at sea level using a Sun-pointing, radiometrically calibrated Fourier transform spectrometer in the window regions between 2000 and 10 000 cm−1. Analysis of these data is challenging, particularly because of the need to remove aerosol extinction and the large uncertainties associated with such field measurements. Nevertheless, we present data that are consistent with recent laboratory datasets in the 4 and 2.1 µm windows (when extrapolated to atmospheric temperatures). These results indicate that the most recent revision (3.2) of the MT_CKD foreign continuum, versions of which are widely used in atmospheric radiation models, requires strengthening by a factor of ∼5 in the centre of the 2.1 µm window. In the higher-wavenumber window at 1.6 µm, our estimated self- and foreign-continua are significantly stronger than MT_CKD. The possible contribution of the self- and foreign-continua to our derived total continuum optical depth is estimated by using laboratory or MT_CKD values of one, to estimate the other. The obtained self-continuum shows some consistency with temperature-extrapolated laboratory data in the centres of the 4 and 2.1 µm windows. The 1.6 µm region is more sensitive to atmospheric aerosol and continuum retrievals and therefore more uncertain than the more robust results at 2.1 and 4 µm. We highlight the difficulties in observing the atmospheric continuum and make the case for additional measurements in both the laboratory and field and discuss the requirements for any future field campaign
Smart homes, control and energy management:How do smart home technologies influence control over energy use and domestic life?
By introducing new ways of automatically and remotely controlling domestic environments smart technologies have the potential to significantly improve domestic energy management. It is argued that they will simplify users’ lives by allowing them to delegate aspects of decision-making and control - relating to energy management, security, leisure and entertainment etc. - to automated smart home systems. Whilst such technologically-optimistic visions are seductive to many, less research attention has so far been paid to how users interact with and make use of the advanced control functionality that smart homes provide within already complex everyday lives. What literature there is on domestic technology use and control, shows that control is a complex and contested concept. Far from merely controlling appliances, householders are also concerned about a wide range of broader understandings of control relating, for example, to control over security, independence, hectic schedules and even over other household members such as through parenting or care relationships. This paper draws on new quantitative and qualitative data from 4 homes involved in a smart home field trial that have been equipped with smart home systems that provide advanced control functionality over appliances and space heating. Quantitative data examines how householders have used the systems both to try and improve their energy efficiency but also for purposes such as enhanced security or scheduling appliances to align with lifestyles. Qualitative data (from in-depth interviews) explores how smart technologies have impacted upon, and were impacted by, broader understandings of control within the home. The paper concludes by proposing an analytical framework for future research on control in the smart home
Identifying the time profile of everyday activities in the home using smart meter data
Activities are a descriptive term for the common ways households spend their time. Examples include cooking, doing laundry, or socialising. Smart meter data can be used to generate time profiles of activities that are meaningful to households’ own lived experience. Activities are therefore a lens through which energy feedback to households can be made salient and understandable. This paper demonstrates a multi-step methodology for inferring hourly time profiles of ten household activities using smart meter data, supplemented by individual appliance plug monitors and environmental sensors. First, household interviews, video ethnography, and technology surveys are used to identify appliances and devices in the home, and their roles in specific activities. Second, ‘ontologies’ are developed to map out the relationships between activities and technologies in the home. One or more technologies may indicate the occurrence of certain activities. Third, data from smart meters, plug monitors and sensor data are collected. Smart meter data measuring aggregate electricity use are disaggregated and processed together with the plug monitor and sensor data to identify when and for how long different activities are occurring. Sensor data are particularly useful for activities that are not always associated with an energy-using device. Fourth, the ontologies are applied to the disaggregated data to make inferences on hourly time profiles of ten everyday activities. These include washing, doing laundry, watching TV (reliably inferred), and cleaning, socialising, working (inferred with uncertainties). Fifth, activity time diaries and structured interviews are used to validate both the ontologies and the inferred activity time profiles. Two case study homes are used to illustrate the methodology using data collected as part of a UK trial of smart home technologies. The methodology is demonstrated to produce reliable time profiles of a range of domestic activities that are meaningful to households. The methodology also emphasises the value of integrating coded interview and video ethnography data into both the development of the activity inference process
