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Hemiparetic walking after stroke is typically slow, asymmetric, and inefficient, significantly impacting activities of daily living. Extensive research shows that functional, intensive, and task-specific gait training is instrumental for effective gait rehabilitation, characteristics that our group aims to encourage with soft robotic exosuits. However, standard clinical assessments may lack the precision and frequency to detect subtle changes in intervention efficacy during both conventional and exosuit-assisted gait training, potentially impeding targeted therapy regimes. In this paper, we use exosuit-integrated inertial sensors to reconstruct three clinically meaningful gait metrics related to circumduction, foot clearance, and stride length. Our method corrects sensor drift using instantaneous information from both sides of the body. This approach makes our method robust to irregular walking conditions poststroke as well as usable in real-time applications, such as real-time movement monitoring, exosuit assistance control, and biofeedback. We validate our algorithm in eight people poststroke in comparison to lab-based optical motion capture. Mean errors were below 0.2 cm (9.9%) for circumduction, −0.6 cm (−3.5%) for foot clearance, and 3.8 cm (3.6%) for stride length. A single-participant case study shows our technique’s promise in daily-living environments by detecting exosuit-induced changes in gait while walking in a busy outdoor plaza.
There is growing evidence that species and communities are responding to, and will continue to be affected by, climate change. For species at risk, vulnerability can be reduced by ensuring that their habitat is extensive, connected and provides opportunities for dispersal and/or gene flow, facilitating a biological response through migration or adaptation. For woodland epiphytes, vulnerability might also be reduced by ensuring sufficient habitat heterogeneity, so that microhabitats provide suitable local microclimates, even as the larger scale climate continues to change (i.e. microrefugia). This study used fuzzy set ordination to compare bryophyte and lichen epiphyte community composition to a large-scale gradient from an oceanic to a relatively more continental macroclimate. The residuals from this relationship identified microhabitats in which species composition reflected a climate that was more oceanic or more continental than would be expected given the prevailing macroclimate. Comparing these residuals to features that operate at different scales to create the microclimate (landscape, stand and tree-scale), it was possible to identify how one might engineer microrefugia into existing or new woodland, in order to reduce epiphyte vulnerability to climate change. Multimodel inference was used to identify the most important features for consideration, which included local effects such as height on the bole, angle of bole lean and bark water holding capacity, as well as tree species and tree age, and within the landscape, topographic wetness and physical exposure.
Implantable neural interfaces are important tools to accelerate neuroscience research and translate clinical neurotechnologies. The promise of a bidirectional communication link between the nervous system of humans and computers is compelling, yet important materials challenges must be first addressed to improve the reliability of implantable neural interfaces. This perspective highlights recent progress and challenges related to arguably two of the most common failure modes for implantable neural interfaces: (1) compromised barrier layers and packaging leading to failure of electronic components; (2) encapsulation and rejection of the implant due to injurious tissue–biomaterials interactions, which erode the quality and bandwidth of signals across the biology–technology interface. Innovative materials and device design concepts could address these failure modes to improve device performance and broaden the translational prospects of neural interfaces. A brief overview of contemporary neural interfaces is presented and followed by recent progress in chemistry, materials, and fabrication techniques to improve in vivo reliability, including novel barrier materials and harmonizing the various incongruences of the tissue–device interface. Challenges and opportunities related to the clinical translation of neural interfaces are also discussed.
We analyze the strategic considerations inherent in legislative subsidies and develop an informational lobbying model with costly policy reforms. In contrast to other models of informational lobbying, we focus on the implications of a policymaker’s and a lobby’s resource constraints for lobbying activities. We allow both a policymaker and a lobby to gather information, and each can either fund or subsidize policymaking. Our analysis highlights that legislative subsidies are both chosen strategically by lobbyists and strategically induced by policymakers, dependent on the circumstances. These involve which resource constraints bind the policymaker’s prior beliefs, the salience of policy, and the policymaker’s and lobby’s expertise in information gathering. Our results highlight five distinct motives for informational lobbying and demonstrate that for both a lobby and policymaker, there can be strategic advantages arising from being resource-constrained.
