5,812 research outputs found

    Mechanistic simulations of kelp populations in a dynamic landscape of light, temperature, and winter storms

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    \ua9 2023 The Author(s). Kelp forests are widely distributed across the coastal ocean, support high levels of biodiversity and primary productivity, and underpin a range of ecosystem services. Laminaria hyperborea is a forest-forming kelp species in the Northeast Atlantic that alters the local environment, providing biogenic structure for a diversity of associated organisms. Populations are strongly affected by light availability, temperature, and storm-related disturbance. We constructed a stage-based, two-season model of L. hyperborea populations along the coast of Great Britain and Ireland to predict biomass across a range of depths, drawing on extensive surveys and data from the literature. Population dynamics were driven by wave exposure, historic winter storm intensity, and simulated interannual variation in temperature and depth-attenuated light intensity, with density-dependent competition for light and space. High biomass was predicted in shallow depths across the domain on suitable substrate, with populations extending deeper in the north and west where light penetration was greater. Detritus production was heavily skewed across years, particularly at greater depths, with 10 % of years comprising more than 50 % of detritus on average below 10 m depth. Annual fluctuations in light and storm intensity produced opposing population oscillations with a ∼6-year period persisting for up to a decade but diminishing sharply with depth. Interannual variation in temperature had minimal impact. Biomass was most sensitive to survival and settlement rates, with negligible sensitivity to individual growth rates. This model highlights the need for an improved understanding of canopy and subcanopy mortality, particularly regarding increasingly frequent heatwaves. Estimations of kelp forest contributions to carbon sequestration should consider the high variability among years or risk underestimating the potential value of kelp forests. Process-based simulations of populations with realistic spatiotemporal environmental variability are a valuable approach to forecasting biotic responses to an increasingly extreme climate

    Clustering based active learning for evolving data streams

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    Data labeling is an expensive and time-consuming task. Choosing which labels to use is increasingly becoming important. In the active learning setting, a classifier is trained by asking for labels for only a small fraction of all instances. While many works exist that deal with this issue in non-streaming scenarios, few works exist in the data stream setting. In this paper we propose a new active learning approach for evolving data streams based on a pre-clustering step, for selecting the most informative instances for labeling. We consider a batch incremental setting: when a new batch arrives, first we cluster the examples, and then, we select the best instances to train the learner. The clustering approach allows to cover the whole data space avoiding to oversample examples from only few areas. We compare our method w.r.t. state of the art active learning strategies over real datasets. The results highlight the improvement in performance of our proposal. Experiments on parameter sensitivity are also reported

    Electrochemically-triggered spatially and temporally resolved multi-component gels

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    Spatial control over gelation with low molecular weight gelators is possible using an electrochemically-driven pH triggering method. Gelation occurs at the electrode surface. We show here that composition control in multi-component low molecular weight hydrogels can also be achieved, allowing simultaneous spatial, temporal and compositional control

    Urban agriculture : evaluating informal and formal practices

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    Urban agriculture (UA) is a fast-increasing element in many settlements in the Global North. This paper reviews the diversity of UA activity, ranging from legal to illegal, formal to informal. Focusing particularly on current research on UA projects in England, including small-scale guerrilla gardening and large community projects supported by community and government funding, we look at the realities of UA. We suggest that it is under-theorised as previous research has focused on practicalities and activism. In particular, we highlight the problematic contribution of UA to food production, the wider value in terms of community development, health and wellbeing, and warn of the danger of the ‘local trap’

    A survey to investigate the association of pain, foot disability and quality of life with corns

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    Background Corns are a common foot problem affecting a large proportion of the population. This study describes the characteristics of corns experienced by 201 participants taking part in a randomised controlled trial to investigate associations between demographic and corn parameters on pain, foot related disability and quality of life (QoL). Methods Pain from the main (index) corn was measured using a visual analogue scale (VAS); foot related disability was assessed with the Foot Disability Questionnaire (now known as the Manchester Foot Pain and Disability Index) and quality of life was recorded with the EQ-5D questionnaire. The effect of demographic and corn parameters on the pain and quality of life outcomes was assessed with analysis of variance (ANOVA) methods. The effect of the same factors on a linear combination of the foot-related disability outcome measures was assessed using multivariate ANOVA methods. Pain was also tested for its mediating properties on the causal pathway between the independent variables and quality of life. Results The mean pain score was 5.29 points on a 10 cm VAS, with females reporting substantively higher pain levels than males. Age affected foot-related disability, with lower levels on all domains of the MFPDI reported in older participants; each year of advancing age was associated with falls of: 0.009 points on the Concern about Appearance (CA) domain; 0.047 points on the Functional Limitation (FL) domain and 0.048 points on the Pain Intensity (PI) domain. Sex and corn type also affected disability, with higher scores reported by females and participants with plantar corns. Conclusions The effect of pain was shown to mediate the relationship between sex and foot-related disability. The presence of plantar corns has a more detrimental effect on QoL than dorsal/inter-digital corns

    Investigating cortico-subcortical circuits during auditory sensory attenuation: A combined magnetoencephalographic and dynamic causal modeling study