Bott Periodicity and Realizations of Chiral Symmetry in Arbitrary Dimensions
We compute the chiral symmetries of the Lagrangian for confining
"vector-like" gauge theories with massless fermions in -dimensional
Minkowski space and, under a few reasonable assumptions, determine the form of
the quadratic fermion condensates which arise through spontaneous breaking of
these symmetries. We find that for each type (complex, real, or pseudoreal) of
representation of the gauge group carried by the fermions, the chiral
symmetries of the Lagrangian, as well as the residual symmetries after
dynamical breaking, exactly follow the pattern of Bott periodicity as the
dimension changes. The consequences of this for the topological features of the
low-energy effective theory are considered.Comment: v2: Small additions and clarifications. To appear in Physics Letters
Substrate and mechanistic investigation of the tannases CbTan1 and 2 - serine hydrolases active on gallotannins
Tannases (tannin acyl hydrolases, EC 3.1.1.20) are serine-based α/β-hydrolases that can degrade gallotannins, which are secondary metabolites that inhibit microbial growth by binding to and precipitating proteins, and that are especially enriched in tree bark. Gallotannins are diverse, as they can contain carbohydrate, aliphatic or aromatic groups. Tannases can help microbes avoid the toxic effect of tannins, or even enable their metabolism. Only a few tannases have been characterized structurally or biochemically, and these can be phylogenetically grouped based on the presence or absence of an acidic residue in the canonical Ser-His-Asp catalytic triad. Recently we produced and characterized three tannases from the anaerobe Clostridium butyricum (CbTan1-3). CbTan1 contains an amidic residue (Gln) in place of a catalytic acidic residue, while CbTan2 and 3 contain a catalytic aspartic acid, making these useful enzymes for investigating the mechanistic differences between types of tannases.Based on crystal structures and AlphaFold2 models, we generated mutant tannases to probe both the substrate binding and mechanism of this understudied class of hydrolases. We show that larger substrates, such as epigallocatechin gallate (EGCG), glucogallin, and aliphatic gallotannins, can be accommodated by modifying or entirely removing the tannase cap domains. Attempts to “restore” the catalytic acid in CbTan1 resulted in reduction of activity, suggesting a complex role for the amidic residue. Conversely, CbTan2 catalysis was dramatically decreased when the catalytic aspartic acid was replaced with an asparagine
The Todd–Coxeter algorithm for semigroups and monoids
The third author was supported by the EPSRC doctoral training partnership number EP/N509759/1 when working on this project. The fourth author would like to thank the School of Mathematics and Statistics of the University of St Andrews and the Cyprus State Scholarship Foundation for their financial support.In this paper we provide an account of the Todd-Coxeter algorithm for computing congruences on semigroups and monoids. We also give a novel description of an analogue for semigroups of the so-called Felsch strategy from the Todd-Coxeter algorithm for groups.Peer reviewe
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Can measurements of the near-infrared solar spectral irradiance be reconciled? A new ground-based assessment between 4000-10000 cm-1
The near-infrared solar spectral irradiance (SSI) is of vital importance for understanding the Earth’s radiation budget, and in Earth observation applications. Differences between previously published solar spectra (including the commonly-used ATLAS3 spectrum) reach up to 10% at the low-wavenumber end of the 4000-10000 cm-1 (2.5 – 1 μm) spectral region. The implications for the atmospheric sciences are significant, since this spectral region contains 25% of the incoming total solar irradiance. This work details an updated analysis of the CAVIAR SSI, featuring additional analysis techniques and an updated uncertainty budget using a Monte Carlo method. We report good consistency with ATLAS3 in the 7000-10000 cm-1 region where there is confidence in these results due to agreement with other spectra, but ~7% lower in the 4000-7000 cm-1 region, in general agreement with several other analyses
Yeasts Have Evolved Divergent Enzyme Strategies To Deconstruct and Metabolize Xylan