The aim of this study was to assess the impact of a urinary tract infection (UTI) management bundle to reduce the treatment of asymptomatic bacteriuria (AB) and to improve the management of symptomatic UTIs.
Before-and-after intervention study.
Consecutive sample of inpatients with positive single or mixed-predominant urine cultures collected and reported while admitted to the hospital.
The UTI management bundle consisted of nursing and prescriber education, modification of the reporting of positive urine cultures, and pharmacists’ prospective audit and feedback. A retrospective chart review of consecutive inpatients with positive urinary cultures was performed before and after implementation of the management bundle.
Prior to the implementation of the management bundle, 276 patients were eligible criteria for chart review. Of these 276 patients, 165 (59·8%) were found to have AB; of these 165 patients with AB, 111 (67·3%) were treated with antimicrobials. Moreover, 268 patients met eligibility criteria for postintervention review. Of these 268, 133 patients (49·6%) were found to have AB; of these 133 with AB, 22 (16·5%) were treated with antimicrobials. Thus, a 75·5% reduction of AB treatment was achieved. Educational components of the bundle resulted in a substantial decrease in nonphysician-directed urine sample submission. Adherence to a UTI management algorithm improved substantially in the intervention period, with a notable decrease in fluoroquinolone prescription for empiric UTI treatment.
A UTI management bundle resulted in a dramatic improvement in the management of urinary tract infection, particularly a reduction in the treatment of AB and improved management of symptomatic UTI.
Within the NHS health check (NHSHC) programme, there is evidence of marked inconsistencies and challenges in practice-level self-reporting of uptake. Consequently, we explored the perceptions of those involved in commissioning of NHSHC to better understand the implications for local and national monitoring and evaluation of programme uptake. Semi-structured, one-to-one, telephone interviews (n=15) were conducted with NHSHC commissioners and leads, and were analysed using inductive thematic analysis. NHSHC data were often collected from practices using online extraction systems but many still relied on self-reported data. Performance targets and indicators used to monitor and feedback to general practices varied between localities. Participants reported a number of issues when collecting and reporting data for NHSHC, namely because of opportunistic checks. Owing to the perceived inaccuracies in reporting, there was concern about the credibility and relevance of national uptake figures. The general practice extraction service will be important to fully understand uptake of NHSHC.
Recent evidence suggests that exercise plays a role in cognition and that the posterior cingulate cortex (PCC) can be divided into dorsal and ventral subregions based on distinct connectivity patterns.
To examine the effect of physical activity and division of the PCC on brain functional connectivity measures in subjective memory complainers (SMC) carrying the epsilon 4 allele of apolipoprotein E (APOE 4) allele.
Participants were 22 SMC carrying the APOE ɛ4 allele (ɛ4+; mean age 72.18 years) and 58 SMC non-carriers (ɛ4–; mean age 72.79 years). Connectivity of four dorsal and ventral seeds was examined. Relationships between PCC connectivity and physical activity measures were explored.
ɛ4+ individuals showed increased connectivity between the dorsal PCC and dorsolateral prefrontal cortex, and the ventral PCC and supplementary motor area (SMA). Greater levels of physical activity correlated with the magnitude of ventral PCC–SMA connectivity.
The results provide the first evidence that ɛ4+ individuals at increased risk of cognitive decline show distinct alterations in dorsal and ventral PCC functional connectivity.