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    Sensory attenuation refers to the decreased intensity of a sensory percept when a sensation is self‐generated compared with when it is externally triggered. However, the underlying brain regions and network interactions that give rise to this phenomenon remain to be determined. To address this issue, we recorded magnetoencephalographic (MEG) data from 35 healthy controls during an auditory task in which pure tones were either elicited through a button press or passively presented. We analyzed the auditory M100 at sensor‐ and source‐level and identified movement‐related magnetic fields (MRMFs). Regression analyses were used to further identify brain regions that contributed significantly to sensory attenuation, followed by a dynamic causal modeling (DCM) approach to explore network interactions between generators. Attenuation of the M100 was pronounced in right Heschl's gyrus (HES), superior temporal cortex (ST), thalamus, rolandic operculum (ROL), precuneus and inferior parietal cortex (IPL). Regression analyses showed that right postcentral gyrus (PoCG) and left precentral gyrus (PreCG) predicted M100 sensory attenuation. In addition, DCM results indicated that auditory sensory attenuation involved bi‐directional information flow between thalamus, IPL, and auditory cortex. In summary, our data show that sensory attenuation is mediated by bottom‐up and top‐down information flow in a thalamocortical network, providing support for the role of predictive processing in sensory‐motor system

    Skills, attitudes and uptake of evidence-based practice: a cross-sectional study of chiropractors in the Swedish Chiropractic Association.

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    BackgroundEvidence-based practice (EBP) is integral to the delivery of high-quality health care. Chiropractic has been a licensed health profession in Sweden since 1989, but little is known of the uptake of EBP in this professional group. This study explored the self-reported skills, attitudes and uptake of EBP, and the enablers and barriers of EBP uptake, among licensed chiropractors in Sweden.MethodsLicensed chiropractors (n = 172) of the Swedish Chiropractic Association (Legitimerade Kiropraktorers Riksorganisation) were invited to participate in an anonymous online questionnaire, using the Evidence-Based Practice Attitude and Utilisation Survey (EBASE) in February 2019.ResultsFifty-six (33%) chiropractors completed the survey. Participants were predominantly male, aged 30-49 years, held a Master's degree, and had received their highest qualification and practiced chiropractic for over a decade. Chiropractors rated their EBP skill-level mostly in the moderate to moderate-high range. The majority of chiropractors reported positive attitudes towards EBP, with most agreeing or strongly agreeing that EBP is necessary in the practice of chiropractic, and that EBP assists in making decisions about patient care. Chiropractors reported an average level of engagement in EBP activities. All participants indicated professional literature and research findings were useful in their day-to-day chiropractic practice. The main perceived enabler of EBP uptake was internet access in the workplace, whereas the main barrier to EBP uptake was lack of clinical evidence in chiropractic.ConclusionsParticipating chiropractors of the Swedish Chiropractic Association were generally favourable of EBP, though only reported modest levels of EBP-related skills and engagement in EBP activities. Our findings suggest future studies investigating interventions focussed on improving chiropractors' skills and uptake of EBP are warranted

    Coping strategies for developmental prosopagnosia

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    Developmental prosopagnosia (DP) is a cognitive condition characterised by a relatively selective deficit in face recognition. Some adults and children with DP experience severe psychosocial consequences related to the condition, yet are reluctant to disclose it to others. The remediation of DP is therefore an urgent issue, but has been met with little success. Given that developmental conditions may only benefit from compensatory rather than remedial training, this study aimed to examine (a) the positive and negative effects of DP disclosure, and (b) compensatory techniques that may circumvent recognition failure. Qualitative questionnaires and interviews were carried out with 79 participants: 50 adults with DP, 26 of their non-affected significant others, and three parents of DP children. Findings indicated positive effects of disclosure, yet most adults choose not to do so in the workplace. Effective compensatory strategies include the use of extra-facial information, identity prompts from others, and preparation for planned encounters. However, changes in appearance, infrequent contact, or encounters in unexpected contexts often cause strategy failure. As strategies are effortful and disrupted by heavily controlled appearance (e.g., the wearing of uniform), disclosure of DP may be necessary for the safety, wellbeing and optimal education of children with the condition

    Solution of the structure of tetrameric human glucose 6-phosphate dehydrogenase by molecular replacement

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    Recombinant human glucose 6-phosphate dehydrogenase (G6PD) has been crystallized and its structure solved by molecular replacement. Crystals of the natural mutant R459L grow under similar conditions in space groups P212121 and C2221 with eight or four 515-residue molecules in the asymmetric unit, respectively. A non-crystallographic 222 tetramer was found in the C2221 crystal form using a 4 A resolution data set and a dimer of the large beta + alpha domains of the Leuconostoc mesenteroides enzyme as a search model. This tetramer was the only successful search model for the P212121 crystal form using data to 3 A. Crystals of the deletion mutant DeltaG6PD grow in space group F222 with a monomer in the asymmetric unit; 2.5 A resolution data have been collected. Comparison of the packing of tetramers in the three space groups suggests that the N-terminal tail of the enzyme prevents crystallization with exact 222 molecular symmetry.published_or_final_versio
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