Together with bacteria and filamentous fungi, yeasts actively take part in the global carbon cycle. Over 100 yeast species have been shown to grow on the major plant polysaccharide xylan, which requires an arsenal of carbohydrate active enzymes. However, which enzymatic strategies yeasts use to deconstruct xylan and what specific biological roles they play in its conversion remain unclear. In fact, genome analyses reveal that many xylan-metabolizing yeasts lack expected xylanolytic enzymes. Guided by bioinformatics, we have here selected three xylan-metabolizing ascomycetous yeasts for in-depth characterization of growth behavior and xylanolytic enzymes. The savanna soil yeast Blastobotrys mokoenaii displays superior growth on xylan thanks to an efficient secreted glycoside hydrolase family 11 (GH11) xylanase; solving its crystal structure revealed a high similarity to xylanases from filamentous fungi. The termite gut-associated Scheffersomyces lignosus, in contrast grows more slowly, and its xylanase activity was found to be mainly cell surface-associated. The wood-isolated Wickerhamomyces canadensis, surprisingly, could not utilize xylan as the sole carbon source without the addition of xylooligosaccharides or exogenous xylanases or even co-culturing with B. mokoenaii, suggesting that W. canadensis relies on initial xylan hydrolysis by neighboring cells. Furthermore, our characterization of a novel W. canadensis GH5 subfamily 49 (GH5_49) xylanase represents the first demonstrated activity in this subfamily. Our collective results provide new information on the variable xylanolytic systems evolved by yeasts and their potential roles in natural carbohydrate conversion. IMPORTANCE Microbes that take part in the degradation of the polysaccharide xylan, the major hemicellulose component in plant biomass, are equipped with specialized enzyme machineries to hydrolyze the polymer into monosaccharides for further metabolism. However, despite being found in virtually every habitat, little is known of how yeasts break down and metabolize xylan and what biological role they may play in its turnover in nature. Here, we have explored the enzymatic xylan deconstruction strategies of three underexplored yeasts from diverse environments, Blastobotrys mokoenaii from soil, Scheffersomyces lignosus from insect guts, and Wickerhamomyces canadensis from trees, and we show that each species has a distinct behavior regarding xylan conversion. These findings may be of high relevance for future design and development of microbial cell factories and biorefineries utilizing renewable plant biomass
Improving behavioral support for smoking cessation in pregnancy: what are the barriers to stopping and which behavior change techniques can influence these? Application of Theoretical Domains Framework.
Behavioral support interventions are used to help pregnant smokers stop; however, of those tested, few are proven effective. Systematic research developing effective pregnancy-specific behavior change techniques (BCTs) is ongoing. This paper reports contributory work identifying potentially-effective BCTs relative to known important barriers and facilitators (B&Fs) to smoking cessation in pregnancy; to detect priority areas for BCTs development. A Nominal Group Technique with cessation experts (n = 12) elicited an expert consensus on B&Fs most influencing women’s smoking cessation and those most modifiable through behavioral support. Effective cessation interventions in randomized trials from a recent Cochrane review were coded into component BCTs using existing taxonomies. B&Fs were categorized using Theoretical Domains Framework (TDF) domains. Matrices, mapping BCT taxonomies against TDF domains, were consulted to investigate the extent to which BCTs in existing interventions target key B&Fs. Experts ranked “smoking a social norm” and “quitting not a priority” as most important barriers and “desire to protect baby” an important facilitator to quitting. From 14 trials, 23 potentially-effective BCTs were identified (e.g., information about consequences). Most B&Fs fell into “Social Influences”, “Knowledge”, “Emotions” and “Intentions” TDF domains; few potentially-effective BCTs mapped onto every TDF domain. B&Fs identified by experts as important to cessation, are not sufficiently targeted by BCT’s currently within interventions for smoking cessation in pregnancy
Prospectus, September 2, 1974
FACULTY, STUDENTS CONQUER REGISTRATION; Enrollment Procedures Eased By Mail; Dr. Staerkel Welcomes Student Body; Lonnie & The Lugnutz Top Activities; All-College Cookout And Activity Day Schedule; Meeting Set For Prospectus Jobs; Campus Artist Needed For Cartoon Series; StuGo Prexy, Karen Coleman, Offers Welcome; Adjusting To College Life; Parking Regulations; Convocations Plans Activities; Debaters Defend Championships; Music Director Ernie Hoffman Looking For Interested Students; Athletic Season Review; Fast Freddy\u27s Football Forecast; Kirby Wins Babe Ruth Scholarship; Don Grothe New Links Coach; Classified Ads; Here Are Your P/C Student Officers; SIMS Lecture Sept. 10; P/C Bridge Club Opens Season In Sunday Session; Prospectus Staff Salary Increase; M*A*S*H Headlines Film Season; StuGo Works Through Summer; Theatre Troupe To Hold Auditionshttps://spark.parkland.edu/prospectus_1974/1011/thumbnail.jp
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