In 1969, Robert E. Gregg collected five species of ants (Hymenoptera: Formicidae) in three Subarctic localities near the town of Churchill, Manitoba, Canada, which he documented in a 1972 publication in The Canadian Entomologist. To determine whether there have been any additions to the local fauna – as might be predicted to occur in response to a warming climate and increased traffic to the Port of Churchill in the intervening 40 years – we re-collected ants from the same localities in 2012. We identified the ants we collected from Gregg’s sampling sites using both traditional morphological preparations and DNA barcoding. In addition, we examined specimens from Gregg’s initial collection that are accessioned at the Field Museum of Natural History (Chicago, Illinois, United States of America). Using this integrative approach we report seven species present at the same sites Gregg sampled 40 years earlier. We conclude that the apparent increase is likely not due to any arrivals from more southerly distributed ants, but to the increased resolution provided by DNA barcodes to resident species complexes with a complicated history. We provide a brief synopsis of these results and their taxonomic context.
Across much of lowland Britain, lichen diversity has been dramatically affected by the Industrial Revolution, including the lasting legacy of pollution, and changes in land use including the loss, intensification, or abandonment of traditional woodland management. We sampled preserved epiphytes on historical timbers in vernacular buildings to reconstruct pre-industrial lichen species occurrence for a site in Exmoor, south-west England, and used these data to quantify biodiversity loss that appears related to shifts in woodland composition. A total of 33 lichen epiphyte species were collected from pre-industrial structural timbers, and these were compared with modern lichen occurrence. Based on a direct comparison with species presence-absence in the same 10 km target grid-square, c. 31% of species recorded from the pre-industrial landscape had disappeared from the post-1960 landscape. Based on statistical inference comparing historical records with present-day biogeographical distributions, up to 38% of species could be inferred to be lost. This study presents a surprisingly high figure for these losses for a region in Britain usually recognized as having a relatively unpolluted environment and a diverse set of lichens. Of 12 species that were inferred to be lost, nine are predominantly found on nutrient-rich bark, and in our study on Ulmus, the dominant timber in the archaeological samples. We conclude that shifts in phorophyte distribution and abundance may be more important in this region than previously understood.
High Speed Sintering (HSS) is a novel additive manufacturing technology which currently uses Nylon 12 as the standard feedstock material. To expand the number of processable materials, the preferred characteristics of polymeric powder as a feedstock powder are presented, appropriate materials identified, parts made, and mechanical properties measured. Two commercially available laser sintering (LS) grade powders previously untested for HSS were selected, DuraForm® HST10 and ALM TPE 210-S. Tensile test specimens were manufactured using each material and mechanical properties analyzed and compared to the manufacturers' specification for LS. Tensile test specimens built using DuraForm® PA show higher tensile strength and elongation at break than LS whereas DuraForm® HST10 shows somewhat reduced tensile strength but slightly increased elongation at break. ALM TPE 210-S shows elongation at break of more than double that of LS demonstrating the capability of HSS to process viscous materials. The results indicate that HSS is capable of processing LS grade polymeric powders and may extend beyond.
Coarse deadwood provides an important habitat for a suite of niche-specialist lichens in old-growth forests, for example, snags (standing dead trees) and fallen logs. Conversely, the scarcity of deadwood in managed forests is a limiting factor to lichen diversity, though cut stumps may provide an alternative habitat for deadwood species. The surface of cut stumps is an ecologically useful study system, facilitating standardized sampling with which to determine the pattern and process of deadwood succession. This study examined vegetation patterns for the surface of cut stumps at Abernethy RSPB Reserve in northern Scotland. We demonstrate the interrelationship between key topographic, management and edaphic factors during a successional process of terrestrialization. Consequently, we recommend that deadwood diversity might be maximized by 1) creating managed plots with varying degrees of canopy openness for sites with different levels of topographic exposure, and 2) providing cut stumps at different heights within plots, to ensure that during a rotational period the process of terrestrialization operates at different speeds among individual microhabitats. The study examined successional processes on cut stumps using two recently accessible and powerful statistical methods: 1) nonparametric multiplicative regression (NPMR), and 2) multivariate regression trees (MRT). The principles on which these techniques are based are becoming the preferred statistical framework with which to provide robust interpretation of field-sampled data; they are unconstrained by prior assumptions as to the form of a species' niche response, and are data-led models evaluated based on cross-validated performance, thereby avoiding the complication of multiple hypothesis tests.
