Turnover in floral composition explains species diversity and temporal stability in the nectar supply of urban residential gardens

Residential gardens are a valuable habitat for insect pollinators worldwide, but differences in individual gardening practices substantially affect their floral composition. It is important to understand how the floral resource supply of gardens varies in both space and time so we can develop evidence‐based management recommendations to support pollinator conservation in towns and cities. We surveyed 59 residential gardens in the city of Bristol, UK, at monthly intervals from March to October. For each of 472 garden surveys, we combined floral abundances with nectar sugar data to quantify the nectar production of each garden, investigating the magnitude, temporal stability, and diversity and composition of garden nectar supplies. We found that individual gardens differ markedly in the quantity of nectar sugar they supply (from 2 to 1,662 g), and nectar production is higher in more affluent neighbourhoods, but not in larger gardens. Nectar supply peaks in July (mid‐summer), when more plant taxa are in flower, but temporal patterns vary among individual gardens. At larger spatial scales, temporal variability averages out through the portfolio effect, meaning insect pollinators foraging across many gardens in urban landscapes have access to a relatively stable and continuous supply of nectar through the year. Turnover in species composition among gardens leads to an extremely high overall plant richness, with 636 taxa recorded flowering. The nectar supply is dominated by non‐natives, which provide 91% of all nectar sugar, while shrubs are the main plant life form contributing to nectar production (58%). Two‐thirds of nectar sugar is only available to relatively specialised pollinators, leaving just one‐third that is accessible to all. Synthesis and applications. By measuring nectar supply in residential gardens, our study demonstrates that pollinator‐friendly management, affecting garden quality, is more important than the size of a garden, giving every gardener an opportunity to contribute to pollinator conservation in urban areas. For gardeners interested in increasing the value of their land to foraging pollinators, we recommend planting nectar‐rich shrubs with complementary flowering periods and prioritising flowers with an open structure in late summer and autumn

A dataset of nectar sugar production for flowering plants found in urban green spaces

Nectar and pollen are floral resources that provide food for insect pollinators, so quantifying their supplies can help us to understand and mitigate pollinator declines. However, most existing datasets of floral resource measurements focus on native plants found in rural landscapes, so cannot be used effectively for estimating supplies in urban green spaces, where non-native ornamental plants often predominate. We sampled floral nectar sugar in 225 plant taxa found in UK residential gardens and other urban green spaces, focussing on the most common species. The vast majority (94%) of our sampled taxa are non-native, filling an important research gap and ensuring these data are also relevant outside of the United Kingdom. Our dataset includes values of daily nectar sugar production for all 225 taxa and nectar sugar concentration for around half (102) of those sampled. Nectar extraction was conducted according to published methods, ensuring our values can be combined with other datasets. We anticipate that the two main uses of these data are (1) to estimate the nectar production of habitats and landscapes and (2) to identify high-nectar plants of conservation importance. To increase the utility of our data, we provide guidance for scaling nectar values up from single flowers to floral units, as is commonly done in field studies

Vacuum-assisted decellularization: an accelerated protocol to generate tissue-engineered human tracheal scaffolds

Patients with large tracheal lesions unsuitable for conventional endoscopic or open operations may require a tracheal replacement but there is no present consensus of how this may be achieved. Tissue engineering using decellularized or synthetic tracheal scaffolds offers a new avenue for airway reconstruction. Decellularized human donor tracheal scaffolds have been applied in compassionate-use clinical cases but naturally derived extracellular matrix (ECM) scaffolds demand lengthy preparation times. Here, we compare a clinically applied detergent-enzymatic method (DEM) with an accelerated vacuum-assisted decellularization (VAD) protocol. We examined the histological appearance, DNA content and extracellular matrix composition of human donor tracheae decellularized using these techniques. Further, we performed scanning electron microscopy (SEM) and biomechanical testing to analyze decellularization performance. To assess the biocompatibility of scaffolds generated using VAD, we seeded scaffolds with primary human airway epithelial cells in vitro and performed in vivo chick chorioallantoic membrane (CAM) and subcutaneous implantation assays. Both DEM and VAD protocols produced well-decellularized tracheal scaffolds with no adverse mechanical effects and scaffolds retained the capacity for in vitro and in vivo cellular integration. We conclude that the substantial reduction in time required to produce scaffolds using VAD compared to DEM (approximately 9 days vs. 3–8 weeks) does not compromise the quality of human tracheal scaffold generated. These findings might inform clinical decellularization techniques as VAD offers accelerated scaffold production and reduces the associated costs

Statistical Mechanics of Horizontal Gene Transfer in Evolutionary Ecology

The biological world, especially its majority microbial component, is strongly interacting and may be dominated by collective effects. In this review, we provide a brief introduction for statistical physicists of the way in which living cells communicate genetically through transferred genes, as well as the ways in which they can reorganize their genomes in response to environmental pressure. We discuss how genome evolution can be thought of as related to the physical phenomenon of annealing, and describe the sense in which genomes can be said to exhibit an analogue of information entropy. As a direct application of these ideas, we analyze the variation with ocean depth of transposons in marine microbial genomes, predicting trends that are consistent with recent observations using metagenomic surveys.Comment: Accepted by Journal of Statistical Physic

Human toxocariasis: contribution by Brazilian researchers

In the present paper the main aspects of the natural history of human infection by Toxocara larvae that occasionally result in the occurrence of visceral and/or ocular larva migrans syndrome were reviewed. The contribution by Brazilian researchers was emphasized, especially the staff of the Tropical Medicine Institute of São Paulo (IMT)

Plasma glial fibrillary acidic protein is raised in progranulin-associated frontotemporal dementia

Background There are few validated fluid biomarkers in frontotemporal dementia (FTD). Glial fibrillary acidic protein (GFAP) is a measure of astrogliosis, a known pathological process of FTD, but has yet to be explored as potential biomarker. Methods Plasma GFAP and neurofilament light chain (NfL) concentration were measured in 469 individuals enrolled in the Genetic FTD Initiative: 114 C9orf72 expansion carriers (74 presymptomatic, 40 symptomatic), 119 GRN mutation carriers (88 presymptomatic, 31 symptomatic), 53 MAPT mutation carriers (34 presymptomatic, 19 symptomatic) and 183 non-carrier controls. Biomarker measures were compared between groups using linear regression models adjusted for age and sex with family membership included as random effect. Participants underwent standardised clinical assessments including the Mini-Mental State Examination (MMSE), Frontotemporal Lobar Degeneration-C linical Dementia Rating scale and MRI. Spearman's correlation coefficient was used to investigate the relationship of plasma GFAP to clinical and imaging measures. Results Plasma GFAP concentration was significantly increased in symptomatic GRN mutation carriers (adjusted mean difference from controls 192.3 pg/mL, 95% CI 126.5 to 445.6), but not in those with C9orf72 expansions (9.0, -61.3 to 54.6), MAPT mutations (12.7, -33.3 to 90.4) or the presymptomatic groups. GFAP concentration was significantly positively correlated with age in both controls and the majority of the disease groups, as well as with NfL concentration. In the presymptomatic period, higher GFAP concentrations were correlated with a lower cognitive score (MMSE) and lower brain volume, while in the symptomatic period, higher concentrations were associated with faster rates of atrophy in the temporal lobe. Conclusions Raised GFAP concentrations appear to be unique to GRN-related FTD, with levels potentially increasing just prior to symptom onset, suggesting that GFAP may be an important marker of proximity to onset, and helpful for forthcoming therapeutic prevention trials