Although beta-amyloid, anxiety and depression have been linked cross-sectionally to reduced memory function in healthy older adults without dementia, prospective data evaluating these associations are lacking. Using data from an observational cohort study of 178 healthy older adults without dementia followed for 3 years, we found that anxiety symptoms significantly moderated the relationship between beta-amyloid level and decline in verbal (Cohen's d = 0.65) and episodic (Cohen's d = 0.38) memory. Anxiety symptoms were additionally linked to greater decline in executive function, irrespective of beta-amyloid and other risk factors. These findings suggest that interventions to mitigate anxiety symptoms may help delay memory decline in otherwise healthy older adults with elevated beta-amyloid.
The Australian Imaging, Biomarkers and Lifestyle (AIBL) Flagship Study of Ageing is a prospective study of 1,112 individuals (211 with Alzheimer's disease (AD), 133 with mild cognitive impairment (MCI), and 768 healthy controls (HCs)). Here we report diagnostic and cognitive findings at the first (18-month) follow-up of the cohort. The first aim was to compute rates of transition from HC to MCI, and MCI to AD. The second aim was to characterize the cognitive profiles of individuals who transitioned to a more severe disease stage compared with those who did not.
Eighteen months after baseline, participants underwent comprehensive cognitive testing and diagnostic review, provided an 80 ml blood sample, and completed health and lifestyle questionnaires. A subgroup also underwent amyloid PET and MRI neuroimaging.
The diagnostic status of 89.9% of the cohorts was determined (972 were reassessed, 28 had died, and 112 did not return for reassessment). The 18-month cohort comprised 692 HCs, 82 MCI cases, 197 AD patients, and one Parkinson's disease dementia case. The transition rate from HC to MCI was 2.5%, and cognitive decline in HCs who transitioned to MCI was greatest in memory and naming domains compared to HCs who remained stable. The transition rate from MCI to AD was 30.5%.
There was a high retention rate after 18 months. Rates of transition from healthy aging to MCI, and MCI to AD, were consistent with established estimates. Follow-up of this cohort over longer periods will elucidate robust predictors of future cognitive decline.
The rational design of new heterogeneous catalysts for clean chemical technologies can be accelerated by molecular level insight into surface chemical processes. In-situ methodologies, able to provide time-resolved and/or pressure dependent information on the evolution of reacting adsorbed layers over catalytically relevant surfaces, are therefore of especial interest. Here we discuss the application of in-situ XPS and in-situ, synchronous DRIFTS/MS/XAS methodologies to elucidate the active site in Pd-catalyzed, selective aerobic oxidation of allylic alcohols.
This paper presents a study to partition the role of three regional-scale drivers – woodland extent and continuity, pollution regime, and climatic setting – in explaining the composition and richness of lichen epiphytes in Scotland. To do this we used partial canonical correspondence analysis and multiple least squares regression, to examine lichen communities across 170 study sites. First, our results demonstrate the importance of climate in explaining species composition. This highlights the relatively clean-air environment of Scotland within a European setting, and emphasizes the important consideration of regional context in the development of bioclimatic species-response models. This result contrasts with a previous similar study which collapsed complex environmental data into summary gradients, and which therefore discounted climate as a key factor. Second, we show a functional decoupling between composition and species richness, which was optimally explained by old-growth woodland extent and pollution, and only weakly explained by climate. The difference in explanatory variables between composition and richness is a focal issue in determining the processes by which species compositional change, driven by rapid and deep climate change, may indirectly impact species richness. For example, this impact may occur through an imbalance in rates of species extinction (for sensitive range-edge species) and establishment in a fragmented landscape (for dispersal-limited colonists), though operating against the ‘stabilizing effect’ of microclimatic setting.
The Crowfield site, excavated in 1981–82, would be a small typical Early Paleoindian campsite except for the added presence of a plough-truncated pit feature containing 182+ burned and destroyed stone artifacts. This paper reports on the latest insights into the feature contents based on continuing attempts to cross-mend fragments, as well as detailed analyses of the spatial distribution of artifact pieces within the feature itself. These results reinforce earlier conclusions that the items were burned where found, represent a cache of still functional tools and preforms, and were purposefully destroyed. They confirm that the site represents the best evidence to date for sacred ritual by eastern North American fluted point users. Contrasts with other reported early sacred and secular caches are documented that highlight the uniqueness of the assemblage. It is argued that these contrasts indicate the Crowfield feature assemblage more closely approximates a transported, functioning tool kit, as opposed to the surplus, seasonal and insurance gear, or offerings, that dominate other early caches.
Autecological information targeted towards rare and threatened lichen species is severely lacking. This study adopts the rare British lichen Vulpicida pinastri as a case study species and examines its ecological response to emerging threats: climate change and the recurrent loss of its primary habitat (juniper scrub). We used predictive niche modelling to examine the response of V. pinastri to a range of present-day climatic variables. A successful model was projected for a period during the 2050s based on IPCC climate change scenarios (UKCIP02 data), and threat was estimated as the proportional change in bioclimatic space. To estimate the potential range now and during the 2050s, projected bioclimatic space was masked by a habitat map equivalent to (i) the present-day distribution of juniper and (ii) theoretical juniper distribution based on existing rates of decline. Our results point to potential range loss of V. pinastri with climate warming, exacerbated by the recurrent decline in juniper habitat. This predictive modelling approach was complemented by an assessment of local stand-scale effects. At four sites in north-east Scotland we examined the occurrence and abundance of V. pinastri thalli, in response to juniper spatial distribution, and the life-stage and structure of individual shrubs. Vulpicida pinastri appeared to be dispersal limited at small-scales, and was significantly more abundant on old and degenerate juniper shrubs. Our results evidence a close relationship between management for habitat quality and effective lichen conservation. Effective conservation of V. pinastri must ensure cohorts of older and degenerate juniper shrubs are maintained at sites where the species is expected to be most resistant to long-term climate warming, i.e. in the uplands of north-east Scotland.
Ecological studies are essential in understanding the response of crustose lichens to habitat dynamics and developing effective conservation strategy. While the combined response of individual crustose species within a community will be tremendously complex, the overall result of individualistic change can be simplified using trait-based analyses. In this paper we examine the response of crustose species with contrasting reproductive traits (predominantly sexual vs asexual reproduction) and which occur within a closely defined habitat (as epiphytes on the lower bole of aspen) to environmental drivers measured at two different scales, i.e. between and within aspen stands. Our results point to the important effect of tree age and subsequent shifts in bark quality (pH) on the composition of the crustose community. However, shifts in community composition putatively controlled by bark quality comprise a change from a community dominated by sexual species to a community with mostly asexual crusts. Our results suggest therefore that variation within this crustose community may be driven by the combined effects of allogenic change (tree age and bark quality) and autogenic processes that are related to a species’ adaptive life-history traits.
We present the results of a study to determine the co-evolution of the virial and stellar masses for a sample of 83 disk galaxies between redshifts z = 0.2 − 1.2. the virial masses of these disks are computed using measured maximum rotational velocities from Keck spectroscopy and scale lengths from Hubble Space Telescope imaging. We compute stellar masses based on stellar population synthesis model fits to spectral energy distributions including K(2.2μm) band magnitudes. We find no apparent evolution with redshift from z = 0.2 − 1.2 in the relationship between stellar masses and maximum rotational velocities through the stellar mass Tully-Fisher relationship. We also find no evolution when comparing disk stellar and virial masses. Massive disk galaxies therefore appear to be already in place, in terms of their virial and stellar masses, out to the highest redshifts where they can be morphologically identified.